X-Git-Url: http://www.aleph1.co.uk/gitweb/?p=yaffs-website;a=blobdiff_plain;f=node_modules%2Fconcat-stream%2Fnode_modules%2Freadable-stream%2Flib%2F_stream_writable.js;fp=node_modules%2Fconcat-stream%2Fnode_modules%2Freadable-stream%2Flib%2F_stream_writable.js;h=95916c992a9507908788c81f22175bb1a0877f68;hp=0000000000000000000000000000000000000000;hb=a2bd1bf0c2c1f1a17d188f4dc0726a45494cefae;hpb=57c063afa3f66b07c4bbddc2d6129a96d90f0aad diff --git a/node_modules/concat-stream/node_modules/readable-stream/lib/_stream_writable.js b/node_modules/concat-stream/node_modules/readable-stream/lib/_stream_writable.js new file mode 100644 index 000000000..95916c992 --- /dev/null +++ b/node_modules/concat-stream/node_modules/readable-stream/lib/_stream_writable.js @@ -0,0 +1,516 @@ +// A bit simpler than readable streams. +// Implement an async ._write(chunk, encoding, cb), and it'll handle all +// the drain event emission and buffering. + +'use strict'; + +module.exports = Writable; + +/**/ +var processNextTick = require('process-nextick-args'); +/**/ + +/**/ +var asyncWrite = !process.browser && ['v0.10', 'v0.9.'].indexOf(process.version.slice(0, 5)) > -1 ? setImmediate : processNextTick; +/**/ + +/**/ +var Buffer = require('buffer').Buffer; +/**/ + +Writable.WritableState = WritableState; + +/**/ +var util = require('core-util-is'); +util.inherits = require('inherits'); +/**/ + +/**/ +var internalUtil = { + deprecate: require('util-deprecate') +}; +/**/ + +/**/ +var Stream; +(function () { + try { + Stream = require('st' + 'ream'); + } catch (_) {} finally { + if (!Stream) Stream = require('events').EventEmitter; + } +})(); +/**/ + +var Buffer = require('buffer').Buffer; + +util.inherits(Writable, Stream); + +function nop() {} + +function WriteReq(chunk, encoding, cb) { + this.chunk = chunk; + this.encoding = encoding; + this.callback = cb; + this.next = null; +} + +var Duplex; +function WritableState(options, stream) { + Duplex = Duplex || require('./_stream_duplex'); + + options = options || {}; + + // object stream flag to indicate whether or not this stream + // contains buffers or objects. + this.objectMode = !!options.objectMode; + + if (stream instanceof Duplex) this.objectMode = this.objectMode || !!options.writableObjectMode; + + // the point at which write() starts returning false + // Note: 0 is a valid value, means that we always return false if + // the entire buffer is not flushed immediately on write() + var hwm = options.highWaterMark; + var defaultHwm = this.objectMode ? 16 : 16 * 1024; + this.highWaterMark = hwm || hwm === 0 ? hwm : defaultHwm; + + // cast to ints. + this.highWaterMark = ~ ~this.highWaterMark; + + this.needDrain = false; + // at the start of calling end() + this.ending = false; + // when end() has been called, and returned + this.ended = false; + // when 'finish' is emitted + this.finished = false; + + // should we decode strings into buffers before passing to _write? + // this is here so that some node-core streams can optimize string + // handling at a lower level. + var noDecode = options.decodeStrings === false; + this.decodeStrings = !noDecode; + + // Crypto is kind of old and crusty. Historically, its default string + // encoding is 'binary' so we have to make this configurable. + // Everything else in the universe uses 'utf8', though. + this.defaultEncoding = options.defaultEncoding || 'utf8'; + + // not an actual buffer we keep track of, but a measurement + // of how much we're waiting to get pushed to some underlying + // socket or file. + this.length = 0; + + // a flag to see when we're in the middle of a write. + this.writing = false; + + // when true all writes will be buffered until .uncork() call + this.corked = 0; + + // a flag to be able to tell if the onwrite cb is called immediately, + // or on a later tick. We set this to true at first, because any + // actions that shouldn't happen until "later" should generally also + // not happen before the first write call. + this.sync = true; + + // a flag to know if we're processing previously buffered items, which + // may call the _write() callback in the same tick, so that we don't + // end up in an overlapped onwrite situation. + this.bufferProcessing = false; + + // the callback that's passed to _write(chunk,cb) + this.onwrite = function (er) { + onwrite(stream, er); + }; + + // the callback that the user supplies to write(chunk,encoding,cb) + this.writecb = null; + + // the amount that is being written when _write is called. + this.writelen = 0; + + this.bufferedRequest = null; + this.lastBufferedRequest = null; + + // number of pending user-supplied write callbacks + // this must be 0 before 'finish' can be emitted + this.pendingcb = 0; + + // emit prefinish if the only thing we're waiting for is _write cbs + // This is relevant for synchronous Transform streams + this.prefinished = false; + + // True if the error was already emitted and should not be thrown again + this.errorEmitted = false; + + // count buffered requests + this.bufferedRequestCount = 0; + + // create the two objects needed to store the corked requests + // they are not a linked list, as no new elements are inserted in there + this.corkedRequestsFree = new CorkedRequest(this); + this.corkedRequestsFree.next = new CorkedRequest(this); +} + +WritableState.prototype.getBuffer = function writableStateGetBuffer() { + var current = this.bufferedRequest; + var out = []; + while (current) { + out.push(current); + current = current.next; + } + return out; +}; + +(function () { + try { + Object.defineProperty(WritableState.prototype, 'buffer', { + get: internalUtil.deprecate(function () { + return this.getBuffer(); + }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.') + }); + } catch (_) {} +})(); + +var Duplex; +function Writable(options) { + Duplex = Duplex || require('./_stream_duplex'); + + // Writable ctor is applied to Duplexes, though they're not + // instanceof Writable, they're instanceof Readable. + if (!(this instanceof Writable) && !(this instanceof Duplex)) return new Writable(options); + + this._writableState = new WritableState(options, this); + + // legacy. + this.writable = true; + + if (options) { + if (typeof options.write === 'function') this._write = options.write; + + if (typeof options.writev === 'function') this._writev = options.writev; + } + + Stream.call(this); +} + +// Otherwise people can pipe Writable streams, which is just wrong. +Writable.prototype.pipe = function () { + this.emit('error', new Error('Cannot pipe. Not readable.')); +}; + +function writeAfterEnd(stream, cb) { + var er = new Error('write after end'); + // TODO: defer error events consistently everywhere, not just the cb + stream.emit('error', er); + processNextTick(cb, er); +} + +// If we get something that is not a buffer, string, null, or undefined, +// and we're not in objectMode, then that's an error. +// Otherwise stream chunks are all considered to be of length=1, and the +// watermarks determine how many objects to keep in the buffer, rather than +// how many bytes or characters. +function validChunk(stream, state, chunk, cb) { + var valid = true; + + if (!Buffer.isBuffer(chunk) && typeof chunk !== 'string' && chunk !== null && chunk !== undefined && !state.objectMode) { + var er = new TypeError('Invalid non-string/buffer chunk'); + stream.emit('error', er); + processNextTick(cb, er); + valid = false; + } + return valid; +} + +Writable.prototype.write = function (chunk, encoding, cb) { + var state = this._writableState; + var ret = false; + + if (typeof encoding === 'function') { + cb = encoding; + encoding = null; + } + + if (Buffer.isBuffer(chunk)) encoding = 'buffer';else if (!encoding) encoding = state.defaultEncoding; + + if (typeof cb !== 'function') cb = nop; + + if (state.ended) writeAfterEnd(this, cb);else if (validChunk(this, state, chunk, cb)) { + state.pendingcb++; + ret = writeOrBuffer(this, state, chunk, encoding, cb); + } + + return ret; +}; + +Writable.prototype.cork = function () { + var state = this._writableState; + + state.corked++; +}; + +Writable.prototype.uncork = function () { + var state = this._writableState; + + if (state.corked) { + state.corked--; + + if (!state.writing && !state.corked && !state.finished && !state.bufferProcessing && state.bufferedRequest) clearBuffer(this, state); + } +}; + +Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) { + // node::ParseEncoding() requires lower case. + if (typeof encoding === 'string') encoding = encoding.toLowerCase(); + if (!(['hex', 'utf8', 'utf-8', 'ascii', 'binary', 'base64', 'ucs2', 'ucs-2', 'utf16le', 'utf-16le', 'raw'].indexOf((encoding + '').toLowerCase()) > -1)) throw new TypeError('Unknown encoding: ' + encoding); + this._writableState.defaultEncoding = encoding; +}; + +function decodeChunk(state, chunk, encoding) { + if (!state.objectMode && state.decodeStrings !== false && typeof chunk === 'string') { + chunk = new Buffer(chunk, encoding); + } + return chunk; +} + +// if we're already writing something, then just put this +// in the queue, and wait our turn. Otherwise, call _write +// If we return false, then we need a drain event, so set that flag. +function writeOrBuffer(stream, state, chunk, encoding, cb) { + chunk = decodeChunk(state, chunk, encoding); + + if (Buffer.isBuffer(chunk)) encoding = 'buffer'; + var len = state.objectMode ? 1 : chunk.length; + + state.length += len; + + var ret = state.length < state.highWaterMark; + // we must ensure that previous needDrain will not be reset to false. + if (!ret) state.needDrain = true; + + if (state.writing || state.corked) { + var last = state.lastBufferedRequest; + state.lastBufferedRequest = new WriteReq(chunk, encoding, cb); + if (last) { + last.next = state.lastBufferedRequest; + } else { + state.bufferedRequest = state.lastBufferedRequest; + } + state.bufferedRequestCount += 1; + } else { + doWrite(stream, state, false, len, chunk, encoding, cb); + } + + return ret; +} + +function doWrite(stream, state, writev, len, chunk, encoding, cb) { + state.writelen = len; + state.writecb = cb; + state.writing = true; + state.sync = true; + if (writev) stream._writev(chunk, state.onwrite);else stream._write(chunk, encoding, state.onwrite); + state.sync = false; +} + +function onwriteError(stream, state, sync, er, cb) { + --state.pendingcb; + if (sync) processNextTick(cb, er);else cb(er); + + stream._writableState.errorEmitted = true; + stream.emit('error', er); +} + +function onwriteStateUpdate(state) { + state.writing = false; + state.writecb = null; + state.length -= state.writelen; + state.writelen = 0; +} + +function onwrite(stream, er) { + var state = stream._writableState; + var sync = state.sync; + var cb = state.writecb; + + onwriteStateUpdate(state); + + if (er) onwriteError(stream, state, sync, er, cb);else { + // Check if we're actually ready to finish, but don't emit yet + var finished = needFinish(state); + + if (!finished && !state.corked && !state.bufferProcessing && state.bufferedRequest) { + clearBuffer(stream, state); + } + + if (sync) { + /**/ + asyncWrite(afterWrite, stream, state, finished, cb); + /**/ + } else { + afterWrite(stream, state, finished, cb); + } + } +} + +function afterWrite(stream, state, finished, cb) { + if (!finished) onwriteDrain(stream, state); + state.pendingcb--; + cb(); + finishMaybe(stream, state); +} + +// Must force callback to be called on nextTick, so that we don't +// emit 'drain' before the write() consumer gets the 'false' return +// value, and has a chance to attach a 'drain' listener. +function onwriteDrain(stream, state) { + if (state.length === 0 && state.needDrain) { + state.needDrain = false; + stream.emit('drain'); + } +} + +// if there's something in the buffer waiting, then process it +function clearBuffer(stream, state) { + state.bufferProcessing = true; + var entry = state.bufferedRequest; + + if (stream._writev && entry && entry.next) { + // Fast case, write everything using _writev() + var l = state.bufferedRequestCount; + var buffer = new Array(l); + var holder = state.corkedRequestsFree; + holder.entry = entry; + + var count = 0; + while (entry) { + buffer[count] = entry; + entry = entry.next; + count += 1; + } + + doWrite(stream, state, true, state.length, buffer, '', holder.finish); + + // doWrite is always async, defer these to save a bit of time + // as the hot path ends with doWrite + state.pendingcb++; + state.lastBufferedRequest = null; + state.corkedRequestsFree = holder.next; + holder.next = null; + } else { + // Slow case, write chunks one-by-one + while (entry) { + var chunk = entry.chunk; + var encoding = entry.encoding; + var cb = entry.callback; + var len = state.objectMode ? 1 : chunk.length; + + doWrite(stream, state, false, len, chunk, encoding, cb); + entry = entry.next; + // if we didn't call the onwrite immediately, then + // it means that we need to wait until it does. + // also, that means that the chunk and cb are currently + // being processed, so move the buffer counter past them. + if (state.writing) { + break; + } + } + + if (entry === null) state.lastBufferedRequest = null; + } + + state.bufferedRequestCount = 0; + state.bufferedRequest = entry; + state.bufferProcessing = false; +} + +Writable.prototype._write = function (chunk, encoding, cb) { + cb(new Error('not implemented')); +}; + +Writable.prototype._writev = null; + +Writable.prototype.end = function (chunk, encoding, cb) { + var state = this._writableState; + + if (typeof chunk === 'function') { + cb = chunk; + chunk = null; + encoding = null; + } else if (typeof encoding === 'function') { + cb = encoding; + encoding = null; + } + + if (chunk !== null && chunk !== undefined) this.write(chunk, encoding); + + // .end() fully uncorks + if (state.corked) { + state.corked = 1; + this.uncork(); + } + + // ignore unnecessary end() calls. + if (!state.ending && !state.finished) endWritable(this, state, cb); +}; + +function needFinish(state) { + return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing; +} + +function prefinish(stream, state) { + if (!state.prefinished) { + state.prefinished = true; + stream.emit('prefinish'); + } +} + +function finishMaybe(stream, state) { + var need = needFinish(state); + if (need) { + if (state.pendingcb === 0) { + prefinish(stream, state); + state.finished = true; + stream.emit('finish'); + } else { + prefinish(stream, state); + } + } + return need; +} + +function endWritable(stream, state, cb) { + state.ending = true; + finishMaybe(stream, state); + if (cb) { + if (state.finished) processNextTick(cb);else stream.once('finish', cb); + } + state.ended = true; + stream.writable = false; +} + +// It seems a linked list but it is not +// there will be only 2 of these for each stream +function CorkedRequest(state) { + var _this = this; + + this.next = null; + this.entry = null; + + this.finish = function (err) { + var entry = _this.entry; + _this.entry = null; + while (entry) { + var cb = entry.callback; + state.pendingcb--; + cb(err); + entry = entry.next; + } + if (state.corkedRequestsFree) { + state.corkedRequestsFree.next = _this; + } else { + state.corkedRequestsFree = _this; + } + }; +} \ No newline at end of file