123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409 |
- '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;
|