first commit

build/node_modules/pngjs/lib/parser-async.js

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+'use strict';
+
+var util = require('util');
+var zlib = require('zlib');
+var ChunkStream = require('./chunkstream');
+var FilterAsync = require('./filter-parse-async');
+var Parser = require('./parser');
+var bitmapper = require('./bitmapper');
+var formatNormaliser = require('./format-normaliser');
+
+var ParserAsync = module.exports = function(options) {
+  ChunkStream.call(this);
+
+  this._parser = new Parser(options, {
+    read: this.read.bind(this),
+    error: this._handleError.bind(this),
+    metadata: this._handleMetaData.bind(this),
+    gamma: this.emit.bind(this, 'gamma'),
+    palette: this._handlePalette.bind(this),
+    transColor: this._handleTransColor.bind(this),
+    finished: this._finished.bind(this),
+    inflateData: this._inflateData.bind(this)
+  });
+  this._options = options;
+  this.writable = true;
+
+  this._parser.start();
+};
+util.inherits(ParserAsync, ChunkStream);
+
+
+ParserAsync.prototype._handleError = function(err) {
+
+  this.emit('error', err);
+
+  this.writable = false;
+
+  this.destroy();
+
+  if (this._inflate && this._inflate.destroy) {
+    this._inflate.destroy();
+  }
+
+  this.errord = true;
+};
+
+ParserAsync.prototype._inflateData = function(data) {
+  if (!this._inflate) {
+    if (this._bitmapInfo.interlace) {
+      this._inflate = zlib.createInflate();
+
+      this._inflate.on('error', this.emit.bind(this, 'error'));
+      this._filter.on('complete', this._complete.bind(this));
+
+      this._inflate.pipe(this._filter);
+    } else {
+      var rowSize = ((this._bitmapInfo.width * this._bitmapInfo.bpp * this._bitmapInfo.depth + 7) >> 3) + 1;
+      var imageSize = rowSize * this._bitmapInfo.height;
+      var chunkSize = Math.max(imageSize, zlib.Z_MIN_CHUNK);
+      
+      this._inflate = zlib.createInflate({ chunkSize: chunkSize });
+      var leftToInflate = imageSize;
+
+      var emitError = this.emit.bind(this, 'error');
+      this._inflate.on('error', function(err) {
+        if (!leftToInflate) {
+          return;
+        }
+
+        emitError(err);
+      });
+      this._filter.on('complete', this._complete.bind(this));
+
+      var filterWrite = this._filter.write.bind(this._filter);
+      this._inflate.on('data', function(chunk) {
+        if (!leftToInflate) {
+          return;
+        }
+
+        if (chunk.length > leftToInflate) {
+          chunk = chunk.slice(0, leftToInflate);
+        }
+
+        leftToInflate -= chunk.length;
+
+        filterWrite(chunk);
+      });
+
+      this._inflate.on('end', this._filter.end.bind(this._filter));
+    }
+  }
+  this._inflate.write(data);
+};
+
+ParserAsync.prototype._handleMetaData = function(metaData) {
+
+  this.emit('metadata', metaData);
+
+  this._bitmapInfo = Object.create(metaData);
+
+  this._filter = new FilterAsync(this._bitmapInfo);
+};
+
+ParserAsync.prototype._handleTransColor = function(transColor) {
+  this._bitmapInfo.transColor = transColor;
+};
+
+ParserAsync.prototype._handlePalette = function(palette) {
+  this._bitmapInfo.palette = palette;
+};
+
+
+ParserAsync.prototype._finished = function() {
+  if (this.errord) {
+    return;
+  }
+
+  if (!this._inflate) {
+    this.emit('error', 'No Inflate block');
+  }
+  else {
+    // no more data to inflate
+    this._inflate.end();
+  }
+  this.destroySoon();
+};
+
+ParserAsync.prototype._complete = function(filteredData) {
+
+  if (this.errord) {
+    return;
+  }
+
+  try {
+    var bitmapData = bitmapper.dataToBitMap(filteredData, this._bitmapInfo);
+
+    var normalisedBitmapData = formatNormaliser(bitmapData, this._bitmapInfo);
+    bitmapData = null;
+  }
+  catch (ex) {
+    this._handleError(ex);
+    return;
+  }
+
+  this.emit('parsed', normalisedBitmapData);
+};