mirror of
https://github.com/mozilla/pdf.js.git
synced 2026-04-18 11:14:02 +02:00
Re-factor the Jbig2Image class, and related code, to use DataViews when reading data
This commit is contained in:
Jonas Jenwald
parent
81c9a34fd3
commit
afbded8da1
@ -14,14 +14,7 @@
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*/
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import { BaseException, shadow } from "../shared/util.js";
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import {
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log2,
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MAX_INT_32,
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MIN_INT_32,
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readInt8,
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readUint16,
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readUint32,
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} from "./core_utils.js";
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import { log2, MAX_INT_32, MIN_INT_32 } from "./core_utils.js";
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import { ArithmeticDecoder } from "./arithmetic_decoder.js";
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import { CCITTFaxDecoder } from "./ccitt.js";
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@ -34,10 +27,7 @@ class Jbig2Error extends BaseException {
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// Utility data structures
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class ContextCache {
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getContexts(id) {
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if (id in this) {
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return this[id];
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}
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return (this[id] = new Int8Array(1 << 16));
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return (this[id] ??= new Int8Array(1 << 16));
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}
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}
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@ -1148,9 +1138,9 @@ function decodeHalftoneRegion(
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return regionBitmap;
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}
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function readSegmentHeader(data, start) {
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function readSegmentHeader(data, view, start) {
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const segmentHeader = {};
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segmentHeader.number = readUint32(data, start);
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segmentHeader.number = view.getUint32(start);
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const flags = data[start + 4];
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const segmentType = flags & 0x3f;
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if (!SegmentTypes[segmentType]) {
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@ -1166,7 +1156,7 @@ function readSegmentHeader(data, start) {
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const retainBits = [referredFlags & 31];
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let position = start + 6;
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if (referredToCount === 7) {
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referredToCount = readUint32(data, position - 1) & 0x1fffffff;
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referredToCount = view.getUint32(position - 1) & 0x1fffffff;
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position += 3;
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let bytes = (referredToCount + 8) >> 3;
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retainBits[0] = data[position++];
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@ -1192,9 +1182,9 @@ function readSegmentHeader(data, start) {
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if (referredToSegmentNumberSize === 1) {
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number = data[position];
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} else if (referredToSegmentNumberSize === 2) {
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number = readUint16(data, position);
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number = view.getUint16(position);
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} else {
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number = readUint32(data, position);
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number = view.getUint32(position);
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}
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referredTo.push(number);
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position += referredToSegmentNumberSize;
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@ -1203,17 +1193,21 @@ function readSegmentHeader(data, start) {
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if (!pageAssociationFieldSize) {
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segmentHeader.pageAssociation = data[position++];
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} else {
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segmentHeader.pageAssociation = readUint32(data, position);
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segmentHeader.pageAssociation = view.getUint32(position);
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position += 4;
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}
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segmentHeader.length = readUint32(data, position);
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segmentHeader.length = view.getUint32(position);
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position += 4;
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if (segmentHeader.length === 0xffffffff) {
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// 7.2.7 Segment data length, unknown segment length
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if (segmentType === 38) {
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// ImmediateGenericRegion
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const genericRegionInfo = readRegionSegmentInformation(data, position);
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const genericRegionInfo = readRegionSegmentInformation(
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data,
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view,
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position
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);
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const genericRegionSegmentFlags =
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data[position + RegionSegmentInformationFieldLength];
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const genericRegionMmr = !!(genericRegionSegmentFlags & 1);
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@ -1250,10 +1244,11 @@ function readSegmentHeader(data, start) {
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}
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function readSegments(header, data, start, end) {
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const view = new DataView(data.buffer, data.byteOffset, data.byteLength);
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const segments = [];
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let position = start;
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while (position < end) {
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const segmentHeader = readSegmentHeader(data, position);
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const segmentHeader = readSegmentHeader(data, view, position);
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position = segmentHeader.headerEnd;
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const segment = {
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header: segmentHeader,
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@ -1280,29 +1275,27 @@ function readSegments(header, data, start, end) {
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}
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// 7.4.1 Region segment information field
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function readRegionSegmentInformation(data, start) {
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function readRegionSegmentInformation(data, view, start) {
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return {
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width: readUint32(data, start),
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height: readUint32(data, start + 4),
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x: readUint32(data, start + 8),
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y: readUint32(data, start + 12),
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width: view.getUint32(start),
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height: view.getUint32(start + 4),
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x: view.getUint32(start + 8),
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y: view.getUint32(start + 12),
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combinationOperator: data[start + 16] & 7,
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};
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}
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const RegionSegmentInformationFieldLength = 17;
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function processSegment(segment, visitor) {
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const header = segment.header;
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const data = segment.data,
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end = segment.end;
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let position = segment.start;
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const { header, data, start, end } = segment;
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const view = new DataView(data.buffer, data.byteOffset, data.byteLength);
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let position = start;
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let args, at, i, atLength;
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switch (header.type) {
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case 0: // SymbolDictionary
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// 7.4.2 Symbol dictionary segment syntax
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const dictionary = {};
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const dictionaryFlags = readUint16(data, position); // 7.4.2.1.1
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const dictionaryFlags = view.getUint16(position); // 7.4.2.1.1
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dictionary.huffman = !!(dictionaryFlags & 1);
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dictionary.refinement = !!(dictionaryFlags & 2);
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dictionary.huffmanDHSelector = (dictionaryFlags >> 2) & 3;
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@ -1319,8 +1312,8 @@ function processSegment(segment, visitor) {
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at = [];
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for (i = 0; i < atLength; i++) {
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at.push({
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x: readInt8(data, position),
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y: readInt8(data, position + 1),
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x: view.getInt8(position),
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y: view.getInt8(position + 1),
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});
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position += 2;
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}
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@ -1330,16 +1323,16 @@ function processSegment(segment, visitor) {
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at = [];
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for (i = 0; i < 2; i++) {
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at.push({
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x: readInt8(data, position),
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y: readInt8(data, position + 1),
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x: view.getInt8(position),
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y: view.getInt8(position + 1),
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});
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position += 2;
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}
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dictionary.refinementAt = at;
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}
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dictionary.numberOfExportedSymbols = readUint32(data, position);
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dictionary.numberOfExportedSymbols = view.getUint32(position);
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position += 4;
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dictionary.numberOfNewSymbols = readUint32(data, position);
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dictionary.numberOfNewSymbols = view.getUint32(position);
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position += 4;
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args = [
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dictionary,
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@ -1353,9 +1346,9 @@ function processSegment(segment, visitor) {
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case 6: // ImmediateTextRegion
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case 7: // ImmediateLosslessTextRegion
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const textRegion = {};
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textRegion.info = readRegionSegmentInformation(data, position);
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textRegion.info = readRegionSegmentInformation(data, view, position);
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position += RegionSegmentInformationFieldLength;
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const textRegionSegmentFlags = readUint16(data, position);
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const textRegionSegmentFlags = view.getUint16(position);
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position += 2;
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textRegion.huffman = !!(textRegionSegmentFlags & 1);
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textRegion.refinement = !!(textRegionSegmentFlags & 2);
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@ -1368,7 +1361,7 @@ function processSegment(segment, visitor) {
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textRegion.dsOffset = (textRegionSegmentFlags << 17) >> 27;
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textRegion.refinementTemplate = (textRegionSegmentFlags >> 15) & 1;
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if (textRegion.huffman) {
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const textRegionHuffmanFlags = readUint16(data, position);
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const textRegionHuffmanFlags = view.getUint16(position);
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position += 2;
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textRegion.huffmanFS = textRegionHuffmanFlags & 3;
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textRegion.huffmanDS = (textRegionHuffmanFlags >> 2) & 3;
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@ -1385,14 +1378,14 @@ function processSegment(segment, visitor) {
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at = [];
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for (i = 0; i < 2; i++) {
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at.push({
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x: readInt8(data, position),
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y: readInt8(data, position + 1),
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x: view.getInt8(position),
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y: view.getInt8(position + 1),
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});
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position += 2;
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}
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textRegion.refinementAt = at;
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}
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textRegion.numberOfSymbolInstances = readUint32(data, position);
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textRegion.numberOfSymbolInstances = view.getUint32(position);
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position += 4;
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args = [textRegion, header.referredTo, data, position, end];
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break;
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@ -1404,7 +1397,7 @@ function processSegment(segment, visitor) {
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patternDictionary.template = (patternDictionaryFlags >> 1) & 3;
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patternDictionary.patternWidth = data[position++];
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patternDictionary.patternHeight = data[position++];
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patternDictionary.maxPatternIndex = readUint32(data, position);
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patternDictionary.maxPatternIndex = view.getUint32(position);
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position += 4;
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args = [patternDictionary, header.number, data, position, end];
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break;
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@ -1412,7 +1405,7 @@ function processSegment(segment, visitor) {
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case 23: // ImmediateLosslessHalftoneRegion
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// 7.4.5 Halftone region segment syntax
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const halftoneRegion = {};
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halftoneRegion.info = readRegionSegmentInformation(data, position);
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halftoneRegion.info = readRegionSegmentInformation(data, view, position);
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position += RegionSegmentInformationFieldLength;
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const halftoneRegionFlags = data[position++];
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halftoneRegion.mmr = !!(halftoneRegionFlags & 1);
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@ -1420,24 +1413,24 @@ function processSegment(segment, visitor) {
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halftoneRegion.enableSkip = !!(halftoneRegionFlags & 8);
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halftoneRegion.combinationOperator = (halftoneRegionFlags >> 4) & 7;
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halftoneRegion.defaultPixelValue = (halftoneRegionFlags >> 7) & 1;
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halftoneRegion.gridWidth = readUint32(data, position);
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halftoneRegion.gridWidth = view.getUint32(position);
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position += 4;
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halftoneRegion.gridHeight = readUint32(data, position);
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halftoneRegion.gridHeight = view.getUint32(position);
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position += 4;
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halftoneRegion.gridOffsetX = readUint32(data, position) & 0xffffffff;
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halftoneRegion.gridOffsetX = view.getUint32(position) & 0xffffffff;
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position += 4;
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halftoneRegion.gridOffsetY = readUint32(data, position) & 0xffffffff;
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halftoneRegion.gridOffsetY = view.getUint32(position) & 0xffffffff;
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position += 4;
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halftoneRegion.gridVectorX = readUint16(data, position);
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halftoneRegion.gridVectorX = view.getUint16(position);
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position += 2;
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halftoneRegion.gridVectorY = readUint16(data, position);
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halftoneRegion.gridVectorY = view.getUint16(position);
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position += 2;
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args = [halftoneRegion, header.referredTo, data, position, end];
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break;
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case 38: // ImmediateGenericRegion
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case 39: // ImmediateLosslessGenericRegion
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const genericRegion = {};
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genericRegion.info = readRegionSegmentInformation(data, position);
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genericRegion.info = readRegionSegmentInformation(data, view, position);
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position += RegionSegmentInformationFieldLength;
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const genericRegionSegmentFlags = data[position++];
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genericRegion.mmr = !!(genericRegionSegmentFlags & 1);
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@ -1448,8 +1441,8 @@ function processSegment(segment, visitor) {
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at = [];
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for (i = 0; i < atLength; i++) {
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at.push({
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x: readInt8(data, position),
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y: readInt8(data, position + 1),
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x: view.getInt8(position),
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y: view.getInt8(position + 1),
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});
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position += 2;
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}
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@ -1459,16 +1452,16 @@ function processSegment(segment, visitor) {
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break;
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case 48: // PageInformation
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const pageInfo = {
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width: readUint32(data, position),
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height: readUint32(data, position + 4),
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resolutionX: readUint32(data, position + 8),
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resolutionY: readUint32(data, position + 12),
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width: view.getUint32(position),
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height: view.getUint32(position + 4),
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resolutionX: view.getUint32(position + 8),
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resolutionY: view.getUint32(position + 12),
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};
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if (pageInfo.height === 0xffffffff) {
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delete pageInfo.height;
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}
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const pageSegmentFlags = data[position + 16];
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readUint16(data, position + 17); // pageStripingInformation
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view.getUint16(position + 17); // pageStripingInformation
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pageInfo.lossless = !!(pageSegmentFlags & 1);
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pageInfo.refinement = !!(pageSegmentFlags & 2);
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pageInfo.defaultPixelValue = (pageSegmentFlags >> 2) & 1;
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@ -1484,7 +1477,7 @@ function processSegment(segment, visitor) {
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case 51: // EndOfFile
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break;
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case 53: // Tables
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args = [header.number, data, position, end];
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args = [header.number, data, view, position, end];
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break;
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case 62: // 7.4.15 defines 2 extension types which
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// are comments and can be ignored.
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@ -1494,11 +1487,8 @@ function processSegment(segment, visitor) {
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`segment type ${header.typeName}(${header.type}) is not implemented`
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);
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}
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const callbackName = "on" + header.typeName;
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if (callbackName in visitor) {
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// eslint-disable-next-line prefer-spread
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visitor[callbackName].apply(visitor, args);
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}
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// eslint-disable-next-line prefer-spread
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visitor["on" + header.typeName]?.apply(visitor, args);
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}
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function processSegments(segments, visitor) {
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@ -1521,6 +1511,7 @@ function parseJbig2(data) {
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if (typeof PDFJSDev === "undefined" || !PDFJSDev.test("IMAGE_DECODERS")) {
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throw new Error("Not implemented: parseJbig2");
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}
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const view = new DataView(data.buffer, data.byteOffset, data.byteLength);
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const end = data.length;
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let position = 0;
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@ -1542,7 +1533,7 @@ function parseJbig2(data) {
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const flags = data[position++];
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header.randomAccess = !(flags & 1);
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if (!(flags & 2)) {
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header.numberOfPages = readUint32(data, position);
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header.numberOfPages = view.getUint32(position);
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position += 4;
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}
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@ -1803,9 +1794,9 @@ class SimpleSegmentVisitor {
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this.onImmediateHalftoneRegion(...arguments);
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}
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onTables(currentSegment, data, start, end) {
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onTables(currentSegment, data, view, start, end) {
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const customTables = (this.customTables ||= {});
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customTables[currentSegment] = decodeTablesSegment(data, start, end);
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customTables[currentSegment] = decodeTablesSegment(data, view, start, end);
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}
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}
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@ -1931,12 +1922,12 @@ class HuffmanTable {
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}
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}
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function decodeTablesSegment(data, start, end) {
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function decodeTablesSegment(data, view, start, end) {
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// Decodes a Tables segment, i.e., a custom Huffman table.
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// Annex B.2 Code table structure.
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const flags = data[start];
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const lowestValue = readUint32(data, start + 1) & 0xffffffff;
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const highestValue = readUint32(data, start + 5) & 0xffffffff;
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const lowestValue = view.getUint32(start + 1) & 0xffffffff;
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const highestValue = view.getUint32(start + 5) & 0xffffffff;
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const reader = new Reader(data, start + 9, end);
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const prefixSizeBits = ((flags >> 1) & 7) + 1;
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