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add model solution
Commit Description:
add model solution
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node_modules/pako/lib/inflate.js
| 418 lines
| 11.9 KiB
| application/javascript
| JavascriptLexer
|
r789 | 'use strict'; | |||
var zlib_inflate = require('./zlib/inflate'); | ||||
var utils = require('./utils/common'); | ||||
var strings = require('./utils/strings'); | ||||
var c = require('./zlib/constants'); | ||||
var msg = require('./zlib/messages'); | ||||
var ZStream = require('./zlib/zstream'); | ||||
var GZheader = require('./zlib/gzheader'); | ||||
var toString = Object.prototype.toString; | ||||
/** | ||||
* class Inflate | ||||
* | ||||
* Generic JS-style wrapper for zlib calls. If you don't need | ||||
* streaming behaviour - use more simple functions: [[inflate]] | ||||
* and [[inflateRaw]]. | ||||
**/ | ||||
/* internal | ||||
* inflate.chunks -> Array | ||||
* | ||||
* Chunks of output data, if [[Inflate#onData]] not overriden. | ||||
**/ | ||||
/** | ||||
* Inflate.result -> Uint8Array|Array|String | ||||
* | ||||
* Uncompressed result, generated by default [[Inflate#onData]] | ||||
* and [[Inflate#onEnd]] handlers. Filled after you push last chunk | ||||
* (call [[Inflate#push]] with `Z_FINISH` / `true` param) or if you | ||||
* push a chunk with explicit flush (call [[Inflate#push]] with | ||||
* `Z_SYNC_FLUSH` param). | ||||
**/ | ||||
/** | ||||
* Inflate.err -> Number | ||||
* | ||||
* Error code after inflate finished. 0 (Z_OK) on success. | ||||
* Should be checked if broken data possible. | ||||
**/ | ||||
/** | ||||
* Inflate.msg -> String | ||||
* | ||||
* Error message, if [[Inflate.err]] != 0 | ||||
**/ | ||||
/** | ||||
* new Inflate(options) | ||||
* - options (Object): zlib inflate options. | ||||
* | ||||
* Creates new inflator instance with specified params. Throws exception | ||||
* on bad params. Supported options: | ||||
* | ||||
* - `windowBits` | ||||
* - `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 inflate | ||||
* - `to` (String) - if equal to 'string', then result will be converted | ||||
* from utf8 to utf16 (javascript) string. When string output requested, | ||||
* chunk length can differ from `chunkSize`, depending on content. | ||||
* | ||||
* By default, when no options set, autodetect deflate/gzip data format via | ||||
* wrapper header. | ||||
* | ||||
* ##### 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 inflate = new pako.Inflate({ level: 3}); | ||||
* | ||||
* inflate.push(chunk1, false); | ||||
* inflate.push(chunk2, true); // true -> last chunk | ||||
* | ||||
* if (inflate.err) { throw new Error(inflate.err); } | ||||
* | ||||
* console.log(inflate.result); | ||||
* ``` | ||||
**/ | ||||
function Inflate(options) { | ||||
if (!(this instanceof Inflate)) return new Inflate(options); | ||||
this.options = utils.assign({ | ||||
chunkSize: 16384, | ||||
windowBits: 0, | ||||
to: '' | ||||
}, options || {}); | ||||
var opt = this.options; | ||||
// Force window size for `raw` data, if not set directly, | ||||
// because we have no header for autodetect. | ||||
if (opt.raw && (opt.windowBits >= 0) && (opt.windowBits < 16)) { | ||||
opt.windowBits = -opt.windowBits; | ||||
if (opt.windowBits === 0) { opt.windowBits = -15; } | ||||
} | ||||
// If `windowBits` not defined (and mode not raw) - set autodetect flag for gzip/deflate | ||||
if ((opt.windowBits >= 0) && (opt.windowBits < 16) && | ||||
!(options && options.windowBits)) { | ||||
opt.windowBits += 32; | ||||
} | ||||
// Gzip header has no info about windows size, we can do autodetect only | ||||
// for deflate. So, if window size not set, force it to max when gzip possible | ||||
if ((opt.windowBits > 15) && (opt.windowBits < 48)) { | ||||
// bit 3 (16) -> gzipped data | ||||
// bit 4 (32) -> autodetect gzip/deflate | ||||
if ((opt.windowBits & 15) === 0) { | ||||
opt.windowBits |= 15; | ||||
} | ||||
} | ||||
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_inflate.inflateInit2( | ||||
this.strm, | ||||
opt.windowBits | ||||
); | ||||
if (status !== c.Z_OK) { | ||||
throw new Error(msg[status]); | ||||
} | ||||
this.header = new GZheader(); | ||||
zlib_inflate.inflateGetHeader(this.strm, this.header); | ||||
} | ||||
/** | ||||
* Inflate#push(data[, mode]) -> Boolean | ||||
* - data (Uint8Array|Array|ArrayBuffer|String): input data | ||||
* - mode (Number|Boolean): 0..6 for corresponding Z_NO_FLUSH..Z_TREE modes. | ||||
* See constants. Skipped or `false` means Z_NO_FLUSH, `true` meansh Z_FINISH. | ||||
* | ||||
* Sends input data to inflate pipe, generating [[Inflate#onData]] calls with | ||||
* new output chunks. Returns `true` on success. The last data block must have | ||||
* mode Z_FINISH (or `true`). That will flush internal pending buffers and call | ||||
* [[Inflate#onEnd]]. For interim explicit flushes (without ending the stream) you | ||||
* can use mode Z_SYNC_FLUSH, keeping the decompression context. | ||||
* | ||||
* On fail call [[Inflate#onEnd]] with error code and return false. | ||||
* | ||||
* We strongly recommend to use `Uint8Array` on input for best speed (output | ||||
* 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 | ||||
* ``` | ||||
**/ | ||||
Inflate.prototype.push = function (data, mode) { | ||||
var strm = this.strm; | ||||
var chunkSize = this.options.chunkSize; | ||||
var dictionary = this.options.dictionary; | ||||
var status, _mode; | ||||
var next_out_utf8, tail, utf8str; | ||||
var dict; | ||||
// Flag to properly process Z_BUF_ERROR on testing inflate call | ||||
// when we check that all output data was flushed. | ||||
var allowBufError = false; | ||||
if (this.ended) { return false; } | ||||
_mode = (mode === ~~mode) ? mode : ((mode === true) ? c.Z_FINISH : c.Z_NO_FLUSH); | ||||
// Convert data if needed | ||||
if (typeof data === 'string') { | ||||
// Only binary strings can be decompressed on practice | ||||
strm.input = strings.binstring2buf(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_inflate.inflate(strm, c.Z_NO_FLUSH); /* no bad return value */ | ||||
if (status === c.Z_NEED_DICT && dictionary) { | ||||
// Convert data if needed | ||||
if (typeof dictionary === 'string') { | ||||
dict = strings.string2buf(dictionary); | ||||
} else if (toString.call(dictionary) === '[object ArrayBuffer]') { | ||||
dict = new Uint8Array(dictionary); | ||||
} else { | ||||
dict = dictionary; | ||||
} | ||||
status = zlib_inflate.inflateSetDictionary(this.strm, dict); | ||||
} | ||||
if (status === c.Z_BUF_ERROR && allowBufError === true) { | ||||
status = c.Z_OK; | ||||
allowBufError = false; | ||||
} | ||||
if (status !== c.Z_STREAM_END && status !== c.Z_OK) { | ||||
this.onEnd(status); | ||||
this.ended = true; | ||||
return false; | ||||
} | ||||
if (strm.next_out) { | ||||
if (strm.avail_out === 0 || status === c.Z_STREAM_END || (strm.avail_in === 0 && (_mode === c.Z_FINISH || _mode === c.Z_SYNC_FLUSH))) { | ||||
if (this.options.to === 'string') { | ||||
next_out_utf8 = strings.utf8border(strm.output, strm.next_out); | ||||
tail = strm.next_out - next_out_utf8; | ||||
utf8str = strings.buf2string(strm.output, next_out_utf8); | ||||
// move tail | ||||
strm.next_out = tail; | ||||
strm.avail_out = chunkSize - tail; | ||||
if (tail) { utils.arraySet(strm.output, strm.output, next_out_utf8, tail, 0); } | ||||
this.onData(utf8str); | ||||
} else { | ||||
this.onData(utils.shrinkBuf(strm.output, strm.next_out)); | ||||
} | ||||
} | ||||
} | ||||
// When no more input data, we should check that internal inflate buffers | ||||
// are flushed. The only way to do it when avail_out = 0 - run one more | ||||
// inflate pass. But if output data not exists, inflate return Z_BUF_ERROR. | ||||
// Here we set flag to process this error properly. | ||||
// | ||||
// NOTE. Deflate does not return error in this case and does not needs such | ||||
// logic. | ||||
if (strm.avail_in === 0 && strm.avail_out === 0) { | ||||
allowBufError = true; | ||||
} | ||||
} while ((strm.avail_in > 0 || strm.avail_out === 0) && status !== c.Z_STREAM_END); | ||||
if (status === c.Z_STREAM_END) { | ||||
_mode = c.Z_FINISH; | ||||
} | ||||
// Finalize on the last chunk. | ||||
if (_mode === c.Z_FINISH) { | ||||
status = zlib_inflate.inflateEnd(this.strm); | ||||
this.onEnd(status); | ||||
this.ended = true; | ||||
return status === c.Z_OK; | ||||
} | ||||
// callback interim results if Z_SYNC_FLUSH. | ||||
if (_mode === c.Z_SYNC_FLUSH) { | ||||
this.onEnd(c.Z_OK); | ||||
strm.avail_out = 0; | ||||
return true; | ||||
} | ||||
return true; | ||||
}; | ||||
/** | ||||
* Inflate#onData(chunk) -> Void | ||||
* - chunk (Uint8Array|Array|String): ouput 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. | ||||
**/ | ||||
Inflate.prototype.onData = function (chunk) { | ||||
this.chunks.push(chunk); | ||||
}; | ||||
/** | ||||
* Inflate#onEnd(status) -> Void | ||||
* - status (Number): inflate status. 0 (Z_OK) on success, | ||||
* other if not. | ||||
* | ||||
* Called either after you tell inflate 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. | ||||
**/ | ||||
Inflate.prototype.onEnd = function (status) { | ||||
// On success - join | ||||
if (status === c.Z_OK) { | ||||
if (this.options.to === 'string') { | ||||
// Glue & convert here, until we teach pako to send | ||||
// utf8 alligned strings to onData | ||||
this.result = this.chunks.join(''); | ||||
} else { | ||||
this.result = utils.flattenChunks(this.chunks); | ||||
} | ||||
} | ||||
this.chunks = []; | ||||
this.err = status; | ||||
this.msg = this.strm.msg; | ||||
}; | ||||
/** | ||||
* inflate(data[, options]) -> Uint8Array|Array|String | ||||
* - data (Uint8Array|Array|String): input data to decompress. | ||||
* - options (Object): zlib inflate options. | ||||
* | ||||
* Decompress `data` with inflate/ungzip and `options`. Autodetect | ||||
* format via wrapper header by default. That's why we don't provide | ||||
* separate `ungzip` method. | ||||
* | ||||
* Supported options are: | ||||
* | ||||
* - windowBits | ||||
* | ||||
* [http://zlib.net/manual.html#Advanced](http://zlib.net/manual.html#Advanced) | ||||
* for more information. | ||||
* | ||||
* 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 converted | ||||
* from utf8 to utf16 (javascript) string. When string output requested, | ||||
* chunk length can differ from `chunkSize`, depending on content. | ||||
* | ||||
* | ||||
* ##### Example: | ||||
* | ||||
* ```javascript | ||||
* var pako = require('pako') | ||||
* , input = pako.deflate([1,2,3,4,5,6,7,8,9]) | ||||
* , output; | ||||
* | ||||
* try { | ||||
* output = pako.inflate(input); | ||||
* } catch (err) | ||||
* console.log(err); | ||||
* } | ||||
* ``` | ||||
**/ | ||||
function inflate(input, options) { | ||||
var inflator = new Inflate(options); | ||||
inflator.push(input, true); | ||||
// That will never happens, if you don't cheat with options :) | ||||
if (inflator.err) { throw inflator.msg; } | ||||
return inflator.result; | ||||
} | ||||
/** | ||||
* inflateRaw(data[, options]) -> Uint8Array|Array|String | ||||
* - data (Uint8Array|Array|String): input data to decompress. | ||||
* - options (Object): zlib inflate options. | ||||
* | ||||
* The same as [[inflate]], but creates raw data, without wrapper | ||||
* (header and adler32 crc). | ||||
**/ | ||||
function inflateRaw(input, options) { | ||||
options = options || {}; | ||||
options.raw = true; | ||||
return inflate(input, options); | ||||
} | ||||
/** | ||||
* ungzip(data[, options]) -> Uint8Array|Array|String | ||||
* - data (Uint8Array|Array|String): input data to decompress. | ||||
* - options (Object): zlib inflate options. | ||||
* | ||||
* Just shortcut to [[inflate]], because it autodetects format | ||||
* by header.content. Done for convenience. | ||||
**/ | ||||
exports.Inflate = Inflate; | ||||
exports.inflate = inflate; | ||||
exports.inflateRaw = inflateRaw; | ||||
exports.ungzip = inflate; | ||||