pdf.js/src/core/to_unicode_map.js

104 lines
2.3 KiB
JavaScript

/* Copyright 2012 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.
*/
import { unreachable } from "../shared/util.js";
class ToUnicodeMap {
constructor(cmap = []) {
// The elements of this._map can be integers or strings, depending on how
// `cmap` was created.
this._map = cmap;
}
get length() {
return this._map.length;
}
forEach(callback) {
for (const charCode in this._map) {
callback(charCode, this._map[charCode].charCodeAt(0));
}
}
has(i) {
return this._map[i] !== undefined;
}
get(i) {
return this._map[i];
}
charCodeOf(value) {
// `Array.prototype.indexOf` is *extremely* inefficient for arrays which
// are both very sparse and very large (see issue8372.pdf).
const map = this._map;
if (map.length <= 0x10000) {
return map.indexOf(value);
}
for (const charCode in map) {
if (map[charCode] === value) {
return charCode | 0;
}
}
return -1;
}
amend(map) {
for (const charCode in map) {
this._map[charCode] = map[charCode];
}
}
}
class IdentityToUnicodeMap {
constructor(firstChar, lastChar) {
this.firstChar = firstChar;
this.lastChar = lastChar;
}
get length() {
return this.lastChar + 1 - this.firstChar;
}
forEach(callback) {
for (let i = this.firstChar, ii = this.lastChar; i <= ii; i++) {
callback(i, i);
}
}
has(i) {
return this.firstChar <= i && i <= this.lastChar;
}
get(i) {
if (this.firstChar <= i && i <= this.lastChar) {
return String.fromCharCode(i);
}
return undefined;
}
charCodeOf(v) {
return Number.isInteger(v) && v >= this.firstChar && v <= this.lastChar
? v
: -1;
}
amend(map) {
unreachable("Should not call amend()");
}
}
export { IdentityToUnicodeMap, ToUnicodeMap };