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Merge pull request #5445 from CodingFabian/fixImageCachingInParser

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Fixes caching of inline images during parsing.
This commit is contained in:
Yury Delendik 2014-12-15 10:51:23 -06:00
commit f5df30f967
2 changed files with 34 additions and 37 deletions
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31
src/core/evaluator.js
View File

@ -171,7 +171,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
buildPaintImageXObject:
function PartialEvaluator_buildPaintImageXObject(resources, image,
inline, operatorList,
cacheKey, cache) {
cacheKey, imageCache) {
var self = this;
var dict = image.dict;
var w = dict.get('Width', 'W');
@ -209,9 +209,10 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
args = [imgData];
operatorList.addOp(OPS.paintImageMaskXObject, args);
if (cacheKey) {
cache.key = cacheKey;
cache.fn = OPS.paintImageMaskXObject;
cache.args = args;
imageCache[cacheKey] = {
fn: OPS.paintImageMaskXObject,
args: args
};
}
return;
}
@ -260,9 +261,10 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
operatorList.addOp(OPS.paintImageXObject, args);
if (cacheKey) {
cache.key = cacheKey;
cache.fn = OPS.paintImageXObject;
cache.args = args;
imageCache[cacheKey] = {
fn: OPS.paintImageXObject,
args: args
};
}
},
@ -656,8 +658,8 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
}
// eagerly compile XForm objects
var name = args[0].name;
if (imageCache.key === name) {
operatorList.addOp(imageCache.fn, imageCache.args);
if (imageCache[name] !== undefined) {
operatorList.addOp(imageCache[name].fn, imageCache[name].args);
args = null;
continue;
}
@ -706,10 +708,13 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
}, reject);
case OPS.endInlineImage:
var cacheKey = args[0].cacheKey;
if (cacheKey && imageCache.key === cacheKey) {
operatorList.addOp(imageCache.fn, imageCache.args);
args = null;
continue;
if (cacheKey) {
var cacheEntry = imageCache[cacheKey];
if (cacheEntry !== undefined) {
operatorList.addOp(cacheEntry.fn, cacheEntry.args);
args = null;
continue;
}
}
self.buildPaintImageXObject(resources, args[0], true,
operatorList, cacheKey, imageCache);

40
src/core/parser.js
View File

@ -28,16 +28,14 @@ function isEOF(v) {
return (v === EOF);
}
var MAX_LENGTH_TO_CACHE = 1000;
var Parser = (function ParserClosure() {
function Parser(lexer, allowStreams, xref) {
this.lexer = lexer;
this.allowStreams = allowStreams;
this.xref = xref;
this.imageCache = {
length: 0,
adler32: 0,
stream: null
};
this.imageCache = {};
this.refill();
}
@ -185,34 +183,29 @@ var Parser = (function ParserClosure() {
var length = (stream.pos - 4) - startPos;
var imageStream = stream.makeSubStream(startPos, length, dict);
// trying to cache repeat images, first we are trying to "warm up" caching
// using length, then comparing adler32
var MAX_LENGTH_TO_CACHE = 1000;
var cacheImage = false, adler32;
if (length < MAX_LENGTH_TO_CACHE && this.imageCache.length === length) {
// cache all images below the MAX_LENGTH_TO_CACHE threshold by their
// adler32 checksum.
var adler32;
if (length < MAX_LENGTH_TO_CACHE) {
var imageBytes = imageStream.getBytes();
imageStream.reset();
var a = 1;
var b = 0;
for (i = 0, ii = imageBytes.length; i < ii; ++i) {
a = (a + (imageBytes[i] & 0xff)) % 65521;
b = (b + a) % 65521;
// no modulo required in the loop if imageBytes.length < 5552
a += imageBytes[i] & 0xff;
b += a;
}
adler32 = (b << 16) | a;
adler32 = ((b % 65521) << 16) | (a % 65521);
if (this.imageCache.stream && this.imageCache.adler32 === adler32) {
if (this.imageCache.adler32 === adler32) {
this.buf2 = Cmd.get('EI');
this.shift();
this.imageCache.stream.reset();
return this.imageCache.stream;
this.imageCache[adler32].reset();
return this.imageCache[adler32];
}
cacheImage = true;
}
if (!cacheImage && !this.imageCache.stream) {
this.imageCache.length = length;
this.imageCache.stream = null;
}
if (cipherTransform) {
@ -221,10 +214,9 @@ var Parser = (function ParserClosure() {
imageStream = this.filter(imageStream, dict, length);
imageStream.dict = dict;
if (cacheImage) {
if (adler32 !== undefined) {
imageStream.cacheKey = 'inline_' + length + '_' + adler32;
this.imageCache.adler32 = adler32;
this.imageCache.stream = imageStream;
this.imageCache[adler32] = imageStream;
}
this.buf2 = Cmd.get('EI');