/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/* 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.
*/
/* globals assert, bytesToString, CipherTransformFactory, error, info,
InvalidPDFException, isArray, isCmd, isDict, isInt, isName, isRef,
isStream, Lexer, Page, Parser, Promise, shadow,
stringToPDFString, stringToUTF8String, warn, isString,
Promise, MissingDataException, XRefParseException, Stream,
ChunkedStream, createPromiseCapability */
'use strict';
var Name = (function NameClosure() {
function Name(name) {
this.name = name;
}
Name.prototype = {};
var nameCache = {};
Name.get = function Name_get(name) {
var nameValue = nameCache[name];
return (nameValue ? nameValue : (nameCache[name] = new Name(name)));
};
return Name;
})();
var Cmd = (function CmdClosure() {
function Cmd(cmd) {
this.cmd = cmd;
}
Cmd.prototype = {};
var cmdCache = {};
Cmd.get = function Cmd_get(cmd) {
var cmdValue = cmdCache[cmd];
return (cmdValue ? cmdValue : (cmdCache[cmd] = new Cmd(cmd)));
};
return Cmd;
})();
var Dict = (function DictClosure() {
var nonSerializable = function nonSerializableClosure() {
return nonSerializable; // creating closure on some variable
};
var GETALL_DICTIONARY_TYPES_WHITELIST = {
'Background': true,
'ExtGState': true,
'Halftone': true,
'Layout': true,
'Mask': true,
'Pagination': true,
'Printing': true
};
function isRecursionAllowedFor(dict) {
if (!isName(dict.Type)) {
return true;
}
var dictType = dict.Type.name;
return GETALL_DICTIONARY_TYPES_WHITELIST[dictType] === true;
}
// xref is optional
function Dict(xref) {
// Map should only be used internally, use functions below to access.
this.map = Object.create(null);
this.xref = xref;
this.objId = null;
this.__nonSerializable__ = nonSerializable; // disable cloning of the Dict
}
Dict.prototype = {
assignXref: function Dict_assignXref(newXref) {
this.xref = newXref;
},
// automatically dereferences Ref objects
get: function Dict_get(key1, key2, key3) {
var value;
var xref = this.xref;
if (typeof (value = this.map[key1]) !== 'undefined' || key1 in this.map ||
typeof key2 === 'undefined') {
return xref ? xref.fetchIfRef(value) : value;
}
if (typeof (value = this.map[key2]) !== 'undefined' || key2 in this.map ||
typeof key3 === 'undefined') {
return xref ? xref.fetchIfRef(value) : value;
}
value = this.map[key3] || null;
return xref ? xref.fetchIfRef(value) : value;
},
// Same as get(), but returns a promise and uses fetchIfRefAsync().
getAsync: function Dict_getAsync(key1, key2, key3) {
var value;
var xref = this.xref;
if (typeof (value = this.map[key1]) !== 'undefined' || key1 in this.map ||
typeof key2 === 'undefined') {
if (xref) {
return xref.fetchIfRefAsync(value);
}
return Promise.resolve(value);
}
if (typeof (value = this.map[key2]) !== 'undefined' || key2 in this.map ||
typeof key3 === 'undefined') {
if (xref) {
return xref.fetchIfRefAsync(value);
}
return Promise.resolve(value);
}
value = this.map[key3] || null;
if (xref) {
return xref.fetchIfRefAsync(value);
}
return Promise.resolve(value);
},
// no dereferencing
getRaw: function Dict_getRaw(key) {
return this.map[key];
},
// creates new map and dereferences all Refs
getAll: function Dict_getAll() {
var all = Object.create(null);
var queue = null;
var key, obj;
for (key in this.map) {
obj = this.get(key);
if (obj instanceof Dict) {
if (isRecursionAllowedFor(obj)) {
(queue || (queue = [])).push({target: all, key: key, obj: obj});
} else {
all[key] = this.getRaw(key);
}
} else {
all[key] = obj;
}
}
if (!queue) {
return all;
}
// trying to take cyclic references into the account
var processed = Object.create(null);
while (queue.length > 0) {
var item = queue.shift();
var itemObj = item.obj;
var objId = itemObj.objId;
if (objId && objId in processed) {
item.target[item.key] = processed[objId];
continue;
}
var dereferenced = Object.create(null);
for (key in itemObj.map) {
obj = itemObj.get(key);
if (obj instanceof Dict) {
if (isRecursionAllowedFor(obj)) {
queue.push({target: dereferenced, key: key, obj: obj});
} else {
dereferenced[key] = itemObj.getRaw(key);
}
} else {
dereferenced[key] = obj;
}
}
if (objId) {
processed[objId] = dereferenced;
}
item.target[item.key] = dereferenced;
}
return all;
},
set: function Dict_set(key, value) {
this.map[key] = value;
},
has: function Dict_has(key) {
return key in this.map;
},
forEach: function Dict_forEach(callback) {
for (var key in this.map) {
callback(key, this.get(key));
}
}
};
Dict.empty = new Dict(null);
return Dict;
})();
var Ref = (function RefClosure() {
function Ref(num, gen) {
this.num = num;
this.gen = gen;
}
Ref.prototype = {
toString: function Ref_toString() {
// This function is hot, so we make the string as compact as possible.
// |this.gen| is almost always zero, so we treat that case specially.
var str = this.num + 'R';
if (this.gen !== 0) {
str += this.gen;
}
return str;
}
};
return Ref;
})();
// The reference is identified by number and generation.
// This structure stores only one instance of the reference.
var RefSet = (function RefSetClosure() {
function RefSet() {
this.dict = {};
}
RefSet.prototype = {
has: function RefSet_has(ref) {
return ref.toString() in this.dict;
},
put: function RefSet_put(ref) {
this.dict[ref.toString()] = true;
},
remove: function RefSet_remove(ref) {
delete this.dict[ref.toString()];
}
};
return RefSet;
})();
var RefSetCache = (function RefSetCacheClosure() {
function RefSetCache() {
this.dict = Object.create(null);
}
RefSetCache.prototype = {
get: function RefSetCache_get(ref) {
return this.dict[ref.toString()];
},
has: function RefSetCache_has(ref) {
return ref.toString() in this.dict;
},
put: function RefSetCache_put(ref, obj) {
this.dict[ref.toString()] = obj;
},
putAlias: function RefSetCache_putAlias(ref, aliasRef) {
this.dict[ref.toString()] = this.get(aliasRef);
},
forEach: function RefSetCache_forEach(fn, thisArg) {
for (var i in this.dict) {
fn.call(thisArg, this.dict[i]);
}
},
clear: function RefSetCache_clear() {
this.dict = Object.create(null);
}
};
return RefSetCache;
})();
var Catalog = (function CatalogClosure() {
function Catalog(pdfManager, xref) {
this.pdfManager = pdfManager;
this.xref = xref;
this.catDict = xref.getCatalogObj();
this.fontCache = new RefSetCache();
assert(isDict(this.catDict),
'catalog object is not a dictionary');
this.pagePromises = [];
}
Catalog.prototype = {
get metadata() {
var streamRef = this.catDict.getRaw('Metadata');
if (!isRef(streamRef)) {
return shadow(this, 'metadata', null);
}
var encryptMetadata = (!this.xref.encrypt ? false :
this.xref.encrypt.encryptMetadata);
var stream = this.xref.fetch(streamRef, !encryptMetadata);
var metadata;
if (stream && isDict(stream.dict)) {
var type = stream.dict.get('Type');
var subtype = stream.dict.get('Subtype');
if (isName(type) && isName(subtype) &&
type.name === 'Metadata' && subtype.name === 'XML') {
// XXX: This should examine the charset the XML document defines,
// however since there are currently no real means to decode
// arbitrary charsets, let's just hope that the author of the PDF
// was reasonable enough to stick with the XML default charset,
// which is UTF-8.
try {
metadata = stringToUTF8String(bytesToString(stream.getBytes()));
} catch (e) {
info('Skipping invalid metadata.');
}
}
}
return shadow(this, 'metadata', metadata);
},
get toplevelPagesDict() {
var pagesObj = this.catDict.get('Pages');
assert(isDict(pagesObj), 'invalid top-level pages dictionary');
// shadow the prototype getter
return shadow(this, 'toplevelPagesDict', pagesObj);
},
get documentOutline() {
var obj = null;
try {
obj = this.readDocumentOutline();
} catch (ex) {
if (ex instanceof MissingDataException) {
throw ex;
}
warn('Unable to read document outline');
}
return shadow(this, 'documentOutline', obj);
},
readDocumentOutline: function Catalog_readDocumentOutline() {
var xref = this.xref;
var obj = this.catDict.get('Outlines');
var root = { items: [] };
if (isDict(obj)) {
obj = obj.getRaw('First');
var processed = new RefSet();
if (isRef(obj)) {
var queue = [{obj: obj, parent: root}];
// to avoid recursion keeping track of the items
// in the processed dictionary
processed.put(obj);
while (queue.length > 0) {
var i = queue.shift();
var outlineDict = xref.fetchIfRef(i.obj);
if (outlineDict === null) {
continue;
}
if (!outlineDict.has('Title')) {
error('Invalid outline item');
}
var dest = outlineDict.get('A');
if (dest) {
dest = dest.get('D');
} else if (outlineDict.has('Dest')) {
dest = outlineDict.getRaw('Dest');
if (isName(dest)) {
dest = dest.name;
}
}
var title = outlineDict.get('Title');
var outlineItem = {
dest: dest,
title: stringToPDFString(title),
color: outlineDict.get('C') || [0, 0, 0],
count: outlineDict.get('Count'),
bold: !!(outlineDict.get('F') & 2),
italic: !!(outlineDict.get('F') & 1),
items: []
};
i.parent.items.push(outlineItem);
obj = outlineDict.getRaw('First');
if (isRef(obj) && !processed.has(obj)) {
queue.push({obj: obj, parent: outlineItem});
processed.put(obj);
}
obj = outlineDict.getRaw('Next');
if (isRef(obj) && !processed.has(obj)) {
queue.push({obj: obj, parent: i.parent});
processed.put(obj);
}
}
}
}
return (root.items.length > 0 ? root.items : null);
},
get numPages() {
var obj = this.toplevelPagesDict.get('Count');
assert(
isInt(obj),
'page count in top level pages object is not an integer'
);
// shadow the prototype getter
return shadow(this, 'num', obj);
},
get destinations() {
function fetchDestination(dest) {
return isDict(dest) ? dest.get('D') : dest;
}
var xref = this.xref;
var dests = {}, nameTreeRef, nameDictionaryRef;
var obj = this.catDict.get('Names');
if (obj && obj.has('Dests')) {
nameTreeRef = obj.getRaw('Dests');
} else if (this.catDict.has('Dests')) {
nameDictionaryRef = this.catDict.get('Dests');
}
if (nameDictionaryRef) {
// reading simple destination dictionary
obj = nameDictionaryRef;
obj.forEach(function catalogForEach(key, value) {
if (!value) {
return;
}
dests[key] = fetchDestination(value);
});
}
if (nameTreeRef) {
var nameTree = new NameTree(nameTreeRef, xref);
var names = nameTree.getAll();
for (var name in names) {
if (!names.hasOwnProperty(name)) {
continue;
}
dests[name] = fetchDestination(names[name]);
}
}
return shadow(this, 'destinations', dests);
},
get attachments() {
var xref = this.xref;
var attachments = null, nameTreeRef;
var obj = this.catDict.get('Names');
if (obj) {
nameTreeRef = obj.getRaw('EmbeddedFiles');
}
if (nameTreeRef) {
var nameTree = new NameTree(nameTreeRef, xref);
var names = nameTree.getAll();
for (var name in names) {
if (!names.hasOwnProperty(name)) {
continue;
}
var fs = new FileSpec(names[name], xref);
if (!attachments) {
attachments = {};
}
attachments[stringToPDFString(name)] = fs.serializable;
}
}
return shadow(this, 'attachments', attachments);
},
get javaScript() {
var xref = this.xref;
var obj = this.catDict.get('Names');
var javaScript = [];
if (obj && obj.has('JavaScript')) {
var nameTree = new NameTree(obj.getRaw('JavaScript'), xref);
var names = nameTree.getAll();
for (var name in names) {
if (!names.hasOwnProperty(name)) {
continue;
}
// We don't really use the JavaScript right now. This code is
// defensive so we don't cause errors on document load.
var jsDict = names[name];
if (!isDict(jsDict)) {
continue;
}
var type = jsDict.get('S');
if (!isName(type) || type.name !== 'JavaScript') {
continue;
}
var js = jsDict.get('JS');
if (!isString(js) && !isStream(js)) {
continue;
}
if (isStream(js)) {
js = bytesToString(js.getBytes());
}
javaScript.push(stringToPDFString(js));
}
}
// Append OpenAction actions to javaScript array
var openactionDict = this.catDict.get('OpenAction');
if (isDict(openactionDict)) {
var objType = openactionDict.get('Type');
var actionType = openactionDict.get('S');
var action = openactionDict.get('N');
var isPrintAction = (isName(objType) && objType.name === 'Action' &&
isName(actionType) && actionType.name === 'Named' &&
isName(action) && action.name === 'Print');
if (isPrintAction) {
javaScript.push('print(true);');
}
}
return shadow(this, 'javaScript', javaScript);
},
cleanup: function Catalog_cleanup() {
var promises = [];
this.fontCache.forEach(function (promise) {
promises.push(promise);
});
return Promise.all(promises).then(function (translatedFonts) {
for (var i = 0, ii = translatedFonts.length; i < ii; i++) {
var font = translatedFonts[i].dict;
delete font.translated;
}
this.fontCache.clear();
}.bind(this));
},
getPage: function Catalog_getPage(pageIndex) {
if (!(pageIndex in this.pagePromises)) {
this.pagePromises[pageIndex] = this.getPageDict(pageIndex).then(
function (a) {
var dict = a[0];
var ref = a[1];
return new Page(this.pdfManager, this.xref, pageIndex, dict, ref,
this.fontCache);
}.bind(this)
);
}
return this.pagePromises[pageIndex];
},
getPageDict: function Catalog_getPageDict(pageIndex) {
var capability = createPromiseCapability();
var nodesToVisit = [this.catDict.getRaw('Pages')];
var currentPageIndex = 0;
var xref = this.xref;
function next() {
while (nodesToVisit.length) {
var currentNode = nodesToVisit.pop();
if (isRef(currentNode)) {
xref.fetchAsync(currentNode).then(function (obj) {
if ((isDict(obj, 'Page') || (isDict(obj) && !obj.has('Kids')))) {
if (pageIndex === currentPageIndex) {
capability.resolve([obj, currentNode]);
} else {
currentPageIndex++;
next();
}
return;
}
nodesToVisit.push(obj);
next();
}, capability.reject);
return;
}
// must be a child page dictionary
assert(
isDict(currentNode),
'page dictionary kid reference points to wrong type of object'
);
var count = currentNode.get('Count');
// Skip nodes where the page can't be.
if (currentPageIndex + count <= pageIndex) {
currentPageIndex += count;
continue;
}
var kids = currentNode.get('Kids');
assert(isArray(kids), 'page dictionary kids object is not an array');
if (count === kids.length) {
// Nodes that don't have the page have been skipped and this is the
// bottom of the tree which means the page requested must be a
// descendant of this pages node. Ideally we would just resolve the
// promise with the page ref here, but there is the case where more
// pages nodes could link to single a page (see issue 3666 pdf). To
// handle this push it back on the queue so if it is a pages node it
// will be descended into.
nodesToVisit = [kids[pageIndex - currentPageIndex]];
currentPageIndex = pageIndex;
continue;
} else {
for (var last = kids.length - 1; last >= 0; last--) {
nodesToVisit.push(kids[last]);
}
}
}
capability.reject('Page index ' + pageIndex + ' not found.');
}
next();
return capability.promise;
},
getPageIndex: function Catalog_getPageIndex(ref) {
// The page tree nodes have the count of all the leaves below them. To get
// how many pages are before we just have to walk up the tree and keep
// adding the count of siblings to the left of the node.
var xref = this.xref;
function pagesBeforeRef(kidRef) {
var total = 0;
var parentRef;
return xref.fetchAsync(kidRef).then(function (node) {
if (!node) {
return null;
}
parentRef = node.getRaw('Parent');
return node.getAsync('Parent');
}).then(function (parent) {
if (!parent) {
return null;
}
return parent.getAsync('Kids');
}).then(function (kids) {
if (!kids) {
return null;
}
var kidPromises = [];
var found = false;
for (var i = 0; i < kids.length; i++) {
var kid = kids[i];
assert(isRef(kid), 'kids must be a ref');
if (kid.num === kidRef.num) {
found = true;
break;
}
kidPromises.push(xref.fetchAsync(kid).then(function (kid) {
if (kid.has('Count')) {
var count = kid.get('Count');
total += count;
} else { // page leaf node
total++;
}
}));
}
if (!found) {
error('kid ref not found in parents kids');
}
return Promise.all(kidPromises).then(function () {
return [total, parentRef];
});
});
}
var total = 0;
function next(ref) {
return pagesBeforeRef(ref).then(function (args) {
if (!args) {
return total;
}
var count = args[0];
var parentRef = args[1];
total += count;
return next(parentRef);
});
}
return next(ref);
}
};
return Catalog;
})();
var XRef = (function XRefClosure() {
function XRef(stream, password) {
this.stream = stream;
this.entries = [];
this.xrefstms = {};
// prepare the XRef cache
this.cache = [];
this.password = password;
this.stats = {
streamTypes: [],
fontTypes: []
};
}
XRef.prototype = {
setStartXRef: function XRef_setStartXRef(startXRef) {
// Store the starting positions of xref tables as we process them
// so we can recover from missing data errors
this.startXRefQueue = [startXRef];
},
parse: function XRef_parse(recoveryMode) {
var trailerDict;
if (!recoveryMode) {
trailerDict = this.readXRef();
} else {
warn('Indexing all PDF objects');
trailerDict = this.indexObjects();
}
trailerDict.assignXref(this);
this.trailer = trailerDict;
var encrypt = trailerDict.get('Encrypt');
if (encrypt) {
var ids = trailerDict.get('ID');
var fileId = (ids && ids.length) ? ids[0] : '';
this.encrypt = new CipherTransformFactory(encrypt, fileId,
this.password);
}
// get the root dictionary (catalog) object
if (!(this.root = trailerDict.get('Root'))) {
error('Invalid root reference');
}
},
processXRefTable: function XRef_processXRefTable(parser) {
if (!('tableState' in this)) {
// Stores state of the table as we process it so we can resume
// from middle of table in case of missing data error
this.tableState = {
entryNum: 0,
streamPos: parser.lexer.stream.pos,
parserBuf1: parser.buf1,
parserBuf2: parser.buf2
};
}
var obj = this.readXRefTable(parser);
// Sanity check
if (!isCmd(obj, 'trailer')) {
error('Invalid XRef table: could not find trailer dictionary');
}
// Read trailer dictionary, e.g.
// trailer
// << /Size 22
// /Root 20R
// /Info 10R
// /ID [ <81b14aafa313db63dbd6f981e49f94f4> ]
// >>
// The parser goes through the entire stream << ... >> and provides
// a getter interface for the key-value table
var dict = parser.getObj();
// The pdflib PDF generator can generate a nested trailer dictionary
if (!isDict(dict) && dict.dict) {
dict = dict.dict;
}
if (!isDict(dict)) {
error('Invalid XRef table: could not parse trailer dictionary');
}
delete this.tableState;
return dict;
},
readXRefTable: function XRef_readXRefTable(parser) {
// Example of cross-reference table:
// xref
// 0 1 <-- subsection header (first obj #, obj count)
// 0000000000 65535 f <-- actual object (offset, generation #, f/n)
// 23 2 <-- subsection header ... and so on ...
// 0000025518 00002 n
// 0000025635 00000 n
// trailer
// ...
var stream = parser.lexer.stream;
var tableState = this.tableState;
stream.pos = tableState.streamPos;
parser.buf1 = tableState.parserBuf1;
parser.buf2 = tableState.parserBuf2;
// Outer loop is over subsection headers
var obj;
while (true) {
if (!('firstEntryNum' in tableState) || !('entryCount' in tableState)) {
if (isCmd(obj = parser.getObj(), 'trailer')) {
break;
}
tableState.firstEntryNum = obj;
tableState.entryCount = parser.getObj();
}
var first = tableState.firstEntryNum;
var count = tableState.entryCount;
if (!isInt(first) || !isInt(count)) {
error('Invalid XRef table: wrong types in subsection header');
}
// Inner loop is over objects themselves
for (var i = tableState.entryNum; i < count; i++) {
tableState.streamPos = stream.pos;
tableState.entryNum = i;
tableState.parserBuf1 = parser.buf1;
tableState.parserBuf2 = parser.buf2;
var entry = {};
entry.offset = parser.getObj();
entry.gen = parser.getObj();
var type = parser.getObj();
if (isCmd(type, 'f')) {
entry.free = true;
} else if (isCmd(type, 'n')) {
entry.uncompressed = true;
}
// Validate entry obj
if (!isInt(entry.offset) || !isInt(entry.gen) ||
!(entry.free || entry.uncompressed)) {
error('Invalid entry in XRef subsection: ' + first + ', ' + count);
}
if (!this.entries[i + first]) {
this.entries[i + first] = entry;
}
}
tableState.entryNum = 0;
tableState.streamPos = stream.pos;
tableState.parserBuf1 = parser.buf1;
tableState.parserBuf2 = parser.buf2;
delete tableState.firstEntryNum;
delete tableState.entryCount;
}
// Per issue 3248: hp scanners generate bad XRef
if (first === 1 && this.entries[1] && this.entries[1].free) {
// shifting the entries
this.entries.shift();
}
// Sanity check: as per spec, first object must be free
if (this.entries[0] && !this.entries[0].free) {
error('Invalid XRef table: unexpected first object');
}
return obj;
},
processXRefStream: function XRef_processXRefStream(stream) {
if (!('streamState' in this)) {
// Stores state of the stream as we process it so we can resume
// from middle of stream in case of missing data error
var streamParameters = stream.dict;
var byteWidths = streamParameters.get('W');
var range = streamParameters.get('Index');
if (!range) {
range = [0, streamParameters.get('Size')];
}
this.streamState = {
entryRanges: range,
byteWidths: byteWidths,
entryNum: 0,
streamPos: stream.pos
};
}
this.readXRefStream(stream);
delete this.streamState;
return stream.dict;
},
readXRefStream: function XRef_readXRefStream(stream) {
var i, j;
var streamState = this.streamState;
stream.pos = streamState.streamPos;
var byteWidths = streamState.byteWidths;
var typeFieldWidth = byteWidths[0];
var offsetFieldWidth = byteWidths[1];
var generationFieldWidth = byteWidths[2];
var entryRanges = streamState.entryRanges;
while (entryRanges.length > 0) {
var first = entryRanges[0];
var n = entryRanges[1];
if (!isInt(first) || !isInt(n)) {
error('Invalid XRef range fields: ' + first + ', ' + n);
}
if (!isInt(typeFieldWidth) || !isInt(offsetFieldWidth) ||
!isInt(generationFieldWidth)) {
error('Invalid XRef entry fields length: ' + first + ', ' + n);
}
for (i = streamState.entryNum; i < n; ++i) {
streamState.entryNum = i;
streamState.streamPos = stream.pos;
var type = 0, offset = 0, generation = 0;
for (j = 0; j < typeFieldWidth; ++j) {
type = (type << 8) | stream.getByte();
}
// if type field is absent, its default value is 1
if (typeFieldWidth === 0) {
type = 1;
}
for (j = 0; j < offsetFieldWidth; ++j) {
offset = (offset << 8) | stream.getByte();
}
for (j = 0; j < generationFieldWidth; ++j) {
generation = (generation << 8) | stream.getByte();
}
var entry = {};
entry.offset = offset;
entry.gen = generation;
switch (type) {
case 0:
entry.free = true;
break;
case 1:
entry.uncompressed = true;
break;
case 2:
break;
default:
error('Invalid XRef entry type: ' + type);
}
if (!this.entries[first + i]) {
this.entries[first + i] = entry;
}
}
streamState.entryNum = 0;
streamState.streamPos = stream.pos;
entryRanges.splice(0, 2);
}
},
indexObjects: function XRef_indexObjects() {
// Simple scan through the PDF content to find objects,
// trailers and XRef streams.
function readToken(data, offset) {
var token = '', ch = data[offset];
while (ch !== 13 && ch !== 10) {
if (++offset >= data.length) {
break;
}
token += String.fromCharCode(ch);
ch = data[offset];
}
return token;
}
function skipUntil(data, offset, what) {
var length = what.length, dataLength = data.length;
var skipped = 0;
// finding byte sequence
while (offset < dataLength) {
var i = 0;
while (i < length && data[offset + i] === what[i]) {
++i;
}
if (i >= length) {
break; // sequence found
}
offset++;
skipped++;
}
return skipped;
}
var trailerBytes = new Uint8Array([116, 114, 97, 105, 108, 101, 114]);
var startxrefBytes = new Uint8Array([115, 116, 97, 114, 116, 120, 114,
101, 102]);
var endobjBytes = new Uint8Array([101, 110, 100, 111, 98, 106]);
var xrefBytes = new Uint8Array([47, 88, 82, 101, 102]);
var stream = this.stream;
stream.pos = 0;
var buffer = stream.getBytes();
var position = stream.start, length = buffer.length;
var trailers = [], xrefStms = [];
while (position < length) {
var ch = buffer[position];
if (ch === 32 || ch === 9 || ch === 13 || ch === 10) {
++position;
continue;
}
if (ch === 37) { // %-comment
do {
++position;
if (position >= length) {
break;
}
ch = buffer[position];
} while (ch !== 13 && ch !== 10);
continue;
}
var token = readToken(buffer, position);
var m;
if (token === 'xref') {
position += skipUntil(buffer, position, trailerBytes);
trailers.push(position);
position += skipUntil(buffer, position, startxrefBytes);
} else if ((m = /^(\d+)\s+(\d+)\s+obj\b/.exec(token))) {
this.entries[m[1]] = {
offset: position,
gen: m[2] | 0,
uncompressed: true
};
var contentLength = skipUntil(buffer, position, endobjBytes) + 7;
var content = buffer.subarray(position, position + contentLength);
// checking XRef stream suspect
// (it shall have '/XRef' and next char is not a letter)
var xrefTagOffset = skipUntil(content, 0, xrefBytes);
if (xrefTagOffset < contentLength &&
content[xrefTagOffset + 5] < 64) {
xrefStms.push(position);
this.xrefstms[position] = 1; // don't read it recursively
}
position += contentLength;
} else {
position += token.length + 1;
}
}
// reading XRef streams
var i, ii;
for (i = 0, ii = xrefStms.length; i < ii; ++i) {
this.startXRefQueue.push(xrefStms[i]);
this.readXRef(/* recoveryMode */ true);
}
// finding main trailer
var dict;
for (i = 0, ii = trailers.length; i < ii; ++i) {
stream.pos = trailers[i];
var parser = new Parser(new Lexer(stream), true, this);
var obj = parser.getObj();
if (!isCmd(obj, 'trailer')) {
continue;
}
// read the trailer dictionary
if (!isDict(dict = parser.getObj())) {
continue;
}
// taking the first one with 'ID'
if (dict.has('ID')) {
return dict;
}
}
// no tailer with 'ID', taking last one (if exists)
if (dict) {
return dict;
}
// nothing helps
// calling error() would reject worker with an UnknownErrorException.
throw new InvalidPDFException('Invalid PDF structure');
},
readXRef: function XRef_readXRef(recoveryMode) {
var stream = this.stream;
try {
while (this.startXRefQueue.length) {
var startXRef = this.startXRefQueue[0];
stream.pos = startXRef + stream.start;
var parser = new Parser(new Lexer(stream), true, this);
var obj = parser.getObj();
var dict;
// Get dictionary
if (isCmd(obj, 'xref')) {
// Parse end-of-file XRef
dict = this.processXRefTable(parser);
if (!this.topDict) {
this.topDict = dict;
}
// Recursively get other XRefs 'XRefStm', if any
obj = dict.get('XRefStm');
if (isInt(obj)) {
var pos = obj;
// ignore previously loaded xref streams
// (possible infinite recursion)
if (!(pos in this.xrefstms)) {
this.xrefstms[pos] = 1;
this.startXRefQueue.push(pos);
}
}
} else if (isInt(obj)) {
// Parse in-stream XRef
if (!isInt(parser.getObj()) ||
!isCmd(parser.getObj(), 'obj') ||
!isStream(obj = parser.getObj())) {
error('Invalid XRef stream');
}
dict = this.processXRefStream(obj);
if (!this.topDict) {
this.topDict = dict;
}
if (!dict) {
error('Failed to read XRef stream');
}
} else {
error('Invalid XRef stream header');
}
// Recursively get previous dictionary, if any
obj = dict.get('Prev');
if (isInt(obj)) {
this.startXRefQueue.push(obj);
} else if (isRef(obj)) {
// The spec says Prev must not be a reference, i.e. "/Prev NNN"
// This is a fallback for non-compliant PDFs, i.e. "/Prev NNN 0 R"
this.startXRefQueue.push(obj.num);
}
this.startXRefQueue.shift();
}
return this.topDict;
} catch (e) {
if (e instanceof MissingDataException) {
throw e;
}
info('(while reading XRef): ' + e);
}
if (recoveryMode) {
return;
}
throw new XRefParseException();
},
getEntry: function XRef_getEntry(i) {
var xrefEntry = this.entries[i];
if (xrefEntry && !xrefEntry.free && xrefEntry.offset) {
return xrefEntry;
}
return null;
},
fetchIfRef: function XRef_fetchIfRef(obj) {
if (!isRef(obj)) {
return obj;
}
return this.fetch(obj);
},
fetch: function XRef_fetch(ref, suppressEncryption) {
assert(isRef(ref), 'ref object is not a reference');
var num = ref.num;
if (num in this.cache) {
var cacheEntry = this.cache[num];
return cacheEntry;
}
var xrefEntry = this.getEntry(num);
// the referenced entry can be free
if (xrefEntry === null) {
return (this.cache[num] = null);
}
if (xrefEntry.uncompressed) {
xrefEntry = this.fetchUncompressed(ref, xrefEntry, suppressEncryption);
} else {
xrefEntry = this.fetchCompressed(xrefEntry, suppressEncryption);
}
if (isDict(xrefEntry)){
xrefEntry.objId = ref.toString();
} else if (isStream(xrefEntry)) {
xrefEntry.dict.objId = ref.toString();
}
return xrefEntry;
},
fetchUncompressed: function XRef_fetchUncompressed(ref, xrefEntry,
suppressEncryption) {
var gen = ref.gen;
var num = ref.num;
if (xrefEntry.gen !== gen) {
error('inconsistent generation in XRef');
}
var stream = this.stream.makeSubStream(xrefEntry.offset +
this.stream.start);
var parser = new Parser(new Lexer(stream), true, this);
var obj1 = parser.getObj();
var obj2 = parser.getObj();
var obj3 = parser.getObj();
if (!isInt(obj1) || parseInt(obj1, 10) !== num ||
!isInt(obj2) || parseInt(obj2, 10) !== gen ||
!isCmd(obj3)) {
error('bad XRef entry');
}
if (!isCmd(obj3, 'obj')) {
// some bad PDFs use "obj1234" and really mean 1234
if (obj3.cmd.indexOf('obj') === 0) {
num = parseInt(obj3.cmd.substring(3), 10);
if (!isNaN(num)) {
return num;
}
}
error('bad XRef entry');
}
if (this.encrypt && !suppressEncryption) {
xrefEntry = parser.getObj(this.encrypt.createCipherTransform(num, gen));
} else {
xrefEntry = parser.getObj();
}
if (!isStream(xrefEntry)) {
this.cache[num] = xrefEntry;
}
return xrefEntry;
},
fetchCompressed: function XRef_fetchCompressed(xrefEntry,
suppressEncryption) {
var tableOffset = xrefEntry.offset;
var stream = this.fetch(new Ref(tableOffset, 0));
if (!isStream(stream)) {
error('bad ObjStm stream');
}
var first = stream.dict.get('First');
var n = stream.dict.get('N');
if (!isInt(first) || !isInt(n)) {
error('invalid first and n parameters for ObjStm stream');
}
var parser = new Parser(new Lexer(stream), false, this);
parser.allowStreams = true;
var i, entries = [], num, nums = [];
// read the object numbers to populate cache
for (i = 0; i < n; ++i) {
num = parser.getObj();
if (!isInt(num)) {
error('invalid object number in the ObjStm stream: ' + num);
}
nums.push(num);
var offset = parser.getObj();
if (!isInt(offset)) {
error('invalid object offset in the ObjStm stream: ' + offset);
}
}
// read stream objects for cache
for (i = 0; i < n; ++i) {
entries.push(parser.getObj());
num = nums[i];
var entry = this.entries[num];
if (entry && entry.offset === tableOffset && entry.gen === i) {
this.cache[num] = entries[i];
}
}
xrefEntry = entries[xrefEntry.gen];
if (xrefEntry === undefined) {
error('bad XRef entry for compressed object');
}
return xrefEntry;
},
fetchIfRefAsync: function XRef_fetchIfRefAsync(obj) {
if (!isRef(obj)) {
return Promise.resolve(obj);
}
return this.fetchAsync(obj);
},
fetchAsync: function XRef_fetchAsync(ref, suppressEncryption) {
var streamManager = this.stream.manager;
var xref = this;
return new Promise(function tryFetch(resolve, reject) {
try {
resolve(xref.fetch(ref, suppressEncryption));
} catch (e) {
if (e instanceof MissingDataException) {
streamManager.requestRange(e.begin, e.end, function () {
tryFetch(resolve, reject);
});
return;
}
reject(e);
}
});
},
getCatalogObj: function XRef_getCatalogObj() {
return this.root;
}
};
return XRef;
})();
/**
* A NameTree is like a Dict but has some advantageous properties, see the
* spec (7.9.6) for more details.
* TODO: implement all the Dict functions and make this more efficent.
*/
var NameTree = (function NameTreeClosure() {
function NameTree(root, xref) {
this.root = root;
this.xref = xref;
}
NameTree.prototype = {
getAll: function NameTree_getAll() {
var dict = {};
if (!this.root) {
return dict;
}
var xref = this.xref;
// reading name tree
var processed = new RefSet();
processed.put(this.root);
var queue = [this.root];
while (queue.length > 0) {
var i, n;
var obj = xref.fetchIfRef(queue.shift());
if (!isDict(obj)) {
continue;
}
if (obj.has('Kids')) {
var kids = obj.get('Kids');
for (i = 0, n = kids.length; i < n; i++) {
var kid = kids[i];
if (processed.has(kid)) {
error('invalid destinations');
}
queue.push(kid);
processed.put(kid);
}
continue;
}
var names = obj.get('Names');
if (names) {
for (i = 0, n = names.length; i < n; i += 2) {
dict[names[i]] = xref.fetchIfRef(names[i + 1]);
}
}
}
return dict;
}
};
return NameTree;
})();
/**
* "A PDF file can refer to the contents of another file by using a File
* Specification (PDF 1.1)", see the spec (7.11) for more details.
* NOTE: Only embedded files are supported (as part of the attachments support)
* TODO: support the 'URL' file system (with caching if !/V), portable
* collections attributes and related files (/RF)
*/
var FileSpec = (function FileSpecClosure() {
function FileSpec(root, xref) {
if (!root || !isDict(root)) {
return;
}
this.xref = xref;
this.root = root;
if (root.has('FS')) {
this.fs = root.get('FS');
}
this.description = root.has('Desc') ?
stringToPDFString(root.get('Desc')) :
'';
if (root.has('RF')) {
warn('Related file specifications are not supported');
}
this.contentAvailable = true;
if (!root.has('EF')) {
this.contentAvailable = false;
warn('Non-embedded file specifications are not supported');
}
}
function pickPlatformItem(dict) {
// Look for the filename in this order:
// UF, F, Unix, Mac, DOS
if (dict.has('UF')) {
return dict.get('UF');
} else if (dict.has('F')) {
return dict.get('F');
} else if (dict.has('Unix')) {
return dict.get('Unix');
} else if (dict.has('Mac')) {
return dict.get('Mac');
} else if (dict.has('DOS')) {
return dict.get('DOS');
} else {
return null;
}
}
FileSpec.prototype = {
get filename() {
if (!this._filename && this.root) {
var filename = pickPlatformItem(this.root) || 'unnamed';
this._filename = stringToPDFString(filename).
replace(/\\\\/g, '\\').
replace(/\\\//g, '/').
replace(/\\/g, '/');
}
return this._filename;
},
get content() {
if (!this.contentAvailable) {
return null;
}
if (!this.contentRef && this.root) {
this.contentRef = pickPlatformItem(this.root.get('EF'));
}
var content = null;
if (this.contentRef) {
var xref = this.xref;
var fileObj = xref.fetchIfRef(this.contentRef);
if (fileObj && isStream(fileObj)) {
content = fileObj.getBytes();
} else {
warn('Embedded file specification points to non-existing/invalid ' +
'content');
}
} else {
warn('Embedded file specification does not have a content');
}
return content;
},
get serializable() {
return {
filename: this.filename,
content: this.content
};
}
};
return FileSpec;
})();
/**
* A helper for loading missing data in object graphs. It traverses the graph
* depth first and queues up any objects that have missing data. Once it has
* has traversed as many objects that are available it attempts to bundle the
* missing data requests and then resume from the nodes that weren't ready.
*
* NOTE: It provides protection from circular references by keeping track of
* of loaded references. However, you must be careful not to load any graphs
* that have references to the catalog or other pages since that will cause the
* entire PDF document object graph to be traversed.
*/
var ObjectLoader = (function() {
function mayHaveChildren(value) {
return isRef(value) || isDict(value) || isArray(value) || isStream(value);
}
function addChildren(node, nodesToVisit) {
var value;
if (isDict(node) || isStream(node)) {
var map;
if (isDict(node)) {
map = node.map;
} else {
map = node.dict.map;
}
for (var key in map) {
value = map[key];
if (mayHaveChildren(value)) {
nodesToVisit.push(value);
}
}
} else if (isArray(node)) {
for (var i = 0, ii = node.length; i < ii; i++) {
value = node[i];
if (mayHaveChildren(value)) {
nodesToVisit.push(value);
}
}
}
}
function ObjectLoader(obj, keys, xref) {
this.obj = obj;
this.keys = keys;
this.xref = xref;
this.refSet = null;
}
ObjectLoader.prototype = {
load: function ObjectLoader_load() {
var keys = this.keys;
this.capability = createPromiseCapability();
// Don't walk the graph if all the data is already loaded.
if (!(this.xref.stream instanceof ChunkedStream) ||
this.xref.stream.getMissingChunks().length === 0) {
this.capability.resolve();
return this.capability.promise;
}
this.refSet = new RefSet();
// Setup the initial nodes to visit.
var nodesToVisit = [];
for (var i = 0; i < keys.length; i++) {
nodesToVisit.push(this.obj[keys[i]]);
}
this.walk(nodesToVisit);
return this.capability.promise;
},
walk: function ObjectLoader_walk(nodesToVisit) {
var nodesToRevisit = [];
var pendingRequests = [];
// DFS walk of the object graph.
while (nodesToVisit.length) {
var currentNode = nodesToVisit.pop();
// Only references or chunked streams can cause missing data exceptions.
if (isRef(currentNode)) {
// Skip nodes that have already been visited.
if (this.refSet.has(currentNode)) {
continue;
}
try {
var ref = currentNode;
this.refSet.put(ref);
currentNode = this.xref.fetch(currentNode);
} catch (e) {
if (!(e instanceof MissingDataException)) {
throw e;
}
nodesToRevisit.push(currentNode);
pendingRequests.push({ begin: e.begin, end: e.end });
}
}
if (currentNode && currentNode.getBaseStreams) {
var baseStreams = currentNode.getBaseStreams();
var foundMissingData = false;
for (var i = 0; i < baseStreams.length; i++) {
var stream = baseStreams[i];
if (stream.getMissingChunks && stream.getMissingChunks().length) {
foundMissingData = true;
pendingRequests.push({
begin: stream.start,
end: stream.end
});
}
}
if (foundMissingData) {
nodesToRevisit.push(currentNode);
}
}
addChildren(currentNode, nodesToVisit);
}
if (pendingRequests.length) {
this.xref.stream.manager.requestRanges(pendingRequests,
function pendingRequestCallback() {
nodesToVisit = nodesToRevisit;
for (var i = 0; i < nodesToRevisit.length; i++) {
var node = nodesToRevisit[i];
// Remove any reference nodes from the currrent refset so they
// aren't skipped when we revist them.
if (isRef(node)) {
this.refSet.remove(node);
}
}
this.walk(nodesToVisit);
}.bind(this));
return;
}
// Everything is loaded.
this.refSet = null;
this.capability.resolve();
}
};
return ObjectLoader;
})();