pdf.js/src/core/decrypt_stream.js
Jonas Jenwald 1b4a7c5965 Introduce more optional chaining in the src/core/ folder
After PR 12563 we're now free to use optional chaining in the worker-thread as well. (This patch also fixes one previously "missed" case in the `web/` folder.)

For the MOZCENTRAL build-target this patch reduces the total bundle-size by `1.6` kilobytes.
2023-05-15 12:38:28 +02:00

58 lines
1.6 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 { DecodeStream } from "./decode_stream.js";
const chunkSize = 512;
class DecryptStream extends DecodeStream {
constructor(str, maybeLength, decrypt) {
super(maybeLength);
this.str = str;
this.dict = str.dict;
this.decrypt = decrypt;
this.nextChunk = null;
this.initialized = false;
}
readBlock() {
let chunk;
if (this.initialized) {
chunk = this.nextChunk;
} else {
chunk = this.str.getBytes(chunkSize);
this.initialized = true;
}
if (!chunk || chunk.length === 0) {
this.eof = true;
return;
}
this.nextChunk = this.str.getBytes(chunkSize);
const hasMoreData = this.nextChunk?.length > 0;
const decrypt = this.decrypt;
chunk = decrypt(chunk, !hasMoreData);
const bufferLength = this.bufferLength,
newLength = bufferLength + chunk.length,
buffer = this.ensureBuffer(newLength);
buffer.set(chunk, bufferLength);
this.bufferLength = newLength;
}
}
export { DecryptStream };