94b4b54ef6
In order to fix bug 1935076, we'll have to add a pure js fallback in case wasm is disabled or simd isn't supported. Unfortunately, this fallback will take some space. So, the main goal of this patch is to reduce the overall size (by ~93k). As a side effect, it should make easier to use an other wasm file (which must export _jp2_decode, _malloc and _free).
143 lines
3.1 KiB
JavaScript
143 lines
3.1 KiB
JavaScript
/* 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 { bytesToString, shadow, unreachable } from "../shared/util.js";
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class BaseStream {
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constructor() {
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if (
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(typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) &&
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this.constructor === BaseStream
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) {
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unreachable("Cannot initialize BaseStream.");
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}
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}
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// eslint-disable-next-line getter-return
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get length() {
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unreachable("Abstract getter `length` accessed");
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}
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// eslint-disable-next-line getter-return
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get isEmpty() {
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unreachable("Abstract getter `isEmpty` accessed");
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}
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get isDataLoaded() {
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return shadow(this, "isDataLoaded", true);
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}
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getByte() {
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unreachable("Abstract method `getByte` called");
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}
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getBytes(length) {
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unreachable("Abstract method `getBytes` called");
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}
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/**
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* NOTE: This method can only be used to get image-data that is guaranteed
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* to be fully loaded, since otherwise intermittent errors may occur;
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* note the `ObjectLoader` class.
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*/
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async getImageData(length, decoderOptions) {
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return this.getBytes(length, decoderOptions);
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}
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async asyncGetBytes() {
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unreachable("Abstract method `asyncGetBytes` called");
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}
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get isAsync() {
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return false;
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}
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get isAsyncDecoder() {
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return false;
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}
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get canAsyncDecodeImageFromBuffer() {
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return false;
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}
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async getTransferableImage() {
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return null;
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}
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peekByte() {
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const peekedByte = this.getByte();
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if (peekedByte !== -1) {
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this.pos--;
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}
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return peekedByte;
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}
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peekBytes(length) {
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const bytes = this.getBytes(length);
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this.pos -= bytes.length;
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return bytes;
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}
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getUint16() {
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const b0 = this.getByte();
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const b1 = this.getByte();
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if (b0 === -1 || b1 === -1) {
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return -1;
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}
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return (b0 << 8) + b1;
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}
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getInt32() {
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const b0 = this.getByte();
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const b1 = this.getByte();
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const b2 = this.getByte();
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const b3 = this.getByte();
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return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
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}
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getByteRange(begin, end) {
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unreachable("Abstract method `getByteRange` called");
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}
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getString(length) {
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return bytesToString(this.getBytes(length));
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}
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skip(n) {
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this.pos += n || 1;
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}
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reset() {
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unreachable("Abstract method `reset` called");
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}
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moveStart() {
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unreachable("Abstract method `moveStart` called");
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}
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makeSubStream(start, length, dict = null) {
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unreachable("Abstract method `makeSubStream` called");
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}
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/**
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* @returns {Array | null}
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*/
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getBaseStreams() {
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return null;
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}
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}
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export { BaseStream };
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