diff options
Diffstat (limited to 'node_modules/line-reader/lib/line_reader.js')
| -rw-r--r-- | node_modules/line-reader/lib/line_reader.js | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/node_modules/line-reader/lib/line_reader.js b/node_modules/line-reader/lib/line_reader.js new file mode 100644 index 00000000000..f1fd87342a2 --- /dev/null +++ b/node_modules/line-reader/lib/line_reader.js @@ -0,0 +1,306 @@ +'use strict'; + +var fs = require('fs'), + StringDecoder = require('string_decoder').StringDecoder; + +function createLineReader(readStream, options, creationCb) { + if (options instanceof Function) { + creationCb = options; + options = undefined; + } + if (!options) options = {}; + + var encoding = options.encoding || 'utf8', + separator = options.separator || /\r\n?|\n/, + bufferSize = options.bufferSize || 1024, + bufferStr = '', + decoder = new StringDecoder(encoding), + closed = false, + eof = false, + separatorIndex = -1, + separatorLen, + readDefer, + moreToRead = false, + findSeparator; + + if (separator instanceof RegExp) { + findSeparator = function() { + var result = separator.exec(bufferStr); + if (result && (result.index + result[0].length < bufferStr.length || eof)) { + separatorIndex = result.index; + separatorLen = result[0].length; + } else { + separatorIndex = -1; + separatorLen = 0; + } + }; + } else { + separatorLen = separator.length; + findSeparator = function() { + separatorIndex = bufferStr.indexOf(separator); + }; + } + + function getReadStream() { + return readStream; + } + + function close(cb) { + if (!closed) { + closed = true; + if (typeof readStream.close == 'function') { + readStream.close(); + } + setImmediate(cb); + } + } + + function onFailure(err) { + close(function(err2) { + return creationCb(err || err2); + }); + } + + function isOpen() { + return !closed; + } + + function isClosed() { + return closed; + } + + function waitForMoreToRead(cb) { + if (moreToRead) { + cb(); + } else { + readDefer = cb; + } + } + + function resumeDeferredRead() { + if (readDefer) { + readDefer(); + readDefer = null; + } + } + + function read(cb) { + waitForMoreToRead(function() { + var chunk; + + try { + chunk = readStream.read(bufferSize); + } catch (err) { + cb(err); + } + + if (chunk) { + bufferStr += decoder.write(chunk.slice(0, chunk.length)); + } else { + moreToRead = false; + } + + cb(); + }); + } + + function onStreamReadable() { + moreToRead = true; + resumeDeferredRead(); + } + + function onStreamEnd() { + eof = true; + resumeDeferredRead(); + } + + readStream.on('readable', onStreamReadable); + readStream.on('end', onStreamEnd); + readStream.on('error', onFailure); + + function shouldReadMore() { + findSeparator(); + + return separatorIndex < 0 && !eof; + } + + function callWhile(conditionFn, bodyFn, doneCallback) { + if (conditionFn()) { + bodyFn(function (err) { + if (err) { + doneCallback(err); + } else { + setImmediate(callWhile, conditionFn, bodyFn, doneCallback); + } + }); + } else { + doneCallback(); + } + } + + function readToSeparator(cb) { + callWhile(shouldReadMore, read, cb); + } + + function hasNextLine() { + return bufferStr.length > 0 || !eof; + } + + function nextLine(cb) { + if (closed) { + return cb(new Error('LineReader has been closed')); + } + + function getLine(err) { + if (err) { + return cb(err); + } + + if (separatorIndex < 0 && eof) { + separatorIndex = bufferStr.length; + } + var ret = bufferStr.substring(0, separatorIndex); + + bufferStr = bufferStr.substring(separatorIndex + separatorLen); + separatorIndex = -1; + cb(undefined, ret); + } + + findSeparator(); + + if (separatorIndex < 0) { + if (eof) { + if (hasNextLine()) { + separatorIndex = bufferStr.length; + getLine(); + } else { + return cb(new Error('No more lines to read.')); + } + } else { + readToSeparator(getLine); + } + } else { + getLine(); + } + } + + readToSeparator(function(err) { + if (err) { + onFailure(err); + } else { + return creationCb(undefined, { + hasNextLine: hasNextLine, + nextLine: nextLine, + close: close, + isOpen: isOpen, + isClosed: isClosed, + getReadStream: getReadStream + }); + } + }); +} + +function open(filenameOrStream, options, cb) { + if (options instanceof Function) { + cb = options; + options = undefined; + } + + var readStream; + + if (typeof filenameOrStream.read == 'function') { + readStream = filenameOrStream; + } else if (typeof filenameOrStream === 'string' || filenameOrStream instanceof String) { + readStream = fs.createReadStream(filenameOrStream); + } else { + cb(new Error('Invalid file argument for LineReader.open. Must be filename or stream.')); + return; + } + + readStream.pause(); + createLineReader(readStream, options, cb); +} + +function eachLine(filename, options, iteratee, cb) { + if (options instanceof Function) { + cb = iteratee; + iteratee = options; + options = undefined; + } + var asyncIteratee = iteratee.length === 3; + + var theReader; + var getReaderCb; + + open(filename, options, function(err, reader) { + theReader = reader; + if (getReaderCb) { + getReaderCb(reader); + } + + if (err) { + if (cb) cb(err); + return; + } + + function finish(err) { + reader.close(function(err2) { + if (cb) cb(err || err2); + }); + } + + function newRead() { + if (reader.hasNextLine()) { + setImmediate(readNext); + } else { + finish(); + } + } + + function continueCb(continueReading) { + if (continueReading !== false) { + newRead(); + } else { + finish(); + } + } + + function readNext() { + reader.nextLine(function(err, line) { + if (err) { + finish(err); + } + + var last = !reader.hasNextLine(); + + if (asyncIteratee) { + iteratee(line, last, continueCb); + } else { + if (iteratee(line, last) !== false) { + newRead(); + } else { + finish(); + } + } + }); + } + + newRead(); + }); + + // this hook is only for the sake of testing; if you choose to use it, + // please don't file any issues (unless you can also reproduce them without + // using this). + return { + getReader: function(cb) { + if (theReader) { + cb(theReader); + } else { + getReaderCb = cb; + } + } + }; +} + +module.exports.open = open; +module.exports.eachLine = eachLine; |