91 lines
2.3 KiB
JavaScript
91 lines
2.3 KiB
JavaScript
/* Copyright 2024 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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/**
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* This class manages the interaction of extracting the text content of the page
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* and passing it back to the external service.
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*/
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class PdfTextExtractor {
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/** @type {PDFViewer} */
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#pdfViewer;
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#externalServices;
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/**
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* @type {?Promise<string>}
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*/
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#textPromise;
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#pendingRequests = new Set();
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constructor(externalServices) {
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this.#externalServices = externalServices;
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window.addEventListener("requestTextContent", ({ detail }) => {
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this.extractTextContent(detail.requestId);
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});
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}
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/**
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* The PDF viewer is required to get the page text.
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*
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* @param {PDFViewer | null}
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*/
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setViewer(pdfViewer) {
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this.#pdfViewer = pdfViewer;
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if (this.#pdfViewer && this.#pendingRequests.size) {
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// Handle any pending requests that came in while things were loading.
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for (const pendingRequest of this.#pendingRequests) {
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this.extractTextContent(pendingRequest);
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}
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this.#pendingRequests = new Set();
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}
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}
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/**
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* Builds up all of the text from a PDF.
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*
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* @param {number} requestId
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*/
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async extractTextContent(requestId) {
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if (!this.#pdfViewer) {
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this.#pendingRequests.add(requestId);
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return;
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}
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if (!this.#textPromise) {
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const textPromise = this.#pdfViewer.getAllText();
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this.#textPromise = textPromise;
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// After the text resolves, cache the text for a little bit in case
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// multiple consumers call it.
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textPromise.then(() => {
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setTimeout(() => {
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if (this.#textPromise === textPromise) {
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this.#textPromise = null;
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}
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}, 5000);
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});
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}
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this.#externalServices.reportText({
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text: await this.#textPromise,
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requestId,
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});
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}
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}
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export { PdfTextExtractor };
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