| 1 | var once = require('once'),
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| 2 | db = require('../db')
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| 3 |
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| 4 | module.exports = function scan(store, data, cb) {
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| 5 | cb = once(cb)
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| 6 |
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| 7 | store.getTable(data.TableName, function(err, table) {
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| 8 | if (err) return cb(err)
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| 9 |
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| 10 | var keySchema = table.KeySchema, startKeyNames = keySchema.map(function(key) { return key.AttributeName }),
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| 11 | fetchFromItemDb = false, isLocal
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| 12 |
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| 13 | if (data.IndexName) {
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| 14 | var index = db.traverseIndexes(table, function(attr, type, index, isGlobal) {
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| 15 | if (index.IndexName == data.IndexName) {
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| 16 | isLocal = !isGlobal
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| 17 | return index
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| 18 | }
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| 19 | })
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| 20 | if (index == null) {
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| 21 | return cb(db.validationError('The table does not have the specified index: ' + data.IndexName))
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| 22 | }
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| 23 | if (!isLocal && data.ConsistentRead) {
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| 24 | return cb(db.validationError('Consistent reads are not supported on global secondary indexes'))
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| 25 | }
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| 26 | keySchema = index.KeySchema
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| 27 | fetchFromItemDb = data.Select == 'ALL_ATTRIBUTES' && index.Projection.ProjectionType != 'ALL'
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| 28 | keySchema.forEach(function(key) { if (!~startKeyNames.indexOf(key.AttributeName)) startKeyNames.push(key.AttributeName) })
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| 29 | }
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| 30 |
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| 31 | if (data.ExclusiveStartKey && Object.keys(data.ExclusiveStartKey).length != startKeyNames.length) {
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| 32 | return data.IndexName ? cb(db.validationError('The provided starting key is invalid')) :
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| 33 | cb(db.validationError('The provided starting key is invalid: The provided key element does not match the schema'))
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| 34 | }
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| 35 |
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| 36 | if (data.IndexName && data.ExclusiveStartKey) {
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| 37 | err = db.traverseKey(table, keySchema, function(attr, type, isHash) {
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| 38 | if (!data.ExclusiveStartKey[attr]) {
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| 39 | return db.validationError('The provided starting key is invalid')
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| 40 | }
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| 41 | return db.validateKeyPiece(data.ExclusiveStartKey, attr, type, isHash)
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| 42 | })
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| 43 | if (err) return cb(err)
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| 44 | }
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| 45 |
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| 46 | if (fetchFromItemDb && !isLocal) {
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| 47 | return cb(db.validationError('One or more parameter values were invalid: ' +
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| 48 | 'Select type ALL_ATTRIBUTES is not supported for global secondary index ' +
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| 49 | data.IndexName + ' because its projection type is not ALL'))
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| 50 | }
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| 51 |
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| 52 | if (data.ExclusiveStartKey) {
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| 53 | var tableStartKey = table.KeySchema.reduce(function(obj, attr) {
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| 54 | obj[attr.AttributeName] = data.ExclusiveStartKey[attr.AttributeName]
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| 55 | return obj
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| 56 | }, {})
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| 57 | if ((err = db.validateKey(tableStartKey, table)) != null) {
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| 58 | return cb(db.validationError('The provided starting key is invalid: ' + err.message))
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| 59 | }
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| 60 | }
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| 61 |
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| 62 | if (data.TotalSegments > 1) {
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| 63 | if (data.Segment > 0)
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| 64 | var hashStart = ('00' + Math.ceil(4096 * data.Segment / data.TotalSegments).toString(16)).slice(-3)
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| 65 | var hashEnd = ('00' + (Math.ceil(4096 * (data.Segment + 1) / data.TotalSegments) - 1).toString(16)).slice(-3) + '~'
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| 66 | }
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| 67 |
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| 68 | if (data.ExclusiveStartKey) {
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| 69 | var startKey = db.createIndexKey(data.ExclusiveStartKey, table, keySchema)
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| 70 |
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| 71 | if (data.TotalSegments > 1 && (startKey < hashStart || startKey > hashEnd)) {
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| 72 | return cb(db.validationError('The provided starting key is invalid: Invalid ExclusiveStartKey. ' +
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| 73 | 'Please use ExclusiveStartKey with correct Segment. ' +
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| 74 | 'TotalSegments: ' + data.TotalSegments + ' Segment: ' + data.Segment))
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| 75 | }
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| 76 |
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| 77 | hashStart = startKey
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| 78 | }
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| 79 |
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| 80 | if ((err = db.validateKeyPaths((data._projection || {}).nestedPaths, table)) != null) return cb(err)
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| 81 |
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| 82 | if ((err = db.validateKeyPaths((data._filter || {}).nestedPaths, table)) != null) return cb(err)
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| 83 |
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| 84 | var opts = {limit: data.Limit ? data.Limit + 1 : -1}
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| 85 |
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| 86 | if (hashStart != null) {
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| 87 | opts.gt = hashStart
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| 88 | }
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| 89 | if (hashEnd != null) {
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| 90 | opts.lt = hashEnd
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| 91 | }
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| 92 |
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| 93 | db.queryTable(store, table, data, opts, isLocal, fetchFromItemDb, startKeyNames, cb)
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| 94 | })
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| 95 | }
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