Move NameTree/NumberTree from src/core/obj.js and into its own file
The size of the `src/core/obj.js` file has increased slowly over the years, and it also contains a fair amount of *distinct* functionality. In order to improve readability and make it easier to navigate through the code, this patch moves `NameTree`/`NumberTree` into its own file.
This commit is contained in:
Jonas Jenwald
parent
92141e0468
commit
24e5ecdf76
169
src/core/name_number_tree.js
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169
src/core/name_number_tree.js
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@ -0,0 +1,169 @@
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/* Copyright 2021 Mozilla Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import { FormatError, info, unreachable, warn } from "../shared/util.js";
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import { isDict, RefSet } from "./primitives.js";
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/**
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* A NameTree/NumberTree is like a Dict but has some advantageous properties,
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* see the specification (7.9.6 and 7.9.7) for additional details.
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* TODO: implement all the Dict functions and make this more efficient.
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*/
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class NameOrNumberTree {
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constructor(root, xref, type) {
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if (this.constructor === NameOrNumberTree) {
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unreachable("Cannot initialize NameOrNumberTree.");
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}
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this.root = root;
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this.xref = xref;
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this._type = type;
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}
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getAll() {
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const dict = Object.create(null);
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if (!this.root) {
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return dict;
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}
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const xref = this.xref;
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// Reading Name/Number tree.
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const processed = new RefSet();
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processed.put(this.root);
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const queue = [this.root];
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while (queue.length > 0) {
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const obj = xref.fetchIfRef(queue.shift());
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if (!isDict(obj)) {
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continue;
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}
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if (obj.has("Kids")) {
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const kids = obj.get("Kids");
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for (let i = 0, ii = kids.length; i < ii; i++) {
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const kid = kids[i];
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if (processed.has(kid)) {
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throw new FormatError(`Duplicate entry in "${this._type}" tree.`);
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}
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queue.push(kid);
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processed.put(kid);
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}
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continue;
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}
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const entries = obj.get(this._type);
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if (Array.isArray(entries)) {
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for (let i = 0, ii = entries.length; i < ii; i += 2) {
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dict[xref.fetchIfRef(entries[i])] = xref.fetchIfRef(entries[i + 1]);
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}
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}
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}
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return dict;
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}
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get(key) {
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if (!this.root) {
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return null;
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}
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const xref = this.xref;
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let kidsOrEntries = xref.fetchIfRef(this.root);
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let loopCount = 0;
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const MAX_LEVELS = 10;
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// Perform a binary search to quickly find the entry that
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// contains the key we are looking for.
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while (kidsOrEntries.has("Kids")) {
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if (++loopCount > MAX_LEVELS) {
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warn(`Search depth limit reached for "${this._type}" tree.`);
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return null;
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}
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const kids = kidsOrEntries.get("Kids");
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if (!Array.isArray(kids)) {
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return null;
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}
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let l = 0,
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r = kids.length - 1;
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while (l <= r) {
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const m = (l + r) >> 1;
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const kid = xref.fetchIfRef(kids[m]);
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const limits = kid.get("Limits");
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if (key < xref.fetchIfRef(limits[0])) {
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r = m - 1;
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} else if (key > xref.fetchIfRef(limits[1])) {
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l = m + 1;
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} else {
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kidsOrEntries = xref.fetchIfRef(kids[m]);
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break;
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}
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}
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if (l > r) {
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return null;
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}
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}
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// If we get here, then we have found the right entry. Now go through the
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// entries in the dictionary until we find the key we're looking for.
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const entries = kidsOrEntries.get(this._type);
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if (Array.isArray(entries)) {
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// Perform a binary search to reduce the lookup time.
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let l = 0,
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r = entries.length - 2;
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while (l <= r) {
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// Check only even indices (0, 2, 4, ...) because the
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// odd indices contain the actual data.
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const tmp = (l + r) >> 1,
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m = tmp + (tmp & 1);
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const currentKey = xref.fetchIfRef(entries[m]);
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if (key < currentKey) {
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r = m - 2;
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} else if (key > currentKey) {
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l = m + 2;
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} else {
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return xref.fetchIfRef(entries[m + 1]);
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}
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}
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// Fallback to an exhaustive search, in an attempt to handle corrupt
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// PDF files where keys are not correctly ordered (fixes issue 10272).
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info(
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`Falling back to an exhaustive search, for key "${key}", ` +
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`in "${this._type}" tree.`
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);
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for (let m = 0, mm = entries.length; m < mm; m += 2) {
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const currentKey = xref.fetchIfRef(entries[m]);
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if (currentKey === key) {
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warn(
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`The "${key}" key was found at an incorrect, ` +
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`i.e. out-of-order, position in "${this._type}" tree.`
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);
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return xref.fetchIfRef(entries[m + 1]);
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}
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}
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}
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return null;
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}
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}
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class NameTree extends NameOrNumberTree {
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constructor(root, xref) {
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super(root, xref, "Names");
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}
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}
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class NumberTree extends NameOrNumberTree {
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constructor(root, xref) {
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super(root, xref, "Nums");
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}
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}
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export { NameTree, NumberTree };
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154
src/core/obj.js
154
src/core/obj.js
@ -31,7 +31,6 @@ import {
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shadow,
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stringToPDFString,
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stringToUTF8String,
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unreachable,
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warn,
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} from "../shared/util.js";
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import {
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@ -56,6 +55,7 @@ import {
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XRefParseException,
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} from "./core_utils.js";
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import { Lexer, Parser } from "./parser.js";
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import { NameTree, NumberTree } from "./name_number_tree.js";
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import { CipherTransformFactory } from "./crypto.js";
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import { ColorSpace } from "./colorspace.js";
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import { FileSpec } from "./file_spec.js";
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@ -2270,154 +2270,4 @@ var XRef = (function XRefClosure() {
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return XRef;
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})();
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/**
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* A NameTree/NumberTree is like a Dict but has some advantageous properties,
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* see the specification (7.9.6 and 7.9.7) for additional details.
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* TODO: implement all the Dict functions and make this more efficient.
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*/
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class NameOrNumberTree {
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constructor(root, xref, type) {
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if (this.constructor === NameOrNumberTree) {
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unreachable("Cannot initialize NameOrNumberTree.");
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}
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this.root = root;
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this.xref = xref;
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this._type = type;
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}
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getAll() {
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const dict = Object.create(null);
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if (!this.root) {
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return dict;
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}
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const xref = this.xref;
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// Reading Name/Number tree.
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const processed = new RefSet();
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processed.put(this.root);
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const queue = [this.root];
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while (queue.length > 0) {
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const obj = xref.fetchIfRef(queue.shift());
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if (!isDict(obj)) {
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continue;
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}
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if (obj.has("Kids")) {
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const kids = obj.get("Kids");
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for (let i = 0, ii = kids.length; i < ii; i++) {
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const kid = kids[i];
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if (processed.has(kid)) {
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throw new FormatError(`Duplicate entry in "${this._type}" tree.`);
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}
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queue.push(kid);
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processed.put(kid);
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}
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continue;
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}
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const entries = obj.get(this._type);
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if (Array.isArray(entries)) {
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for (let i = 0, ii = entries.length; i < ii; i += 2) {
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dict[xref.fetchIfRef(entries[i])] = xref.fetchIfRef(entries[i + 1]);
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}
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}
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}
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return dict;
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}
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get(key) {
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if (!this.root) {
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return null;
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}
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const xref = this.xref;
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let kidsOrEntries = xref.fetchIfRef(this.root);
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let loopCount = 0;
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const MAX_LEVELS = 10;
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// Perform a binary search to quickly find the entry that
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// contains the key we are looking for.
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while (kidsOrEntries.has("Kids")) {
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if (++loopCount > MAX_LEVELS) {
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warn(`Search depth limit reached for "${this._type}" tree.`);
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return null;
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}
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const kids = kidsOrEntries.get("Kids");
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if (!Array.isArray(kids)) {
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return null;
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}
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let l = 0,
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r = kids.length - 1;
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while (l <= r) {
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const m = (l + r) >> 1;
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const kid = xref.fetchIfRef(kids[m]);
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const limits = kid.get("Limits");
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if (key < xref.fetchIfRef(limits[0])) {
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r = m - 1;
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} else if (key > xref.fetchIfRef(limits[1])) {
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l = m + 1;
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} else {
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kidsOrEntries = xref.fetchIfRef(kids[m]);
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break;
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}
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}
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if (l > r) {
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return null;
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}
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}
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// If we get here, then we have found the right entry. Now go through the
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// entries in the dictionary until we find the key we're looking for.
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const entries = kidsOrEntries.get(this._type);
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if (Array.isArray(entries)) {
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// Perform a binary search to reduce the lookup time.
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let l = 0,
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r = entries.length - 2;
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while (l <= r) {
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// Check only even indices (0, 2, 4, ...) because the
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// odd indices contain the actual data.
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const tmp = (l + r) >> 1,
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m = tmp + (tmp & 1);
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const currentKey = xref.fetchIfRef(entries[m]);
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if (key < currentKey) {
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r = m - 2;
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} else if (key > currentKey) {
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l = m + 2;
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} else {
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return xref.fetchIfRef(entries[m + 1]);
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}
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}
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// Fallback to an exhaustive search, in an attempt to handle corrupt
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// PDF files where keys are not correctly ordered (fixes issue 10272).
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info(
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`Falling back to an exhaustive search, for key "${key}", ` +
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`in "${this._type}" tree.`
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);
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for (let m = 0, mm = entries.length; m < mm; m += 2) {
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const currentKey = xref.fetchIfRef(entries[m]);
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if (currentKey === key) {
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warn(
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`The "${key}" key was found at an incorrect, ` +
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`i.e. out-of-order, position in "${this._type}" tree.`
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);
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return xref.fetchIfRef(entries[m + 1]);
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}
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}
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}
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return null;
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}
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}
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class NameTree extends NameOrNumberTree {
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constructor(root, xref) {
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super(root, xref, "Names");
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}
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}
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class NumberTree extends NameOrNumberTree {
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constructor(root, xref) {
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super(root, xref, "Nums");
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}
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}
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export { Catalog, NumberTree, XRef };
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export { Catalog, XRef };
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@ -15,7 +15,7 @@
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import { isDict, isName, isRef } from "./primitives.js";
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import { isString, stringToPDFString, warn } from "../shared/util.js";
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import { NumberTree } from "./obj.js";
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import { NumberTree } from "./name_number_tree.js";
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const MAX_DEPTH = 40;
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