Sakurai/pdf.js
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finish inflate code, still untested

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Andreas Gal 2011-05-10 23:57:03 -07:00
parent 903e6e2b9d
commit c8ab1c014e
1 changed files with 49 additions and 21 deletions
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pdf.js
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@ -665,6 +665,7 @@ var FlateStream = (function() {
], 5]; ], 5];
function constructor() { function constructor() {
this.reset();
} }
constructor.prototype = { constructor.prototype = {
@ -684,6 +685,7 @@ var FlateStream = (function() {
this.eof = false; this.eof = false;
this.codeSize = 0; this.codeSize = 0;
this.codeBuf = 0; this.codeBuf = 0;
this.pos = 0;
}, },
getBits: function(bits) { getBits: function(bits) {
var stream = this.stream; var stream = this.stream;
@ -701,6 +703,27 @@ var FlateStream = (function() {
this.codeSize = codeSize -= bits; this.codeSize = codeSize -= bits;
return b; return b;
}, },
getCode: function(table) {
var codes = table.codes;
var maxLen = table.maxLen;
var codeSize = this.codeSize;
var codeBuf = this.codeBuf;
while (codeSize < maxlen) {
var b;
if ((b = stream.getByte()) == -1)
error("Bad encoding in flate stream");
codeBuf |= (b << codeSize);
codeSize += 8;
}
var code = table.codes[codeBuf & ((1 << table.maxLen) - 1)];
var codeLen = code[0];
var codeVal = code[1];
if (codeSize == 0|| codeSize < codeLen || codeLen == 0)
error("Bad encoding in flate stream");
this.codeBuf = (codeBuf >> codeLen);
this.codeLen = (codeLen - codeLen);
return codeVal;
},
ensureBuffer: function(requested, copy) { ensureBuffer: function(requested, copy) {
var buffer = this.buffer; var buffer = this.buffer;
var current = buffer ? buffer.byteLength : 0; var current = buffer ? buffer.byteLength : 0;
@ -716,6 +739,30 @@ var FlateStream = (function() {
} }
return this.buffer = buffer2; return this.buffer = buffer2;
}, },
lookChar: function() {
var bufferLength = this.bufferLength;
var bufferPos = this.bufferPos;
if (bufferLength == bufferPos) {
if (this.eof)
return;
this.readBlock();
}
return String.fromChar(this.buffer[bufferPos]);
},
getChar: function() {
var ch = this.lookChar();
if (!ch)
return;
this.pos++;
this.bufferPos++;
return ch;
},
skip: function(n) {
if (!n)
n = 1;
while (n-- > 0)
this.getChar();
}
generateHuffmanTable: function(lengths) { generateHuffmanTable: function(lengths) {
var n = lengths.length; var n = lengths.length;
@ -753,27 +800,6 @@ var FlateStream = (function() {
return { codes: codes, maxLen: maxLen }; return { codes: codes, maxLen: maxLen };
}, },
getCode: function(table) {
var codes = table.codes;
var maxLen = table.maxLen;
var codeSize = this.codeSize;
var codeBuf = this.codeBuf;
while (codeSize < maxlen) {
var b;
if ((b = stream.getByte()) == -1)
error("Bad encoding in flate stream");
codeBuf |= (b << codeSize);
codeSize += 8;
}
var code = table.codes[codeBuf & ((1 << table.maxLen) - 1)];
var codeLen = code[0];
var codeVal = code[1];
if (codeSize == 0|| codeSize < codeLen || codeLen == 0)
error("Bad encoding in flate stream");
this.codeBuf = (codeBuf >> codeLen);
this.codeLen = (codeLen - codeLen);
return codeVal;
},
readBlock: function() { readBlock: function() {
var stream = this.stream; var stream = this.stream;
@ -801,6 +827,7 @@ var FlateStream = (function() {
error("Bad uncompressed block length in flate stream"); error("Bad uncompressed block length in flate stream");
var buffer = this.ensureBuffer(blockLen); var buffer = this.ensureBuffer(blockLen);
this.bufferLength = blockLen; this.bufferLength = blockLen;
this.bufferPos = 0;
for (var n = 0; n < blockLen; ++n) { for (var n = 0; n < blockLen; ++n) {
if ((b = stream.getByte()) == -1) { if ((b = stream.getByte()) == -1) {
this.eof = true; this.eof = true;
@ -864,6 +891,7 @@ var FlateStream = (function() {
var code1 = this.getCode(litCodeTable); var code1 = this.getCode(litCodeTable);
if (code1 == 256) { if (code1 == 256) {
this.bufferLength = pos; this.bufferLength = pos;
this.bufferPos = 0;
return; return;
} }
if (code1 < 256) { if (code1 < 256) {