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Diffstat (limited to 'school/node_modules/pako/lib/deflate.js')
| -rw-r--r-- | school/node_modules/pako/lib/deflate.js | 400 |
1 files changed, 0 insertions, 400 deletions
diff --git a/school/node_modules/pako/lib/deflate.js b/school/node_modules/pako/lib/deflate.js deleted file mode 100644 index efeb00c..0000000 --- a/school/node_modules/pako/lib/deflate.js +++ /dev/null @@ -1,400 +0,0 @@ -'use strict'; - - -var zlib_deflate = require('./zlib/deflate'); -var utils = require('./utils/common'); -var strings = require('./utils/strings'); -var msg = require('./zlib/messages'); -var ZStream = require('./zlib/zstream'); - -var toString = Object.prototype.toString; - -/* Public constants ==========================================================*/ -/* ===========================================================================*/ - -var Z_NO_FLUSH = 0; -var Z_FINISH = 4; - -var Z_OK = 0; -var Z_STREAM_END = 1; -var Z_SYNC_FLUSH = 2; - -var Z_DEFAULT_COMPRESSION = -1; - -var Z_DEFAULT_STRATEGY = 0; - -var Z_DEFLATED = 8; - -/* ===========================================================================*/ - - -/** - * class Deflate - * - * Generic JS-style wrapper for zlib calls. If you don't need - * streaming behaviour - use more simple functions: [[deflate]], - * [[deflateRaw]] and [[gzip]]. - **/ - -/* internal - * Deflate.chunks -> Array - * - * Chunks of output data, if [[Deflate#onData]] not overridden. - **/ - -/** - * Deflate.result -> Uint8Array|Array - * - * Compressed result, generated by default [[Deflate#onData]] - * and [[Deflate#onEnd]] handlers. Filled after you push last chunk - * (call [[Deflate#push]] with `Z_FINISH` / `true` param) or if you - * push a chunk with explicit flush (call [[Deflate#push]] with - * `Z_SYNC_FLUSH` param). - **/ - -/** - * Deflate.err -> Number - * - * Error code after deflate finished. 0 (Z_OK) on success. - * You will not need it in real life, because deflate errors - * are possible only on wrong options or bad `onData` / `onEnd` - * custom handlers. - **/ - -/** - * Deflate.msg -> String - * - * Error message, if [[Deflate.err]] != 0 - **/ - - -/** - * new Deflate(options) - * - options (Object): zlib deflate options. - * - * Creates new deflator instance with specified params. Throws exception - * on bad params. Supported options: - * - * - `level` - * - `windowBits` - * - `memLevel` - * - `strategy` - * - `dictionary` - * - * [http://zlib.net/manual.html#Advanced](http://zlib.net/manual.html#Advanced) - * for more information on these. - * - * Additional options, for internal needs: - * - * - `chunkSize` - size of generated data chunks (16K by default) - * - `raw` (Boolean) - do raw deflate - * - `gzip` (Boolean) - create gzip wrapper - * - `to` (String) - if equal to 'string', then result will be "binary string" - * (each char code [0..255]) - * - `header` (Object) - custom header for gzip - * - `text` (Boolean) - true if compressed data believed to be text - * - `time` (Number) - modification time, unix timestamp - * - `os` (Number) - operation system code - * - `extra` (Array) - array of bytes with extra data (max 65536) - * - `name` (String) - file name (binary string) - * - `comment` (String) - comment (binary string) - * - `hcrc` (Boolean) - true if header crc should be added - * - * ##### Example: - * - * ```javascript - * var pako = require('pako') - * , chunk1 = Uint8Array([1,2,3,4,5,6,7,8,9]) - * , chunk2 = Uint8Array([10,11,12,13,14,15,16,17,18,19]); - * - * var deflate = new pako.Deflate({ level: 3}); - * - * deflate.push(chunk1, false); - * deflate.push(chunk2, true); // true -> last chunk - * - * if (deflate.err) { throw new Error(deflate.err); } - * - * console.log(deflate.result); - * ``` - **/ -function Deflate(options) { - if (!(this instanceof Deflate)) return new Deflate(options); - - this.options = utils.assign({ - level: Z_DEFAULT_COMPRESSION, - method: Z_DEFLATED, - chunkSize: 16384, - windowBits: 15, - memLevel: 8, - strategy: Z_DEFAULT_STRATEGY, - to: '' - }, options || {}); - - var opt = this.options; - - if (opt.raw && (opt.windowBits > 0)) { - opt.windowBits = -opt.windowBits; - } - - else if (opt.gzip && (opt.windowBits > 0) && (opt.windowBits < 16)) { - opt.windowBits += 16; - } - - this.err = 0; // error code, if happens (0 = Z_OK) - this.msg = ''; // error message - this.ended = false; // used to avoid multiple onEnd() calls - this.chunks = []; // chunks of compressed data - - this.strm = new ZStream(); - this.strm.avail_out = 0; - - var status = zlib_deflate.deflateInit2( - this.strm, - opt.level, - opt.method, - opt.windowBits, - opt.memLevel, - opt.strategy - ); - - if (status !== Z_OK) { - throw new Error(msg[status]); - } - - if (opt.header) { - zlib_deflate.deflateSetHeader(this.strm, opt.header); - } - - if (opt.dictionary) { - var dict; - // Convert data if needed - if (typeof opt.dictionary === 'string') { - // If we need to compress text, change encoding to utf8. - dict = strings.string2buf(opt.dictionary); - } else if (toString.call(opt.dictionary) === '[object ArrayBuffer]') { - dict = new Uint8Array(opt.dictionary); - } else { - dict = opt.dictionary; - } - - status = zlib_deflate.deflateSetDictionary(this.strm, dict); - - if (status !== Z_OK) { - throw new Error(msg[status]); - } - - this._dict_set = true; - } -} - -/** - * Deflate#push(data[, mode]) -> Boolean - * - data (Uint8Array|Array|ArrayBuffer|String): input data. Strings will be - * converted to utf8 byte sequence. - * - mode (Number|Boolean): 0..6 for corresponding Z_NO_FLUSH..Z_TREE modes. - * See constants. Skipped or `false` means Z_NO_FLUSH, `true` means Z_FINISH. - * - * Sends input data to deflate pipe, generating [[Deflate#onData]] calls with - * new compressed chunks. Returns `true` on success. The last data block must have - * mode Z_FINISH (or `true`). That will flush internal pending buffers and call - * [[Deflate#onEnd]]. For interim explicit flushes (without ending the stream) you - * can use mode Z_SYNC_FLUSH, keeping the compression context. - * - * On fail call [[Deflate#onEnd]] with error code and return false. - * - * We strongly recommend to use `Uint8Array` on input for best speed (output - * array format is detected automatically). Also, don't skip last param and always - * use the same type in your code (boolean or number). That will improve JS speed. - * - * For regular `Array`-s make sure all elements are [0..255]. - * - * ##### Example - * - * ```javascript - * push(chunk, false); // push one of data chunks - * ... - * push(chunk, true); // push last chunk - * ``` - **/ -Deflate.prototype.push = function (data, mode) { - var strm = this.strm; - var chunkSize = this.options.chunkSize; - var status, _mode; - - if (this.ended) { return false; } - - _mode = (mode === ~~mode) ? mode : ((mode === true) ? Z_FINISH : Z_NO_FLUSH); - - // Convert data if needed - if (typeof data === 'string') { - // If we need to compress text, change encoding to utf8. - strm.input = strings.string2buf(data); - } else if (toString.call(data) === '[object ArrayBuffer]') { - strm.input = new Uint8Array(data); - } else { - strm.input = data; - } - - strm.next_in = 0; - strm.avail_in = strm.input.length; - - do { - if (strm.avail_out === 0) { - strm.output = new utils.Buf8(chunkSize); - strm.next_out = 0; - strm.avail_out = chunkSize; - } - status = zlib_deflate.deflate(strm, _mode); /* no bad return value */ - - if (status !== Z_STREAM_END && status !== Z_OK) { - this.onEnd(status); - this.ended = true; - return false; - } - if (strm.avail_out === 0 || (strm.avail_in === 0 && (_mode === Z_FINISH || _mode === Z_SYNC_FLUSH))) { - if (this.options.to === 'string') { - this.onData(strings.buf2binstring(utils.shrinkBuf(strm.output, strm.next_out))); - } else { - this.onData(utils.shrinkBuf(strm.output, strm.next_out)); - } - } - } while ((strm.avail_in > 0 || strm.avail_out === 0) && status !== Z_STREAM_END); - - // Finalize on the last chunk. - if (_mode === Z_FINISH) { - status = zlib_deflate.deflateEnd(this.strm); - this.onEnd(status); - this.ended = true; - return status === Z_OK; - } - - // callback interim results if Z_SYNC_FLUSH. - if (_mode === Z_SYNC_FLUSH) { - this.onEnd(Z_OK); - strm.avail_out = 0; - return true; - } - - return true; -}; - - -/** - * Deflate#onData(chunk) -> Void - * - chunk (Uint8Array|Array|String): output data. Type of array depends - * on js engine support. When string output requested, each chunk - * will be string. - * - * By default, stores data blocks in `chunks[]` property and glue - * those in `onEnd`. Override this handler, if you need another behaviour. - **/ -Deflate.prototype.onData = function (chunk) { - this.chunks.push(chunk); -}; - - -/** - * Deflate#onEnd(status) -> Void - * - status (Number): deflate status. 0 (Z_OK) on success, - * other if not. - * - * Called once after you tell deflate that the input stream is - * complete (Z_FINISH) or should be flushed (Z_SYNC_FLUSH) - * or if an error happened. By default - join collected chunks, - * free memory and fill `results` / `err` properties. - **/ -Deflate.prototype.onEnd = function (status) { - // On success - join - if (status === Z_OK) { - if (this.options.to === 'string') { - this.result = this.chunks.join(''); - } else { - this.result = utils.flattenChunks(this.chunks); - } - } - this.chunks = []; - this.err = status; - this.msg = this.strm.msg; -}; - - -/** - * deflate(data[, options]) -> Uint8Array|Array|String - * - data (Uint8Array|Array|String): input data to compress. - * - options (Object): zlib deflate options. - * - * Compress `data` with deflate algorithm and `options`. - * - * Supported options are: - * - * - level - * - windowBits - * - memLevel - * - strategy - * - dictionary - * - * [http://zlib.net/manual.html#Advanced](http://zlib.net/manual.html#Advanced) - * for more information on these. - * - * Sugar (options): - * - * - `raw` (Boolean) - say that we work with raw stream, if you don't wish to specify - * negative windowBits implicitly. - * - `to` (String) - if equal to 'string', then result will be "binary string" - * (each char code [0..255]) - * - * ##### Example: - * - * ```javascript - * var pako = require('pako') - * , data = Uint8Array([1,2,3,4,5,6,7,8,9]); - * - * console.log(pako.deflate(data)); - * ``` - **/ -function deflate(input, options) { - var deflator = new Deflate(options); - - deflator.push(input, true); - - // That will never happens, if you don't cheat with options :) - if (deflator.err) { throw deflator.msg || msg[deflator.err]; } - - return deflator.result; -} - - -/** - * deflateRaw(data[, options]) -> Uint8Array|Array|String - * - data (Uint8Array|Array|String): input data to compress. - * - options (Object): zlib deflate options. - * - * The same as [[deflate]], but creates raw data, without wrapper - * (header and adler32 crc). - **/ -function deflateRaw(input, options) { - options = options || {}; - options.raw = true; - return deflate(input, options); -} - - -/** - * gzip(data[, options]) -> Uint8Array|Array|String - * - data (Uint8Array|Array|String): input data to compress. - * - options (Object): zlib deflate options. - * - * The same as [[deflate]], but create gzip wrapper instead of - * deflate one. - **/ -function gzip(input, options) { - options = options || {}; - options.gzip = true; - return deflate(input, options); -} - - -exports.Deflate = Deflate; -exports.deflate = deflate; -exports.deflateRaw = deflateRaw; -exports.gzip = gzip; |