{EventEmitter} = require('events') resolveKey = (k) -> if (k) if (k.key) return if typeof(k.key) is 'function' then k.key() else k.key else if k.rawPrefix return k.rawPrefix else return k return ###* * Get a Reader class to perform a range read operation over the database * @method * @param {object} FDBBoost FDBBoost instance. * @return {Reader} Reader ### module.exports = (fdb, debug) -> db = fdb.open() ###* * The callback format for the iterate method * @callback iterateCallback * @param {Error} error An error instance representing the error during the execution. * @param {Result} result A Result value on completion of the iteration. ### ###* * Iterate over the range results * @method * @param {object} tr Transaction. * @param {object} reader RangeReader instance. * @param {string} iteratorType batch|each|array. * @param {iterateCallback} callback Callback. * @fires RangeReader#data * @return {undefined} ### iterate = (tr, reader, iteratorType, callback) -> debug (writer) -> writer.buffer('iteratorType', iteratorType) getIteratorCallback = (err, iterator) -> if (err) callback(err) else debug (writer) -> writer.log('iterate') switch iteratorType when 'array' then reader.toArray(iterator, callback) when 'batch' then reader.forEachBatch(iterator, callback) when 'each' then reader.forEach(iterator, callback) return reader.getIterator(tr, getIteratorCallback) return transactionalIterate = fdb.transactional(iterate) fdb.RangeReader = class RangeReader extends EventEmitter ###* * Creates a new Reader instance * @class * @param {object} options Settings. * @param {(Buffer|fdb.KeySelector)} [options.begin] First key in the reader range. * @param {(Buffer|fdb.KeySelector)}} [options.end=undefined] Last key in the reader range. * @param {number} [options.limit=undefined] Only the first limit keys (and their values) in the range will be returned. * @param {boolean} [options.reverse=undefined] Specified if the keys in the range will be returned in reverse order * @param {(iterator|want_all|small|medium|large|serial|exact)} [options.streamingMode=undefined] fdb.streamingMode property that permits the API client to customize performance tradeoff by providing extra information about how the iterator will be used. * @param {boolean} [options.nonTransactional=false] Reset transaction on expiry and start. * @param {boolean} [options.snapshot=false] Defines whether range reads should be snapshot reads. * @property {array} instances Collection of Document Layer db instances. * @property {number} index Current index of the instances collection. * @property {(Buffer|fdb.KeySelector)}} begin First key in the reader range. * @property {(Buffer|fdb.KeySelector)}} end Last key in the reader range. * @property {Buffer} marker Marker key for transaction expiration continuation point. * @property {number} limit Only the first limit keys (and their values) in the range will be returned. * @property {boolean} reverse Specified if the keys in the range will be returned in reverse order * @property {(iterator|want_all|small|medium|large|serial|exact)} streamingMode fdb.streamingMode property that permits the API client to customize performance tradeoff by providing extra information about how the iterator will be used. * @property {boolean} nonTransactional Reset transaction on expiry and start. * @property {boolean} snapshot Defines whether range reads should be snapshot reads. * @return {Reader} a Reader instance. ### constructor: (options) -> super() @begin = options.begin @end = options.end @marker = null @limit = options.limit @reverse = options.reverse @streamingMode = options.streamingMode @nonTransactional = options.nonTransactional || false @snapshot = options.snapshot || false debug (writer) -> writer.buffer('begin', resolveKey(options.begin).toString('utf8')) if options.begin writer.buffer('end', resolveKey(options.end).toString('utf8')) if options.end writer.buffer('limit', options.limit) writer.buffer('reverse', options.reverse) writer.buffer('streamingMode', options.streamingMode) writer.buffer('nonTransactional', options.nonTransactional) writer.buffer('snapshot', options.snapshot) @on 'data', (data) => if (data instanceof Array) @marker = kv.key for kv in data else @marker = data.key return ###* * The callback format for the getLastKey method * @callback getLastKeyCallback * @param {Error} error An error instance representing the error during the execution. * @param {Buffer} lastKey The Buffer value if the getLastKey method was successful. ### ###* * Get the last key of the range if no end key is provided to the RangeReader * @method * @param {object} tr Transaction. * @param {object} reader RangeReader instance. * @param {getLastKeyCallback} callback Callback. * @return {undefined} ### getLastKey: (tr, callback) -> if (@end) debug (writer) -> writer.buffer('end', @end.key.toString('utf8')) callback(null, @end) else tr.getLastKey(@begin, callback) return ###* * The callback format for the init method * @callback initCallback * @param {Error} error An error instance representing the error during the execution. ### ###* * Initialize the reader before iteration * @abstract * @param {object} tr Transaction. * @param {object} reader RangeReader instance. * @param {initCallback} callback Callback. * @return {undefined} ### init: (tr, callback) -> callback(null) ###* * The callback format for the getIterator method * @callback getIteratorCallback * @param {Error} error An error instance representing the error during the execution. * @param {LazyIterator} iterator The LazyIterator instance if the getIterator method was successful. ### ###* * Get a LazyIterator instance for the current range read operation * @method * @param {object} tr Transaction. * @param {object} reader RangeReader instance. * @param {getIteratorCallback} callback Callback. * @return {undefined} ### getIterator: (tr, callback) -> debug (writer) -> writer.log('getIterator') options = limit: @limit reverse: @reverse streamingMode: @streamingMode ts = if @snapshot then tr.snapshot else tr if (@end || @marker) begin = if @marker then fdb.KeySelector.firstGreaterThan(@marker) else @begin @getLastKey tr, (err, lastKey) -> if (err) callback(err) else iterator = ts.getRange(begin, lastKey, options) debug (writer) -> writer.log('getLastKey') writer.buffer('method', 'getRange') writer.buffer('begin', resolveKey(begin).toString('utf8')) writer.buffer('end', resolveKey(lastKey).toString('utf8')) writer.buffer('options', options) callback(null, iterator) return else iterator = ts.getRangeStartsWith(@begin, options) debug (writer) => writer.buffer('method', 'getRangeStartsWith') writer.buffer('prefix', resolveKey(@begin).toString('utf8')) writer.buffer('options', options) callback(null, iterator) return ###* * Iterate over array results * @virtual * @param {LazyIterator} iterator LazyIterator instance. * @param {iterateCallback} callback Callback. * @fires RangeReader#data * @return {undefined} ### toArray: (iterator, callback) -> iterator.toArray (err, arr) => @emit('data', arr) callback(err) return return ###* * Iterate over batch results * @virtual * @param {LazyIterator} iterator LazyIterator instance. * @param {iterateCallback} callback Callback. * @fires RangeReader#data * @return {undefined} ### forEachBatch: (iterator, callback) -> func = (arr, next) => @emit('data', arr) next() return iterator.forEachBatch(func, callback) return ###* * Iterate over key-value pair results * @virtual * @param {LazyIterator} iterator LazyIterator instance. * @param {iterateCallback} callback Callback. * @fires RangeReader#data * @return {undefined} ### forEach: (iterator, callback) -> func = (kv, next) => @emit('data', kv) next() return iterator.forEach(func, callback) return ###* * Execute the reader using an iterator type * @virtual * @param {object} [tr=null] transaction. * @param {string} iteratorType batch|each|array. * @fires RangeReader#error * @fires RangeReader#continue * @fires RangeReader#end * @return {undefined} ### execute: (tr, iteratorType) -> if (typeof(tr) is 'string') iteratorType = tr tr = db debug (writer) -> writer.log('execute') complete = (err, result) => if (err) @emit('error', err) else @emit('end', result) return toBeContinued = => debug (writer) -> writer.log('continue') tr.reset() @emit('continue') txi() return pastVersionCatchingCallback = (err, result) => if (err && @nonTransactional && err.message is 'past_version') toBeContinued() else complete(err, result) return txi = => transactionalIterate(tr || db, @, iteratorType, pastVersionCatchingCallback) return txi() return return