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Diffstat (limited to 'node_modules/bl/bl.js')
-rw-r--r-- | node_modules/bl/bl.js | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/node_modules/bl/bl.js b/node_modules/bl/bl.js new file mode 100644 index 0000000..0c8de18 --- /dev/null +++ b/node_modules/bl/bl.js @@ -0,0 +1,290 @@ +var DuplexStream = require('readable-stream/duplex') + , util = require('util') + , Buffer = require('safe-buffer').Buffer + + +function BufferList (callback) { + if (!(this instanceof BufferList)) + return new BufferList(callback) + + this._bufs = [] + this.length = 0 + + if (typeof callback == 'function') { + this._callback = callback + + var piper = function piper (err) { + if (this._callback) { + this._callback(err) + this._callback = null + } + }.bind(this) + + this.on('pipe', function onPipe (src) { + src.on('error', piper) + }) + this.on('unpipe', function onUnpipe (src) { + src.removeListener('error', piper) + }) + } else { + this.append(callback) + } + + DuplexStream.call(this) +} + + +util.inherits(BufferList, DuplexStream) + + +BufferList.prototype._offset = function _offset (offset) { + var tot = 0, i = 0, _t + if (offset === 0) return [ 0, 0 ] + for (; i < this._bufs.length; i++) { + _t = tot + this._bufs[i].length + if (offset < _t || i == this._bufs.length - 1) + return [ i, offset - tot ] + tot = _t + } +} + + +BufferList.prototype.append = function append (buf) { + var i = 0 + + if (Buffer.isBuffer(buf)) { + this._appendBuffer(buf); + } else if (Array.isArray(buf)) { + for (; i < buf.length; i++) + this.append(buf[i]) + } else if (buf instanceof BufferList) { + // unwrap argument into individual BufferLists + for (; i < buf._bufs.length; i++) + this.append(buf._bufs[i]) + } else if (buf != null) { + // coerce number arguments to strings, since Buffer(number) does + // uninitialized memory allocation + if (typeof buf == 'number') + buf = buf.toString() + + this._appendBuffer(Buffer.from(buf)); + } + + return this +} + + +BufferList.prototype._appendBuffer = function appendBuffer (buf) { + this._bufs.push(buf) + this.length += buf.length +} + + +BufferList.prototype._write = function _write (buf, encoding, callback) { + this._appendBuffer(buf) + + if (typeof callback == 'function') + callback() +} + + +BufferList.prototype._read = function _read (size) { + if (!this.length) + return this.push(null) + + size = Math.min(size, this.length) + this.push(this.slice(0, size)) + this.consume(size) +} + + +BufferList.prototype.end = function end (chunk) { + DuplexStream.prototype.end.call(this, chunk) + + if (this._callback) { + this._callback(null, this.slice()) + this._callback = null + } +} + + +BufferList.prototype.get = function get (index) { + return this.slice(index, index + 1)[0] +} + + +BufferList.prototype.slice = function slice (start, end) { + if (typeof start == 'number' && start < 0) + start += this.length + if (typeof end == 'number' && end < 0) + end += this.length + return this.copy(null, 0, start, end) +} + + +BufferList.prototype.copy = function copy (dst, dstStart, srcStart, srcEnd) { + if (typeof srcStart != 'number' || srcStart < 0) + srcStart = 0 + if (typeof srcEnd != 'number' || srcEnd > this.length) + srcEnd = this.length + if (srcStart >= this.length) + return dst || Buffer.alloc(0) + if (srcEnd <= 0) + return dst || Buffer.alloc(0) + + var copy = !!dst + , off = this._offset(srcStart) + , len = srcEnd - srcStart + , bytes = len + , bufoff = (copy && dstStart) || 0 + , start = off[1] + , l + , i + + // copy/slice everything + if (srcStart === 0 && srcEnd == this.length) { + if (!copy) { // slice, but full concat if multiple buffers + return this._bufs.length === 1 + ? this._bufs[0] + : Buffer.concat(this._bufs, this.length) + } + + // copy, need to copy individual buffers + for (i = 0; i < this._bufs.length; i++) { + this._bufs[i].copy(dst, bufoff) + bufoff += this._bufs[i].length + } + + return dst + } + + // easy, cheap case where it's a subset of one of the buffers + if (bytes <= this._bufs[off[0]].length - start) { + return copy + ? this._bufs[off[0]].copy(dst, dstStart, start, start + bytes) + : this._bufs[off[0]].slice(start, start + bytes) + } + + if (!copy) // a slice, we need something to copy in to + dst = Buffer.allocUnsafe(len) + + for (i = off[0]; i < this._bufs.length; i++) { + l = this._bufs[i].length - start + + if (bytes > l) { + this._bufs[i].copy(dst, bufoff, start) + bufoff += l + } else { + this._bufs[i].copy(dst, bufoff, start, start + bytes) + bufoff += l + break + } + + bytes -= l + + if (start) + start = 0 + } + + // safeguard so that we don't return uninitialized memory + if (dst.length > bufoff) return dst.slice(0, bufoff) + + return dst +} + +BufferList.prototype.shallowSlice = function shallowSlice (start, end) { + start = start || 0 + end = end || this.length + + if (start < 0) + start += this.length + if (end < 0) + end += this.length + + var startOffset = this._offset(start) + , endOffset = this._offset(end) + , buffers = this._bufs.slice(startOffset[0], endOffset[0] + 1) + + if (endOffset[1] == 0) + buffers.pop() + else + buffers[buffers.length-1] = buffers[buffers.length-1].slice(0, endOffset[1]) + + if (startOffset[1] != 0) + buffers[0] = buffers[0].slice(startOffset[1]) + + return new BufferList(buffers) +} + +BufferList.prototype.toString = function toString (encoding, start, end) { + return this.slice(start, end).toString(encoding) +} + +BufferList.prototype.consume = function consume (bytes) { + // first, normalize the argument, in accordance with how Buffer does it + bytes = Math.trunc(bytes) + // do nothing if not a positive number + if (Number.isNaN(bytes) || bytes <= 0) return this + + while (this._bufs.length) { + if (bytes >= this._bufs[0].length) { + bytes -= this._bufs[0].length + this.length -= this._bufs[0].length + this._bufs.shift() + } else { + this._bufs[0] = this._bufs[0].slice(bytes) + this.length -= bytes + break + } + } + return this +} + + +BufferList.prototype.duplicate = function duplicate () { + var i = 0 + , copy = new BufferList() + + for (; i < this._bufs.length; i++) + copy.append(this._bufs[i]) + + return copy +} + + +BufferList.prototype.destroy = function destroy () { + this._bufs.length = 0 + this.length = 0 + this.push(null) +} + + +;(function () { + var methods = { + 'readDoubleBE' : 8 + , 'readDoubleLE' : 8 + , 'readFloatBE' : 4 + , 'readFloatLE' : 4 + , 'readInt32BE' : 4 + , 'readInt32LE' : 4 + , 'readUInt32BE' : 4 + , 'readUInt32LE' : 4 + , 'readInt16BE' : 2 + , 'readInt16LE' : 2 + , 'readUInt16BE' : 2 + , 'readUInt16LE' : 2 + , 'readInt8' : 1 + , 'readUInt8' : 1 + } + + for (var m in methods) { + (function (m) { + BufferList.prototype[m] = function (offset) { + return this.slice(offset, offset + methods[m])[m](0) + } + }(m)) + } +}()) + + +module.exports = BufferList |