diff --git a/pdf.js b/pdf.js index 8ea56ae22..3331d5d4d 100644 --- a/pdf.js +++ b/pdf.js @@ -71,11 +71,6 @@ var Stream = (function() { get length() { return this.end - this.start; }, - lookByte: function() { - if (this.pos >= this.end) - return; - return this.bytes[this.pos]; - }, getByte: function() { if (this.pos >= this.end) return; @@ -99,10 +94,14 @@ var Stream = (function() { return bytes.subarray(pos, end); }, lookChar: function() { - return String.fromCharCode(this.lookByte()); + if (this.pos >= this.end) + return; + return String.fromCharCode(this.bytes[this.pos]); }, getChar: function() { - return String.fromCharCode(this.getByte()); + if (this.pos >= this.end) + return; + return String.fromCharCode(this.bytes[this.pos++]); }, skip: function(n) { if (!n) @@ -137,6 +136,84 @@ var StringStream = (function() { return constructor; })(); +// super class for the decoding streams +var DecodeStream = (function() { + function constructor() { + this.pos = 0; + this.bufferLength = 0; + this.eof = false; + this.buffer = null; + } + + constructor.prototype = { + ensureBuffer: function(requested) { + var buffer = this.buffer; + var current = buffer ? buffer.byteLength : 0; + if (requested < current) + return buffer; + var size = 512; + while (size < requested) + size <<= 1; + var buffer2 = Uint8Array(size); + for (var i = 0; i < current; ++i) + buffer2[i] = buffer[i]; + return this.buffer = buffer2; + }, + getByte: function() { + var pos = this.pos; + while (this.bufferLength <= pos) { + if (this.eof) + return; + this.readBlock(); + } + return this.buffer[this.pos++]; + }, + getBytes: function(length) { + var pos = this.pos; + + this.ensureBuffer(pos + length); + while (!this.eof && this.bufferLength < pos + length) + this.readBlock(); + + var end = pos + length; + var bufEnd = this.bufferLength; + + if (end > bufEnd) + end = bufEnd; + + this.pos = end; + return this.buffer.subarray(pos, end) + }, + lookChar: function() { + var pos = this.pos; + while (this.bufferLength <= pos) { + if (this.eof) + return; + this.readBlock(); + } + return String.fromCharCode(this.buffer[this.pos]); + }, + getChar: function() { + var pos = this.pos; + while (this.bufferLength <= pos) { + if (this.eof) + return; + this.readBlock(); + } + return String.fromCharCode(this.buffer[this.pos++]); + }, + skip: function(n) { + if (!n) + n = 1; + this.pos += n; + } + }; + + return constructor; +})(); + + + var FlateStream = (function() { const codeLenCodeMap = Uint32Array([ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 @@ -261,12 +338,11 @@ var FlateStream = (function() { this.bytes = bytes; this.bytesPos = bytesPos; - this.eof = false; + this.codeSize = 0; this.codeBuf = 0; - - this.pos = 0; - this.bufferLength = 0; + + DecodeStream.call(this); } constructor.prototype = { @@ -314,64 +390,6 @@ var FlateStream = (function() { this.bytesPos = bytesPos; return codeVal; }, - ensureBuffer: function(requested) { - var buffer = this.buffer; - var current = buffer ? buffer.byteLength : 0; - if (requested < current) - return buffer; - var size = 512; - while (size < requested) - size <<= 1; - var buffer2 = Uint8Array(size); - for (var i = 0; i < current; ++i) - buffer2[i] = buffer[i]; - return this.buffer = buffer2; - }, - getByte: function() { - var pos = this.pos; - while (this.bufferLength <= pos) { - if (this.eof) - return; - this.readBlock(); - } - return this.buffer[this.pos++]; - }, - getBytes: function(length) { - var pos = this.pos; - - while (!this.eof && this.bufferLength < pos + length) - this.readBlock(); - - var end = pos + length; - var bufEnd = this.bufferLength; - - if (end > bufEnd) - end = bufEnd; - - this.pos = end; - return this.buffer.subarray(pos, end) - }, - lookChar: function() { - var pos = this.pos; - while (this.bufferLength <= pos) { - if (this.eof) - return; - this.readBlock(); - } - return String.fromCharCode(this.buffer[pos]); - }, - getChar: function() { - var ch = this.lookChar(); - // shouldnt matter what the position is if we get past the eof - // so no need to check if ch is undefined - this.pos++; - return ch; - }, - skip: function(n) { - if (!n) - n = 1; - this.pos += n; - }, generateHuffmanTable: function(lengths) { var n = lengths.length; @@ -489,8 +507,10 @@ var FlateStream = (function() { } } - litCodeTable = this.generateHuffmanTable(codeLengths.slice(0, numLitCodes)); - distCodeTable = this.generateHuffmanTable(codeLengths.slice(numLitCodes, codes)); + litCodeTable = this.generateHuffmanTable( + codeLengths.slice(0, numLitCodes)); + distCodeTable = this.generateHuffmanTable( + codeLengths.slice(numLitCodes, codes)); } else { error("Unknown block type in flate stream"); } @@ -526,30 +546,13 @@ var FlateStream = (function() { } }; - return constructor; -})(); -// A JpegStream can't be read directly. We use the platform to render the underlying -// JPEG data for us. -var JpegStream = (function() { - function constructor(bytes, dict) { - // TODO: per poppler, some images may have "junk" before that need to be removed - this.dict = dict; - - // create DOM image - var img = new Image(); - img.src = "data:image/jpeg;base64," + window.btoa(bytesToString(bytes)); - this.domImage = img; + var thisPrototype = constructor.prototype; + var superPrototype = DecodeStream.prototype; + for (var i in superPrototype) { + if (!thisPrototype[i]) + thisPrototype[i] = superPrototype[i]; } - constructor.prototype = { - getImage: function() { - return this.domImage; - }, - getChar: function() { - error("internal error: getChar is not valid on JpegStream"); - } - }; - return constructor; })(); @@ -563,9 +566,9 @@ var PredictorStream = (function() { error("Unsupported predictor"); if (predictor === 2) - this.readRow = this.readRowTiff; + this.readBlock = this.readBlockTiff; else - this.readRow = this.readRowPng; + this.readBlock = this.readBlockPng; this.stream = stream; this.dict = stream.dict; @@ -578,27 +581,34 @@ var PredictorStream = (function() { var pixBytes = this.pixBytes = (colors * bits + 7) >> 3; // add an extra pixByte to represent the pixel left of column 0 - var rowBytes = this.rowBytes = ((columns * colors * bits + 7) >> 3) + pixBytes; - - this.currentRow = new Uint8Array(rowBytes); - this.bufferLength = rowBytes; - this.pos = rowBytes; + var rowBytes = this.rowBytes = (columns * colors * bits + 7) >> 3; + + DecodeStream.call(this); } constructor.prototype = { - readRowTiff : function() { - var currentRow = this.currentRow; + readBlockTiff : function() { + var buffer = this.buffer; + var pos = this.pos; + var rowBytes = this.rowBytes; var pixBytes = this.pixBytes; + + + var buffer = this.buffer; + var bufferLength = this.bufferLength; + this.ensureBuffer(bufferLength + rowBytes); + var currentRow = buffer.subarray(bufferLength, bufferLength + rowBytes); + var bits = this.bits; var colors = this.colors; - var rawBytes = this.stream.getBytes(rowBytes - pixBytes); - + var rawBytes = this.stream.getBytes(rowBytes); + if (bits === 1) { var inbuf = 0; - for (var i = pixBytes, j = 0; i < rowBytes; ++i, ++j) { - var c = rawBytes[j]; + for (var i = 0; i < rowBytes; ++i) { + var c = rawBytes[i]; inBuf = (inBuf << 8) | c; // bitwise addition is exclusive or // first shift inBuf and then add @@ -607,14 +617,16 @@ var PredictorStream = (function() { inBuf &= 0xFFFF; } } else if (bits === 8) { - for (var i = pixBytes, j = 0; i < rowBytes; ++i, ++j) - currentRow[i] = currentRow[i - colors] + rawBytes[j]; + for (var i = 0; i < colors; ++i) + currentRow[i] = rawBytes[i]; + for (; i < rowBytes; ++i) + currentRow[i] = currentRow[i - colors] + rawBytes[i]; } else { var compArray = new Uint8Array(colors + 1); var bitMask = (1 << bits) - 1; var inbuf = 0, outbut = 0; var inbits = 0, outbits = 0; - var j = 0, k = pixBytes; + var j = 0, k = 0; var columns = this.columns; for (var i = 0; i < columns; ++i) { for (var kk = 0; kk < colors; ++kk) { @@ -638,40 +650,54 @@ var PredictorStream = (function() { (inbuf & ((1 << (8 - outbits)) - 1)) } } - this.pos = pixBytes; + this.bufferLength += rowBytes; }, - readRowPng : function() { - var currentRow = this.currentRow; + readBlockPng : function() { + var buffer = this.buffer; + var pos = this.pos; var rowBytes = this.rowBytes; var pixBytes = this.pixBytes; var predictor = this.stream.getByte(); - var rawBytes = this.stream.getBytes(rowBytes - pixBytes); + var rawBytes = this.stream.getBytes(rowBytes); + + var buffer = this.buffer; + var bufferLength = this.bufferLength; + this.ensureBuffer(bufferLength + pixBytes); + + var currentRow = buffer.subarray(bufferLength, bufferLength + rowBytes); + var prevRow = buffer.subarray(bufferLength - rowBytes, bufferLength); + if (prevRow.length == 0) + prevRow = currentRow; switch (predictor) { case 0: break; case 1: - for (var i = pixBytes, j = 0; i < rowBytes; ++i, ++j) - currentRow[i] = (currentRow[i - pixBytes] + rawBytes[j]) & 0xFF; + for (var i = 0; i < pixBytes; ++i) + currentRow[i] = rawBytes[i]; + for (; i < rowBytes; ++i) + currentRow[i] = (currentRow[i - pixBytes] + rawBytes[i]) & 0xFF; break; case 2: - for (var i = pixBytes, j = 0; i < rowBytes; ++i, ++j) - currentRow[i] = (currentRow[i] + rawBytes[j]) & 0xFF; + for (var i = 0; i < rowBytes; ++i) + currentRow[i] = (prevRow[i] + rawBytes[i]) & 0xFF; break; case 3: - for (var i = pixBytes, j = 0; i < rowBytes; ++i, ++j) - currentRow[i] = (((currentRow[i] + currentRow[i - pixBytes]) - >> 1) + rawBytes[j]) & 0xFF; + for (var i = 0; i < pixBytes; ++i) + currentRow[i] = (prevRow[i] >> 1) + rawBytes[i]; + for (; i < rowBytes; ++i) + currentRow[i] = (((prevRow[i] + currentRow[i - pixBytes]) + >> 1) + rawBytes[i]) & 0xFF; break; case 4: // we need to save the up left pixels values. the simplest way // is to create a new buffer - var lastRow = currentRow; - var currentRow = new Uint8Array(rowBytes); - for (var i = pixBytes, j = 0; i < rowBytes; ++i, ++j) { - var up = lastRow[i]; + for (var i = 0; i < pixBytes; ++i) + currentRow[i] = rawBytes[i]; + for (; i < rowBytes; ++i) { + var up = prevRow[i]; var upLeft = lastRow[i - pixBytes]; var left = currentRow[i - pixBytes]; var p = left + up - upLeft; @@ -686,7 +712,7 @@ var PredictorStream = (function() { if (pc < 0) pc = -pc; - var c = rawBytes[j]; + var c = rawBytes[i]; if (pa <= pb && pa <= pc) currentRow[i] = left + c; else if (pb <= pc) @@ -694,54 +720,49 @@ var PredictorStream = (function() { else currentRow[i] = upLeft + c; break; - this.currentRow = currentRow; } default: error("Unsupported predictor"); break; } - this.pos = pixBytes; - }, - getByte : function() { - if (this.pos >= this.bufferLength) - this.readRow(); - return this.currentRow[this.pos++]; - }, - getBytes : function(n) { - var i, bytes; - bytes = new Uint8Array(n); - for (i = 0; i < n; ++i) { - if (this.pos >= this.bufferLength) - this.readRow(); - bytes[i] = this.currentRow[this.pos++]; - } - return bytes; - }, - getChar : function() { - return String.formCharCode(this.getByte()); + this.bufferLength += rowBytes; }, - lookChar : function() { - if (this.pos >= this.bufferLength) - this.readRow(); - return String.formCharCode(this.currentRow[this.pos]); + }; + + var thisPrototype = constructor.prototype; + var superPrototype = DecodeStream.prototype; + for (var i in superPrototype) { + if (!thisPrototype[i]) + thisPrototype[i] = superPrototype[i]; + } + + return constructor; +})(); + +// A JpegStream can't be read directly. We use the platform to render the underlying +// JPEG data for us. +var JpegStream = (function() { + function constructor(bytes, dict) { + // TODO: per poppler, some images may have "junk" before that need to be removed + this.dict = dict; + + // create DOM image + var img = new Image(); + img.src = "data:image/jpeg;base64," + window.btoa(bytesToString(bytes)); + this.domImage = img; + } + + constructor.prototype = { + getImage: function() { + return this.domImage; }, - skip : function(n) { - var i; - if (!n) { - n = 1; - } - while (n > this.bufferLength - this.pos) { - n -= this.bufferLength - this.pos; - this.readRow(); - if (this.bufferLength === 0) break; - } - this.pos += n; + getChar: function() { + error("internal error: getChar is not valid on JpegStream"); } }; return constructor; })(); - var DecryptStream = (function() { function constructor(str, fileKey, encAlgorithm, keyLength) { TODO("decrypt stream is not implemented");