Sakurai/pdf.js
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Merge pull request #20 from sbarman/streamrewrite2

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Changed flate stream to get the entire buffer instead of calling getBytes()
This commit is contained in:
Chris Jones 2011-06-20 16:17:21 -07:00
commit 08f6ae438e
1 changed files with 31 additions and 22 deletions
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pdf.js
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@ -74,7 +74,7 @@ var Stream = (function() {
var pos = this.pos;
var end = pos + length;
var strEnd = this.end;
if (end > strEnd)
if (!end || end > strEnd)
end = strEnd;
this.pos = end;
@ -233,10 +233,12 @@ var FlateStream = (function() {
]), 5];
function constructor(stream) {
this.stream = stream;
var bytes = stream.getBytes();
var bytesPos = 0;
this.dict = stream.dict;
var cmf = stream.getByte();
var flg = stream.getByte();
var cmf = bytes[bytesPos++];
var flg = bytes[bytesPos++];
if (cmf == -1 || flg == -1)
error("Invalid header in flate stream");
if ((cmf & 0x0f) != 0x08)
@ -245,6 +247,9 @@ var FlateStream = (function() {
error("Bad FCHECK in flate stream");
if (flg & 0x20)
error("FDICT bit set in flate stream");
this.bytes = bytes;
this.bytesPos = bytesPos;
this.eof = false;
this.codeSize = 0;
this.codeBuf = 0;
@ -255,12 +260,14 @@ var FlateStream = (function() {
constructor.prototype = {
getBits: function(bits) {
var stream = this.stream;
var codeSize = this.codeSize;
var codeBuf = this.codeBuf;
var bytes = this.bytes;
var bytesPos = this.bytesPos;
var b;
while (codeSize < bits) {
if ((b = stream.getByte()) == -1)
if (typeof (b = bytes[bytesPos++]) == "undefined")
error("Bad encoding in flate stream");
codeBuf |= b << codeSize;
codeSize += 8;
@ -268,6 +275,7 @@ var FlateStream = (function() {
b = codeBuf & ((1 << bits) - 1);
this.codeBuf = codeBuf >> bits;
this.codeSize = codeSize -= bits;
this.bytesPos = bytesPos;
return b;
},
getCode: function(table) {
@ -275,10 +283,12 @@ var FlateStream = (function() {
var maxLen = table[1];
var codeSize = this.codeSize;
var codeBuf = this.codeBuf;
var stream = this.stream;
var bytes = this.bytes;
var bytesPos = this.bytesPos;
while (codeSize < maxLen) {
var b;
if ((b = stream.getByte()) == -1)
if (typeof (b = bytes[bytesPos++]) == "undefined")
error("Bad encoding in flate stream");
codeBuf |= (b << codeSize);
codeSize += 8;
@ -290,6 +300,7 @@ var FlateStream = (function() {
error("Bad encoding in flate stream");
this.codeBuf = (codeBuf >> codeLen);
this.codeSize = (codeSize - codeLen);
this.bytesPos = bytesPos;
return codeVal;
},
ensureBuffer: function(requested) {
@ -306,9 +317,8 @@ var FlateStream = (function() {
return this.buffer = buffer2;
},
getByte: function() {
var bufferLength = this.bufferLength;
var pos = this.pos;
if (bufferLength <= pos) {
while (this.bufferLength <= pos) {
if (this.eof)
return;
this.readBlock();
@ -331,9 +341,8 @@ var FlateStream = (function() {
return this.buffer.subarray(pos, end)
},
lookChar: function() {
var bufferLength = this.bufferLength;
var pos = this.pos;
if (bufferLength <= pos) {
while (this.bufferLength <= pos) {
if (this.eof)
return;
this.readBlock();
@ -342,16 +351,15 @@ var FlateStream = (function() {
},
getChar: function() {
var ch = this.lookChar();
if (!ch)
return;
// 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;
while (n-- > 0)
this.getChar();
this.pos += n;
},
generateHuffmanTable: function(lengths) {
var n = lengths.length;
@ -397,7 +405,8 @@ var FlateStream = (function() {
array[i++] = what;
}
var stream = this.stream;
var bytes = this.bytes;
var bytesPos = this.bytesPos;
// read block header
var hdr = this.getBits(3);
@ -407,16 +416,16 @@ var FlateStream = (function() {
var b;
if (hdr == 0) { // uncompressed block
if ((b = stream.getByte()) == -1)
if (typeof (b = bytes[bytesPos++]) == "undefined")
error("Bad block header in flate stream");
var blockLen = b;
if ((b = stream.getByte()) == -1)
if (typeof (b = bytes[bytesPos++]) == "undefined")
error("Bad block header in flate stream");
blockLen |= (b << 8);
if ((b = stream.getByte()) == -1)
if (typeof (b = bytes[bytesPos++]) == "undefined")
error("Bad block header in flate stream");
var check = b;
if ((b = stream.getByte()) == -1)
if (typeof (b = bytes[bytesPos++]) == "undefined")
error("Bad block header in flate stream");
check |= (b << 8);
if (check != (~this.blockLen & 0xffff))
@ -425,7 +434,7 @@ var FlateStream = (function() {
var buffer = this.ensureBuffer(bufferLength + blockLen);
this.bufferLength = bufferLength + blockLen;
for (var n = bufferLength; n < blockLen; ++n) {
if ((b = stream.getByte()) == -1) {
if (typeof (b = bytes[bytesPos++]) == "undefined") {
this.eof = true;
break;
}