/******************************************************************************
 *
 * Project:  OpenGIS Simple Features Reference Implementation
 * Author:   Even Rouault, <even dot rouault at spatialys.com>
 * Purpose:  OSM XML and OSM PBF parser
 *
 ******************************************************************************
 * Copyright (c) 2012-2013, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "osm_parser.h"
#include "gpb.h"

#include <climits>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <exception>
#include <string>
#include <vector>

#include "cpl_config.h"
#include "cpl_conv.h"
#include "cpl_error.h"
#include "cpl_multiproc.h"
#include "cpl_string.h"
#include "cpl_vsi.h"
#include "cpl_worker_thread_pool.h"

#ifdef HAVE_EXPAT
#include "ogr_expat.h"
#endif

// The buffer that are passed to GPB decoding are extended with 0's
// to be sure that we will be able to read a single 64bit value without
// doing checks for each byte.
constexpr int EXTRA_BYTES = 1;

#ifdef HAVE_EXPAT
constexpr int XML_BUFSIZE = 64 * 1024;
#endif

// Per OSM PBF spec
constexpr unsigned int MAX_BLOB_HEADER_SIZE = 64 * 1024;

// Per OSM PBF spec (usually much smaller !)
constexpr unsigned int MAX_BLOB_SIZE = 64 * 1024 * 1024;

// GDAL implementation limits
constexpr unsigned int MAX_ACC_BLOB_SIZE = 50 * 1024 * 1024;
constexpr unsigned int MAX_ACC_UNCOMPRESSED_SIZE = 100 * 1024 * 1024;
constexpr int N_MAX_JOBS = 1024;

#if defined(__GNUC__)
#define CPL_NO_INLINE __attribute__((noinline))
#else
#define CPL_NO_INLINE
#endif

class OSMParsingException : public std::exception
{
    std::string m_osMessage;

  public:
    explicit OSMParsingException(int nLine)
        : m_osMessage(CPLSPrintf("Parsing error occurred at line %d", nLine))
    {
    }

    const char *what() const noexcept override
    {
        return m_osMessage.c_str();
    }
};

#define THROW_OSM_PARSING_EXCEPTION throw OSMParsingException(__LINE__)

/************************************************************************/
/*                            INIT_INFO()                               */
/************************************************************************/

static void INIT_INFO(OSMInfo *sInfo)
{
    sInfo->ts.nTimeStamp = 0;
    sInfo->nChangeset = 0;
    sInfo->nVersion = 0;
    sInfo->nUID = 0;
    sInfo->bTimeStampIsStr = false;
    sInfo->pszUserSID = nullptr;
}

/************************************************************************/
/*                            _OSMContext                               */
/************************************************************************/

typedef struct
{
    const GByte *pabySrc;
    size_t nSrcSize;
    GByte *pabyDstBase;
    size_t nDstOffset;
    size_t nDstSize;
    bool bStatus;
} DecompressionJob;

struct _OSMContext
{
    char *pszStrBuf;
    int *panStrOff;
    unsigned int nStrCount;
    unsigned int nStrAllocated;

    OSMNode *pasNodes;
    unsigned int nNodesAllocated;

    OSMTag *pasTags;
    unsigned int nTagsAllocated;

    OSMMember *pasMembers;
    unsigned int nMembersAllocated;

    GIntBig *panNodeRefs;
    unsigned int nNodeRefsAllocated;

    int nGranularity;
    int nDateGranularity;
    GIntBig nLatOffset;
    GIntBig nLonOffset;

    // concatenated protocol buffer messages BLOB_OSMDATA, or single
    // BLOB_OSMHEADER
    GByte *pabyBlob;
    unsigned int nBlobSizeAllocated;
    unsigned int nBlobOffset;
    unsigned int nBlobSize;

    GByte *pabyBlobHeader;  // MAX_BLOB_HEADER_SIZE+EXTRA_BYTES large

    CPLWorkerThreadPool *poWTP;

    GByte *pabyUncompressed;
    unsigned int nUncompressedAllocated;
    unsigned int nTotalUncompressedSize;

    DecompressionJob asJobs[N_MAX_JOBS];
    int nJobs;
    int iNextJob;

#ifdef HAVE_EXPAT
    XML_Parser hXMLParser;
    bool bEOF;
    bool bStopParsing;
    bool bHasFoundFeature;
    int nWithoutEventCounter;
    int nDataHandlerCounter;

    unsigned int nStrLength;
    unsigned int nTags;

    bool bInNode;
    bool bInWay;
    bool bInRelation;

    OSMWay sWay;
    OSMRelation sRelation;

    bool bTryToFetchBounds;
#endif

    VSILFILE *fp;

    bool bPBF;

    double dfLeft;
    double dfRight;
    double dfTop;
    double dfBottom;

    GUIntBig nBytesRead;

    NotifyNodesFunc pfnNotifyNodes;
    NotifyWayFunc pfnNotifyWay;
    NotifyRelationFunc pfnNotifyRelation;
    NotifyBoundsFunc pfnNotifyBounds;
    void *user_data;
};

/************************************************************************/
/*                          ReadBlobHeader()                            */
/************************************************************************/

constexpr int BLOBHEADER_IDX_TYPE = 1;
constexpr int BLOBHEADER_IDX_INDEXDATA = 2;
constexpr int BLOBHEADER_IDX_DATASIZE = 3;

typedef enum
{
    BLOB_UNKNOWN,
    BLOB_OSMHEADER,
    BLOB_OSMDATA
} BlobType;

static bool ReadBlobHeader(const GByte *pabyData, const GByte *pabyDataLimit,
                           unsigned int *pnBlobSize, BlobType *peBlobType)
{
    *pnBlobSize = 0;
    *peBlobType = BLOB_UNKNOWN;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(BLOBHEADER_IDX_TYPE, WT_DATA))
            {
                unsigned int nDataLength = 0;
                READ_SIZE(pabyData, pabyDataLimit, nDataLength);

                if (nDataLength == 7 && memcmp(pabyData, "OSMData", 7) == 0)
                {
                    *peBlobType = BLOB_OSMDATA;
                }
                else if (nDataLength == 9 &&
                         memcmp(pabyData, "OSMHeader", 9) == 0)
                {
                    *peBlobType = BLOB_OSMHEADER;
                }

                pabyData += nDataLength;
            }
            else if (nKey == MAKE_KEY(BLOBHEADER_IDX_INDEXDATA, WT_DATA))
            {
                // Ignored if found.
                unsigned int nDataLength = 0;
                READ_SIZE(pabyData, pabyDataLimit, nDataLength);
                pabyData += nDataLength;
            }
            else if (nKey == MAKE_KEY(BLOBHEADER_IDX_DATASIZE, WT_VARINT))
            {
                unsigned int nBlobSize = 0;
                READ_VARUINT32(pabyData, pabyDataLimit, nBlobSize);
                // printf("nBlobSize = %d\n", nBlobSize);
                *pnBlobSize = nBlobSize;
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        return pabyData == pabyDataLimit;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                          ReadHeaderBBox()                            */
/************************************************************************/

constexpr int HEADERBBOX_IDX_LEFT = 1;
constexpr int HEADERBBOX_IDX_RIGHT = 2;
constexpr int HEADERBBOX_IDX_TOP = 3;
constexpr int HEADERBBOX_IDX_BOTTOM = 4;

static bool ReadHeaderBBox(const GByte *pabyData, const GByte *pabyDataLimit,
                           OSMContext *psCtxt)
{
    psCtxt->dfLeft = 0.0;
    psCtxt->dfRight = 0.0;
    psCtxt->dfTop = 0.0;
    psCtxt->dfBottom = 0.0;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(HEADERBBOX_IDX_LEFT, WT_VARINT))
            {
                GIntBig nLeft = 0;
                READ_VARSINT64(pabyData, pabyDataLimit, nLeft);
                psCtxt->dfLeft = nLeft * 1e-9;
            }
            else if (nKey == MAKE_KEY(HEADERBBOX_IDX_RIGHT, WT_VARINT))
            {
                GIntBig nRight = 0;
                READ_VARSINT64(pabyData, pabyDataLimit, nRight);
                psCtxt->dfRight = nRight * 1e-9;
            }
            else if (nKey == MAKE_KEY(HEADERBBOX_IDX_TOP, WT_VARINT))
            {
                GIntBig nTop = 0;
                READ_VARSINT64(pabyData, pabyDataLimit, nTop);
                psCtxt->dfTop = nTop * 1e-9;
            }
            else if (nKey == MAKE_KEY(HEADERBBOX_IDX_BOTTOM, WT_VARINT))
            {
                GIntBig nBottom = 0;
                READ_VARSINT64(pabyData, pabyDataLimit, nBottom);
                psCtxt->dfBottom = nBottom * 1e-9;
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        psCtxt->pfnNotifyBounds(psCtxt->dfLeft, psCtxt->dfBottom,
                                psCtxt->dfRight, psCtxt->dfTop, psCtxt,
                                psCtxt->user_data);

        return pabyData == pabyDataLimit;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                          ReadOSMHeader()                             */
/************************************************************************/

constexpr int OSMHEADER_IDX_BBOX = 1;
constexpr int OSMHEADER_IDX_REQUIRED_FEATURES = 4;
constexpr int OSMHEADER_IDX_OPTIONAL_FEATURES = 5;
constexpr int OSMHEADER_IDX_WRITING_PROGRAM = 16;
constexpr int OSMHEADER_IDX_SOURCE = 17;

/* Ignored */
constexpr int OSMHEADER_IDX_OSMOSIS_REPLICATION_TIMESTAMP = 32;
constexpr int OSMHEADER_IDX_OSMOSIS_REPLICATION_SEQ_NUMBER = 33;
constexpr int OSMHEADER_IDX_OSMOSIS_REPLICATION_BASE_URL = 34;

static bool ReadOSMHeader(const GByte *pabyData, const GByte *pabyDataLimit,
                          OSMContext *psCtxt)
{
    char *pszTxt = nullptr;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(OSMHEADER_IDX_BBOX, WT_DATA))
            {
                unsigned int nBBOXSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nBBOXSize);

                if (!ReadHeaderBBox(pabyData, pabyData + nBBOXSize, psCtxt))
                    THROW_OSM_PARSING_EXCEPTION;

                pabyData += nBBOXSize;
            }
            else if (nKey == MAKE_KEY(OSMHEADER_IDX_REQUIRED_FEATURES, WT_DATA))
            {
                READ_TEXT(pabyData, pabyDataLimit, pszTxt);
                // printf("OSMHEADER_IDX_REQUIRED_FEATURES = %s\n", pszTxt)
                if (!(strcmp(pszTxt, "OsmSchema-V0.6") == 0 ||
                      strcmp(pszTxt, "DenseNodes") == 0))
                {
                    CPLError(CE_Failure, CPLE_NotSupported,
                             "Error: unsupported required feature : %s",
                             pszTxt);
                    VSIFree(pszTxt);
                    THROW_OSM_PARSING_EXCEPTION;
                }
                VSIFree(pszTxt);
            }
            else if (nKey == MAKE_KEY(OSMHEADER_IDX_OPTIONAL_FEATURES, WT_DATA))
            {
                READ_TEXT(pabyData, pabyDataLimit, pszTxt);
                // printf("OSMHEADER_IDX_OPTIONAL_FEATURES = %s\n", pszTxt);
                VSIFree(pszTxt);
            }
            else if (nKey == MAKE_KEY(OSMHEADER_IDX_WRITING_PROGRAM, WT_DATA))
            {
                READ_TEXT(pabyData, pabyDataLimit, pszTxt);
                // printf("OSMHEADER_IDX_WRITING_PROGRAM = %s\n", pszTxt);
                VSIFree(pszTxt);
            }
            else if (nKey == MAKE_KEY(OSMHEADER_IDX_SOURCE, WT_DATA))
            {
                READ_TEXT(pabyData, pabyDataLimit, pszTxt);
                // printf("OSMHEADER_IDX_SOURCE = %s\n", pszTxt);
                VSIFree(pszTxt);
            }
            else if (nKey ==
                     MAKE_KEY(OSMHEADER_IDX_OSMOSIS_REPLICATION_TIMESTAMP,
                              WT_VARINT))
            {
                SKIP_VARINT(pabyData, pabyDataLimit);
            }
            else if (nKey ==
                     MAKE_KEY(OSMHEADER_IDX_OSMOSIS_REPLICATION_SEQ_NUMBER,
                              WT_VARINT))
            {
                SKIP_VARINT(pabyData, pabyDataLimit);
            }
            else if (nKey ==
                     MAKE_KEY(OSMHEADER_IDX_OSMOSIS_REPLICATION_BASE_URL,
                              WT_DATA))
            {
                READ_TEXT(pabyData, pabyDataLimit, pszTxt);
                /* printf("OSMHEADER_IDX_OSMOSIS_REPLICATION_BASE_URL = %s\n",
                 * pszTxt); */
                VSIFree(pszTxt);
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        return pabyData == pabyDataLimit;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                         ReadStringTable()                            */
/************************************************************************/

constexpr int READSTRINGTABLE_IDX_STRING = 1;

static bool ReadStringTable(const GByte *pabyData, const GByte *pabyDataLimit,
                            OSMContext *psCtxt)
{
    const GByte *const pabyDataStart = pabyData;

    unsigned int nStrCount = 0;
    int *panStrOff = psCtxt->panStrOff;

    psCtxt->pszStrBuf = reinterpret_cast<char *>(const_cast<GByte *>(pabyData));

    try
    {
        if (static_cast<unsigned>(pabyDataLimit - pabyData) >
            psCtxt->nStrAllocated)
        {
            psCtxt->nStrAllocated =
                std::max(psCtxt->nStrAllocated * 2,
                         static_cast<unsigned>(pabyDataLimit - pabyData));
            int *panStrOffNew = static_cast<int *>(VSI_REALLOC_VERBOSE(
                panStrOff, psCtxt->nStrAllocated * sizeof(int)));
            if (panStrOffNew == nullptr)
                THROW_OSM_PARSING_EXCEPTION;
            panStrOff = panStrOffNew;
        }

        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            while (nKey == MAKE_KEY(READSTRINGTABLE_IDX_STRING, WT_DATA))
            {
                unsigned int nDataLength = 0;
                READ_SIZE(pabyData, pabyDataLimit, nDataLength);

                panStrOff[nStrCount++] =
                    static_cast<int>(pabyData - pabyDataStart);
                GByte *pbSaved = const_cast<GByte *>(&pabyData[nDataLength]);

                pabyData += nDataLength;

                if (pabyData < pabyDataLimit)
                {
                    READ_FIELD_KEY(nKey);
                    *pbSaved = 0;
                    /* printf("string[%d] = %s\n", nStrCount-1, pbSaved -
                     * nDataLength); */
                }
                else
                {
                    *pbSaved = 0;
                    /* printf("string[%d] = %s\n", nStrCount-1, pbSaved -
                     * nDataLength); */
                    break;
                }
            }

            if (pabyData < pabyDataLimit)
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        psCtxt->panStrOff = panStrOff;
        psCtxt->nStrCount = nStrCount;

        return pabyData == pabyDataLimit;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        psCtxt->panStrOff = panStrOff;
        psCtxt->nStrCount = nStrCount;
        return false;
    }
}

/************************************************************************/
/*                     AddWithOverflowAccepted()                        */
/************************************************************************/

CPL_NOSANITIZE_UNSIGNED_INT_OVERFLOW
static GIntBig AddWithOverflowAccepted(GIntBig a, GIntBig b)
{
    // Assumes complement-to-two signed integer representation and that
    // the compiler will safely cast a negative number to unsigned and a
    // big unsigned to negative integer.
    return static_cast<GIntBig>(static_cast<GUIntBig>(a) +
                                static_cast<GUIntBig>(b));
}

CPL_NOSANITIZE_UNSIGNED_INT_OVERFLOW
static int AddWithOverflowAccepted(int a, int b)
{
    // Assumes complement-to-two signed integer representation and that
    // the compiler will safely cast a negative number to unsigned and a
    // big unsigned to negative integer.
    return static_cast<int>(static_cast<unsigned>(a) +
                            static_cast<unsigned>(b));
}

CPL_NOSANITIZE_UNSIGNED_INT_OVERFLOW
static unsigned AddWithOverflowAccepted(unsigned a, int b)
{
    // Assumes complement-to-two signed integer representation and that
    // the compiler will safely cast a negative number to unsigned.
    return a + static_cast<unsigned>(b);
}

/************************************************************************/
/*                         ReadDenseNodes()                             */
/************************************************************************/

constexpr int DENSEINFO_IDX_VERSION = 1;
constexpr int DENSEINFO_IDX_TIMESTAMP = 2;
constexpr int DENSEINFO_IDX_CHANGESET = 3;
constexpr int DENSEINFO_IDX_UID = 4;
constexpr int DENSEINFO_IDX_USER_SID = 5;
constexpr int DENSEINFO_IDX_VISIBLE = 6;

constexpr int DENSENODES_IDX_ID = 1;
constexpr int DENSENODES_IDX_DENSEINFO = 5;
constexpr int DENSENODES_IDX_LAT = 8;
constexpr int DENSENODES_IDX_LON = 9;
constexpr int DENSENODES_IDX_KEYVALS = 10;

static bool ReadDenseNodes(const GByte *pabyData, const GByte *pabyDataLimit,
                           OSMContext *psCtxt)
{
    const GByte *pabyDataIDs = nullptr;
    const GByte *pabyDataIDsLimit = nullptr;
    const GByte *pabyDataLat = nullptr;
    const GByte *pabyDataLon = nullptr;
    const GByte *apabyData[DENSEINFO_IDX_VISIBLE] = {nullptr, nullptr, nullptr,
                                                     nullptr, nullptr, nullptr};
    const GByte *pabyDataKeyVal = nullptr;
    unsigned int nMaxTags = 0;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(DENSENODES_IDX_ID, WT_DATA))
            {
                unsigned int nSize = 0;

                if (pabyDataIDs != nullptr)
                    THROW_OSM_PARSING_EXCEPTION;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (nSize > psCtxt->nNodesAllocated)
                {
                    psCtxt->nNodesAllocated =
                        std::max(psCtxt->nNodesAllocated * 2, nSize);
                    OSMNode *pasNodesNew =
                        static_cast<OSMNode *>(VSI_REALLOC_VERBOSE(
                            psCtxt->pasNodes,
                            psCtxt->nNodesAllocated * sizeof(OSMNode)));
                    if (pasNodesNew == nullptr)
                        THROW_OSM_PARSING_EXCEPTION;
                    psCtxt->pasNodes = pasNodesNew;
                }

                pabyDataIDs = pabyData;
                pabyDataIDsLimit = pabyData + nSize;
                pabyData += nSize;
            }
            else if (nKey == MAKE_KEY(DENSENODES_IDX_DENSEINFO, WT_DATA))
            {
                unsigned int nSize = 0;

                READ_SIZE(pabyData, pabyDataLimit, nSize);

                /* Inline reading of DenseInfo structure */

                const GByte *pabyDataNewLimit = pabyData + nSize;
                while (pabyData < pabyDataNewLimit)
                {
                    READ_FIELD_KEY(nKey);

                    const int nFieldNumber = GET_FIELDNUMBER(nKey);
                    if (GET_WIRETYPE(nKey) == WT_DATA &&
                        nFieldNumber >= DENSEINFO_IDX_VERSION &&
                        nFieldNumber <= DENSEINFO_IDX_VISIBLE)
                    {
                        if (apabyData[nFieldNumber - 1] != nullptr)
                            THROW_OSM_PARSING_EXCEPTION;
                        READ_SIZE(pabyData, pabyDataNewLimit, nSize);

                        apabyData[nFieldNumber - 1] = pabyData;
                        pabyData += nSize;
                    }
                    else
                    {
                        SKIP_UNKNOWN_FIELD(pabyData, pabyDataNewLimit, TRUE);
                    }
                }

                if (pabyData != pabyDataNewLimit)
                    THROW_OSM_PARSING_EXCEPTION;
            }
            else if (nKey == MAKE_KEY(DENSENODES_IDX_LAT, WT_DATA))
            {
                if (pabyDataLat != nullptr)
                    THROW_OSM_PARSING_EXCEPTION;
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);
                pabyDataLat = pabyData;
                pabyData += nSize;
            }
            else if (nKey == MAKE_KEY(DENSENODES_IDX_LON, WT_DATA))
            {
                if (pabyDataLon != nullptr)
                    THROW_OSM_PARSING_EXCEPTION;
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);
                pabyDataLon = pabyData;
                pabyData += nSize;
            }
            else if (nKey == MAKE_KEY(DENSENODES_IDX_KEYVALS, WT_DATA))
            {
                if (pabyDataKeyVal != nullptr)
                    THROW_OSM_PARSING_EXCEPTION;
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                pabyDataKeyVal = pabyData;
                nMaxTags = nSize / 2;

                if (nMaxTags > psCtxt->nTagsAllocated)
                {

                    psCtxt->nTagsAllocated =
                        std::max(psCtxt->nTagsAllocated * 2, nMaxTags);
                    OSMTag *pasTagsNew =
                        static_cast<OSMTag *>(VSI_REALLOC_VERBOSE(
                            psCtxt->pasTags,
                            psCtxt->nTagsAllocated * sizeof(OSMTag)));
                    if (pasTagsNew == nullptr)
                        THROW_OSM_PARSING_EXCEPTION;
                    psCtxt->pasTags = pasTagsNew;
                }

                pabyData += nSize;
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        if (pabyData != pabyDataLimit)
            THROW_OSM_PARSING_EXCEPTION;

        if (pabyDataIDs != nullptr && pabyDataLat != nullptr &&
            pabyDataLon != nullptr)
        {
            const GByte *pabyDataVersion = apabyData[DENSEINFO_IDX_VERSION - 1];
            const GByte *pabyDataTimeStamp =
                apabyData[DENSEINFO_IDX_TIMESTAMP - 1];
            const GByte *pabyDataChangeset =
                apabyData[DENSEINFO_IDX_CHANGESET - 1];
            const GByte *pabyDataUID = apabyData[DENSEINFO_IDX_UID - 1];
            const GByte *pabyDataUserSID =
                apabyData[DENSEINFO_IDX_USER_SID - 1];
            /* GByte* pabyDataVisible = apabyData[DENSEINFO_IDX_VISIBLE - 1]; */

            GIntBig nID = 0;
            GIntBig nLat = 0;
            GIntBig nLon = 0;
            GIntBig nTimeStamp = 0;
            GIntBig nChangeset = 0;
            int nUID = 0;
            unsigned int nUserSID = 0;
            int nTags = 0;
            int nNodes = 0;

            const char *pszStrBuf = psCtxt->pszStrBuf;
            int *panStrOff = psCtxt->panStrOff;
            const unsigned int nStrCount = psCtxt->nStrCount;
            OSMTag *pasTags = psCtxt->pasTags;
            OSMNode *pasNodes = psCtxt->pasNodes;

            int nVersion = 0;
            /* int nVisible = 1; */

            while (pabyDataIDs < pabyDataIDsLimit)
            {
                GIntBig nDelta1, nDelta2;
                int nKVIndexStart = nTags;

                READ_VARSINT64_NOCHECK(pabyDataIDs, pabyDataIDsLimit, nDelta1);
                READ_VARSINT64(pabyDataLat, pabyDataLimit, nDelta2);
                nID = AddWithOverflowAccepted(nID, nDelta1);
                nLat = AddWithOverflowAccepted(nLat, nDelta2);

                READ_VARSINT64(pabyDataLon, pabyDataLimit, nDelta1);
                nLon = AddWithOverflowAccepted(nLon, nDelta1);

                if (pabyDataTimeStamp)
                {
                    READ_VARSINT64(pabyDataTimeStamp, pabyDataLimit, nDelta2);
                    nTimeStamp = AddWithOverflowAccepted(nTimeStamp, nDelta2);
                }
                if (pabyDataChangeset)
                {
                    READ_VARSINT64(pabyDataChangeset, pabyDataLimit, nDelta1);
                    nChangeset = AddWithOverflowAccepted(nChangeset, nDelta1);
                }
                if (pabyDataVersion)
                {
                    READ_VARINT32(pabyDataVersion, pabyDataLimit, nVersion);
                }
                if (pabyDataUID)
                {
                    int nDeltaUID = 0;
                    READ_VARSINT32(pabyDataUID, pabyDataLimit, nDeltaUID);
                    nUID = AddWithOverflowAccepted(nUID, nDeltaUID);
                }
                if (pabyDataUserSID)
                {
                    int nDeltaUserSID = 0;
                    READ_VARSINT32(pabyDataUserSID, pabyDataLimit,
                                   nDeltaUserSID);
                    nUserSID = AddWithOverflowAccepted(nUserSID, nDeltaUserSID);
                    if (nUserSID >= nStrCount)
                        THROW_OSM_PARSING_EXCEPTION;
                }
                /* if( pabyDataVisible )
                    READ_VARINT32(pabyDataVisible, pabyDataLimit, nVisible); */

                if (pabyDataKeyVal != nullptr && pasTags != nullptr)
                {
                    while (static_cast<unsigned>(nTags) < nMaxTags)
                    {
                        unsigned int nKey, nVal;
                        READ_VARUINT32(pabyDataKeyVal, pabyDataLimit, nKey);
                        if (nKey == 0)
                            break;
                        if (nKey >= nStrCount)
                            THROW_OSM_PARSING_EXCEPTION;

                        READ_VARUINT32(pabyDataKeyVal, pabyDataLimit, nVal);
                        if (nVal >= nStrCount)
                            THROW_OSM_PARSING_EXCEPTION;

                        pasTags[nTags].pszK = pszStrBuf + panStrOff[nKey];
                        pasTags[nTags].pszV = pszStrBuf + panStrOff[nVal];
                        nTags++;

                        /* printf("nKey = %d, nVal = %d\n", nKey, nVal); */
                    }
                }

                if (pasTags != nullptr && nTags > nKVIndexStart)
                    pasNodes[nNodes].pasTags = pasTags + nKVIndexStart;
                else
                    pasNodes[nNodes].pasTags = nullptr;
                pasNodes[nNodes].nTags = nTags - nKVIndexStart;

                pasNodes[nNodes].nID = nID;
                pasNodes[nNodes].dfLat =
                    .000000001 *
                    (psCtxt->nLatOffset +
                     (static_cast<double>(psCtxt->nGranularity) * nLat));
                pasNodes[nNodes].dfLon =
                    .000000001 *
                    (psCtxt->nLonOffset +
                     (static_cast<double>(psCtxt->nGranularity) * nLon));
                if (pasNodes[nNodes].dfLon < -180 ||
                    pasNodes[nNodes].dfLon > 180 ||
                    pasNodes[nNodes].dfLat < -90 || pasNodes[nNodes].dfLat > 90)
                    THROW_OSM_PARSING_EXCEPTION;
                pasNodes[nNodes].sInfo.bTimeStampIsStr = false;
                pasNodes[nNodes].sInfo.ts.nTimeStamp = nTimeStamp;
                pasNodes[nNodes].sInfo.nChangeset = nChangeset;
                pasNodes[nNodes].sInfo.nVersion = nVersion;
                pasNodes[nNodes].sInfo.nUID = nUID;
                if (nUserSID >= nStrCount)
                    pasNodes[nNodes].sInfo.pszUserSID = "";
                else
                    pasNodes[nNodes].sInfo.pszUserSID =
                        pszStrBuf + panStrOff[nUserSID];
                /* pasNodes[nNodes].sInfo.nVisible = nVisible; */
                nNodes++;
                /* printf("nLat = " CPL_FRMT_GIB "\n", nLat); printf("nLon = "
                 * CPL_FRMT_GIB "\n", nLon); */
            }

            psCtxt->pfnNotifyNodes(nNodes, pasNodes, psCtxt, psCtxt->user_data);

            if (pabyDataIDs != pabyDataIDsLimit)
                THROW_OSM_PARSING_EXCEPTION;
        }

        return true;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                           ReadOSMInfo()                              */
/************************************************************************/

constexpr int INFO_IDX_VERSION = 1;
constexpr int INFO_IDX_TIMESTAMP = 2;
constexpr int INFO_IDX_CHANGESET = 3;
constexpr int INFO_IDX_UID = 4;
constexpr int INFO_IDX_USER_SID = 5;
constexpr int INFO_IDX_VISIBLE = 6;

static bool ReadOSMInfo(const GByte *pabyData, const GByte *pabyDataLimit,
                        OSMInfo *psInfo, OSMContext *psContext) CPL_NO_INLINE;

static bool ReadOSMInfo(const GByte *pabyData, const GByte *pabyDataLimit,
                        OSMInfo *psInfo, OSMContext *psContext)
{
    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(INFO_IDX_VERSION, WT_VARINT))
            {
                READ_VARINT32(pabyData, pabyDataLimit, psInfo->nVersion);
            }
            else if (nKey == MAKE_KEY(INFO_IDX_TIMESTAMP, WT_VARINT))
            {
                READ_VARINT64(pabyData, pabyDataLimit, psInfo->ts.nTimeStamp);
            }
            else if (nKey == MAKE_KEY(INFO_IDX_CHANGESET, WT_VARINT))
            {
                READ_VARINT64(pabyData, pabyDataLimit, psInfo->nChangeset);
            }
            else if (nKey == MAKE_KEY(INFO_IDX_UID, WT_VARINT))
            {
                READ_VARINT32(pabyData, pabyDataLimit, psInfo->nUID);
            }
            else if (nKey == MAKE_KEY(INFO_IDX_USER_SID, WT_VARINT))
            {
                unsigned int nUserSID = 0;
                READ_VARUINT32(pabyData, pabyDataLimit, nUserSID);
                if (nUserSID < psContext->nStrCount)
                    psInfo->pszUserSID =
                        psContext->pszStrBuf + psContext->panStrOff[nUserSID];
            }
            else if (nKey == MAKE_KEY(INFO_IDX_VISIBLE, WT_VARINT))
            {
                SKIP_VARINT(pabyData, pabyDataLimit);
                // int nVisible = 0;
                // READ_VARINT32(pabyData, pabyDataLimit, /*psInfo->*/nVisible);
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        return pabyData == pabyDataLimit;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                             ReadNode()                               */
/************************************************************************/

/* From
 * https://github.com/openstreetmap/osmosis/blob/master/osmosis-osm-binary/src/main/protobuf/osmformat.proto
 */
/* The one advertized in http://wiki.openstreetmap.org/wiki/PBF_Format and */
/* used previously seem wrong/old-dated */

constexpr int NODE_IDX_ID = 1;
constexpr int NODE_IDX_LAT = 8;
constexpr int NODE_IDX_LON = 9;
constexpr int NODE_IDX_KEYS = 2;
constexpr int NODE_IDX_VALS = 3;
constexpr int NODE_IDX_INFO = 4;

static bool ReadNode(const GByte *pabyData, const GByte *pabyDataLimit,
                     OSMContext *psCtxt)
{
    OSMNode sNode;

    sNode.nID = 0;
    sNode.dfLat = 0.0;
    sNode.dfLon = 0.0;
    INIT_INFO(&(sNode.sInfo));
    sNode.nTags = 0;
    sNode.pasTags = nullptr;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(NODE_IDX_ID, WT_VARINT))
            {
                READ_VARSINT64_NOCHECK(pabyData, pabyDataLimit, sNode.nID);
            }
            else if (nKey == MAKE_KEY(NODE_IDX_LAT, WT_VARINT))
            {
                GIntBig nLat = 0;
                READ_VARSINT64_NOCHECK(pabyData, pabyDataLimit, nLat);
                sNode.dfLat =
                    0.000000001 *
                    (psCtxt->nLatOffset +
                     (static_cast<double>(psCtxt->nGranularity) * nLat));
            }
            else if (nKey == MAKE_KEY(NODE_IDX_LON, WT_VARINT))
            {
                GIntBig nLon = 0;
                READ_VARSINT64_NOCHECK(pabyData, pabyDataLimit, nLon);
                sNode.dfLon =
                    0.000000001 *
                    (psCtxt->nLonOffset +
                     (static_cast<double>(psCtxt->nGranularity) * nLon));
            }
            else if (nKey == MAKE_KEY(NODE_IDX_KEYS, WT_DATA))
            {
                unsigned int nSize = 0;
                const GByte *pabyDataNewLimit = nullptr;
                if (sNode.nTags != 0)
                    THROW_OSM_PARSING_EXCEPTION;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (nSize > psCtxt->nTagsAllocated)
                {
                    psCtxt->nTagsAllocated =
                        std::max(psCtxt->nTagsAllocated * 2, nSize);
                    OSMTag *pasTagsNew =
                        static_cast<OSMTag *>(VSI_REALLOC_VERBOSE(
                            psCtxt->pasTags,
                            psCtxt->nTagsAllocated * sizeof(OSMTag)));
                    if (pasTagsNew == nullptr)
                        THROW_OSM_PARSING_EXCEPTION;
                    psCtxt->pasTags = pasTagsNew;
                }

                pabyDataNewLimit = pabyData + nSize;
                while (pabyData < pabyDataNewLimit)
                {
                    unsigned int nKey2 = 0;
                    READ_VARUINT32(pabyData, pabyDataNewLimit, nKey2);

                    if (nKey2 >= psCtxt->nStrCount)
                        THROW_OSM_PARSING_EXCEPTION;

                    psCtxt->pasTags[sNode.nTags].pszK =
                        psCtxt->pszStrBuf + psCtxt->panStrOff[nKey2];
                    psCtxt->pasTags[sNode.nTags].pszV = "";
                    sNode.nTags++;
                }
                if (pabyData != pabyDataNewLimit)
                    THROW_OSM_PARSING_EXCEPTION;
            }
            else if (nKey == MAKE_KEY(NODE_IDX_VALS, WT_DATA))
            {
                unsigned int nIter = 0;
                if (sNode.nTags == 0)
                    THROW_OSM_PARSING_EXCEPTION;
                // unsigned int nSize = 0;
                // READ_VARUINT32(pabyData, pabyDataLimit, nSize);
                SKIP_VARINT(pabyData, pabyDataLimit);

                for (; nIter < sNode.nTags; nIter++)
                {
                    unsigned int nVal = 0;
                    READ_VARUINT32(pabyData, pabyDataLimit, nVal);

                    if (nVal >= psCtxt->nStrCount)
                        THROW_OSM_PARSING_EXCEPTION;

                    psCtxt->pasTags[nIter].pszV =
                        psCtxt->pszStrBuf + psCtxt->panStrOff[nVal];
                }
            }
            else if (nKey == MAKE_KEY(NODE_IDX_INFO, WT_DATA))
            {
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (!ReadOSMInfo(pabyData, pabyDataLimit + nSize, &sNode.sInfo,
                                 psCtxt))
                    THROW_OSM_PARSING_EXCEPTION;

                pabyData += nSize;
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        if (sNode.dfLon < -180 || sNode.dfLon > 180 || sNode.dfLat < -90 ||
            sNode.dfLat > 90)
            THROW_OSM_PARSING_EXCEPTION;

        if (pabyData != pabyDataLimit)
            THROW_OSM_PARSING_EXCEPTION;

        if (sNode.nTags)
            sNode.pasTags = psCtxt->pasTags;
        else
            sNode.pasTags = nullptr;
        psCtxt->pfnNotifyNodes(1, &sNode, psCtxt, psCtxt->user_data);

        return true;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                              ReadWay()                               */
/************************************************************************/

constexpr int WAY_IDX_ID = 1;
constexpr int WAY_IDX_KEYS = 2;
constexpr int WAY_IDX_VALS = 3;
constexpr int WAY_IDX_INFO = 4;
constexpr int WAY_IDX_REFS = 8;

static bool ReadWay(const GByte *pabyData, const GByte *pabyDataLimit,
                    OSMContext *psCtxt)
{
    OSMWay sWay;
    sWay.nID = 0;
    INIT_INFO(&(sWay.sInfo));
    sWay.nTags = 0;
    sWay.nRefs = 0;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(WAY_IDX_ID, WT_VARINT))
            {
                READ_VARINT64(pabyData, pabyDataLimit, sWay.nID);
            }
            else if (nKey == MAKE_KEY(WAY_IDX_KEYS, WT_DATA))
            {
                unsigned int nSize = 0;
                const GByte *pabyDataNewLimit = nullptr;
                if (sWay.nTags != 0)
                    THROW_OSM_PARSING_EXCEPTION;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (nSize > psCtxt->nTagsAllocated)
                {
                    psCtxt->nTagsAllocated =
                        std::max(psCtxt->nTagsAllocated * 2, nSize);
                    OSMTag *pasTagsNew =
                        static_cast<OSMTag *>(VSI_REALLOC_VERBOSE(
                            psCtxt->pasTags,
                            psCtxt->nTagsAllocated * sizeof(OSMTag)));
                    if (pasTagsNew == nullptr)
                        THROW_OSM_PARSING_EXCEPTION;
                    psCtxt->pasTags = pasTagsNew;
                }

                pabyDataNewLimit = pabyData + nSize;
                while (pabyData < pabyDataNewLimit)
                {
                    unsigned int nKey2 = 0;
                    READ_VARUINT32(pabyData, pabyDataNewLimit, nKey2);

                    if (nKey2 >= psCtxt->nStrCount)
                        THROW_OSM_PARSING_EXCEPTION;

                    psCtxt->pasTags[sWay.nTags].pszK =
                        psCtxt->pszStrBuf + psCtxt->panStrOff[nKey2];
                    psCtxt->pasTags[sWay.nTags].pszV = "";
                    sWay.nTags++;
                }
                if (pabyData != pabyDataNewLimit)
                    THROW_OSM_PARSING_EXCEPTION;
            }
            else if (nKey == MAKE_KEY(WAY_IDX_VALS, WT_DATA))
            {
                unsigned int nIter = 0;
                if (sWay.nTags == 0)
                    THROW_OSM_PARSING_EXCEPTION;
                // unsigned int nSize = 0;
                // READ_VARUINT32(pabyData, pabyDataLimit, nSize);
                SKIP_VARINT(pabyData, pabyDataLimit);

                for (; nIter < sWay.nTags; nIter++)
                {
                    unsigned int nVal = 0;
                    READ_VARUINT32(pabyData, pabyDataLimit, nVal);

                    if (nVal >= psCtxt->nStrCount)
                        THROW_OSM_PARSING_EXCEPTION;

                    psCtxt->pasTags[nIter].pszV =
                        psCtxt->pszStrBuf + psCtxt->panStrOff[nVal];
                }
            }
            else if (nKey == MAKE_KEY(WAY_IDX_INFO, WT_DATA))
            {
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (!ReadOSMInfo(pabyData, pabyData + nSize, &sWay.sInfo,
                                 psCtxt))
                    THROW_OSM_PARSING_EXCEPTION;

                pabyData += nSize;
            }
            else if (nKey == MAKE_KEY(WAY_IDX_REFS, WT_DATA))
            {
                GIntBig nRefVal = 0;
                unsigned int nSize = 0;
                const GByte *pabyDataNewLimit = nullptr;
                if (sWay.nRefs != 0)
                    THROW_OSM_PARSING_EXCEPTION;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (nSize > psCtxt->nNodeRefsAllocated)
                {
                    psCtxt->nNodeRefsAllocated =
                        std::max(psCtxt->nNodeRefsAllocated * 2, nSize);
                    GIntBig *panNodeRefsNew =
                        static_cast<GIntBig *>(VSI_REALLOC_VERBOSE(
                            psCtxt->panNodeRefs,
                            psCtxt->nNodeRefsAllocated * sizeof(GIntBig)));
                    if (panNodeRefsNew == nullptr)
                        THROW_OSM_PARSING_EXCEPTION;
                    psCtxt->panNodeRefs = panNodeRefsNew;
                }

                pabyDataNewLimit = pabyData + nSize;
                while (pabyData < pabyDataNewLimit)
                {
                    GIntBig nDeltaRef = 0;
                    READ_VARSINT64_NOCHECK(pabyData, pabyDataNewLimit,
                                           nDeltaRef);
                    nRefVal = AddWithOverflowAccepted(nRefVal, nDeltaRef);

                    psCtxt->panNodeRefs[sWay.nRefs++] = nRefVal;
                }

                if (pabyData != pabyDataNewLimit)
                    THROW_OSM_PARSING_EXCEPTION;
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        if (pabyData != pabyDataLimit)
            THROW_OSM_PARSING_EXCEPTION;

        if (sWay.nTags)
            sWay.pasTags = psCtxt->pasTags;
        else
            sWay.pasTags = nullptr;
        sWay.panNodeRefs = psCtxt->panNodeRefs;

        psCtxt->pfnNotifyWay(&sWay, psCtxt, psCtxt->user_data);

        return true;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                            ReadRelation()                            */
/************************************************************************/

constexpr int RELATION_IDX_ID = 1;
constexpr int RELATION_IDX_KEYS = 2;
constexpr int RELATION_IDX_VALS = 3;
constexpr int RELATION_IDX_INFO = 4;
constexpr int RELATION_IDX_ROLES_SID = 8;
constexpr int RELATION_IDX_MEMIDS = 9;
constexpr int RELATION_IDX_TYPES = 10;

static bool ReadRelation(const GByte *pabyData, const GByte *pabyDataLimit,
                         OSMContext *psCtxt)
{
    OSMRelation sRelation;
    sRelation.nID = 0;
    INIT_INFO(&(sRelation.sInfo));
    sRelation.nTags = 0;
    sRelation.nMembers = 0;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(RELATION_IDX_ID, WT_VARINT))
            {
                READ_VARINT64(pabyData, pabyDataLimit, sRelation.nID);
            }
            else if (nKey == MAKE_KEY(RELATION_IDX_KEYS, WT_DATA))
            {
                unsigned int nSize = 0;
                const GByte *pabyDataNewLimit = nullptr;
                if (sRelation.nTags != 0)
                    THROW_OSM_PARSING_EXCEPTION;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (nSize > psCtxt->nTagsAllocated)
                {
                    psCtxt->nTagsAllocated =
                        std::max(psCtxt->nTagsAllocated * 2, nSize);
                    OSMTag *pasTagsNew =
                        static_cast<OSMTag *>(VSI_REALLOC_VERBOSE(
                            psCtxt->pasTags,
                            psCtxt->nTagsAllocated * sizeof(OSMTag)));
                    if (pasTagsNew == nullptr)
                        THROW_OSM_PARSING_EXCEPTION;
                    psCtxt->pasTags = pasTagsNew;
                }

                pabyDataNewLimit = pabyData + nSize;
                while (pabyData < pabyDataNewLimit)
                {
                    unsigned int nKey2 = 0;
                    READ_VARUINT32(pabyData, pabyDataNewLimit, nKey2);

                    if (nKey2 >= psCtxt->nStrCount)
                        THROW_OSM_PARSING_EXCEPTION;

                    psCtxt->pasTags[sRelation.nTags].pszK =
                        psCtxt->pszStrBuf + psCtxt->panStrOff[nKey2];
                    psCtxt->pasTags[sRelation.nTags].pszV = "";
                    sRelation.nTags++;
                }
                if (pabyData != pabyDataNewLimit)
                    THROW_OSM_PARSING_EXCEPTION;
            }
            else if (nKey == MAKE_KEY(RELATION_IDX_VALS, WT_DATA))
            {
                unsigned int nIter = 0;
                if (sRelation.nTags == 0)
                    THROW_OSM_PARSING_EXCEPTION;
                // unsigned int nSize = 0;
                // READ_VARUINT32(pabyData, pabyDataLimit, nSize);
                SKIP_VARINT(pabyData, pabyDataLimit);

                for (; nIter < sRelation.nTags; nIter++)
                {
                    unsigned int nVal = 0;
                    READ_VARUINT32(pabyData, pabyDataLimit, nVal);

                    if (nVal >= psCtxt->nStrCount)
                        THROW_OSM_PARSING_EXCEPTION;

                    psCtxt->pasTags[nIter].pszV =
                        psCtxt->pszStrBuf + psCtxt->panStrOff[nVal];
                }
            }
            else if (nKey == MAKE_KEY(RELATION_IDX_INFO, WT_DATA))
            {
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (!ReadOSMInfo(pabyData, pabyData + nSize, &sRelation.sInfo,
                                 psCtxt))
                    THROW_OSM_PARSING_EXCEPTION;

                pabyData += nSize;
            }
            else if (nKey == MAKE_KEY(RELATION_IDX_ROLES_SID, WT_DATA))
            {
                unsigned int nSize = 0;
                const GByte *pabyDataNewLimit = nullptr;
                if (sRelation.nMembers != 0)
                    THROW_OSM_PARSING_EXCEPTION;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (nSize > psCtxt->nMembersAllocated)
                {
                    psCtxt->nMembersAllocated =
                        std::max(psCtxt->nMembersAllocated * 2, nSize);
                    OSMMember *pasMembersNew =
                        static_cast<OSMMember *>(VSI_REALLOC_VERBOSE(
                            psCtxt->pasMembers,
                            psCtxt->nMembersAllocated * sizeof(OSMMember)));
                    if (pasMembersNew == nullptr)
                        THROW_OSM_PARSING_EXCEPTION;
                    psCtxt->pasMembers = pasMembersNew;
                }

                pabyDataNewLimit = pabyData + nSize;
                while (pabyData < pabyDataNewLimit)
                {
                    unsigned int nRoleSID = 0;
                    READ_VARUINT32(pabyData, pabyDataNewLimit, nRoleSID);
                    if (nRoleSID >= psCtxt->nStrCount)
                        THROW_OSM_PARSING_EXCEPTION;

                    psCtxt->pasMembers[sRelation.nMembers].pszRole =
                        psCtxt->pszStrBuf + psCtxt->panStrOff[nRoleSID];
                    psCtxt->pasMembers[sRelation.nMembers].nID = 0;
                    psCtxt->pasMembers[sRelation.nMembers].eType = MEMBER_NODE;
                    sRelation.nMembers++;
                }

                if (pabyData != pabyDataNewLimit)
                    THROW_OSM_PARSING_EXCEPTION;
            }
            else if (nKey == MAKE_KEY(RELATION_IDX_MEMIDS, WT_DATA))
            {
                unsigned int nIter = 0;
                GIntBig nMemID = 0;
                if (sRelation.nMembers == 0)
                    THROW_OSM_PARSING_EXCEPTION;
                // unsigned int nSize = 0;
                // READ_VARUINT32(pabyData, pabyDataLimit, nSize);
                SKIP_VARINT(pabyData, pabyDataLimit);

                for (; nIter < sRelation.nMembers; nIter++)
                {
                    GIntBig nDeltaMemID = 0;
                    READ_VARSINT64(pabyData, pabyDataLimit, nDeltaMemID);
                    nMemID = AddWithOverflowAccepted(nMemID, nDeltaMemID);

                    psCtxt->pasMembers[nIter].nID = nMemID;
                }
            }
            else if (nKey == MAKE_KEY(RELATION_IDX_TYPES, WT_DATA))
            {
                unsigned int nIter = 0;
                if (sRelation.nMembers == 0)
                    THROW_OSM_PARSING_EXCEPTION;
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);
                if (nSize != sRelation.nMembers)
                    THROW_OSM_PARSING_EXCEPTION;

                for (; nIter < sRelation.nMembers; nIter++)
                {
                    unsigned int nType = pabyData[nIter];
                    if (nType > MEMBER_RELATION)
                        THROW_OSM_PARSING_EXCEPTION;

                    psCtxt->pasMembers[nIter].eType =
                        static_cast<OSMMemberType>(nType);
                }
                pabyData += nSize;
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }
        /* printf("<ReadRelation\n"); */

        if (pabyData != pabyDataLimit)
            THROW_OSM_PARSING_EXCEPTION;

        if (sRelation.nTags)
            sRelation.pasTags = psCtxt->pasTags;
        else
            sRelation.pasTags = nullptr;

        sRelation.pasMembers = psCtxt->pasMembers;

        psCtxt->pfnNotifyRelation(&sRelation, psCtxt, psCtxt->user_data);

        return true;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                          ReadPrimitiveGroup()                        */
/************************************************************************/

constexpr int PRIMITIVEGROUP_IDX_NODES = 1;
// constexpr int PRIMITIVEGROUP_IDX_DENSE = 2;
// constexpr int PRIMITIVEGROUP_IDX_WAYS = 3;
constexpr int PRIMITIVEGROUP_IDX_RELATIONS = 4;
// constexpr int PRIMITIVEGROUP_IDX_CHANGESETS = 5;

typedef bool (*PrimitiveFuncType)(const GByte *pabyData,
                                  const GByte *pabyDataLimit,
                                  OSMContext *psCtxt);

static const PrimitiveFuncType apfnPrimitives[] = {ReadNode, ReadDenseNodes,
                                                   ReadWay, ReadRelation};

static bool ReadPrimitiveGroup(const GByte *pabyData,
                               const GByte *pabyDataLimit, OSMContext *psCtxt)
{
    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            const int nFieldNumber = GET_FIELDNUMBER(nKey) - 1;
            if (GET_WIRETYPE(nKey) == WT_DATA &&
                nFieldNumber >= PRIMITIVEGROUP_IDX_NODES - 1 &&
                nFieldNumber <= PRIMITIVEGROUP_IDX_RELATIONS - 1)
            {
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (!apfnPrimitives[nFieldNumber](pabyData, pabyData + nSize,
                                                  psCtxt))
                    THROW_OSM_PARSING_EXCEPTION;

                pabyData += nSize;
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        return pabyData == pabyDataLimit;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                          ReadPrimitiveBlock()                        */
/************************************************************************/

constexpr int PRIMITIVEBLOCK_IDX_STRINGTABLE = 1;
constexpr int PRIMITIVEBLOCK_IDX_PRIMITIVEGROUP = 2;
constexpr int PRIMITIVEBLOCK_IDX_GRANULARITY = 17;
constexpr int PRIMITIVEBLOCK_IDX_DATE_GRANULARITY = 18;
constexpr int PRIMITIVEBLOCK_IDX_LAT_OFFSET = 19;
constexpr int PRIMITIVEBLOCK_IDX_LON_OFFSET = 20;

static bool ReadPrimitiveBlock(const GByte *pabyData,
                               const GByte *pabyDataLimit, OSMContext *psCtxt)
{
    const GByte *pabyDataSave = pabyData;

    psCtxt->pszStrBuf = nullptr;
    psCtxt->nStrCount = 0;
    psCtxt->nGranularity = 100;
    psCtxt->nDateGranularity = 1000;
    psCtxt->nLatOffset = 0;
    psCtxt->nLonOffset = 0;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(PRIMITIVEBLOCK_IDX_GRANULARITY, WT_VARINT))
            {
                READ_VARINT32(pabyData, pabyDataLimit, psCtxt->nGranularity);
                if (psCtxt->nGranularity <= 0)
                    THROW_OSM_PARSING_EXCEPTION;
            }
            else if (nKey ==
                     MAKE_KEY(PRIMITIVEBLOCK_IDX_DATE_GRANULARITY, WT_VARINT))
            {
                READ_VARINT32(pabyData, pabyDataLimit,
                              psCtxt->nDateGranularity);
            }
            else if (nKey == MAKE_KEY(PRIMITIVEBLOCK_IDX_LAT_OFFSET, WT_VARINT))
            {
                READ_VARINT64(pabyData, pabyDataLimit, psCtxt->nLatOffset);
            }
            else if (nKey == MAKE_KEY(PRIMITIVEBLOCK_IDX_LON_OFFSET, WT_VARINT))
            {
                READ_VARINT64(pabyData, pabyDataLimit, psCtxt->nLonOffset);
            }
            else
            {
                SKIP_UNKNOWN_FIELD_INLINE(pabyData, pabyDataLimit, FALSE);
            }
        }

        if (pabyData != pabyDataLimit)
            THROW_OSM_PARSING_EXCEPTION;

        pabyData = pabyDataSave;
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(PRIMITIVEBLOCK_IDX_STRINGTABLE, WT_DATA))
            {
                GByte bSaveAfterByte = 0;
                GByte *pbSaveAfterByte = nullptr;
                if (psCtxt->nStrCount != 0)
                    THROW_OSM_PARSING_EXCEPTION;
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                // Dirty little trick:
                // ReadStringTable() will over-write the byte after the
                // StringTable message with a NUL character, so we backup
                // it to be able to restore it just before issuing the next
                // READ_FIELD_KEY. Then we will re-NUL it to have valid
                // NUL terminated strings.
                // This trick enable us to keep the strings where there are
                // in RAM.
                pbSaveAfterByte = const_cast<GByte *>(pabyData + nSize);
                bSaveAfterByte = *pbSaveAfterByte;

                if (!ReadStringTable(pabyData, pabyData + nSize, psCtxt))
                    THROW_OSM_PARSING_EXCEPTION;

                pabyData += nSize;

                *pbSaveAfterByte = bSaveAfterByte;
                if (pabyData == pabyDataLimit)
                    break;

                READ_FIELD_KEY(nKey);
                *pbSaveAfterByte = 0;

                if (nKey == MAKE_KEY(PRIMITIVEBLOCK_IDX_STRINGTABLE, WT_DATA))
                    THROW_OSM_PARSING_EXCEPTION;

                /* Yes we go on ! */
            }

            if (nKey == MAKE_KEY(PRIMITIVEBLOCK_IDX_PRIMITIVEGROUP, WT_DATA))
            {
                unsigned int nSize = 0;
                READ_SIZE(pabyData, pabyDataLimit, nSize);

                if (!ReadPrimitiveGroup(pabyData, pabyData + nSize, psCtxt))
                    THROW_OSM_PARSING_EXCEPTION;

                pabyData += nSize;
            }
            else
            {
                SKIP_UNKNOWN_FIELD_INLINE(pabyData, pabyDataLimit, FALSE);
            }
        }

        return pabyData == pabyDataLimit;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                          DecompressFunction()                        */
/************************************************************************/

static void DecompressFunction(void *pDataIn)
{
    DecompressionJob *psJob = static_cast<DecompressionJob *>(pDataIn);
    psJob->bStatus = CPLZLibInflate(psJob->pabySrc, psJob->nSrcSize,
                                    psJob->pabyDstBase + psJob->nDstOffset,
                                    psJob->nDstSize, nullptr) != nullptr;
}

/************************************************************************/
/*                      RunDecompressionJobs()                          */
/************************************************************************/

static bool RunDecompressionJobs(OSMContext *psCtxt)
{
    psCtxt->nTotalUncompressedSize = 0;

    GByte *pabyDstBase = psCtxt->pabyUncompressed;
    std::vector<void *> ahJobs;
    for (int i = 0; i < psCtxt->nJobs; i++)
    {
        psCtxt->asJobs[i].pabyDstBase = pabyDstBase;
        if (psCtxt->poWTP)
            ahJobs.push_back(&psCtxt->asJobs[i]);
        else
            DecompressFunction(&psCtxt->asJobs[i]);
    }
    if (psCtxt->poWTP)
    {
        psCtxt->poWTP->SubmitJobs(DecompressFunction, ahJobs);
        psCtxt->poWTP->WaitCompletion();
    }

    bool bRet = true;
    for (int i = 0; bRet && i < psCtxt->nJobs; i++)
    {
        bRet &= psCtxt->asJobs[i].bStatus;
    }
    return bRet;
}

/************************************************************************/
/*                          ProcessSingleBlob()                         */
/************************************************************************/

// cppcheck-suppress constParameterReference
static bool ProcessSingleBlob(OSMContext *psCtxt, DecompressionJob &sJob,
                              BlobType eType)
{
    if (eType == BLOB_OSMHEADER)
    {
        return ReadOSMHeader(sJob.pabyDstBase + sJob.nDstOffset,
                             sJob.pabyDstBase + sJob.nDstOffset + sJob.nDstSize,
                             psCtxt);
    }
    else
    {
        CPLAssert(eType == BLOB_OSMDATA);
        return ReadPrimitiveBlock(
            sJob.pabyDstBase + sJob.nDstOffset,
            sJob.pabyDstBase + sJob.nDstOffset + sJob.nDstSize, psCtxt);
    }
}

/************************************************************************/
/*                   RunDecompressionJobsAndProcessAll()                */
/************************************************************************/

static bool RunDecompressionJobsAndProcessAll(OSMContext *psCtxt,
                                              BlobType eType)
{
    if (!RunDecompressionJobs(psCtxt))
    {
        return false;
    }
    for (int i = 0; i < psCtxt->nJobs; i++)
    {
        if (!ProcessSingleBlob(psCtxt, psCtxt->asJobs[i], eType))
        {
            return false;
        }
    }
    psCtxt->iNextJob = 0;
    psCtxt->nJobs = 0;
    return true;
}

/************************************************************************/
/*                              ReadBlob()                              */
/************************************************************************/

constexpr int BLOB_IDX_RAW = 1;
constexpr int BLOB_IDX_RAW_SIZE = 2;
constexpr int BLOB_IDX_ZLIB_DATA = 3;

static bool ReadBlob(OSMContext *psCtxt, BlobType eType)
{
    unsigned int nUncompressedSize = 0;
    bool bRet = true;
    const GByte *pabyData = psCtxt->pabyBlob + psCtxt->nBlobOffset;
    const GByte *pabyLastCheckpointData = pabyData;
    const GByte *pabyDataLimit = psCtxt->pabyBlob + psCtxt->nBlobSize;

    try
    {
        while (pabyData < pabyDataLimit)
        {
            int nKey = 0;
            READ_FIELD_KEY(nKey);

            if (nKey == MAKE_KEY(BLOB_IDX_RAW, WT_DATA))
            {
                if (psCtxt->nJobs > 0 &&
                    !RunDecompressionJobsAndProcessAll(psCtxt, eType))
                {
                    THROW_OSM_PARSING_EXCEPTION;
                }

                unsigned int nDataLength = 0;
                READ_SIZE(pabyData, pabyDataLimit, nDataLength);
                if (nDataLength > MAX_BLOB_SIZE)
                    THROW_OSM_PARSING_EXCEPTION;

                // printf("raw data size = %d\n", nDataLength);

                if (eType == BLOB_OSMHEADER)
                {
                    bRet =
                        ReadOSMHeader(pabyData, pabyData + nDataLength, psCtxt);
                }
                else if (eType == BLOB_OSMDATA)
                {
                    bRet = ReadPrimitiveBlock(pabyData, pabyData + nDataLength,
                                              psCtxt);
                }

                pabyData += nDataLength;
            }
            else if (nKey == MAKE_KEY(BLOB_IDX_RAW_SIZE, WT_VARINT))
            {
                READ_VARUINT32(pabyData, pabyDataLimit, nUncompressedSize);
                // printf("nUncompressedSize = %d\n", nUncompressedSize);
            }
            else if (nKey == MAKE_KEY(BLOB_IDX_ZLIB_DATA, WT_DATA))
            {
                unsigned int nZlibCompressedSize = 0;
                READ_VARUINT32(pabyData, pabyDataLimit, nZlibCompressedSize);
                if (CHECK_OOB && nZlibCompressedSize >
                                     psCtxt->nBlobSize - psCtxt->nBlobOffset)
                {
                    THROW_OSM_PARSING_EXCEPTION;
                }

                // printf("nZlibCompressedSize = %d\n", nZlibCompressedSize);

                if (nUncompressedSize != 0)
                {
                    if (nUncompressedSize / 100 > nZlibCompressedSize)
                    {
                        // Too prevent excessive memory allocations
                        CPLError(CE_Failure, CPLE_AppDefined,
                                 "Excessive uncompressed vs compressed ratio");
                        THROW_OSM_PARSING_EXCEPTION;
                    }
                    if (psCtxt->nJobs > 0 &&
                        (psCtxt->nTotalUncompressedSize >
                             UINT_MAX - nUncompressedSize ||
                         psCtxt->nTotalUncompressedSize + nUncompressedSize >
                             MAX_ACC_UNCOMPRESSED_SIZE))
                    {
                        pabyData = pabyLastCheckpointData;
                        break;
                    }
                    unsigned nSizeNeeded =
                        psCtxt->nTotalUncompressedSize + nUncompressedSize;
                    if (nSizeNeeded > psCtxt->nUncompressedAllocated)
                    {

                        GByte *pabyUncompressedNew = nullptr;
                        if (psCtxt->nUncompressedAllocated <=
                                UINT_MAX - psCtxt->nUncompressedAllocated / 3 &&
                            psCtxt->nUncompressedAllocated +
                                    psCtxt->nUncompressedAllocated / 3 <
                                MAX_ACC_UNCOMPRESSED_SIZE)
                        {
                            psCtxt->nUncompressedAllocated =
                                std::max(psCtxt->nUncompressedAllocated +
                                             psCtxt->nUncompressedAllocated / 3,
                                         nSizeNeeded);
                        }
                        else
                        {
                            psCtxt->nUncompressedAllocated = nSizeNeeded;
                        }
                        if (psCtxt->nUncompressedAllocated >
                            UINT_MAX - EXTRA_BYTES)
                            THROW_OSM_PARSING_EXCEPTION;
                        pabyUncompressedNew =
                            static_cast<GByte *>(VSI_REALLOC_VERBOSE(
                                psCtxt->pabyUncompressed,
                                psCtxt->nUncompressedAllocated + EXTRA_BYTES));
                        if (pabyUncompressedNew == nullptr)
                            THROW_OSM_PARSING_EXCEPTION;
                        psCtxt->pabyUncompressed = pabyUncompressedNew;
                    }
                    memset(psCtxt->pabyUncompressed + nSizeNeeded, 0,
                           EXTRA_BYTES);

                    psCtxt->asJobs[psCtxt->nJobs].pabySrc = pabyData;
                    psCtxt->asJobs[psCtxt->nJobs].nSrcSize =
                        nZlibCompressedSize;
                    psCtxt->asJobs[psCtxt->nJobs].nDstOffset =
                        psCtxt->nTotalUncompressedSize;
                    psCtxt->asJobs[psCtxt->nJobs].nDstSize = nUncompressedSize;
                    psCtxt->nJobs++;
                    if (psCtxt->poWTP == nullptr || eType != BLOB_OSMDATA)
                    {
                        if (!RunDecompressionJobsAndProcessAll(psCtxt, eType))
                        {
                            THROW_OSM_PARSING_EXCEPTION;
                        }
                    }
                    else
                    {
                        // Make sure that uncompressed blobs are separated by
                        // EXTRA_BYTES in the case where in the future we would
                        // implement parallel decoding of them (not sure if
                        // that's doable)
                        psCtxt->nTotalUncompressedSize +=
                            nUncompressedSize + EXTRA_BYTES;
                    }
                }

                nUncompressedSize = 0;
                pabyData += nZlibCompressedSize;
                pabyLastCheckpointData = pabyData;
                if (psCtxt->nJobs == N_MAX_JOBS)
                    break;
            }
            else
            {
                SKIP_UNKNOWN_FIELD(pabyData, pabyDataLimit, TRUE);
            }
        }

        if (psCtxt->nJobs > 0)
        {
            if (!RunDecompressionJobs(psCtxt))
            {
                THROW_OSM_PARSING_EXCEPTION;
            }
            // Just process one blob at a time
            if (!ProcessSingleBlob(psCtxt, psCtxt->asJobs[0], eType))
            {
                THROW_OSM_PARSING_EXCEPTION;
            }
            psCtxt->iNextJob = 1;
        }

        psCtxt->nBlobOffset =
            static_cast<unsigned>(pabyData - psCtxt->pabyBlob);
        return bRet;
    }
    catch (const std::exception &e)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "%s", e.what());
        return false;
    }
}

/************************************************************************/
/*                          OSM_ProcessBlock()                          */
/************************************************************************/

static OSMRetCode PBF_ProcessBlock(OSMContext *psCtxt)
{
    // Process any remaining queued jobs one by one
    if (psCtxt->iNextJob < psCtxt->nJobs)
    {
        if (!(ProcessSingleBlob(psCtxt, psCtxt->asJobs[psCtxt->iNextJob],
                                BLOB_OSMDATA)))
        {
            return OSM_ERROR;
        }
        psCtxt->iNextJob++;
        return OSM_OK;
    }
    psCtxt->iNextJob = 0;
    psCtxt->nJobs = 0;

    // Make sure to finish parsing the last concatenated blocks
    if (psCtxt->nBlobOffset < psCtxt->nBlobSize)
    {
        return ReadBlob(psCtxt, BLOB_OSMDATA) ? OSM_OK : OSM_ERROR;
    }
    psCtxt->nBlobOffset = 0;
    psCtxt->nBlobSize = 0;

    int nBlobCount = 0;
    OSMRetCode eRetCode = OSM_OK;
    unsigned int nBlobSizeAcc = 0;
    BlobType eType = BLOB_UNKNOWN;
    while (true)
    {
        GByte abyHeaderSize[4];
        unsigned int nBlobSize = 0;

        if (VSIFReadL(abyHeaderSize, 4, 1, psCtxt->fp) != 1)
        {
            eRetCode = OSM_EOF;
            break;
        }
        const unsigned int nHeaderSize =
            (static_cast<unsigned int>(abyHeaderSize[0]) << 24) |
            (abyHeaderSize[1] << 16) | (abyHeaderSize[2] << 8) |
            abyHeaderSize[3];

        psCtxt->nBytesRead += 4;

        /* printf("nHeaderSize = %d\n", nHeaderSize); */
        if (nHeaderSize > MAX_BLOB_HEADER_SIZE)
        {
            eRetCode = OSM_ERROR;
            break;
        }
        if (VSIFReadL(psCtxt->pabyBlobHeader, 1, nHeaderSize, psCtxt->fp) !=
            nHeaderSize)
        {
            eRetCode = OSM_ERROR;
            break;
        }

        psCtxt->nBytesRead += nHeaderSize;

        memset(psCtxt->pabyBlobHeader + nHeaderSize, 0, EXTRA_BYTES);
        const bool bRet = ReadBlobHeader(psCtxt->pabyBlobHeader,
                                         psCtxt->pabyBlobHeader + nHeaderSize,
                                         &nBlobSize, &eType);
        if (!bRet || eType == BLOB_UNKNOWN)
        {
            eRetCode = OSM_ERROR;
            break;
        }

        // Limit in OSM PBF spec
        if (nBlobSize > MAX_BLOB_SIZE)
        {
            eRetCode = OSM_ERROR;
            break;
        }
        if (nBlobSize + nBlobSizeAcc > psCtxt->nBlobSizeAllocated)
        {
            psCtxt->nBlobSizeAllocated = std::max(
                std::min(MAX_ACC_BLOB_SIZE, psCtxt->nBlobSizeAllocated * 2),
                nBlobSize + nBlobSizeAcc);
            GByte *pabyBlobNew = static_cast<GByte *>(VSI_REALLOC_VERBOSE(
                psCtxt->pabyBlob, psCtxt->nBlobSizeAllocated + EXTRA_BYTES));
            if (pabyBlobNew == nullptr)
            {
                eRetCode = OSM_ERROR;
                break;
            }
            psCtxt->pabyBlob = pabyBlobNew;
        }
        // Given how Protocol buffer work, we can merge several buffers
        // by just appending them to the previous ones.
        if (VSIFReadL(psCtxt->pabyBlob + nBlobSizeAcc, 1, nBlobSize,
                      psCtxt->fp) != nBlobSize)
        {
            eRetCode = OSM_ERROR;
            break;
        }
        psCtxt->nBytesRead += nBlobSize;
        nBlobSizeAcc += nBlobSize;
        memset(psCtxt->pabyBlob + nBlobSizeAcc, 0, EXTRA_BYTES);

        nBlobCount++;

        if (eType == BLOB_OSMDATA && psCtxt->poWTP != nullptr)
        {
            // Accumulate BLOB_OSMDATA until we reach either the maximum
            // number of jobs or a threshold in bytes
            if (nBlobCount == N_MAX_JOBS || nBlobSizeAcc > MAX_ACC_BLOB_SIZE)
            {
                break;
            }
        }
        else
        {
            break;
        }
    }

    if (nBlobCount > 0)
    {
        psCtxt->nBlobOffset = 0;
        psCtxt->nBlobSize = nBlobSizeAcc;
        const bool bRet = ReadBlob(psCtxt, eType);
        if (bRet)
        {
            if (eRetCode == OSM_EOF &&
                (psCtxt->iNextJob < psCtxt->nJobs ||
                 psCtxt->nBlobOffset < psCtxt->nBlobSize))
            {
                eRetCode = OSM_OK;
            }
            CPLAssert(psCtxt->iNextJob == psCtxt->nJobs ||
                      eType == BLOB_OSMDATA);
        }
        else
        {
            eRetCode = OSM_ERROR;
        }
    }

    return eRetCode;
}

/************************************************************************/
/*                        EmptyNotifyNodesFunc()                        */
/************************************************************************/

static void EmptyNotifyNodesFunc(unsigned int /* nNodes */,
                                 OSMNode * /* pasNodes */,
                                 OSMContext * /* psCtxt */,
                                 void * /* user_data */)
{
}

/************************************************************************/
/*                         EmptyNotifyWayFunc()                         */
/************************************************************************/

static void EmptyNotifyWayFunc(OSMWay * /* psWay */, OSMContext * /* psCtxt */,
                               void * /* user_data */)
{
}

/************************************************************************/
/*                       EmptyNotifyRelationFunc()                      */
/************************************************************************/

static void EmptyNotifyRelationFunc(OSMRelation * /* psRelation */,
                                    OSMContext * /* psCtxt */,
                                    void * /* user_data */)
{
}

/************************************************************************/
/*                         EmptyNotifyBoundsFunc()                      */
/************************************************************************/

static void EmptyNotifyBoundsFunc(double /* dfXMin */, double /* dfYMin */,
                                  double /* dfXMax */, double /* dfYMax */,
                                  OSMContext * /*psCtxt */,
                                  void * /* user_data */)
{
}

#ifdef HAVE_EXPAT

/************************************************************************/
/*                          OSM_AddString()                             */
/************************************************************************/

static const char *OSM_AddString(OSMContext *psCtxt, const char *pszStr)
{
    const auto nLen = strlen(pszStr);
    if (psCtxt->nStrLength + nLen + 1 > psCtxt->nStrAllocated)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "String buffer too small");
        return "";
    }
    char *pszRet = psCtxt->pszStrBuf + psCtxt->nStrLength;
    memcpy(pszRet, pszStr, nLen);
    pszRet[nLen] = '\0';
    psCtxt->nStrLength += static_cast<unsigned>(nLen) + 1;
    return pszRet;
}

/************************************************************************/
/*                            OSM_Atoi64()                              */
/************************************************************************/

static GIntBig OSM_Atoi64(const char *pszString)
{
    return atoll(pszString);
}

/************************************************************************/
/*                      OSM_XML_startElementCbk()                       */
/************************************************************************/

static void XMLCALL OSM_XML_startElementCbk(void *pUserData,
                                            const char *pszName,
                                            const char **ppszAttr)
{
    OSMContext *psCtxt = static_cast<OSMContext *>(pUserData);
    const char **ppszIter = ppszAttr;

    if (psCtxt->bStopParsing)
        return;

    psCtxt->nWithoutEventCounter = 0;

    if (psCtxt->bTryToFetchBounds)
    {
        if (strcmp(pszName, "bounds") == 0 ||
            strcmp(pszName, "bound") == 0 /* osmosis uses bound */)
        {
            int nCountCoords = 0;

            psCtxt->bTryToFetchBounds = false;

            if (ppszIter)
            {
                while (ppszIter[0] != nullptr)
                {
                    if (strcmp(ppszIter[0], "minlon") == 0)
                    {
                        psCtxt->dfLeft = CPLAtof(ppszIter[1]);
                        nCountCoords++;
                    }
                    else if (strcmp(ppszIter[0], "minlat") == 0)
                    {
                        psCtxt->dfBottom = CPLAtof(ppszIter[1]);
                        nCountCoords++;
                    }
                    else if (strcmp(ppszIter[0], "maxlon") == 0)
                    {
                        psCtxt->dfRight = CPLAtof(ppszIter[1]);
                        nCountCoords++;
                    }
                    else if (strcmp(ppszIter[0], "maxlat") == 0)
                    {
                        psCtxt->dfTop = CPLAtof(ppszIter[1]);
                        nCountCoords++;
                    }
                    else if (strcmp(ppszIter[0], "box") ==
                             0 /* osmosis uses box */)
                    {
                        char **papszTokens =
                            CSLTokenizeString2(ppszIter[1], ",", 0);
                        if (CSLCount(papszTokens) == 4)
                        {
                            psCtxt->dfBottom = CPLAtof(papszTokens[0]);
                            psCtxt->dfLeft = CPLAtof(papszTokens[1]);
                            psCtxt->dfTop = CPLAtof(papszTokens[2]);
                            psCtxt->dfRight = CPLAtof(papszTokens[3]);
                            nCountCoords = 4;
                        }
                        CSLDestroy(papszTokens);
                    }
                    ppszIter += 2;
                }
            }

            if (nCountCoords == 4)
            {
                psCtxt->pfnNotifyBounds(psCtxt->dfLeft, psCtxt->dfBottom,
                                        psCtxt->dfRight, psCtxt->dfTop, psCtxt,
                                        psCtxt->user_data);
            }
        }
    }

    if (!psCtxt->bInNode && !psCtxt->bInWay && !psCtxt->bInRelation &&
        strcmp(pszName, "node") == 0)
    {
        psCtxt->bInNode = true;
        psCtxt->bTryToFetchBounds = false;

        psCtxt->nStrLength = 0;
        psCtxt->pszStrBuf[0] = '\0';
        psCtxt->nTags = 0;

        memset(&(psCtxt->pasNodes[0]), 0, sizeof(OSMNode));
        psCtxt->pasNodes[0].sInfo.pszUserSID = "";

        if (ppszIter)
        {
            while (ppszIter[0] != nullptr)
            {
                if (strcmp(ppszIter[0], "id") == 0)
                {
                    psCtxt->pasNodes[0].nID = OSM_Atoi64(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "lat") == 0)
                {
                    psCtxt->pasNodes[0].dfLat = CPLAtof(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "lon") == 0)
                {
                    psCtxt->pasNodes[0].dfLon = CPLAtof(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "version") == 0)
                {
                    psCtxt->pasNodes[0].sInfo.nVersion = atoi(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "changeset") == 0)
                {
                    psCtxt->pasNodes[0].sInfo.nChangeset =
                        OSM_Atoi64(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "user") == 0)
                {
                    psCtxt->pasNodes[0].sInfo.pszUserSID =
                        OSM_AddString(psCtxt, ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "uid") == 0)
                {
                    psCtxt->pasNodes[0].sInfo.nUID = atoi(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "timestamp") == 0)
                {
                    psCtxt->pasNodes[0].sInfo.ts.pszTimeStamp =
                        OSM_AddString(psCtxt, ppszIter[1]);
                    psCtxt->pasNodes[0].sInfo.bTimeStampIsStr = true;
                }
                ppszIter += 2;
            }
        }
    }

    else if (!psCtxt->bInNode && !psCtxt->bInWay && !psCtxt->bInRelation &&
             strcmp(pszName, "way") == 0)
    {
        psCtxt->bInWay = true;

        psCtxt->nStrLength = 0;
        psCtxt->pszStrBuf[0] = '\0';
        psCtxt->nTags = 0;

        memset(&(psCtxt->sWay), 0, sizeof(OSMWay));
        psCtxt->sWay.sInfo.pszUserSID = "";

        if (ppszIter)
        {
            while (ppszIter[0] != nullptr)
            {
                if (strcmp(ppszIter[0], "id") == 0)
                {
                    psCtxt->sWay.nID = OSM_Atoi64(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "version") == 0)
                {
                    psCtxt->sWay.sInfo.nVersion = atoi(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "changeset") == 0)
                {
                    psCtxt->sWay.sInfo.nChangeset = OSM_Atoi64(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "user") == 0)
                {
                    psCtxt->sWay.sInfo.pszUserSID =
                        OSM_AddString(psCtxt, ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "uid") == 0)
                {
                    psCtxt->sWay.sInfo.nUID = atoi(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "timestamp") == 0)
                {
                    psCtxt->sWay.sInfo.ts.pszTimeStamp =
                        OSM_AddString(psCtxt, ppszIter[1]);
                    psCtxt->sWay.sInfo.bTimeStampIsStr = true;
                }
                ppszIter += 2;
            }
        }
    }

    else if (!psCtxt->bInNode && !psCtxt->bInWay && !psCtxt->bInRelation &&
             strcmp(pszName, "relation") == 0)
    {
        psCtxt->bInRelation = true;

        psCtxt->nStrLength = 0;
        psCtxt->pszStrBuf[0] = '\0';
        psCtxt->nTags = 0;

        memset(&(psCtxt->sRelation), 0, sizeof(OSMRelation));
        psCtxt->sRelation.sInfo.pszUserSID = "";

        if (ppszIter)
        {
            while (ppszIter[0] != nullptr)
            {
                if (strcmp(ppszIter[0], "id") == 0)
                {
                    psCtxt->sRelation.nID = OSM_Atoi64(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "version") == 0)
                {
                    psCtxt->sRelation.sInfo.nVersion = atoi(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "changeset") == 0)
                {
                    psCtxt->sRelation.sInfo.nChangeset =
                        OSM_Atoi64(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "user") == 0)
                {
                    psCtxt->sRelation.sInfo.pszUserSID =
                        OSM_AddString(psCtxt, ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "uid") == 0)
                {
                    psCtxt->sRelation.sInfo.nUID = atoi(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "timestamp") == 0)
                {
                    psCtxt->sRelation.sInfo.ts.pszTimeStamp =
                        OSM_AddString(psCtxt, ppszIter[1]);
                    psCtxt->sRelation.sInfo.bTimeStampIsStr = true;
                }
                ppszIter += 2;
            }
        }
    }

    else if (psCtxt->bInWay && strcmp(pszName, "nd") == 0)
    {
        if (ppszAttr != nullptr && ppszAttr[0] != nullptr &&
            strcmp(ppszAttr[0], "ref") == 0)
        {
            if (psCtxt->sWay.nRefs < psCtxt->nNodeRefsAllocated)
            {
                psCtxt->panNodeRefs[psCtxt->sWay.nRefs] =
                    OSM_Atoi64(ppszAttr[1]);
                psCtxt->sWay.nRefs++;
            }
            else
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                         "Too many nodes referenced in way " CPL_FRMT_GIB,
                         psCtxt->sWay.nID);
            }
        }
    }

    else if (psCtxt->bInRelation && strcmp(pszName, "member") == 0)
    {
        /* 300 is the recommended value, but there are files with more than 2000
         * so we should be able */
        /* to realloc over that value */
        if (psCtxt->sRelation.nMembers >= psCtxt->nMembersAllocated)
        {
            int nMembersAllocated = std::max(psCtxt->nMembersAllocated * 2,
                                             psCtxt->sRelation.nMembers + 1);
            OSMMember *pasMembersNew =
                static_cast<OSMMember *>(VSI_REALLOC_VERBOSE(
                    psCtxt->pasMembers, nMembersAllocated * sizeof(OSMMember)));
            if (pasMembersNew == nullptr)
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                         "Cannot allocate enough memory to store members of "
                         "relation " CPL_FRMT_GIB,
                         psCtxt->sRelation.nID);
                return;
            }
            psCtxt->nMembersAllocated = nMembersAllocated;
            psCtxt->pasMembers = pasMembersNew;
        }

        OSMMember *psMember = &(psCtxt->pasMembers[psCtxt->sRelation.nMembers]);
        psCtxt->sRelation.nMembers++;

        psMember->nID = 0;
        psMember->pszRole = "";
        psMember->eType = MEMBER_NODE;

        if (ppszIter)
        {
            while (ppszIter[0] != nullptr)
            {
                if (strcmp(ppszIter[0], "ref") == 0)
                {
                    psMember->nID = OSM_Atoi64(ppszIter[1]);
                }
                else if (strcmp(ppszIter[0], "type") == 0)
                {
                    if (strcmp(ppszIter[1], "node") == 0)
                        psMember->eType = MEMBER_NODE;
                    else if (strcmp(ppszIter[1], "way") == 0)
                        psMember->eType = MEMBER_WAY;
                    else if (strcmp(ppszIter[1], "relation") == 0)
                        psMember->eType = MEMBER_RELATION;
                }
                else if (strcmp(ppszIter[0], "role") == 0)
                {
                    psMember->pszRole = OSM_AddString(psCtxt, ppszIter[1]);
                }
                ppszIter += 2;
            }
        }
    }
    else if ((psCtxt->bInNode || psCtxt->bInWay || psCtxt->bInRelation) &&
             strcmp(pszName, "tag") == 0)
    {
        if (psCtxt->nTags == psCtxt->nTagsAllocated)
        {
            psCtxt->nTagsAllocated = psCtxt->nTagsAllocated * 2;
            OSMTag *pasTagsNew = static_cast<OSMTag *>(VSI_REALLOC_VERBOSE(
                psCtxt->pasTags, psCtxt->nTagsAllocated * sizeof(OSMTag)));
            if (pasTagsNew == nullptr)
            {
                if (psCtxt->bInNode)
                    CPLError(CE_Failure, CPLE_AppDefined,
                             "Too many tags in node " CPL_FRMT_GIB,
                             psCtxt->pasNodes[0].nID);
                else if (psCtxt->bInWay)
                    CPLError(CE_Failure, CPLE_AppDefined,
                             "Too many tags in way " CPL_FRMT_GIB,
                             psCtxt->sWay.nID);
                else if (psCtxt->bInRelation)
                    CPLError(CE_Failure, CPLE_AppDefined,
                             "Too many tags in relation " CPL_FRMT_GIB,
                             psCtxt->sRelation.nID);
                return;
            }
            psCtxt->pasTags = pasTagsNew;
        }

        OSMTag *psTag = &(psCtxt->pasTags[psCtxt->nTags]);
        psCtxt->nTags++;

        psTag->pszK = "";
        psTag->pszV = "";

        if (ppszIter)
        {
            while (ppszIter[0] != nullptr)
            {
                if (ppszIter[0][0] == 'k')
                {
                    psTag->pszK = OSM_AddString(psCtxt, ppszIter[1]);
                }
                else if (ppszIter[0][0] == 'v')
                {
                    psTag->pszV = OSM_AddString(psCtxt, ppszIter[1]);
                }
                ppszIter += 2;
            }
        }
    }
}

/************************************************************************/
/*                       OSM_XML_endElementCbk()                        */
/************************************************************************/

static void XMLCALL OSM_XML_endElementCbk(void *pUserData, const char *pszName)
{
    OSMContext *psCtxt = static_cast<OSMContext *>(pUserData);

    if (psCtxt->bStopParsing)
        return;

    psCtxt->nWithoutEventCounter = 0;

    if (psCtxt->bInNode && strcmp(pszName, "node") == 0)
    {
        // Written this way to deal with NaN
        if (!(psCtxt->pasNodes[0].dfLon >= -180 &&
              psCtxt->pasNodes[0].dfLon <= 180 &&
              psCtxt->pasNodes[0].dfLat >= -90 &&
              psCtxt->pasNodes[0].dfLat <= 90))
        {
            CPLError(CE_Failure, CPLE_AppDefined, "Invalid lon=%f lat=%f",
                     psCtxt->pasNodes[0].dfLon, psCtxt->pasNodes[0].dfLat);
        }
        else
        {
            psCtxt->pasNodes[0].nTags = psCtxt->nTags;
            psCtxt->pasNodes[0].pasTags = psCtxt->pasTags;

            psCtxt->pfnNotifyNodes(1, psCtxt->pasNodes, psCtxt,
                                   psCtxt->user_data);

            psCtxt->bHasFoundFeature = true;
        }
        psCtxt->bInNode = false;
    }

    else if (psCtxt->bInWay && strcmp(pszName, "way") == 0)
    {
        psCtxt->sWay.nTags = psCtxt->nTags;
        psCtxt->sWay.pasTags = psCtxt->pasTags;

        psCtxt->sWay.panNodeRefs = psCtxt->panNodeRefs;

        psCtxt->pfnNotifyWay(&(psCtxt->sWay), psCtxt, psCtxt->user_data);

        psCtxt->bHasFoundFeature = true;

        psCtxt->bInWay = false;
    }

    else if (psCtxt->bInRelation && strcmp(pszName, "relation") == 0)
    {
        psCtxt->sRelation.nTags = psCtxt->nTags;
        psCtxt->sRelation.pasTags = psCtxt->pasTags;

        psCtxt->sRelation.pasMembers = psCtxt->pasMembers;

        psCtxt->pfnNotifyRelation(&(psCtxt->sRelation), psCtxt,
                                  psCtxt->user_data);

        psCtxt->bHasFoundFeature = true;

        psCtxt->bInRelation = false;
    }
}

/************************************************************************/
/*                           dataHandlerCbk()                           */
/************************************************************************/

static void XMLCALL OSM_XML_dataHandlerCbk(void *pUserData,
                                           const char * /* data */,
                                           int /* nLen */)
{
    OSMContext *psCtxt = static_cast<OSMContext *>(pUserData);

    if (psCtxt->bStopParsing)
        return;

    psCtxt->nWithoutEventCounter = 0;

    psCtxt->nDataHandlerCounter++;
    if (psCtxt->nDataHandlerCounter >= XML_BUFSIZE)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "File probably corrupted (million laugh pattern)");
        XML_StopParser(psCtxt->hXMLParser, false);
        psCtxt->bStopParsing = true;
        return;
    }
}

/************************************************************************/
/*                          XML_ProcessBlock()                          */
/************************************************************************/

static OSMRetCode XML_ProcessBlock(OSMContext *psCtxt)
{
    if (psCtxt->bEOF)
        return OSM_EOF;
    if (psCtxt->bStopParsing)
        return OSM_ERROR;

    psCtxt->bHasFoundFeature = false;
    psCtxt->nWithoutEventCounter = 0;

    do
    {
        psCtxt->nDataHandlerCounter = 0;

        const unsigned int nLen = static_cast<unsigned int>(
            VSIFReadL(psCtxt->pabyBlob, 1, XML_BUFSIZE, psCtxt->fp));

        psCtxt->nBytesRead += nLen;

        psCtxt->bEOF = nLen < XML_BUFSIZE;
        const int eErr =
            XML_Parse(psCtxt->hXMLParser,
                      reinterpret_cast<const char *>(psCtxt->pabyBlob), nLen,
                      psCtxt->bEOF);

        if (eErr == XML_STATUS_ERROR)
        {
            CPLError(
                CE_Failure, CPLE_AppDefined,
                "XML parsing of OSM file failed : %s "
                "at line %d, column %d",
                XML_ErrorString(XML_GetErrorCode(psCtxt->hXMLParser)),
                static_cast<int>(XML_GetCurrentLineNumber(psCtxt->hXMLParser)),
                static_cast<int>(
                    XML_GetCurrentColumnNumber(psCtxt->hXMLParser)));
            psCtxt->bStopParsing = true;
        }
        psCtxt->nWithoutEventCounter++;
    } while (!psCtxt->bEOF && !psCtxt->bStopParsing &&
             !psCtxt->bHasFoundFeature && psCtxt->nWithoutEventCounter < 10);

    if (psCtxt->nWithoutEventCounter == 10)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "Too much data inside one element. File probably corrupted");
        psCtxt->bStopParsing = true;
    }

    return psCtxt->bStopParsing ? OSM_ERROR : psCtxt->bEOF ? OSM_EOF : OSM_OK;
}

#endif

/************************************************************************/
/*                              OSM_Open()                              */
/************************************************************************/

OSMContext *OSM_Open(const char *pszFilename, NotifyNodesFunc pfnNotifyNodes,
                     NotifyWayFunc pfnNotifyWay,
                     NotifyRelationFunc pfnNotifyRelation,
                     NotifyBoundsFunc pfnNotifyBounds, void *user_data)
{

    VSILFILE *fp = VSIFOpenL(pszFilename, "rb");
    if (fp == nullptr)
        return nullptr;

    GByte abyHeader[1024];
    int nRead =
        static_cast<int>(VSIFReadL(abyHeader, 1, sizeof(abyHeader) - 1, fp));
    abyHeader[nRead] = '\0';

    bool bPBF = false;

    if (strstr(reinterpret_cast<const char *>(abyHeader), "<osm") != nullptr)
    {
        /* OSM XML */
#ifndef HAVE_EXPAT
        CPLError(CE_Failure, CPLE_AppDefined,
                 "OSM XML detected, but Expat parser not available");
        VSIFCloseL(fp);
        return nullptr;
#endif
    }
    else
    {
        const int nLimitI = nRead - static_cast<int>(strlen("OSMHeader"));
        for (int i = 0; i < nLimitI; i++)
        {
            if (memcmp(abyHeader + i, "OSMHeader", strlen("OSMHeader")) == 0)
            {
                bPBF = true;
                break;
            }
        }
        if (!bPBF)
        {
            VSIFCloseL(fp);
            return nullptr;
        }
    }

    VSIFSeekL(fp, 0, SEEK_SET);

    OSMContext *psCtxt =
        static_cast<OSMContext *>(VSI_MALLOC_VERBOSE(sizeof(OSMContext)));
    if (psCtxt == nullptr)
    {
        VSIFCloseL(fp);
        return nullptr;
    }
    memset(psCtxt, 0, sizeof(OSMContext));
    psCtxt->bPBF = bPBF;
    psCtxt->fp = fp;
    psCtxt->pfnNotifyNodes = pfnNotifyNodes;
    if (pfnNotifyNodes == nullptr)
        psCtxt->pfnNotifyNodes = EmptyNotifyNodesFunc;
    psCtxt->pfnNotifyWay = pfnNotifyWay;
    if (pfnNotifyWay == nullptr)
        psCtxt->pfnNotifyWay = EmptyNotifyWayFunc;
    psCtxt->pfnNotifyRelation = pfnNotifyRelation;
    if (pfnNotifyRelation == nullptr)
        psCtxt->pfnNotifyRelation = EmptyNotifyRelationFunc;
    psCtxt->pfnNotifyBounds = pfnNotifyBounds;
    if (pfnNotifyBounds == nullptr)
        psCtxt->pfnNotifyBounds = EmptyNotifyBoundsFunc;
    psCtxt->user_data = user_data;

    if (bPBF)
    {
        psCtxt->nBlobSizeAllocated = 64 * 1024 + EXTRA_BYTES;
    }
#ifdef HAVE_EXPAT
    else
    {
        psCtxt->nBlobSizeAllocated = XML_BUFSIZE;

        psCtxt->nStrAllocated = 1024 * 1024;
        psCtxt->pszStrBuf =
            static_cast<char *>(VSI_MALLOC_VERBOSE(psCtxt->nStrAllocated));
        if (psCtxt->pszStrBuf)
            psCtxt->pszStrBuf[0] = '\0';

        psCtxt->hXMLParser = OGRCreateExpatXMLParser();
        XML_SetUserData(psCtxt->hXMLParser, psCtxt);
        XML_SetElementHandler(psCtxt->hXMLParser, OSM_XML_startElementCbk,
                              OSM_XML_endElementCbk);
        XML_SetCharacterDataHandler(psCtxt->hXMLParser, OSM_XML_dataHandlerCbk);

        psCtxt->bTryToFetchBounds = true;

        psCtxt->nNodesAllocated = 1;
        psCtxt->pasNodes = static_cast<OSMNode *>(
            VSI_MALLOC_VERBOSE(sizeof(OSMNode) * psCtxt->nNodesAllocated));

        psCtxt->nTagsAllocated = 256;
        psCtxt->pasTags = static_cast<OSMTag *>(
            VSI_MALLOC_VERBOSE(sizeof(OSMTag) * psCtxt->nTagsAllocated));

        /* 300 is the recommended value, but there are files with more than 2000
         * so we should be able */
        /* to realloc over that value */
        psCtxt->nMembersAllocated = 2000;
        psCtxt->pasMembers = static_cast<OSMMember *>(
            VSI_MALLOC_VERBOSE(sizeof(OSMMember) * psCtxt->nMembersAllocated));

        psCtxt->nNodeRefsAllocated = 10000;
        psCtxt->panNodeRefs = static_cast<GIntBig *>(
            VSI_MALLOC_VERBOSE(sizeof(GIntBig) * psCtxt->nNodeRefsAllocated));

        if (psCtxt->pszStrBuf == nullptr || psCtxt->pasNodes == nullptr ||
            psCtxt->pasTags == nullptr || psCtxt->pasMembers == nullptr ||
            psCtxt->panNodeRefs == nullptr)
        {
            OSM_Close(psCtxt);
            return nullptr;
        }
    }
#endif

    psCtxt->pabyBlob =
        static_cast<GByte *>(VSI_MALLOC_VERBOSE(psCtxt->nBlobSizeAllocated));
    if (psCtxt->pabyBlob == nullptr)
    {
        OSM_Close(psCtxt);
        return nullptr;
    }
    psCtxt->pabyBlobHeader = static_cast<GByte *>(
        VSI_MALLOC_VERBOSE(MAX_BLOB_HEADER_SIZE + EXTRA_BYTES));
    if (psCtxt->pabyBlobHeader == nullptr)
    {
        OSM_Close(psCtxt);
        return nullptr;
    }
    const char *pszNumThreads =
        CPLGetConfigOption("GDAL_NUM_THREADS", "ALL_CPUS");
    int nNumCPUs = CPLGetNumCPUs();
    if (pszNumThreads && !EQUAL(pszNumThreads, "ALL_CPUS"))
        nNumCPUs = std::max(0, std::min(2 * nNumCPUs, atoi(pszNumThreads)));
    if (nNumCPUs > 1)
    {
        psCtxt->poWTP = new CPLWorkerThreadPool();
        // coverity[tainted_data]
        if (!psCtxt->poWTP->Setup(nNumCPUs, nullptr, nullptr))
        {
            delete psCtxt->poWTP;
            psCtxt->poWTP = nullptr;
        }
    }

    return psCtxt;
}

/************************************************************************/
/*                              OSM_Close()                             */
/************************************************************************/

void OSM_Close(OSMContext *psCtxt)
{
    if (psCtxt == nullptr)
        return;

#ifdef HAVE_EXPAT
    if (!psCtxt->bPBF)
    {
        if (psCtxt->hXMLParser)
            XML_ParserFree(psCtxt->hXMLParser);

        CPLFree(psCtxt->pszStrBuf); /* only for XML case ! */
    }
#endif

    VSIFree(psCtxt->pabyBlob);
    VSIFree(psCtxt->pabyBlobHeader);
    VSIFree(psCtxt->pabyUncompressed);
    VSIFree(psCtxt->panStrOff);
    VSIFree(psCtxt->pasNodes);
    VSIFree(psCtxt->pasTags);
    VSIFree(psCtxt->pasMembers);
    VSIFree(psCtxt->panNodeRefs);
    delete psCtxt->poWTP;

    VSIFCloseL(psCtxt->fp);
    VSIFree(psCtxt);
}

/************************************************************************/
/*                          OSM_ResetReading()                          */
/************************************************************************/

void OSM_ResetReading(OSMContext *psCtxt)
{
    VSIFSeekL(psCtxt->fp, 0, SEEK_SET);

    psCtxt->nBytesRead = 0;
    psCtxt->nJobs = 0;
    psCtxt->iNextJob = 0;
    psCtxt->nBlobOffset = 0;
    psCtxt->nBlobSize = 0;
    psCtxt->nTotalUncompressedSize = 0;

#ifdef HAVE_EXPAT
    if (!psCtxt->bPBF)
    {
        XML_ParserFree(psCtxt->hXMLParser);
        psCtxt->hXMLParser = OGRCreateExpatXMLParser();
        XML_SetUserData(psCtxt->hXMLParser, psCtxt);
        XML_SetElementHandler(psCtxt->hXMLParser, OSM_XML_startElementCbk,
                              OSM_XML_endElementCbk);
        XML_SetCharacterDataHandler(psCtxt->hXMLParser, OSM_XML_dataHandlerCbk);
        psCtxt->bEOF = false;
        psCtxt->bStopParsing = false;
        psCtxt->nStrLength = 0;
        psCtxt->pszStrBuf[0] = '\0';
        psCtxt->nTags = 0;

        psCtxt->bTryToFetchBounds = true;
        psCtxt->bInNode = false;
        psCtxt->bInWay = false;
        psCtxt->bInRelation = false;
    }
#endif
}

/************************************************************************/
/*                          OSM_ProcessBlock()                          */
/************************************************************************/

OSMRetCode OSM_ProcessBlock(OSMContext *psCtxt)
{
#ifdef HAVE_EXPAT
    if (psCtxt->bPBF)
        return PBF_ProcessBlock(psCtxt);
    else
        return XML_ProcessBlock(psCtxt);
#else
    return PBF_ProcessBlock(psCtxt);
#endif
}

/************************************************************************/
/*                          OSM_GetBytesRead()                          */
/************************************************************************/

GUIntBig OSM_GetBytesRead(OSMContext *psCtxt)
{
    return psCtxt->nBytesRead;
}