pdfjs-dist
Version:
Generic build of Mozilla's PDF.js library.
249 lines (248 loc) • 7 kB
JavaScript
/**
* @licstart The following is the entire license notice for the
* JavaScript code in this page
*
* Copyright 2022 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @licend The above is the entire license notice for the
* JavaScript code in this page
*/
"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.LocalTilingPatternCache = exports.LocalImageCache = exports.LocalGStateCache = exports.LocalFunctionCache = exports.LocalColorSpaceCache = exports.GlobalImageCache = void 0;
var _util = require("../shared/util.js");
var _primitives = require("./primitives.js");
class BaseLocalCache {
constructor(options) {
if (this.constructor === BaseLocalCache) {
(0, _util.unreachable)("Cannot initialize BaseLocalCache.");
}
this._onlyRefs = (options && options.onlyRefs) === true;
if (!this._onlyRefs) {
this._nameRefMap = new Map();
this._imageMap = new Map();
}
this._imageCache = new _primitives.RefSetCache();
}
getByName(name) {
if (this._onlyRefs) {
(0, _util.unreachable)("Should not call `getByName` method.");
}
const ref = this._nameRefMap.get(name);
if (ref) {
return this.getByRef(ref);
}
return this._imageMap.get(name) || null;
}
getByRef(ref) {
return this._imageCache.get(ref) || null;
}
set(name, ref, data) {
(0, _util.unreachable)("Abstract method `set` called.");
}
}
class LocalImageCache extends BaseLocalCache {
set(name, ref = null, data) {
if (typeof name !== "string") {
throw new Error('LocalImageCache.set - expected "name" argument.');
}
if (ref) {
if (this._imageCache.has(ref)) {
return;
}
this._nameRefMap.set(name, ref);
this._imageCache.put(ref, data);
return;
}
if (this._imageMap.has(name)) {
return;
}
this._imageMap.set(name, data);
}
}
exports.LocalImageCache = LocalImageCache;
class LocalColorSpaceCache extends BaseLocalCache {
set(name = null, ref = null, data) {
if (typeof name !== "string" && !ref) {
throw new Error('LocalColorSpaceCache.set - expected "name" and/or "ref" argument.');
}
if (ref) {
if (this._imageCache.has(ref)) {
return;
}
if (name !== null) {
this._nameRefMap.set(name, ref);
}
this._imageCache.put(ref, data);
return;
}
if (this._imageMap.has(name)) {
return;
}
this._imageMap.set(name, data);
}
}
exports.LocalColorSpaceCache = LocalColorSpaceCache;
class LocalFunctionCache extends BaseLocalCache {
constructor(options) {
super({
onlyRefs: true
});
}
set(name = null, ref, data) {
if (!ref) {
throw new Error('LocalFunctionCache.set - expected "ref" argument.');
}
if (this._imageCache.has(ref)) {
return;
}
this._imageCache.put(ref, data);
}
}
exports.LocalFunctionCache = LocalFunctionCache;
class LocalGStateCache extends BaseLocalCache {
set(name, ref = null, data) {
if (typeof name !== "string") {
throw new Error('LocalGStateCache.set - expected "name" argument.');
}
if (ref) {
if (this._imageCache.has(ref)) {
return;
}
this._nameRefMap.set(name, ref);
this._imageCache.put(ref, data);
return;
}
if (this._imageMap.has(name)) {
return;
}
this._imageMap.set(name, data);
}
}
exports.LocalGStateCache = LocalGStateCache;
class LocalTilingPatternCache extends BaseLocalCache {
constructor(options) {
super({
onlyRefs: true
});
}
set(name = null, ref, data) {
if (!ref) {
throw new Error('LocalTilingPatternCache.set - expected "ref" argument.');
}
if (this._imageCache.has(ref)) {
return;
}
this._imageCache.put(ref, data);
}
}
exports.LocalTilingPatternCache = LocalTilingPatternCache;
class GlobalImageCache {
static get NUM_PAGES_THRESHOLD() {
return (0, _util.shadow)(this, "NUM_PAGES_THRESHOLD", 2);
}
static get MIN_IMAGES_TO_CACHE() {
return (0, _util.shadow)(this, "MIN_IMAGES_TO_CACHE", 10);
}
static get MAX_BYTE_SIZE() {
return (0, _util.shadow)(this, "MAX_BYTE_SIZE", 40e6);
}
constructor() {
this._refCache = new _primitives.RefSetCache();
this._imageCache = new _primitives.RefSetCache();
}
get _byteSize() {
let byteSize = 0;
for (const imageData of this._imageCache) {
byteSize += imageData.byteSize;
}
return byteSize;
}
get _cacheLimitReached() {
if (this._imageCache.size < GlobalImageCache.MIN_IMAGES_TO_CACHE) {
return false;
}
if (this._byteSize < GlobalImageCache.MAX_BYTE_SIZE) {
return false;
}
return true;
}
shouldCache(ref, pageIndex) {
const pageIndexSet = this._refCache.get(ref);
const numPages = pageIndexSet ? pageIndexSet.size + (pageIndexSet.has(pageIndex) ? 0 : 1) : 1;
if (numPages < GlobalImageCache.NUM_PAGES_THRESHOLD) {
return false;
}
if (!this._imageCache.has(ref) && this._cacheLimitReached) {
return false;
}
return true;
}
addPageIndex(ref, pageIndex) {
let pageIndexSet = this._refCache.get(ref);
if (!pageIndexSet) {
pageIndexSet = new Set();
this._refCache.put(ref, pageIndexSet);
}
pageIndexSet.add(pageIndex);
}
addByteSize(ref, byteSize) {
const imageData = this._imageCache.get(ref);
if (!imageData) {
return;
}
if (imageData.byteSize) {
return;
}
imageData.byteSize = byteSize;
}
getData(ref, pageIndex) {
const pageIndexSet = this._refCache.get(ref);
if (!pageIndexSet) {
return null;
}
if (pageIndexSet.size < GlobalImageCache.NUM_PAGES_THRESHOLD) {
return null;
}
const imageData = this._imageCache.get(ref);
if (!imageData) {
return null;
}
pageIndexSet.add(pageIndex);
return imageData;
}
setData(ref, data) {
if (!this._refCache.has(ref)) {
throw new Error('GlobalImageCache.setData - expected "addPageIndex" to have been called.');
}
if (this._imageCache.has(ref)) {
return;
}
if (this._cacheLimitReached) {
(0, _util.warn)("GlobalImageCache.setData - cache limit reached.");
return;
}
this._imageCache.put(ref, data);
}
clear(onlyData = false) {
if (!onlyData) {
this._refCache.clear();
}
this._imageCache.clear();
}
}
exports.GlobalImageCache = GlobalImageCache;