diff options
Diffstat (limited to 'node_modules/browserify-zlib/src/binding.js')
| -rw-r--r-- | node_modules/browserify-zlib/src/binding.js | 432 |
1 files changed, 432 insertions, 0 deletions
diff --git a/node_modules/browserify-zlib/src/binding.js b/node_modules/browserify-zlib/src/binding.js new file mode 100644 index 0000000..14e419d --- /dev/null +++ b/node_modules/browserify-zlib/src/binding.js @@ -0,0 +1,432 @@ +'use strict' +/* eslint camelcase: "off" */ + +var assert = require('assert') + +var Zstream = require('pako/lib/zlib/zstream') +var zlib_deflate = require('pako/lib/zlib/deflate.js') +var zlib_inflate = require('pako/lib/zlib/inflate.js') +var constants = require('pako/lib/zlib/constants') + +for (var key in constants) { + exports[key] = constants[key] +} + +// zlib modes +exports.NONE = 0 +exports.DEFLATE = 1 +exports.INFLATE = 2 +exports.GZIP = 3 +exports.GUNZIP = 4 +exports.DEFLATERAW = 5 +exports.INFLATERAW = 6 +exports.UNZIP = 7 + +var GZIP_HEADER_ID1 = 0x1f +var GZIP_HEADER_ID2 = 0x8b + +/** + * Emulate Node's zlib C++ layer for use by the JS layer in index.js + */ +function Zlib (mode) { + if (typeof mode !== 'number' || mode < exports.DEFLATE || mode > exports.UNZIP) { + throw new TypeError('Bad argument') + } + + this.dictionary = null + this.err = 0 + this.flush = 0 + this.init_done = false + this.level = 0 + this.memLevel = 0 + this.mode = mode + this.strategy = 0 + this.windowBits = 0 + this.write_in_progress = false + this.pending_close = false + this.gzip_id_bytes_read = 0 +} + +Zlib.prototype.close = function () { + if (this.write_in_progress) { + this.pending_close = true + return + } + + this.pending_close = false + + assert(this.init_done, 'close before init') + assert(this.mode <= exports.UNZIP) + + if (this.mode === exports.DEFLATE || this.mode === exports.GZIP || this.mode === exports.DEFLATERAW) { + zlib_deflate.deflateEnd(this.strm) + } else if (this.mode === exports.INFLATE || this.mode === exports.GUNZIP || + this.mode === exports.INFLATERAW || this.mode === exports.UNZIP) { + zlib_inflate.inflateEnd(this.strm) + } + + this.mode = exports.NONE + + this.dictionary = null +} + +Zlib.prototype.write = function (flush, input, in_off, in_len, out, out_off, out_len) { + return this._write(true, flush, input, in_off, in_len, out, out_off, out_len) +} + +Zlib.prototype.writeSync = function (flush, input, in_off, in_len, out, out_off, out_len) { + return this._write(false, flush, input, in_off, in_len, out, out_off, out_len) +} + +Zlib.prototype._write = function (async, flush, input, in_off, in_len, out, out_off, out_len) { + assert.equal(arguments.length, 8) + + assert(this.init_done, 'write before init') + assert(this.mode !== exports.NONE, 'already finalized') + assert.equal(false, this.write_in_progress, 'write already in progress') + assert.equal(false, this.pending_close, 'close is pending') + + this.write_in_progress = true + + assert.equal(false, flush === undefined, 'must provide flush value') + + this.write_in_progress = true + + if (flush !== exports.Z_NO_FLUSH && + flush !== exports.Z_PARTIAL_FLUSH && + flush !== exports.Z_SYNC_FLUSH && + flush !== exports.Z_FULL_FLUSH && + flush !== exports.Z_FINISH && + flush !== exports.Z_BLOCK) { + throw new Error('Invalid flush value') + } + + if (input == null) { + input = Buffer.alloc(0) + in_len = 0 + in_off = 0 + } + + this.strm.avail_in = in_len + this.strm.input = input + this.strm.next_in = in_off + this.strm.avail_out = out_len + this.strm.output = out + this.strm.next_out = out_off + this.flush = flush + + if (!async) { + // sync version + this._process() + + if (this._checkError()) { + return this._afterSync() + } + return + } + + // async version + var self = this + process.nextTick(function () { + self._process() + self._after() + }) + + return this +} + +Zlib.prototype._afterSync = function () { + var avail_out = this.strm.avail_out + var avail_in = this.strm.avail_in + + this.write_in_progress = false + + return [avail_in, avail_out] +} + +Zlib.prototype._process = function () { + var next_expected_header_byte = null + + // If the avail_out is left at 0, then it means that it ran out + // of room. If there was avail_out left over, then it means + // that all of the input was consumed. + switch (this.mode) { + case exports.DEFLATE: + case exports.GZIP: + case exports.DEFLATERAW: + this.err = zlib_deflate.deflate(this.strm, this.flush) + break + case exports.UNZIP: + if (this.strm.avail_in > 0) { + next_expected_header_byte = this.strm.next_in + } + + switch (this.gzip_id_bytes_read) { + case 0: + if (next_expected_header_byte === null) { + break + } + + if (this.strm.input[next_expected_header_byte] === GZIP_HEADER_ID1) { + this.gzip_id_bytes_read = 1 + next_expected_header_byte++ + + if (this.strm.avail_in === 1) { + // The only available byte was already read. + break + } + } else { + this.mode = exports.INFLATE + break + } + + // fallthrough + case 1: + if (next_expected_header_byte === null) { + break + } + + if (this.strm.input[next_expected_header_byte] === GZIP_HEADER_ID2) { + this.gzip_id_bytes_read = 2 + this.mode = exports.GUNZIP + } else { + // There is no actual difference between INFLATE and INFLATERAW + // (after initialization). + this.mode = exports.INFLATE + } + + break + default: + throw new Error('invalid number of gzip magic number bytes read') + } + + // fallthrough + case exports.INFLATE: + case exports.GUNZIP: + case exports.INFLATERAW: + this.err = zlib_inflate.inflate(this.strm, this.flush) + + // If data was encoded with dictionary + if (this.err === exports.Z_NEED_DICT && this.dictionary) { + // Load it + this.err = zlib_inflate.inflateSetDictionary(this.strm, this.dictionary) + if (this.err === exports.Z_OK) { + // And try to decode again + this.err = zlib_inflate.inflate(this.strm, this.flush) + } else if (this.err === exports.Z_DATA_ERROR) { + // Both inflateSetDictionary() and inflate() return Z_DATA_ERROR. + // Make it possible for After() to tell a bad dictionary from bad + // input. + this.err = exports.Z_NEED_DICT + } + } + while (this.strm.avail_in > 0 && + this.mode === exports.GUNZIP && + this.err === exports.Z_STREAM_END && + this.strm.next_in[0] !== 0x00) { + // Bytes remain in input buffer. Perhaps this is another compressed + // member in the same archive, or just trailing garbage. + // Trailing zero bytes are okay, though, since they are frequently + // used for padding. + + this.reset() + this.err = zlib_inflate.inflate(this.strm, this.flush) + } + break + default: + throw new Error('Unknown mode ' + this.mode) + } +} + +Zlib.prototype._checkError = function () { + // Acceptable error states depend on the type of zlib stream. + switch (this.err) { + case exports.Z_OK: + case exports.Z_BUF_ERROR: + if (this.strm.avail_out !== 0 && this.flush === exports.Z_FINISH) { + this._error('unexpected end of file') + return false + } + break + case exports.Z_STREAM_END: + // normal statuses, not fatal + break + case exports.Z_NEED_DICT: + if (this.dictionary == null) { + this._error('Missing dictionary') + } else { + this._error('Bad dictionary') + } + return false + default: + // something else. + this._error('Zlib error') + return false + } + + return true +} + +Zlib.prototype._after = function () { + if (!this._checkError()) { + return + } + + var avail_out = this.strm.avail_out + var avail_in = this.strm.avail_in + + this.write_in_progress = false + + // call the write() cb + this.callback(avail_in, avail_out) + + if (this.pending_close) { + this.close() + } +} + +Zlib.prototype._error = function (message) { + if (this.strm.msg) { + message = this.strm.msg + } + this.onerror(message, this.err) + + // no hope of rescue. + this.write_in_progress = false + if (this.pending_close) { + this.close() + } +} + +Zlib.prototype.init = function (windowBits, level, memLevel, strategy, dictionary) { + assert(arguments.length === 4 || arguments.length === 5, 'init(windowBits, level, memLevel, strategy, [dictionary])') + + assert(windowBits >= 8 && windowBits <= 15, 'invalid windowBits') + assert(level >= -1 && level <= 9, 'invalid compression level') + + assert(memLevel >= 1 && memLevel <= 9, 'invalid memlevel') + + assert(strategy === exports.Z_FILTERED || + strategy === exports.Z_HUFFMAN_ONLY || + strategy === exports.Z_RLE || + strategy === exports.Z_FIXED || + strategy === exports.Z_DEFAULT_STRATEGY, 'invalid strategy') + + this._init(level, windowBits, memLevel, strategy, dictionary) + this._setDictionary() +} + +Zlib.prototype.params = function () { + throw new Error('deflateParams Not supported') +} + +Zlib.prototype.reset = function () { + this._reset() + this._setDictionary() +} + +Zlib.prototype._init = function (level, windowBits, memLevel, strategy, dictionary) { + this.level = level + this.windowBits = windowBits + this.memLevel = memLevel + this.strategy = strategy + + this.flush = exports.Z_NO_FLUSH + + this.err = exports.Z_OK + + if (this.mode === exports.GZIP || this.mode === exports.GUNZIP) { + this.windowBits += 16 + } + + if (this.mode === exports.UNZIP) { + this.windowBits += 32 + } + + if (this.mode === exports.DEFLATERAW || this.mode === exports.INFLATERAW) { + this.windowBits = -1 * this.windowBits + } + + this.strm = new Zstream() + + switch (this.mode) { + case exports.DEFLATE: + case exports.GZIP: + case exports.DEFLATERAW: + this.err = zlib_deflate.deflateInit2( + this.strm, + this.level, + exports.Z_DEFLATED, + this.windowBits, + this.memLevel, + this.strategy + ) + break + case exports.INFLATE: + case exports.GUNZIP: + case exports.INFLATERAW: + case exports.UNZIP: + this.err = zlib_inflate.inflateInit2( + this.strm, + this.windowBits + ) + break + default: + throw new Error('Unknown mode ' + this.mode) + } + + if (this.err !== exports.Z_OK) { + this._error('Init error') + } + + this.dictionary = dictionary + + this.write_in_progress = false + this.init_done = true +} + +Zlib.prototype._setDictionary = function () { + if (this.dictionary == null) { + return + } + + this.err = exports.Z_OK + + switch (this.mode) { + case exports.DEFLATE: + case exports.DEFLATERAW: + this.err = zlib_deflate.deflateSetDictionary(this.strm, this.dictionary) + break + default: + break + } + + if (this.err !== exports.Z_OK) { + this._error('Failed to set dictionary') + } +} + +Zlib.prototype._reset = function () { + this.err = exports.Z_OK + + switch (this.mode) { + case exports.DEFLATE: + case exports.DEFLATERAW: + case exports.GZIP: + this.err = zlib_deflate.deflateReset(this.strm) + break + case exports.INFLATE: + case exports.INFLATERAW: + case exports.GUNZIP: + this.err = zlib_inflate.inflateReset(this.strm) + break + default: + break + } + + if (this.err !== exports.Z_OK) { + this._error('Failed to reset stream') + } +} + +exports.Zlib = Zlib |