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6ff0f8690f
Given that these classes are, with the exception of their `decode` methods, virtually identical this helps reduce code duplication and simplifies maintenance. These changes reduce the size of the `gulp mozcentral` build-target by `1292` bytes, which obviously isn't a lot but still cannot hurt.
82 lines
2.2 KiB
JavaScript
82 lines
2.2 KiB
JavaScript
/* Copyright 2012 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 { DecodeStream } from "./decode_stream.js";
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import { Dict } from "./primitives.js";
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import { JBig2CCITTFaxImage } from "./jbig2_ccittFax.js";
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import { shadow } from "../shared/util.js";
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class CCITTFaxStream extends DecodeStream {
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constructor(str, maybeLength, params) {
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super(maybeLength);
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this.stream = str;
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this.maybeLength = maybeLength;
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this.dict = str.dict;
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if (!(params instanceof Dict)) {
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params = Dict.empty;
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}
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this.params = {
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K: params.get("K") || 0,
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EndOfLine: !!params.get("EndOfLine"),
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EncodedByteAlign: !!params.get("EncodedByteAlign"),
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Columns: params.get("Columns") || 1728,
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Rows: params.get("Rows") || 0,
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EndOfBlock: !!(params.get("EndOfBlock") ?? true),
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BlackIs1: !!params.get("BlackIs1"),
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};
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}
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get bytes() {
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// If `this.maybeLength` is null, we'll get the entire stream.
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return shadow(this, "bytes", this.stream.getBytes(this.maybeLength));
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}
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get isImageStream() {
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return true;
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}
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get isAsyncDecoder() {
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return true;
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}
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async decodeImage(bytes, length, _decoderOptions) {
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if (this.eof) {
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return this.buffer;
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}
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if (!bytes) {
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bytes = this.stream.isAsync
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? (await this.stream.asyncGetBytes()) || this.bytes
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: this.bytes;
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}
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this.buffer = await JBig2CCITTFaxImage.instance.decode(
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bytes,
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this.dict.get("W", "Width"),
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this.dict.get("H", "Height"),
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null,
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this.params
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);
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this.bufferLength = this.buffer.length;
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this.eof = true;
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return this.buffer;
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}
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}
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export { CCITTFaxStream };
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