Sakurai/pdf.js
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

finish inflate code, still untested

Browse Source
This commit is contained in:
Andreas Gal 2011-05-10 23:57:03 -07:00
parent 903e6e2b9d
commit c8ab1c014e
1 changed files with 49 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
pdf.js
View File

@ -665,6 +665,7 @@ var FlateStream = (function() {
], 5];
function constructor() {
this.reset();
}
constructor.prototype = {
@ -684,6 +685,7 @@ var FlateStream = (function() {
this.eof = false;
this.codeSize = 0;
this.codeBuf = 0;
this.pos = 0;
},
getBits: function(bits) {
var stream = this.stream;
@ -701,6 +703,27 @@ var FlateStream = (function() {
this.codeSize = codeSize -= bits;
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) {
var buffer = this.buffer;
var current = buffer ? buffer.byteLength : 0;
@ -716,6 +739,30 @@ var FlateStream = (function() {
}
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) {
var n = lengths.length;
@ -753,27 +800,6 @@ var FlateStream = (function() {
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() {
var stream = this.stream;
@ -801,6 +827,7 @@ var FlateStream = (function() {
error("Bad uncompressed block length in flate stream");
var buffer = this.ensureBuffer(blockLen);
this.bufferLength = blockLen;
this.bufferPos = 0;
for (var n = 0; n < blockLen; ++n) {
if ((b = stream.getByte()) == -1) {
this.eof = true;
@ -864,6 +891,7 @@ var FlateStream = (function() {
var code1 = this.getCode(litCodeTable);
if (code1 == 256) {
this.bufferLength = pos;
this.bufferPos = 0;
return;
}
if (code1 < 256) {