pdf.js/src/core/document.js

1825 lines
51 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 {
AnnotationEditorPrefix,
assert,
FormatError,
info,
InvalidPDFException,
isArrayEqual,
PageActionEventType,
RenderingIntentFlag,
shadow,
stringToBytes,
stringToPDFString,
stringToUTF8String,
unreachable,
Util,
warn,
} from "../shared/util.js";
import { AnnotationFactory, PopupAnnotation } from "./annotation.js";
import {
collectActions,
getInheritableProperty,
getNewAnnotationsMap,
isWhiteSpace,
MissingDataException,
PDF_VERSION_REGEXP,
validateCSSFont,
XRefEntryException,
XRefParseException,
} from "./core_utils.js";
import { Dict, isName, isRefsEqual, Name, Ref, RefSet } from "./primitives.js";
import { getXfaFontDict, getXfaFontName } from "./xfa_fonts.js";
import { BaseStream } from "./base_stream.js";
import { calculateMD5 } from "./crypto.js";
import { Catalog } from "./catalog.js";
import { clearGlobalCaches } from "./cleanup_helper.js";
import { DatasetReader } from "./dataset_reader.js";
import { Linearization } from "./parser.js";
import { NullStream } from "./stream.js";
import { ObjectLoader } from "./object_loader.js";
import { OperatorList } from "./operator_list.js";
import { PartialEvaluator } from "./evaluator.js";
import { StreamsSequenceStream } from "./decode_stream.js";
import { StructTreePage } from "./struct_tree.js";
import { writeObject } from "./writer.js";
import { XFAFactory } from "./xfa/factory.js";
import { XRef } from "./xref.js";
const DEFAULT_USER_UNIT = 1.0;
const LETTER_SIZE_MEDIABOX = [0, 0, 612, 792];
class Page {
constructor({
pdfManager,
xref,
pageIndex,
pageDict,
ref,
globalIdFactory,
fontCache,
builtInCMapCache,
standardFontDataCache,
globalImageCache,
systemFontCache,
nonBlendModesSet,
xfaFactory,
}) {
this.pdfManager = pdfManager;
this.pageIndex = pageIndex;
this.pageDict = pageDict;
this.xref = xref;
this.ref = ref;
this.fontCache = fontCache;
this.builtInCMapCache = builtInCMapCache;
this.standardFontDataCache = standardFontDataCache;
this.globalImageCache = globalImageCache;
this.systemFontCache = systemFontCache;
this.nonBlendModesSet = nonBlendModesSet;
this.evaluatorOptions = pdfManager.evaluatorOptions;
this.resourcesPromise = null;
this.xfaFactory = xfaFactory;
const idCounters = {
obj: 0,
};
this._localIdFactory = class extends globalIdFactory {
static createObjId() {
return `p${pageIndex}_${++idCounters.obj}`;
}
static getPageObjId() {
return `p${ref.toString()}`;
}
};
}
/**
* @private
*/
_getInheritableProperty(key, getArray = false) {
const value = getInheritableProperty({
dict: this.pageDict,
key,
getArray,
stopWhenFound: false,
});
if (!Array.isArray(value)) {
return value;
}
if (value.length === 1 || !(value[0] instanceof Dict)) {
return value[0];
}
return Dict.merge({ xref: this.xref, dictArray: value });
}
get content() {
return this.pageDict.getArray("Contents");
}
get resources() {
// For robustness: The spec states that a \Resources entry has to be
// present, but can be empty. Some documents still omit it; in this case
// we return an empty dictionary.
const resources = this._getInheritableProperty("Resources");
return shadow(
this,
"resources",
resources instanceof Dict ? resources : Dict.empty
);
}
_getBoundingBox(name) {
if (this.xfaData) {
return this.xfaData.bbox;
}
let box = this._getInheritableProperty(name, /* getArray = */ true);
if (Array.isArray(box) && box.length === 4) {
box = Util.normalizeRect(box);
if (box[2] - box[0] > 0 && box[3] - box[1] > 0) {
return box;
}
warn(`Empty, or invalid, /${name} entry.`);
}
return null;
}
get mediaBox() {
// Reset invalid media box to letter size.
return shadow(
this,
"mediaBox",
this._getBoundingBox("MediaBox") || LETTER_SIZE_MEDIABOX
);
}
get cropBox() {
// Reset invalid crop box to media box.
return shadow(
this,
"cropBox",
this._getBoundingBox("CropBox") || this.mediaBox
);
}
get userUnit() {
let obj = this.pageDict.get("UserUnit");
if (typeof obj !== "number" || obj <= 0) {
obj = DEFAULT_USER_UNIT;
}
return shadow(this, "userUnit", obj);
}
get view() {
// From the spec, 6th ed., p.963:
// "The crop, bleed, trim, and art boxes should not ordinarily
// extend beyond the boundaries of the media box. If they do, they are
// effectively reduced to their intersection with the media box."
const { cropBox, mediaBox } = this;
if (cropBox !== mediaBox && !isArrayEqual(cropBox, mediaBox)) {
const box = Util.intersect(cropBox, mediaBox);
if (box && box[2] - box[0] > 0 && box[3] - box[1] > 0) {
return shadow(this, "view", box);
}
warn("Empty /CropBox and /MediaBox intersection.");
}
return shadow(this, "view", mediaBox);
}
get rotate() {
let rotate = this._getInheritableProperty("Rotate") || 0;
// Normalize rotation so it's a multiple of 90 and between 0 and 270.
if (rotate % 90 !== 0) {
rotate = 0;
} else if (rotate >= 360) {
rotate %= 360;
} else if (rotate < 0) {
// The spec doesn't cover negatives. Assume it's counterclockwise
// rotation. The following is the other implementation of modulo.
rotate = ((rotate % 360) + 360) % 360;
}
return shadow(this, "rotate", rotate);
}
/**
* @private
*/
_onSubStreamError(reason, objId) {
if (this.evaluatorOptions.ignoreErrors) {
warn(`getContentStream - ignoring sub-stream (${objId}): "${reason}".`);
return;
}
throw reason;
}
/**
* @returns {Promise<BaseStream>}
*/
getContentStream() {
return this.pdfManager.ensure(this, "content").then(content => {
if (content instanceof BaseStream) {
return content;
}
if (Array.isArray(content)) {
return new StreamsSequenceStream(
content,
this._onSubStreamError.bind(this)
);
}
// Replace non-existent page content with empty content.
return new NullStream();
});
}
get xfaData() {
return shadow(
this,
"xfaData",
this.xfaFactory
? { bbox: this.xfaFactory.getBoundingBox(this.pageIndex) }
: null
);
}
#replaceIdByRef(annotations, deletedAnnotations, existingAnnotations) {
for (const annotation of annotations) {
if (annotation.id) {
const ref = Ref.fromString(annotation.id);
if (!ref) {
warn(`A non-linked annotation cannot be modified: ${annotation.id}`);
continue;
}
if (annotation.deleted) {
deletedAnnotations.put(ref);
continue;
}
existingAnnotations?.put(ref);
annotation.ref = ref;
delete annotation.id;
}
}
}
async saveNewAnnotations(handler, task, annotations, imagePromises) {
if (this.xfaFactory) {
throw new Error("XFA: Cannot save new annotations.");
}
const partialEvaluator = new PartialEvaluator({
xref: this.xref,
handler,
pageIndex: this.pageIndex,
idFactory: this._localIdFactory,
fontCache: this.fontCache,
builtInCMapCache: this.builtInCMapCache,
standardFontDataCache: this.standardFontDataCache,
globalImageCache: this.globalImageCache,
systemFontCache: this.systemFontCache,
options: this.evaluatorOptions,
});
const deletedAnnotations = new RefSet();
const existingAnnotations = new RefSet();
this.#replaceIdByRef(annotations, deletedAnnotations, existingAnnotations);
const pageDict = this.pageDict;
const annotationsArray = this.annotations.filter(
a => !(a instanceof Ref && deletedAnnotations.has(a))
);
const newData = await AnnotationFactory.saveNewAnnotations(
partialEvaluator,
task,
annotations,
imagePromises
);
for (const { ref } of newData.annotations) {
// Don't add an existing annotation ref to the annotations array.
if (ref instanceof Ref && !existingAnnotations.has(ref)) {
annotationsArray.push(ref);
}
}
const savedDict = pageDict.get("Annots");
pageDict.set("Annots", annotationsArray);
const buffer = [];
let transform = null;
if (this.xref.encrypt) {
transform = this.xref.encrypt.createCipherTransform(
this.ref.num,
this.ref.gen
);
}
await writeObject(this.ref, pageDict, buffer, transform);
if (savedDict) {
pageDict.set("Annots", savedDict);
}
const objects = newData.dependencies;
objects.push(
{ ref: this.ref, data: buffer.join("") },
...newData.annotations
);
return objects;
}
save(handler, task, annotationStorage) {
const partialEvaluator = new PartialEvaluator({
xref: this.xref,
handler,
pageIndex: this.pageIndex,
idFactory: this._localIdFactory,
fontCache: this.fontCache,
builtInCMapCache: this.builtInCMapCache,
standardFontDataCache: this.standardFontDataCache,
globalImageCache: this.globalImageCache,
systemFontCache: this.systemFontCache,
options: this.evaluatorOptions,
});
// Fetch the page's annotations and save the content
// in case of interactive form fields.
return this._parsedAnnotations.then(function (annotations) {
const newRefsPromises = [];
for (const annotation of annotations) {
if (!annotation.mustBePrinted(annotationStorage)) {
continue;
}
newRefsPromises.push(
annotation
.save(partialEvaluator, task, annotationStorage)
.catch(function (reason) {
warn(
"save - ignoring annotation data during " +
`"${task.name}" task: "${reason}".`
);
return null;
})
);
}
return Promise.all(newRefsPromises).then(function (newRefs) {
return newRefs.filter(newRef => !!newRef);
});
});
}
loadResources(keys) {
if (!this.resourcesPromise) {
// TODO: add async `_getInheritableProperty` and remove this.
this.resourcesPromise = this.pdfManager.ensure(this, "resources");
}
return this.resourcesPromise.then(() => {
const objectLoader = new ObjectLoader(this.resources, keys, this.xref);
return objectLoader.load();
});
}
getOperatorList({
handler,
sink,
task,
intent,
cacheKey,
annotationStorage = null,
}) {
const contentStreamPromise = this.getContentStream();
const resourcesPromise = this.loadResources([
"ColorSpace",
"ExtGState",
"Font",
"Pattern",
"Properties",
"Shading",
"XObject",
]);
const partialEvaluator = new PartialEvaluator({
xref: this.xref,
handler,
pageIndex: this.pageIndex,
idFactory: this._localIdFactory,
fontCache: this.fontCache,
builtInCMapCache: this.builtInCMapCache,
standardFontDataCache: this.standardFontDataCache,
globalImageCache: this.globalImageCache,
systemFontCache: this.systemFontCache,
options: this.evaluatorOptions,
});
const newAnnotationsByPage = !this.xfaFactory
? getNewAnnotationsMap(annotationStorage)
: null;
let deletedAnnotations = null;
let newAnnotationsPromise = Promise.resolve(null);
if (newAnnotationsByPage) {
let imagePromises;
const newAnnotations = newAnnotationsByPage.get(this.pageIndex);
if (newAnnotations) {
// An annotation can contain a reference to a bitmap, but this bitmap
// is defined in another annotation. So we need to find this annotation
// and generate the bitmap.
const missingBitmaps = new Set();
for (const { bitmapId, bitmap } of newAnnotations) {
if (bitmapId && !bitmap && !missingBitmaps.has(bitmapId)) {
missingBitmaps.add(bitmapId);
}
}
const { isOffscreenCanvasSupported } = this.evaluatorOptions;
if (missingBitmaps.size > 0) {
const annotationWithBitmaps = newAnnotations.slice();
for (const [key, annotation] of annotationStorage) {
if (!key.startsWith(AnnotationEditorPrefix)) {
continue;
}
if (annotation.bitmap && missingBitmaps.has(annotation.bitmapId)) {
annotationWithBitmaps.push(annotation);
}
}
// The array annotationWithBitmaps cannot be empty: the check above
// makes sure to have at least one annotation containing the bitmap.
imagePromises = AnnotationFactory.generateImages(
annotationWithBitmaps,
this.xref,
isOffscreenCanvasSupported
);
} else {
imagePromises = AnnotationFactory.generateImages(
newAnnotations,
this.xref,
isOffscreenCanvasSupported
);
}
deletedAnnotations = new RefSet();
this.#replaceIdByRef(newAnnotations, deletedAnnotations, null);
newAnnotationsPromise = AnnotationFactory.printNewAnnotations(
partialEvaluator,
task,
newAnnotations,
imagePromises
);
}
}
const dataPromises = Promise.all([contentStreamPromise, resourcesPromise]);
const pageListPromise = dataPromises.then(([contentStream]) => {
const opList = new OperatorList(intent, sink);
handler.send("StartRenderPage", {
transparency: partialEvaluator.hasBlendModes(
this.resources,
this.nonBlendModesSet
),
pageIndex: this.pageIndex,
cacheKey,
});
return partialEvaluator
.getOperatorList({
stream: contentStream,
task,
resources: this.resources,
operatorList: opList,
})
.then(function () {
return opList;
});
});
// Fetch the page's annotations and add their operator lists to the
// page's operator list to render them.
return Promise.all([
pageListPromise,
this._parsedAnnotations,
newAnnotationsPromise,
]).then(function ([pageOpList, annotations, newAnnotations]) {
if (newAnnotations) {
// Some annotations can already exist (if it has the refToReplace
// property). In this case, we replace the old annotation by the new
// one.
annotations = annotations.filter(
a => !(a.ref && deletedAnnotations.has(a.ref))
);
for (let i = 0, ii = newAnnotations.length; i < ii; i++) {
const newAnnotation = newAnnotations[i];
if (newAnnotation.refToReplace) {
const j = annotations.findIndex(
a => a.ref && isRefsEqual(a.ref, newAnnotation.refToReplace)
);
if (j >= 0) {
annotations.splice(j, 1, newAnnotation);
newAnnotations.splice(i--, 1);
ii--;
}
}
}
annotations = annotations.concat(newAnnotations);
}
if (
annotations.length === 0 ||
intent & RenderingIntentFlag.ANNOTATIONS_DISABLE
) {
pageOpList.flush(/* lastChunk = */ true);
return { length: pageOpList.totalLength };
}
const renderForms = !!(intent & RenderingIntentFlag.ANNOTATIONS_FORMS),
intentAny = !!(intent & RenderingIntentFlag.ANY),
intentDisplay = !!(intent & RenderingIntentFlag.DISPLAY),
intentPrint = !!(intent & RenderingIntentFlag.PRINT);
// Collect the operator list promises for the annotations. Each promise
// is resolved with the complete operator list for a single annotation.
const opListPromises = [];
for (const annotation of annotations) {
if (
intentAny ||
(intentDisplay &&
annotation.mustBeViewed(annotationStorage, renderForms)) ||
(intentPrint && annotation.mustBePrinted(annotationStorage))
) {
opListPromises.push(
annotation
.getOperatorList(
partialEvaluator,
task,
intent,
renderForms,
annotationStorage
)
.catch(function (reason) {
warn(
"getOperatorList - ignoring annotation data during " +
`"${task.name}" task: "${reason}".`
);
return {
opList: null,
separateForm: false,
separateCanvas: false,
};
})
);
}
}
return Promise.all(opListPromises).then(function (opLists) {
let form = false,
canvas = false;
for (const { opList, separateForm, separateCanvas } of opLists) {
pageOpList.addOpList(opList);
form ||= separateForm;
canvas ||= separateCanvas;
}
pageOpList.flush(
/* lastChunk = */ true,
/* separateAnnots = */ { form, canvas }
);
return { length: pageOpList.totalLength };
});
});
}
extractTextContent({
handler,
task,
includeMarkedContent,
disableNormalization,
sink,
}) {
const contentStreamPromise = this.getContentStream();
const resourcesPromise = this.loadResources([
"ExtGState",
"Font",
"Properties",
"XObject",
]);
const dataPromises = Promise.all([contentStreamPromise, resourcesPromise]);
return dataPromises.then(([contentStream]) => {
const partialEvaluator = new PartialEvaluator({
xref: this.xref,
handler,
pageIndex: this.pageIndex,
idFactory: this._localIdFactory,
fontCache: this.fontCache,
builtInCMapCache: this.builtInCMapCache,
standardFontDataCache: this.standardFontDataCache,
globalImageCache: this.globalImageCache,
systemFontCache: this.systemFontCache,
options: this.evaluatorOptions,
});
return partialEvaluator.getTextContent({
stream: contentStream,
task,
resources: this.resources,
includeMarkedContent,
disableNormalization,
sink,
viewBox: this.view,
});
});
}
async getStructTree() {
const structTreeRoot = await this.pdfManager.ensureCatalog(
"structTreeRoot"
);
if (!structTreeRoot) {
return null;
}
const structTree = await this.pdfManager.ensure(this, "_parseStructTree", [
structTreeRoot,
]);
return structTree.serializable;
}
/**
* @private
*/
_parseStructTree(structTreeRoot) {
const tree = new StructTreePage(structTreeRoot, this.pageDict);
tree.parse();
return tree;
}
async getAnnotationsData(handler, task, intent) {
const annotations = await this._parsedAnnotations;
if (annotations.length === 0) {
return [];
}
const annotationsData = [],
textContentPromises = [];
let partialEvaluator;
const intentAny = !!(intent & RenderingIntentFlag.ANY),
intentDisplay = !!(intent & RenderingIntentFlag.DISPLAY),
intentPrint = !!(intent & RenderingIntentFlag.PRINT);
for (const annotation of annotations) {
// Get the annotation even if it's hidden because
// JS can change its display.
const isVisible = intentAny || (intentDisplay && annotation.viewable);
if (isVisible || (intentPrint && annotation.printable)) {
annotationsData.push(annotation.data);
}
if (annotation.hasTextContent && isVisible) {
partialEvaluator ||= new PartialEvaluator({
xref: this.xref,
handler,
pageIndex: this.pageIndex,
idFactory: this._localIdFactory,
fontCache: this.fontCache,
builtInCMapCache: this.builtInCMapCache,
standardFontDataCache: this.standardFontDataCache,
globalImageCache: this.globalImageCache,
systemFontCache: this.systemFontCache,
options: this.evaluatorOptions,
});
textContentPromises.push(
annotation
.extractTextContent(partialEvaluator, task, [
-Infinity,
-Infinity,
Infinity,
Infinity,
])
.catch(function (reason) {
warn(
`getAnnotationsData - ignoring textContent during "${task.name}" task: "${reason}".`
);
})
);
}
}
await Promise.all(textContentPromises);
return annotationsData;
}
get annotations() {
const annots = this._getInheritableProperty("Annots");
return shadow(this, "annotations", Array.isArray(annots) ? annots : []);
}
get _parsedAnnotations() {
const parsedAnnotations = this.pdfManager
.ensure(this, "annotations")
.then(() => {
const annotationPromises = [];
for (const annotationRef of this.annotations) {
annotationPromises.push(
AnnotationFactory.create(
this.xref,
annotationRef,
this.pdfManager,
this._localIdFactory,
/* collectFields */ false
).catch(function (reason) {
warn(`_parsedAnnotations: "${reason}".`);
return null;
})
);
}
return Promise.all(annotationPromises).then(function (annotations) {
if (annotations.length === 0) {
return annotations;
}
const sortedAnnotations = [];
let popupAnnotations;
// Ensure that PopupAnnotations are handled last, since they depend on
// their parent Annotation in the display layer; fixes issue 11362.
for (const annotation of annotations) {
if (!annotation) {
continue;
}
if (annotation instanceof PopupAnnotation) {
(popupAnnotations ||= []).push(annotation);
continue;
}
sortedAnnotations.push(annotation);
}
if (popupAnnotations) {
sortedAnnotations.push(...popupAnnotations);
}
return sortedAnnotations;
});
});
return shadow(this, "_parsedAnnotations", parsedAnnotations);
}
get jsActions() {
const actions = collectActions(
this.xref,
this.pageDict,
PageActionEventType
);
return shadow(this, "jsActions", actions);
}
}
const PDF_HEADER_SIGNATURE = new Uint8Array([0x25, 0x50, 0x44, 0x46, 0x2d]);
const STARTXREF_SIGNATURE = new Uint8Array([
0x73, 0x74, 0x61, 0x72, 0x74, 0x78, 0x72, 0x65, 0x66,
]);
const ENDOBJ_SIGNATURE = new Uint8Array([0x65, 0x6e, 0x64, 0x6f, 0x62, 0x6a]);
const FINGERPRINT_FIRST_BYTES = 1024;
const EMPTY_FINGERPRINT =
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00";
function find(stream, signature, limit = 1024, backwards = false) {
if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
assert(limit > 0, 'The "limit" must be a positive integer.');
}
const signatureLength = signature.length;
const scanBytes = stream.peekBytes(limit);
const scanLength = scanBytes.length - signatureLength;
if (scanLength <= 0) {
return false;
}
if (backwards) {
const signatureEnd = signatureLength - 1;
let pos = scanBytes.length - 1;
while (pos >= signatureEnd) {
let j = 0;
while (
j < signatureLength &&
scanBytes[pos - j] === signature[signatureEnd - j]
) {
j++;
}
if (j >= signatureLength) {
// `signature` found.
stream.pos += pos - signatureEnd;
return true;
}
pos--;
}
} else {
// forwards
let pos = 0;
while (pos <= scanLength) {
let j = 0;
while (j < signatureLength && scanBytes[pos + j] === signature[j]) {
j++;
}
if (j >= signatureLength) {
// `signature` found.
stream.pos += pos;
return true;
}
pos++;
}
}
return false;
}
/**
* The `PDFDocument` class holds all the (worker-thread) data of the PDF file.
*/
class PDFDocument {
constructor(pdfManager, stream) {
if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
assert(
stream instanceof BaseStream,
'PDFDocument: Invalid "stream" argument.'
);
}
if (stream.length <= 0) {
throw new InvalidPDFException(
"The PDF file is empty, i.e. its size is zero bytes."
);
}
this.pdfManager = pdfManager;
this.stream = stream;
this.xref = new XRef(stream, pdfManager);
this._pagePromises = new Map();
this._version = null;
const idCounters = {
font: 0,
};
this._globalIdFactory = class {
static getDocId() {
return `g_${pdfManager.docId}`;
}
static createFontId() {
return `f${++idCounters.font}`;
}
static createObjId() {
unreachable("Abstract method `createObjId` called.");
}
static getPageObjId() {
unreachable("Abstract method `getPageObjId` called.");
}
};
}
parse(recoveryMode) {
this.xref.parse(recoveryMode);
this.catalog = new Catalog(this.pdfManager, this.xref);
}
get linearization() {
let linearization = null;
try {
linearization = Linearization.create(this.stream);
} catch (err) {
if (err instanceof MissingDataException) {
throw err;
}
info(err);
}
return shadow(this, "linearization", linearization);
}
get startXRef() {
const stream = this.stream;
let startXRef = 0;
if (this.linearization) {
// Find the end of the first object.
stream.reset();
if (find(stream, ENDOBJ_SIGNATURE)) {
startXRef = stream.pos + 6 - stream.start;
}
} else {
// Find `startxref` by checking backwards from the end of the file.
const step = 1024;
const startXRefLength = STARTXREF_SIGNATURE.length;
let found = false,
pos = stream.end;
while (!found && pos > 0) {
pos -= step - startXRefLength;
if (pos < 0) {
pos = 0;
}
stream.pos = pos;
found = find(stream, STARTXREF_SIGNATURE, step, true);
}
if (found) {
stream.skip(9);
let ch;
do {
ch = stream.getByte();
} while (isWhiteSpace(ch));
let str = "";
while (ch >= /* Space = */ 0x20 && ch <= /* '9' = */ 0x39) {
str += String.fromCharCode(ch);
ch = stream.getByte();
}
startXRef = parseInt(str, 10);
if (isNaN(startXRef)) {
startXRef = 0;
}
}
}
return shadow(this, "startXRef", startXRef);
}
// Find the header, get the PDF format version and setup the
// stream to start from the header.
checkHeader() {
const stream = this.stream;
stream.reset();
if (!find(stream, PDF_HEADER_SIGNATURE)) {
// May not be a PDF file, but don't throw an error and let
// parsing continue.
return;
}
stream.moveStart();
// Skip over the "%PDF-" prefix, since it was found above.
stream.skip(PDF_HEADER_SIGNATURE.length);
// Read the PDF format version.
let version = "",
ch;
while (
(ch = stream.getByte()) > /* Space = */ 0x20 &&
version.length < /* MAX_PDF_VERSION_LENGTH = */ 7
) {
version += String.fromCharCode(ch);
}
if (PDF_VERSION_REGEXP.test(version)) {
this._version = version;
} else {
warn(`Invalid PDF header version: ${version}`);
}
}
parseStartXRef() {
this.xref.setStartXRef(this.startXRef);
}
get numPages() {
let num = 0;
if (this.catalog.hasActualNumPages) {
num = this.catalog.numPages;
} else if (this.xfaFactory) {
// num is a Promise.
num = this.xfaFactory.getNumPages();
} else if (this.linearization) {
num = this.linearization.numPages;
} else {
num = this.catalog.numPages;
}
return shadow(this, "numPages", num);
}
/**
* @private
*/
_hasOnlyDocumentSignatures(fields, recursionDepth = 0) {
const RECURSION_LIMIT = 10;
if (!Array.isArray(fields)) {
return false;
}
return fields.every(field => {
field = this.xref.fetchIfRef(field);
if (!(field instanceof Dict)) {
return false;
}
if (field.has("Kids")) {
if (++recursionDepth > RECURSION_LIMIT) {
warn("_hasOnlyDocumentSignatures: maximum recursion depth reached");
return false;
}
return this._hasOnlyDocumentSignatures(
field.get("Kids"),
recursionDepth
);
}
const isSignature = isName(field.get("FT"), "Sig");
const rectangle = field.get("Rect");
const isInvisible =
Array.isArray(rectangle) && rectangle.every(value => value === 0);
return isSignature && isInvisible;
});
}
get _xfaStreams() {
const acroForm = this.catalog.acroForm;
if (!acroForm) {
return null;
}
const xfa = acroForm.get("XFA");
const entries = {
"xdp:xdp": "",
template: "",
datasets: "",
config: "",
connectionSet: "",
localeSet: "",
stylesheet: "",
"/xdp:xdp": "",
};
if (xfa instanceof BaseStream && !xfa.isEmpty) {
entries["xdp:xdp"] = xfa;
return entries;
}
if (!Array.isArray(xfa) || xfa.length === 0) {
return null;
}
for (let i = 0, ii = xfa.length; i < ii; i += 2) {
let name;
if (i === 0) {
name = "xdp:xdp";
} else if (i === ii - 2) {
name = "/xdp:xdp";
} else {
name = xfa[i];
}
if (!entries.hasOwnProperty(name)) {
continue;
}
const data = this.xref.fetchIfRef(xfa[i + 1]);
if (!(data instanceof BaseStream) || data.isEmpty) {
continue;
}
entries[name] = data;
}
return entries;
}
get xfaDatasets() {
const streams = this._xfaStreams;
if (!streams) {
return shadow(this, "xfaDatasets", null);
}
for (const key of ["datasets", "xdp:xdp"]) {
const stream = streams[key];
if (!stream) {
continue;
}
try {
const str = stringToUTF8String(stream.getString());
const data = { [key]: str };
return shadow(this, "xfaDatasets", new DatasetReader(data));
} catch {
warn("XFA - Invalid utf-8 string.");
break;
}
}
return shadow(this, "xfaDatasets", null);
}
get xfaData() {
const streams = this._xfaStreams;
if (!streams) {
return null;
}
const data = Object.create(null);
for (const [key, stream] of Object.entries(streams)) {
if (!stream) {
continue;
}
try {
data[key] = stringToUTF8String(stream.getString());
} catch {
warn("XFA - Invalid utf-8 string.");
return null;
}
}
return data;
}
get xfaFactory() {
let data;
if (
this.pdfManager.enableXfa &&
this.catalog.needsRendering &&
this.formInfo.hasXfa &&
!this.formInfo.hasAcroForm
) {
data = this.xfaData;
}
return shadow(this, "xfaFactory", data ? new XFAFactory(data) : null);
}
get isPureXfa() {
return this.xfaFactory ? this.xfaFactory.isValid() : false;
}
get htmlForXfa() {
return this.xfaFactory ? this.xfaFactory.getPages() : null;
}
async loadXfaImages() {
const xfaImagesDict = await this.pdfManager.ensureCatalog("xfaImages");
if (!xfaImagesDict) {
return;
}
const keys = xfaImagesDict.getKeys();
const objectLoader = new ObjectLoader(xfaImagesDict, keys, this.xref);
await objectLoader.load();
const xfaImages = new Map();
for (const key of keys) {
const stream = xfaImagesDict.get(key);
if (stream instanceof BaseStream) {
xfaImages.set(key, stream.getBytes());
}
}
this.xfaFactory.setImages(xfaImages);
}
async loadXfaFonts(handler, task) {
const acroForm = await this.pdfManager.ensureCatalog("acroForm");
if (!acroForm) {
return;
}
const resources = await acroForm.getAsync("DR");
if (!(resources instanceof Dict)) {
return;
}
const objectLoader = new ObjectLoader(resources, ["Font"], this.xref);
await objectLoader.load();
const fontRes = resources.get("Font");
if (!(fontRes instanceof Dict)) {
return;
}
const options = Object.assign(
Object.create(null),
this.pdfManager.evaluatorOptions
);
options.useSystemFonts = false;
const partialEvaluator = new PartialEvaluator({
xref: this.xref,
handler,
pageIndex: -1,
idFactory: this._globalIdFactory,
fontCache: this.catalog.fontCache,
builtInCMapCache: this.catalog.builtInCMapCache,
standardFontDataCache: this.catalog.standardFontDataCache,
options,
});
const operatorList = new OperatorList();
const pdfFonts = [];
const initialState = {
get font() {
return pdfFonts.at(-1);
},
set font(font) {
pdfFonts.push(font);
},
clone() {
return this;
},
};
const fonts = new Map();
fontRes.forEach((fontName, font) => {
fonts.set(fontName, font);
});
const promises = [];
for (const [fontName, font] of fonts) {
const descriptor = font.get("FontDescriptor");
if (!(descriptor instanceof Dict)) {
continue;
}
let fontFamily = descriptor.get("FontFamily");
// For example, "Wingdings 3" is not a valid font name in the css specs.
fontFamily = fontFamily.replaceAll(/[ ]+(\d)/g, "$1");
const fontWeight = descriptor.get("FontWeight");
// Angle is expressed in degrees counterclockwise in PDF
// when it's clockwise in CSS
// (see https://drafts.csswg.org/css-fonts-4/#valdef-font-style-oblique-angle)
const italicAngle = -descriptor.get("ItalicAngle");
const cssFontInfo = { fontFamily, fontWeight, italicAngle };
if (!validateCSSFont(cssFontInfo)) {
continue;
}
promises.push(
partialEvaluator
.handleSetFont(
resources,
[Name.get(fontName), 1],
/* fontRef = */ null,
operatorList,
task,
initialState,
/* fallbackFontDict = */ null,
/* cssFontInfo = */ cssFontInfo
)
.catch(function (reason) {
warn(`loadXfaFonts: "${reason}".`);
return null;
})
);
}
await Promise.all(promises);
const missingFonts = this.xfaFactory.setFonts(pdfFonts);
if (!missingFonts) {
return;
}
options.ignoreErrors = true;
promises.length = 0;
pdfFonts.length = 0;
const reallyMissingFonts = new Set();
for (const missing of missingFonts) {
if (!getXfaFontName(`${missing}-Regular`)) {
// No substitution available: we'll fallback on Myriad.
reallyMissingFonts.add(missing);
}
}
if (reallyMissingFonts.size) {
missingFonts.push("PdfJS-Fallback");
}
for (const missing of missingFonts) {
if (reallyMissingFonts.has(missing)) {
continue;
}
for (const fontInfo of [
{ name: "Regular", fontWeight: 400, italicAngle: 0 },
{ name: "Bold", fontWeight: 700, italicAngle: 0 },
{ name: "Italic", fontWeight: 400, italicAngle: 12 },
{ name: "BoldItalic", fontWeight: 700, italicAngle: 12 },
]) {
const name = `${missing}-${fontInfo.name}`;
const dict = getXfaFontDict(name);
promises.push(
partialEvaluator
.handleSetFont(
resources,
[Name.get(name), 1],
/* fontRef = */ null,
operatorList,
task,
initialState,
/* fallbackFontDict = */ dict,
/* cssFontInfo = */ {
fontFamily: missing,
fontWeight: fontInfo.fontWeight,
italicAngle: fontInfo.italicAngle,
}
)
.catch(function (reason) {
warn(`loadXfaFonts: "${reason}".`);
return null;
})
);
}
}
await Promise.all(promises);
this.xfaFactory.appendFonts(pdfFonts, reallyMissingFonts);
}
async serializeXfaData(annotationStorage) {
return this.xfaFactory
? this.xfaFactory.serializeData(annotationStorage)
: null;
}
/**
* The specification states in section 7.5.2 that the version from
* the catalog, if present, should overwrite the version from the header.
*/
get version() {
return this.catalog.version || this._version;
}
get formInfo() {
const formInfo = {
hasFields: false,
hasAcroForm: false,
hasXfa: false,
hasSignatures: false,
};
const acroForm = this.catalog.acroForm;
if (!acroForm) {
return shadow(this, "formInfo", formInfo);
}
try {
const fields = acroForm.get("Fields");
const hasFields = Array.isArray(fields) && fields.length > 0;
formInfo.hasFields = hasFields; // Used by the `fieldObjects` getter.
// The document contains XFA data if the `XFA` entry is a non-empty
// array or stream.
const xfa = acroForm.get("XFA");
formInfo.hasXfa =
(Array.isArray(xfa) && xfa.length > 0) ||
(xfa instanceof BaseStream && !xfa.isEmpty);
// The document contains AcroForm data if the `Fields` entry is a
// non-empty array and it doesn't consist of only document signatures.
// This second check is required for files that don't actually contain
// AcroForm data (only XFA data), but that use the `Fields` entry to
// store (invisible) document signatures. This can be detected using
// the first bit of the `SigFlags` integer (see Table 219 in the
// specification).
const sigFlags = acroForm.get("SigFlags");
const hasSignatures = !!(sigFlags & 0x1);
const hasOnlyDocumentSignatures =
hasSignatures && this._hasOnlyDocumentSignatures(fields);
formInfo.hasAcroForm = hasFields && !hasOnlyDocumentSignatures;
formInfo.hasSignatures = hasSignatures;
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
warn(`Cannot fetch form information: "${ex}".`);
}
return shadow(this, "formInfo", formInfo);
}
get documentInfo() {
const docInfo = {
PDFFormatVersion: this.version,
Language: this.catalog.lang,
EncryptFilterName: this.xref.encrypt
? this.xref.encrypt.filterName
: null,
IsLinearized: !!this.linearization,
IsAcroFormPresent: this.formInfo.hasAcroForm,
IsXFAPresent: this.formInfo.hasXfa,
IsCollectionPresent: !!this.catalog.collection,
IsSignaturesPresent: this.formInfo.hasSignatures,
};
let infoDict;
try {
infoDict = this.xref.trailer.get("Info");
} catch (err) {
if (err instanceof MissingDataException) {
throw err;
}
info("The document information dictionary is invalid.");
}
if (!(infoDict instanceof Dict)) {
return shadow(this, "documentInfo", docInfo);
}
for (const key of infoDict.getKeys()) {
const value = infoDict.get(key);
switch (key) {
case "Title":
case "Author":
case "Subject":
case "Keywords":
case "Creator":
case "Producer":
case "CreationDate":
case "ModDate":
if (typeof value === "string") {
docInfo[key] = stringToPDFString(value);
continue;
}
break;
case "Trapped":
if (value instanceof Name) {
docInfo[key] = value;
continue;
}
break;
default:
// For custom values, only accept white-listed types to prevent
// errors that would occur when trying to send non-serializable
// objects to the main-thread (for example `Dict` or `Stream`).
let customValue;
switch (typeof value) {
case "string":
customValue = stringToPDFString(value);
break;
case "number":
case "boolean":
customValue = value;
break;
default:
if (value instanceof Name) {
customValue = value;
}
break;
}
if (customValue === undefined) {
warn(`Bad value, for custom key "${key}", in Info: ${value}.`);
continue;
}
if (!docInfo.Custom) {
docInfo.Custom = Object.create(null);
}
docInfo.Custom[key] = customValue;
continue;
}
warn(`Bad value, for key "${key}", in Info: ${value}.`);
}
return shadow(this, "documentInfo", docInfo);
}
get fingerprints() {
function validate(data) {
return (
typeof data === "string" &&
data.length > 0 &&
data !== EMPTY_FINGERPRINT
);
}
function hexString(hash) {
const buf = [];
for (const num of hash) {
const hex = num.toString(16);
buf.push(hex.padStart(2, "0"));
}
return buf.join("");
}
const idArray = this.xref.trailer.get("ID");
let hashOriginal, hashModified;
if (Array.isArray(idArray) && validate(idArray[0])) {
hashOriginal = stringToBytes(idArray[0]);
if (idArray[1] !== idArray[0] && validate(idArray[1])) {
hashModified = stringToBytes(idArray[1]);
}
} else {
hashOriginal = calculateMD5(
this.stream.getByteRange(0, FINGERPRINT_FIRST_BYTES),
0,
FINGERPRINT_FIRST_BYTES
);
}
return shadow(this, "fingerprints", [
hexString(hashOriginal),
hashModified ? hexString(hashModified) : null,
]);
}
async _getLinearizationPage(pageIndex) {
const { catalog, linearization, xref } = this;
if (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) {
assert(
linearization?.pageFirst === pageIndex,
"_getLinearizationPage - invalid pageIndex argument."
);
}
const ref = Ref.get(linearization.objectNumberFirst, 0);
try {
const obj = await xref.fetchAsync(ref);
// Ensure that the object that was found is actually a Page dictionary.
if (obj instanceof Dict) {
let type = obj.getRaw("Type");
if (type instanceof Ref) {
type = await xref.fetchAsync(type);
}
if (isName(type, "Page") || (!obj.has("Type") && !obj.has("Kids"))) {
if (!catalog.pageKidsCountCache.has(ref)) {
catalog.pageKidsCountCache.put(ref, 1); // Cache the Page reference.
}
// Help improve performance of the `Catalog.getPageIndex` method.
if (!catalog.pageIndexCache.has(ref)) {
catalog.pageIndexCache.put(ref, 0);
}
return [obj, ref];
}
}
throw new FormatError(
"The Linearization dictionary doesn't point to a valid Page dictionary."
);
} catch (reason) {
warn(`_getLinearizationPage: "${reason.message}".`);
return catalog.getPageDict(pageIndex);
}
}
getPage(pageIndex) {
const cachedPromise = this._pagePromises.get(pageIndex);
if (cachedPromise) {
return cachedPromise;
}
const { catalog, linearization, xfaFactory } = this;
let promise;
if (xfaFactory) {
promise = Promise.resolve([Dict.empty, null]);
} else if (linearization?.pageFirst === pageIndex) {
promise = this._getLinearizationPage(pageIndex);
} else {
promise = catalog.getPageDict(pageIndex);
}
promise = promise.then(([pageDict, ref]) => {
return new Page({
pdfManager: this.pdfManager,
xref: this.xref,
pageIndex,
pageDict,
ref,
globalIdFactory: this._globalIdFactory,
fontCache: catalog.fontCache,
builtInCMapCache: catalog.builtInCMapCache,
standardFontDataCache: catalog.standardFontDataCache,
globalImageCache: catalog.globalImageCache,
systemFontCache: catalog.systemFontCache,
nonBlendModesSet: catalog.nonBlendModesSet,
xfaFactory,
});
});
this._pagePromises.set(pageIndex, promise);
return promise;
}
async checkFirstPage(recoveryMode = false) {
if (recoveryMode) {
return;
}
try {
await this.getPage(0);
} catch (reason) {
if (reason instanceof XRefEntryException) {
// Clear out the various caches to ensure that we haven't stored any
// inconsistent and/or incorrect state, since that could easily break
// subsequent `this.getPage` calls.
this._pagePromises.delete(0);
await this.cleanup();
throw new XRefParseException();
}
}
}
async checkLastPage(recoveryMode = false) {
const { catalog, pdfManager } = this;
catalog.setActualNumPages(); // Ensure that it's always reset.
let numPages;
try {
await Promise.all([
pdfManager.ensureDoc("xfaFactory"),
pdfManager.ensureDoc("linearization"),
pdfManager.ensureCatalog("numPages"),
]);
if (this.xfaFactory) {
return; // The Page count is always calculated for XFA-documents.
} else if (this.linearization) {
numPages = this.linearization.numPages;
} else {
numPages = catalog.numPages;
}
if (!Number.isInteger(numPages)) {
throw new FormatError("Page count is not an integer.");
} else if (numPages <= 1) {
return;
}
await this.getPage(numPages - 1);
} catch (reason) {
// Clear out the various caches to ensure that we haven't stored any
// inconsistent and/or incorrect state, since that could easily break
// subsequent `this.getPage` calls.
this._pagePromises.delete(numPages - 1);
await this.cleanup();
if (reason instanceof XRefEntryException && !recoveryMode) {
throw new XRefParseException();
}
warn(`checkLastPage - invalid /Pages tree /Count: ${numPages}.`);
let pagesTree;
try {
pagesTree = await catalog.getAllPageDicts(recoveryMode);
} catch (reasonAll) {
if (reasonAll instanceof XRefEntryException && !recoveryMode) {
throw new XRefParseException();
}
catalog.setActualNumPages(1);
return;
}
for (const [pageIndex, [pageDict, ref]] of pagesTree) {
let promise;
if (pageDict instanceof Error) {
promise = Promise.reject(pageDict);
// Prevent "uncaught exception: Object"-messages in the console.
promise.catch(() => {});
} else {
promise = Promise.resolve(
new Page({
pdfManager,
xref: this.xref,
pageIndex,
pageDict,
ref,
globalIdFactory: this._globalIdFactory,
fontCache: catalog.fontCache,
builtInCMapCache: catalog.builtInCMapCache,
standardFontDataCache: catalog.standardFontDataCache,
globalImageCache: catalog.globalImageCache,
systemFontCache: catalog.systemFontCache,
nonBlendModesSet: catalog.nonBlendModesSet,
xfaFactory: null,
})
);
}
this._pagePromises.set(pageIndex, promise);
}
catalog.setActualNumPages(pagesTree.size);
}
}
fontFallback(id, handler) {
return this.catalog.fontFallback(id, handler);
}
async cleanup(manuallyTriggered = false) {
return this.catalog
? this.catalog.cleanup(manuallyTriggered)
: clearGlobalCaches();
}
/**
* @private
*/
_collectFieldObjects(name, fieldRef, promises) {
const field = this.xref.fetchIfRef(fieldRef);
if (field.has("T")) {
const partName = stringToPDFString(field.get("T"));
name = name === "" ? partName : `${name}.${partName}`;
}
if (!field.has("Kids") && field.has("T") && /\[\d+\]$/.test(name)) {
// We've a terminal node: strip the index.
name = name.substring(0, name.lastIndexOf("["));
}
if (!promises.has(name)) {
promises.set(name, []);
}
promises.get(name).push(
AnnotationFactory.create(
this.xref,
fieldRef,
this.pdfManager,
this._localIdFactory,
/* collectFields */ true
)
.then(annotation => annotation?.getFieldObject())
.catch(function (reason) {
warn(`_collectFieldObjects: "${reason}".`);
return null;
})
);
if (field.has("Kids")) {
const kids = field.get("Kids");
for (const kid of kids) {
this._collectFieldObjects(name, kid, promises);
}
}
}
get fieldObjects() {
if (!this.formInfo.hasFields) {
return shadow(this, "fieldObjects", Promise.resolve(null));
}
const allFields = Object.create(null);
const fieldPromises = new Map();
for (const fieldRef of this.catalog.acroForm.get("Fields")) {
this._collectFieldObjects("", fieldRef, fieldPromises);
}
const allPromises = [];
for (const [name, promises] of fieldPromises) {
allPromises.push(
Promise.all(promises).then(fields => {
fields = fields.filter(field => !!field);
if (fields.length > 0) {
allFields[name] = fields;
}
})
);
}
return shadow(
this,
"fieldObjects",
Promise.all(allPromises).then(() => allFields)
);
}
get hasJSActions() {
const promise = this.pdfManager.ensureDoc("_parseHasJSActions");
return shadow(this, "hasJSActions", promise);
}
/**
* @private
*/
async _parseHasJSActions() {
const [catalogJsActions, fieldObjects] = await Promise.all([
this.pdfManager.ensureCatalog("jsActions"),
this.pdfManager.ensureDoc("fieldObjects"),
]);
if (catalogJsActions) {
return true;
}
if (fieldObjects) {
return Object.values(fieldObjects).some(fieldObject =>
fieldObject.some(object => object.actions !== null)
);
}
return false;
}
get calculationOrderIds() {
const acroForm = this.catalog.acroForm;
if (!acroForm?.has("CO")) {
return shadow(this, "calculationOrderIds", null);
}
const calculationOrder = acroForm.get("CO");
if (!Array.isArray(calculationOrder) || calculationOrder.length === 0) {
return shadow(this, "calculationOrderIds", null);
}
const ids = [];
for (const id of calculationOrder) {
if (id instanceof Ref) {
ids.push(id.toString());
}
}
if (ids.length === 0) {
return shadow(this, "calculationOrderIds", null);
}
return shadow(this, "calculationOrderIds", ids);
}
}
export { Page, PDFDocument };