/* SDS (Simple Dynamic Strings), A C dynamic strings library.
*
* Copyright (c) 2006-2014, Salvatore Sanfilippo <antirez at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
*   * Redistributions of source code must retain the above copyright notice,
*     this list of conditions and the following disclaimer.
*   * Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in the
*     documentation and/or other materials provided with the distribution.
*   * Neither the name of Redis nor the names of its contributors may be used
*     to endorse or promote products derived from this software without
*     specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>

#include "sds.h"

/* Create a new sds string with the content specified by the 'init' pointer
* and 'initlen'.
* If NULL is used for 'init' the string is initialized with zero bytes.
*
* The string is always null-termined (all the sds strings are, always) so
* even if you create an sds string with:
*
* mystring = sdsnewlen("abc",3");
*
* You can print the string with printf() as there is an implicit \0 at the
* end of the string. However the string is binary safe and can contain
* \0 characters in the middle, as the length is stored in the sds header. */
sds sdsnewlen(const void *init, size_t initlen) {
	struct sdshdr *sh;

	if (init) {
		sh = malloc(sizeof *sh + initlen + 1);
	}
	else {
		sh = calloc(sizeof *sh + initlen + 1, 1);
	}
	if (sh == NULL) return NULL;
	sh->len = initlen;
	sh->free = 0;
	if (initlen && init)
		memcpy(sh->buf, init, initlen);
	sh->buf[initlen] = '\0';
	return (char*)sh->buf;
}

/* Create an empty (zero length) sds string. Even in this case the string
* always has an implicit null term. */
sds sdsempty(void) {
	return sdsnewlen("", 0);
}

/* Create a new sds string starting from a null termined C string. */
sds sdsnew(const char *init) {
	size_t initlen = (init == NULL) ? 0 : strlen(init);
	return sdsnewlen(init, initlen);
}

/* Duplicate an sds string. */
sds sdsdup(const sds s) {
	return sdsnewlen(s, sdslen(s));
}

/* Free an sds string. No operation is performed if 's' is NULL. */
void sdsfree(sds s) {
	if (s == NULL) return;
	free(s - sizeof(struct sdshdr));
}

/* Set the sds string length to the length as obtained with strlen(), so
* considering as content only up to the first null term character.
*
* This function is useful when the sds string is hacked manually in some
* way, like in the following example:
*
* s = sdsnew("foobar");
* s[2] = '\0';
* sdsupdatelen(s);
* printf("%d\n", sdslen(s));
*
* The output will be "2", but if we comment out the call to sdsupdatelen()
* the output will be "6" as the string was modified but the logical length
* remains 6 bytes. */
void sdsupdatelen(sds s) {
	struct sdshdr *sh = (void*)(s - sizeof *sh);;
	int reallen = strlen(s);
	sh->free += (sh->len - reallen);
	sh->len = reallen;
}

/* Modify an sds string on-place to make it empty (zero length).
* However all the existing buffer is not discarded but set as free space
* so that next append operations will not require allocations up to the
* number of bytes previously available. */
void sdsclear(sds s) {
	struct sdshdr *sh = (void*)(s - sizeof *sh);;
	sh->free += sh->len;
	sh->len = 0;
	sh->buf[0] = '\0';
}

/* Enlarge the free space at the end of the sds string so that the caller
* is sure that after calling this function can overwrite up to addlen
* bytes after the end of the string, plus one more byte for nul term.
*
* Note: this does not change the *length* of the sds string as returned
* by sdslen(), but only the free buffer space we have. */
sds sdsMakeRoomFor(sds s, size_t addlen) {
	struct sdshdr *sh, *newsh;
	size_t free = sdsavail(s);
	size_t len, newlen;

	if (free >= addlen) return s;
	len = sdslen(s);
	sh = (void*)(s - sizeof *sh);;
	newlen = (len + addlen);
	if (newlen < SDS_MAX_PREALLOC)
		newlen *= 2;
	else
		newlen += SDS_MAX_PREALLOC;
	newsh = realloc(sh, sizeof *newsh + newlen + 1);
	if (newsh == NULL) return NULL;

	newsh->free = newlen - len;
	return newsh->buf;
}

/* Reallocate the sds string so that it has no free space at the end. The
* contained string remains not altered, but next concatenation operations
* will require a reallocation.
*
* After the call, the passed sds string is no longer valid and all the
* references must be substituted with the new pointer returned by the call. */
sds sdsRemoveFreeSpace(sds s) {
	struct sdshdr *sh;

	sh = (void*)(s - sizeof *sh);;
	sh = realloc(sh, sizeof *sh + sh->len + 1);
	sh->free = 0;
	return sh->buf;
}

/* Return the total size of the allocation of the specifed sds string,
* including:
* 1) The sds header before the pointer.
* 2) The string.
* 3) The free buffer at the end if any.
* 4) The implicit null term.
*/
size_t sdsAllocSize(sds s) {
	struct sdshdr *sh = (void*)(s - sizeof *sh);;

	return sizeof(*sh) + sh->len + sh->free + 1;
}

/* Increment the sds length and decrements the left free space at the
* end of the string according to 'incr'. Also set the null term
* in the new end of the string.
*
* This function is used in order to fix the string length after the
* user calls sdsMakeRoomFor(), writes something after the end of
* the current string, and finally needs to set the new length.
*
* Note: it is possible to use a negative increment in order to
* right-trim the string.
*
* Usage example:
*
* Using sdsIncrLen() and sdsMakeRoomFor() it is possible to mount the
* following schema, to cat bytes coming from the kernel to the end of an
* sds string without copying into an intermediate buffer:
*
* oldlen = sdslen(s);
* s = sdsMakeRoomFor(s, BUFFER_SIZE);
* nread = read(fd, s+oldlen, BUFFER_SIZE);
* ... check for nread <= 0 and handle it ...
* sdsIncrLen(s, nread);
*/
void sdsIncrLen(sds s, int incr) {
	struct sdshdr *sh = (void*)(s - sizeof *sh);;

	assert(sh->free >= incr);
	sh->len += incr;
	sh->free -= incr;
	assert(sh->free >= 0);
	s[sh->len] = '\0';
}

/* Grow the sds to have the specified length. Bytes that were not part of
* the original length of the sds will be set to zero.
*
* if the specified length is smaller than the current length, no operation
* is performed. */
sds sdsgrowzero(sds s, size_t len) {
	struct sdshdr *sh = (void*)(s - sizeof *sh);
	size_t totlen, curlen = sh->len;

	if (len <= curlen) return s;
	s = sdsMakeRoomFor(s, len - curlen);
	if (s == NULL) return NULL;

	/* Make sure added region doesn't contain garbage */
	sh = (void*)(s - sizeof *sh);
	memset(s + curlen, 0, (len - curlen + 1)); /* also set trailing \0 byte */
	totlen = sh->len + sh->free;
	sh->len = len;
	sh->free = totlen - sh->len;
	return s;
}

/* Append the specified binary-safe string pointed by 't' of 'len' bytes to the
* end of the specified sds string 's'.
*
* After the call, the passed sds string is no longer valid and all the
* references must be substituted with the new pointer returned by the call. */
sds sdscatlen(sds s, const void *t, size_t len) {
	struct sdshdr *sh;
	size_t curlen = sdslen(s);

	s = sdsMakeRoomFor(s, len);
	if (s == NULL) return NULL;
	sh = (void*)(s - sizeof *sh);;
	memcpy(s + curlen, t, len);
	sh->len = curlen + len;
	sh->free = sh->free - len;
	s[curlen + len] = '\0';
	return s;
}

/* Append the specified null termianted C string to the sds string 's'.
*
* After the call, the passed sds string is no longer valid and all the
* references must be substituted with the new pointer returned by the call. */
sds sdscat(sds s, const char *t) {
	return sdscatlen(s, t, strlen(t));
}

/* Append the specified sds 't' to the existing sds 's'.
*
* After the call, the modified sds string is no longer valid and all the
* references must be substituted with the new pointer returned by the call. */
sds sdscatsds(sds s, const sds t) {
	return sdscatlen(s, t, sdslen(t));
}

/* Destructively modify the sds string 's' to hold the specified binary
* safe string pointed by 't' of length 'len' bytes. */
sds sdscpylen(sds s, const char *t, size_t len) {
	struct sdshdr *sh = (void*)(s - sizeof *sh);;
	size_t totlen = sh->free + sh->len;

	if (totlen < len) {
		s = sdsMakeRoomFor(s, len - sh->len);
		if (s == NULL) return NULL;
		sh = (void*)(s - sizeof *sh);;
		totlen = sh->free + sh->len;
	}
	memcpy(s, t, len);
	s[len] = '\0';
	sh->len = len;
	sh->free = totlen - len;
	return s;
}

/* Like sdscpylen() but 't' must be a null-termined string so that the length
* of the string is obtained with strlen(). */
sds sdscpy(sds s, const char *t) {
	return sdscpylen(s, t, strlen(t));
}

/* Like sdscatpritf() but gets va_list instead of being variadic. */
sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
	va_list cpy;
	char *buf, *t;
	size_t buflen = 16;

	while (1) {
		buf = malloc(buflen);
		if (buf == NULL) return NULL;
		buf[buflen - 2] = '\0';
		va_copy(cpy, ap);
#ifdef WIN32
		vsnprintf_s(buf, buflen, _TRUNCATE, fmt, cpy);
#else
		vsnprintf(buf, buflen, fmt, cpy);
#endif
		if (buf[buflen - 2] != '\0') {
			free(buf);
			buflen *= 2;
			continue;
		}
		break;
	}
	t = sdscat(s, buf);
	free(buf);
	return t;
}

/* Append to the sds string 's' a string obtained using printf-alike format
* specifier.
*
* After the call, the modified sds string is no longer valid and all the
* references must be substituted with the new pointer returned by the call.
*
* Example:
*
* s = sdsempty("Sum is: ");
* s = sdscatprintf(s,"%d+%d = %d",a,b,a+b).
*
* Often you need to create a string from scratch with the printf-alike
* format. When this is the need, just use sdsempty() as the target string:
*
* s = sdscatprintf(sdsempty(), "... your format ...", args);
*/
sds sdscatprintf(sds s, const char *fmt, ...) {
	va_list ap;
	char *t;
	va_start(ap, fmt);
	t = sdscatvprintf(s, fmt, ap);
	va_end(ap);
	return t;
}

/* Remove the part of the string from left and from right composed just of
* contiguous characters found in 'cset', that is a null terminted C string.
*
* After the call, the modified sds string is no longer valid and all the
* references must be substituted with the new pointer returned by the call.
*
* Example:
*
* s = sdsnew("AA...AA.a.aa.aHelloWorld     :::");
* s = sdstrim(s,"A. :");
* printf("%s\n", s);
*
* Output will be just "Hello World".
*/
void sdstrim(sds s, const char *cset) {
	struct sdshdr *sh = (void*)(s - sizeof *sh);;
	char *start, *end, *sp, *ep;
	size_t len;

	sp = start = s;
	ep = end = s + sdslen(s) - 1;
	while (sp <= end && strchr(cset, *sp)) sp++;
	while (ep > start && strchr(cset, *ep)) ep--;
	len = (sp > ep) ? 0 : ((ep - sp) + 1);
	if (sh->buf != sp) memmove(sh->buf, sp, len);
	sh->buf[len] = '\0';
	sh->free = sh->free + (sh->len - len);
	sh->len = len;
}

/* Turn the string into a smaller (or equal) string containing only the
* substring specified by the 'start' and 'end' indexes.
*
* start and end can be negative, where -1 means the last character of the
* string, -2 the penultimate character, and so forth.
*
* The interval is inclusive, so the start and end characters will be part
* of the resulting string.
*
* The string is modified in-place.
*
* Example:
*
* s = sdsnew("Hello World");
* sdsrange(s,1,-1); => "ello World"
*/
void sdsrange(sds s, int start, int end) {
	struct sdshdr *sh = (void*)(s - sizeof *sh);;
	size_t newlen, len = sdslen(s);

	if (len == 0) return;
	if (start < 0) {
		start = len + start;
		if (start < 0) start = 0;
	}
	if (end < 0) {
		end = len + end;
		if (end < 0) end = 0;
	}
	newlen = (start > end) ? 0 : (end - start) + 1;
	if (newlen != 0) {
		if (start >= (signed)len) {
			newlen = 0;
		}
		else if (end >= (signed)len) {
			end = len - 1;
			newlen = (start > end) ? 0 : (end - start) + 1;
		}
	}
	else {
		start = 0;
	}
	if (start && newlen) memmove(sh->buf, sh->buf + start, newlen);
	sh->buf[newlen] = 0;
	sh->free = sh->free + (sh->len - newlen);
	sh->len = newlen;
}

/* Apply tolower() to every character of the sds string 's'. */
void sdstolower(sds s) {
	int len = sdslen(s), j;

	for (j = 0; j < len; j++) s[j] = tolower(s[j]);
}

/* Apply toupper() to every character of the sds string 's'. */
void sdstoupper(sds s) {
	int len = sdslen(s), j;

	for (j = 0; j < len; j++) s[j] = toupper(s[j]);
}

/* Compare two sds strings s1 and s2 with memcmp().
*
* Return value:
*
*     1 if s1 > s2.
*    -1 if s1 < s2.
*     0 if s1 and s2 are exactly the same binary string.
*
* If two strings share exactly the same prefix, but one of the two has
* additional characters, the longer string is considered to be greater than
* the smaller one. */
int sdscmp(const sds s1, const sds s2) {
	size_t l1, l2, minlen;
	int cmp;

	l1 = sdslen(s1);
	l2 = sdslen(s2);
	minlen = (l1 < l2) ? l1 : l2;
	cmp = memcmp(s1, s2, minlen);
	if (cmp == 0) return l1 - l2;
	return cmp;
}

/* Split 's' with separator in 'sep'. An array
* of sds strings is returned. *count will be set
* by reference to the number of tokens returned.
*
* On out of memory, zero length string, zero length
* separator, NULL is returned.
*
* Note that 'sep' is able to split a string using
* a multi-character separator. For example
* sdssplit("foo_-_bar","_-_"); will return two
* elements "foo" and "bar".
*
* This version of the function is binary-safe but
* requires length arguments. sdssplit() is just the
* same function but for zero-terminated strings.
*/
sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count) {
	int elements = 0, slots = 5, start = 0, j;
	sds *tokens;

	if (seplen < 1 || len < 0) return NULL;

	tokens = malloc(sizeof(sds)*slots);
	if (tokens == NULL) return NULL;

	if (len == 0) {
		*count = 0;
		return tokens;
	}
	for (j = 0; j < (len - (seplen - 1)); j++) {
		/* make sure there is room for the next element and the final one */
		if (slots < elements + 2) {
			sds *newtokens;

			slots *= 2;
			newtokens = realloc(tokens, sizeof(sds)*slots);
			if (newtokens == NULL) goto cleanup;
			tokens = newtokens;
		}
		/* search the separator */
		if ((seplen == 1 && *(s + j) == sep[0]) || (memcmp(s + j, sep, seplen) == 0)) {
			tokens[elements] = sdsnewlen(s + start, j - start);
			if (tokens[elements] == NULL) goto cleanup;
			elements++;
			start = j + seplen;
			j = j + seplen - 1; /* skip the separator */
		}
	}
	/* Add the final element. We are sure there is room in the tokens array. */
	tokens[elements] = sdsnewlen(s + start, len - start);
	if (tokens[elements] == NULL) goto cleanup;
	elements++;
	*count = elements;
	return tokens;

cleanup:
	{
		int i;
		for (i = 0; i < elements; i++) sdsfree(tokens[i]);
		free(tokens);
		*count = 0;
		return NULL;
	}
}

/* Free the result returned by sdssplitlen(), or do nothing if 'tokens' is NULL. */
void sdsfreesplitres(sds *tokens, int count) {
	if (!tokens) return;
	while (count--)
		sdsfree(tokens[count]);
	free(tokens);
}

/* Create an sds string from a long long value. It is much faster than:
*
* sdscatprintf(sdsempty(),"%lld\n", value);
*/
sds sdsfromlonglong(long long value) {
	char buf[32], *p;
	unsigned long long v;

	v = (value < 0) ? -value : value;
	p = buf + 31; /* point to the last character */
	do {
		*p-- = '0' + (v % 10);
		v /= 10;
	} while (v);
	if (value < 0) *p-- = '-';
	p++;
	return sdsnewlen(p, 32 - (p - buf));
}

/* Append to the sds string "s" an escaped string representation where
* all the non-printable characters (tested with isprint()) are turned into
* escapes in the form "\n\r\a...." or "\x<hex-number>".
*
* After the call, the modified sds string is no longer valid and all the
* references must be substituted with the new pointer returned by the call. */
sds sdscatrepr(sds s, const char *p, size_t len) {
	s = sdscatlen(s, "\"", 1);
	while (len--) {
		switch (*p) {
		case '\\':
		case '"':
			s = sdscatprintf(s, "\\%c", *p);
			break;
		case '\n': s = sdscatlen(s, "\\n", 2); break;
		case '\r': s = sdscatlen(s, "\\r", 2); break;
		case '\t': s = sdscatlen(s, "\\t", 2); break;
		case '\a': s = sdscatlen(s, "\\a", 2); break;
		case '\b': s = sdscatlen(s, "\\b", 2); break;
		default:
			if (isprint(*p))
				s = sdscatprintf(s, "%c", *p);
			else
				s = sdscatprintf(s, "\\x%02x", (unsigned char)*p);
			break;
		}
		p++;
	}
	return sdscatlen(s, "\"", 1);
}

/* Helper function for sdssplitargs() that returns non zero if 'c'
* is a valid hex digit. */
int is_hex_digit(char c) {
	return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') ||
		(c >= 'A' && c <= 'F');
}

/* Helper function for sdssplitargs() that converts a hex digit into an
* integer from 0 to 15 */
int hex_digit_to_int(char c) {
	switch (c) {
	case '0': return 0;
	case '1': return 1;
	case '2': return 2;
	case '3': return 3;
	case '4': return 4;
	case '5': return 5;
	case '6': return 6;
	case '7': return 7;
	case '8': return 8;
	case '9': return 9;
	case 'a': case 'A': return 10;
	case 'b': case 'B': return 11;
	case 'c': case 'C': return 12;
	case 'd': case 'D': return 13;
	case 'e': case 'E': return 14;
	case 'f': case 'F': return 15;
	default: return 0;
	}
}

/* Split a line into arguments, where every argument can be in the
* following programming-language REPL-alike form:
*
* foo bar "newline are supported\n" and "\xff\x00otherstuff"
*
* The number of arguments is stored into *argc, and an array
* of sds is returned.
*
* The caller should free the resulting array of sds strings with
* sdsfreesplitres().
*
* Note that sdscatrepr() is able to convert back a string into
* a quoted string in the same format sdssplitargs() is able to parse.
*
* The function returns the allocated tokens on success, even when the
* input string is empty, or NULL if the input contains unbalanced
* quotes or closed quotes followed by non space characters
* as in: "foo"bar or "foo'
*/
sds *sdssplitargs(const char *line, int *argc) {
	const char *p = line;
	char *current = NULL;
	char **vector = NULL;

	*argc = 0;
	while (1) {
		/* skip blanks */
		while (*p && isspace(*p)) p++;
		if (*p) {
			/* get a token */
			int inq = 0;  /* set to 1 if we are in "quotes" */
			int insq = 0; /* set to 1 if we are in 'single quotes' */
			int done = 0;

			if (current == NULL) current = sdsempty();
			while (!done) {
				if (inq) {
					if (*p == '\\' && *(p + 1) == 'x' &&
						is_hex_digit(*(p + 2)) &&
						is_hex_digit(*(p + 3)))
					{
						unsigned char byte;

						byte = (hex_digit_to_int(*(p + 2)) * 16) +
							hex_digit_to_int(*(p + 3));
						current = sdscatlen(current, (char*)&byte, 1);
						p += 3;
					}
					else if (*p == '\\' && *(p + 1)) {
						char c;

						p++;
						switch (*p) {
						case 'n': c = '\n'; break;
						case 'r': c = '\r'; break;
						case 't': c = '\t'; break;
						case 'b': c = '\b'; break;
						case 'a': c = '\a'; break;
						default: c = *p; break;
						}
						current = sdscatlen(current, &c, 1);
					}
					else if (*p == '"') {
						/* closing quote must be followed by a space or
						* nothing at all. */
						if (*(p + 1) && !isspace(*(p + 1))) goto err;
						done = 1;
					}
					else if (!*p) {
						/* unterminated quotes */
						goto err;
					}
					else {
						current = sdscatlen(current, p, 1);
					}
				}
				else if (insq) {
					if (*p == '\\' && *(p + 1) == '\'') {
						p++;
						current = sdscatlen(current, "'", 1);
					}
					else if (*p == '\'') {
						/* closing quote must be followed by a space or
						* nothing at all. */
						if (*(p + 1) && !isspace(*(p + 1))) goto err;
						done = 1;
					}
					else if (!*p) {
						/* unterminated quotes */
						goto err;
					}
					else {
						current = sdscatlen(current, p, 1);
					}
				}
				else {
					switch (*p) {
					case ' ':
					case '\n':
					case '\r':
					case '\t':
					case '\0':
						done = 1;
						break;
					case '"':
						inq = 1;
						break;
					case '\'':
						insq = 1;
						break;
					default:
						current = sdscatlen(current, p, 1);
						break;
					}
				}
				if (*p) p++;
			}
			/* add the token to the vector */
			vector = realloc(vector, ((*argc) + 1)*sizeof(char*));
			vector[*argc] = current;
			(*argc)++;
			current = NULL;
		}
		else {
			/* Even on empty input string return something not NULL. */
			if (vector == NULL) vector = malloc(sizeof(void*));
			return vector;
		}
	}

err:
	while ((*argc)--)
		sdsfree(vector[*argc]);
	free(vector);
	if (current) sdsfree(current);
	*argc = 0;
	return NULL;
}

/* Modify the string substituting all the occurrences of the set of
* characters specified in the 'from' string to the corresponding character
* in the 'to' array.
*
* For instance: sdsmapchars(mystring, "ho", "01", 2)
* will have the effect of turning the string "hello" into "0ell1".
*
* The function returns the sds string pointer, that is always the same
* as the input pointer since no resize is needed. */
sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen) {
	size_t j, i, l = sdslen(s);

	for (j = 0; j < l; j++) {
		for (i = 0; i < setlen; i++) {
			if (s[j] == from[i]) {
				s[j] = to[i];
				break;
			}
		}
	}
	return s;
}

/* Join an array of C strings using the specified separator (also a C string).
* Returns the result as an sds string. */
sds sdsjoin(char **argv, int argc, char *sep, size_t seplen) {
	sds join = sdsempty();
	int j;

	for (j = 0; j < argc; j++) {
		join = sdscat(join, argv[j]);
		if (j != argc - 1) join = sdscatlen(join, sep, seplen);
	}
	return join;
}

/* Like sdsjoin, but joins an array of SDS strings. */
sds sdsjoinsds(sds *argv, int argc, const char *sep, size_t seplen) {
	sds join = sdsempty();
	int j;

	for (j = 0; j < argc; j++) {
		join = sdscatsds(join, argv[j]);
		if (j != argc - 1) join = sdscatlen(join, sep, seplen);
	}
	return join;
}

#ifdef SDS_TEST_MAIN
#include <stdio.h>
#include "testhelp.h"

int main(void) {
	{
		struct sdshdr *sh;
		sds x = sdsnew("foo"), y;

		test_cond("Create a string and obtain the length",
			sdslen(x) == 3 && memcmp(x, "foo\0", 4) == 0)

			sdsfree(x);
		x = sdsnewlen("foo", 2);
		test_cond("Create a string with specified length",
			sdslen(x) == 2 && memcmp(x, "fo\0", 3) == 0)

			x = sdscat(x, "bar");
		test_cond("Strings concatenation",
			sdslen(x) == 5 && memcmp(x, "fobar\0", 6) == 0);

		x = sdscpy(x, "a");
		test_cond("sdscpy() against an originally longer string",
			sdslen(x) == 1 && memcmp(x, "a\0", 2) == 0)

			x = sdscpy(x, "xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk");
		test_cond("sdscpy() against an originally shorter string",
			sdslen(x) == 33 &&
			memcmp(x, "xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk\0", 33) == 0)

			sdsfree(x);
		x = sdscatprintf(sdsempty(), "%d", 123);
		test_cond("sdscatprintf() seems working in the base case",
			sdslen(x) == 3 && memcmp(x, "123\0", 4) == 0)

			sdsfree(x);
		x = sdsnew("xxciaoyyy");
		sdstrim(x, "xy");
		test_cond("sdstrim() correctly trims characters",
			sdslen(x) == 4 && memcmp(x, "ciao\0", 5) == 0)

			y = sdsdup(x);
		sdsrange(y, 1, 1);
		test_cond("sdsrange(...,1,1)",
			sdslen(y) == 1 && memcmp(y, "i\0", 2) == 0)

			sdsfree(y);
		y = sdsdup(x);
		sdsrange(y, 1, -1);
		test_cond("sdsrange(...,1,-1)",
			sdslen(y) == 3 && memcmp(y, "iao\0", 4) == 0)

			sdsfree(y);
		y = sdsdup(x);
		sdsrange(y, -2, -1);
		test_cond("sdsrange(...,-2,-1)",
			sdslen(y) == 2 && memcmp(y, "ao\0", 3) == 0)

			sdsfree(y);
		y = sdsdup(x);
		sdsrange(y, 2, 1);
		test_cond("sdsrange(...,2,1)",
			sdslen(y) == 0 && memcmp(y, "\0", 1) == 0)

			sdsfree(y);
		y = sdsdup(x);
		sdsrange(y, 1, 100);
		test_cond("sdsrange(...,1,100)",
			sdslen(y) == 3 && memcmp(y, "iao\0", 4) == 0)

			sdsfree(y);
		y = sdsdup(x);
		sdsrange(y, 100, 100);
		test_cond("sdsrange(...,100,100)",
			sdslen(y) == 0 && memcmp(y, "\0", 1) == 0)

			sdsfree(y);
		sdsfree(x);
		x = sdsnew("foo");
		y = sdsnew("foa");
		test_cond("sdscmp(foo,foa)", sdscmp(x, y) > 0)

			sdsfree(y);
		sdsfree(x);
		x = sdsnew("bar");
		y = sdsnew("bar");
		test_cond("sdscmp(bar,bar)", sdscmp(x, y) == 0)

			sdsfree(y);
		sdsfree(x);
		x = sdsnew("aar");
		y = sdsnew("bar");
		test_cond("sdscmp(bar,bar)", sdscmp(x, y) < 0)

			sdsfree(y);
		sdsfree(x);
		x = sdsnewlen("\a\n\0foo\r", 7);
		y = sdscatrepr(sdsempty(), x, sdslen(x));
		test_cond("sdscatrepr(...data...)",
			memcmp(y, "\"\\a\\n\\x00foo\\r\"", 15) == 0)

		{
			int oldfree;

			sdsfree(x);
			x = sdsnew("0");
			sh = (void*)(x - (sizeof(struct sdshdr)));
			test_cond("sdsnew() free/len buffers", sh->len == 1 && sh->free == 0);
			x = sdsMakeRoomFor(x, 1);
			sh = (void*)(x - (sizeof(struct sdshdr)));
			test_cond("sdsMakeRoomFor()", sh->len == 1 && sh->free > 0);
			oldfree = sh->free;
			x[1] = '1';
			sdsIncrLen(x, 1);
			test_cond("sdsIncrLen() -- content", x[0] == '0' && x[1] == '1');
			test_cond("sdsIncrLen() -- len", sh->len == 2);
			test_cond("sdsIncrLen() -- free", sh->free == oldfree - 1);
		}
	}
	test_report()
		return 0;
}
#endif