# All files / node_modules/upng-js/node_modules/pako/lib deflate.js

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     '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) {
    I  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;
      }

    I  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
      );

    I  if (status !== Z_OK) {
        throw new Error(msg[status]);
      }

    I  if (opt.header) {
        zlib_deflate.deflateSetHeader(this.strm, opt.header);
      }

    I  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);

    I    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;

    I  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 {
    I    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 */

    I    if (status !== Z_STREAM_END && status !== Z_OK) {
          this.onEnd(status);
          this.ended = true;
          return false;
        }
    I    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.
    I  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.
    I  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
    I  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 :)
    I  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;