pdf.js/src/core/core_utils.js
Jonas Jenwald 6d4d402a78 Move the arrayBuffersToBytes helper function into the worker-thread
Given that this helper function is only used on the worker-thread, there's no reason to duplicate it in both of the *built* `pdf.js` and `pdf.worker.js` files.
2023-02-11 21:34:37 +01:00

649 lines
17 KiB
JavaScript

/* Copyright 2019 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,
BaseException,
objectSize,
stringToPDFString,
warn,
} from "../shared/util.js";
import { Dict, isName, Ref, RefSet } from "./primitives.js";
import { BaseStream } from "./base_stream.js";
const PDF_VERSION_REGEXP = /^[1-9]\.\d$/;
function getLookupTableFactory(initializer) {
let lookup;
return function () {
if (initializer) {
lookup = Object.create(null);
initializer(lookup);
initializer = null;
}
return lookup;
};
}
function getArrayLookupTableFactory(initializer) {
let lookup;
return function () {
if (initializer) {
let arr = initializer();
initializer = null;
lookup = Object.create(null);
for (let i = 0, ii = arr.length; i < ii; i += 2) {
lookup[arr[i]] = arr[i + 1];
}
arr = null;
}
return lookup;
};
}
class MissingDataException extends BaseException {
constructor(begin, end) {
super(`Missing data [${begin}, ${end})`, "MissingDataException");
this.begin = begin;
this.end = end;
}
}
class ParserEOFException extends BaseException {
constructor(msg) {
super(msg, "ParserEOFException");
}
}
class XRefEntryException extends BaseException {
constructor(msg) {
super(msg, "XRefEntryException");
}
}
class XRefParseException extends BaseException {
constructor(msg) {
super(msg, "XRefParseException");
}
}
/**
* Combines multiple ArrayBuffers into a single Uint8Array.
* @param {Array<ArrayBuffer>} arr - An array of ArrayBuffers.
* @returns {Uint8Array}
*/
function arrayBuffersToBytes(arr) {
if (
typeof PDFJSDev === "undefined" ||
PDFJSDev.test("!PRODUCTION || TESTING")
) {
for (const item of arr) {
assert(
item instanceof ArrayBuffer,
"arrayBuffersToBytes - expected an ArrayBuffer."
);
}
}
const length = arr.length;
if (length === 0) {
return new Uint8Array(0);
}
if (length === 1) {
return new Uint8Array(arr[0]);
}
let dataLength = 0;
for (let i = 0; i < length; i++) {
dataLength += arr[i].byteLength;
}
const data = new Uint8Array(dataLength);
let pos = 0;
for (let i = 0; i < length; i++) {
const item = new Uint8Array(arr[i]);
data.set(item, pos);
pos += item.byteLength;
}
return data;
}
/**
* Get the value of an inheritable property.
*
* If the PDF specification explicitly lists a property in a dictionary as
* inheritable, then the value of the property may be present in the dictionary
* itself or in one or more parents of the dictionary.
*
* If the key is not found in the tree, `undefined` is returned. Otherwise,
* the value for the key is returned or, if `stopWhenFound` is `false`, a list
* of values is returned.
*
* @param {Dict} dict - Dictionary from where to start the traversal.
* @param {string} key - The key of the property to find the value for.
* @param {boolean} getArray - Whether or not the value should be fetched as an
* array. The default value is `false`.
* @param {boolean} stopWhenFound - Whether or not to stop the traversal when
* the key is found. If set to `false`, we always walk up the entire parent
* chain, for example to be able to find `\Resources` placed on multiple
* levels of the tree. The default value is `true`.
*/
function getInheritableProperty({
dict,
key,
getArray = false,
stopWhenFound = true,
}) {
let values;
const visited = new RefSet();
while (dict instanceof Dict && !(dict.objId && visited.has(dict.objId))) {
if (dict.objId) {
visited.put(dict.objId);
}
const value = getArray ? dict.getArray(key) : dict.get(key);
if (value !== undefined) {
if (stopWhenFound) {
return value;
}
if (!values) {
values = [];
}
values.push(value);
}
dict = dict.get("Parent");
}
return values;
}
// prettier-ignore
const ROMAN_NUMBER_MAP = [
"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM",
"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC",
"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"
];
/**
* Converts positive integers to (upper case) Roman numerals.
* @param {number} number - The number that should be converted.
* @param {boolean} lowerCase - Indicates if the result should be converted
* to lower case letters. The default value is `false`.
* @returns {string} The resulting Roman number.
*/
function toRomanNumerals(number, lowerCase = false) {
assert(
Number.isInteger(number) && number > 0,
"The number should be a positive integer."
);
const romanBuf = [];
let pos;
// Thousands
while (number >= 1000) {
number -= 1000;
romanBuf.push("M");
}
// Hundreds
pos = (number / 100) | 0;
number %= 100;
romanBuf.push(ROMAN_NUMBER_MAP[pos]);
// Tens
pos = (number / 10) | 0;
number %= 10;
romanBuf.push(ROMAN_NUMBER_MAP[10 + pos]);
// Ones
romanBuf.push(ROMAN_NUMBER_MAP[20 + number]); // eslint-disable-line unicorn/no-array-push-push
const romanStr = romanBuf.join("");
return lowerCase ? romanStr.toLowerCase() : romanStr;
}
// Calculate the base 2 logarithm of the number `x`. This differs from the
// native function in the sense that it returns the ceiling value and that it
// returns 0 instead of `Infinity`/`NaN` for `x` values smaller than/equal to 0.
function log2(x) {
if (x <= 0) {
return 0;
}
return Math.ceil(Math.log2(x));
}
function readInt8(data, offset) {
return (data[offset] << 24) >> 24;
}
function readUint16(data, offset) {
return (data[offset] << 8) | data[offset + 1];
}
function readUint32(data, offset) {
return (
((data[offset] << 24) |
(data[offset + 1] << 16) |
(data[offset + 2] << 8) |
data[offset + 3]) >>>
0
);
}
// Checks if ch is one of the following characters: SPACE, TAB, CR or LF.
function isWhiteSpace(ch) {
return ch === 0x20 || ch === 0x09 || ch === 0x0d || ch === 0x0a;
}
/**
* AcroForm field names use an array like notation to refer to
* repeated XFA elements e.g. foo.bar[nnn].
* see: XFA Spec Chapter 3 - Repeated Elements
*
* @param {string} path - XFA path name.
* @returns {Array} - Array of Objects with the name and pos of
* each part of the path.
*/
function parseXFAPath(path) {
const positionPattern = /(.+)\[(\d+)\]$/;
return path.split(".").map(component => {
const m = component.match(positionPattern);
if (m) {
return { name: m[1], pos: parseInt(m[2], 10) };
}
return { name: component, pos: 0 };
});
}
function escapePDFName(str) {
const buffer = [];
let start = 0;
for (let i = 0, ii = str.length; i < ii; i++) {
const char = str.charCodeAt(i);
// Whitespace or delimiters aren't regular chars, so escape them.
if (
char < 0x21 ||
char > 0x7e ||
char === 0x23 /* # */ ||
char === 0x28 /* ( */ ||
char === 0x29 /* ) */ ||
char === 0x3c /* < */ ||
char === 0x3e /* > */ ||
char === 0x5b /* [ */ ||
char === 0x5d /* ] */ ||
char === 0x7b /* { */ ||
char === 0x7d /* } */ ||
char === 0x2f /* / */ ||
char === 0x25 /* % */
) {
if (start < i) {
buffer.push(str.substring(start, i));
}
buffer.push(`#${char.toString(16)}`);
start = i + 1;
}
}
if (buffer.length === 0) {
return str;
}
if (start < str.length) {
buffer.push(str.substring(start, str.length));
}
return buffer.join("");
}
// Replace "(", ")", "\n", "\r" and "\" by "\(", "\)", "\\n", "\\r" and "\\"
// in order to write it in a PDF file.
function escapeString(str) {
return str.replace(/([()\\\n\r])/g, match => {
if (match === "\n") {
return "\\n";
} else if (match === "\r") {
return "\\r";
}
return `\\${match}`;
});
}
function _collectJS(entry, xref, list, parents) {
if (!entry) {
return;
}
let parent = null;
if (entry instanceof Ref) {
if (parents.has(entry)) {
// If we've already found entry then we've a cycle.
return;
}
parent = entry;
parents.put(parent);
entry = xref.fetch(entry);
}
if (Array.isArray(entry)) {
for (const element of entry) {
_collectJS(element, xref, list, parents);
}
} else if (entry instanceof Dict) {
if (isName(entry.get("S"), "JavaScript")) {
const js = entry.get("JS");
let code;
if (js instanceof BaseStream) {
code = js.getString();
} else if (typeof js === "string") {
code = js;
}
code = code && stringToPDFString(code).replace(/\u0000/g, "");
if (code) {
list.push(code);
}
}
_collectJS(entry.getRaw("Next"), xref, list, parents);
}
if (parent) {
parents.remove(parent);
}
}
function collectActions(xref, dict, eventType) {
const actions = Object.create(null);
const additionalActionsDicts = getInheritableProperty({
dict,
key: "AA",
stopWhenFound: false,
});
if (additionalActionsDicts) {
// additionalActionsDicts contains dicts from ancestors
// as they're found in the tree from bottom to top.
// So the dicts are visited in reverse order to guarantee
// that actions from elder ancestors will be overwritten
// by ones from younger ancestors.
for (let i = additionalActionsDicts.length - 1; i >= 0; i--) {
const additionalActions = additionalActionsDicts[i];
if (!(additionalActions instanceof Dict)) {
continue;
}
for (const key of additionalActions.getKeys()) {
const action = eventType[key];
if (!action) {
continue;
}
const actionDict = additionalActions.getRaw(key);
const parents = new RefSet();
const list = [];
_collectJS(actionDict, xref, list, parents);
if (list.length > 0) {
actions[action] = list;
}
}
}
}
// Collect the Action if any (we may have one on pushbutton).
if (dict.has("A")) {
const actionDict = dict.get("A");
const parents = new RefSet();
const list = [];
_collectJS(actionDict, xref, list, parents);
if (list.length > 0) {
actions.Action = list;
}
}
return objectSize(actions) > 0 ? actions : null;
}
const XMLEntities = {
/* < */ 0x3c: "&lt;",
/* > */ 0x3e: "&gt;",
/* & */ 0x26: "&amp;",
/* " */ 0x22: "&quot;",
/* ' */ 0x27: "&apos;",
};
function encodeToXmlString(str) {
const buffer = [];
let start = 0;
for (let i = 0, ii = str.length; i < ii; i++) {
const char = str.codePointAt(i);
if (0x20 <= char && char <= 0x7e) {
// ascii
const entity = XMLEntities[char];
if (entity) {
if (start < i) {
buffer.push(str.substring(start, i));
}
buffer.push(entity);
start = i + 1;
}
} else {
if (start < i) {
buffer.push(str.substring(start, i));
}
buffer.push(`&#x${char.toString(16).toUpperCase()};`);
if (char > 0xd7ff && (char < 0xe000 || char > 0xfffd)) {
// char is represented by two u16
i++;
}
start = i + 1;
}
}
if (buffer.length === 0) {
return str;
}
if (start < str.length) {
buffer.push(str.substring(start, str.length));
}
return buffer.join("");
}
function validateCSSFont(cssFontInfo) {
// See https://developer.mozilla.org/en-US/docs/Web/CSS/font-style.
const DEFAULT_CSS_FONT_OBLIQUE = "14";
// See https://developer.mozilla.org/en-US/docs/Web/CSS/font-weight.
const DEFAULT_CSS_FONT_WEIGHT = "400";
const CSS_FONT_WEIGHT_VALUES = new Set([
"100",
"200",
"300",
"400",
"500",
"600",
"700",
"800",
"900",
"1000",
"normal",
"bold",
"bolder",
"lighter",
]);
const { fontFamily, fontWeight, italicAngle } = cssFontInfo;
// See https://developer.mozilla.org/en-US/docs/Web/CSS/string.
if (/^".*"$/.test(fontFamily)) {
if (/[^\\]"/.test(fontFamily.slice(1, fontFamily.length - 1))) {
warn(`XFA - FontFamily contains some unescaped ": ${fontFamily}.`);
return false;
}
} else if (/^'.*'$/.test(fontFamily)) {
if (/[^\\]'/.test(fontFamily.slice(1, fontFamily.length - 1))) {
warn(`XFA - FontFamily contains some unescaped ': ${fontFamily}.`);
return false;
}
} else {
// See https://developer.mozilla.org/en-US/docs/Web/CSS/custom-ident.
for (const ident of fontFamily.split(/[ \t]+/)) {
if (/^(\d|(-(\d|-)))/.test(ident) || !/^[\w-\\]+$/.test(ident)) {
warn(
`XFA - FontFamily contains some invalid <custom-ident>: ${fontFamily}.`
);
return false;
}
}
}
const weight = fontWeight ? fontWeight.toString() : "";
cssFontInfo.fontWeight = CSS_FONT_WEIGHT_VALUES.has(weight)
? weight
: DEFAULT_CSS_FONT_WEIGHT;
const angle = parseFloat(italicAngle);
cssFontInfo.italicAngle =
isNaN(angle) || angle < -90 || angle > 90
? DEFAULT_CSS_FONT_OBLIQUE
: italicAngle.toString();
return true;
}
function recoverJsURL(str) {
// Attempt to recover valid URLs from `JS` entries with certain
// white-listed formats:
// - window.open('http://example.com')
// - app.launchURL('http://example.com', true)
// - xfa.host.gotoURL('http://example.com')
const URL_OPEN_METHODS = ["app.launchURL", "window.open", "xfa.host.gotoURL"];
const regex = new RegExp(
"^\\s*(" +
URL_OPEN_METHODS.join("|").split(".").join("\\.") +
")\\((?:'|\")([^'\"]*)(?:'|\")(?:,\\s*(\\w+)\\)|\\))",
"i"
);
const jsUrl = regex.exec(str);
if (jsUrl && jsUrl[2]) {
const url = jsUrl[2];
let newWindow = false;
if (jsUrl[3] === "true" && jsUrl[1] === "app.launchURL") {
newWindow = true;
}
return { url, newWindow };
}
return null;
}
function numberToString(value) {
if (Number.isInteger(value)) {
return value.toString();
}
const roundedValue = Math.round(value * 100);
if (roundedValue % 100 === 0) {
return (roundedValue / 100).toString();
}
if (roundedValue % 10 === 0) {
return value.toFixed(1);
}
return value.toFixed(2);
}
function getNewAnnotationsMap(annotationStorage) {
if (!annotationStorage) {
return null;
}
const newAnnotationsByPage = new Map();
// The concept of page in a XFA is very different, so
// editing is just not implemented.
for (const [key, value] of annotationStorage) {
if (!key.startsWith(AnnotationEditorPrefix)) {
continue;
}
let annotations = newAnnotationsByPage.get(value.pageIndex);
if (!annotations) {
annotations = [];
newAnnotationsByPage.set(value.pageIndex, annotations);
}
annotations.push(value);
}
return newAnnotationsByPage.size > 0 ? newAnnotationsByPage : null;
}
function isAscii(str) {
return /^[\x00-\x7F]*$/.test(str);
}
function stringToUTF16HexString(str) {
const buf = [];
for (let i = 0, ii = str.length; i < ii; i++) {
const char = str.charCodeAt(i);
buf.push(
((char >> 8) & 0xff).toString(16).padStart(2, "0"),
(char & 0xff).toString(16).padStart(2, "0")
);
}
return buf.join("");
}
function stringToUTF16String(str, bigEndian = false) {
const buf = [];
if (bigEndian) {
buf.push("\xFE\xFF");
}
for (let i = 0, ii = str.length; i < ii; i++) {
const char = str.charCodeAt(i);
buf.push(
String.fromCharCode((char >> 8) & 0xff),
String.fromCharCode(char & 0xff)
);
}
return buf.join("");
}
function getRotationMatrix(rotation, width, height) {
switch (rotation) {
case 90:
return [0, 1, -1, 0, width, 0];
case 180:
return [-1, 0, 0, -1, width, height];
case 270:
return [0, -1, 1, 0, 0, height];
default:
throw new Error("Invalid rotation");
}
}
export {
arrayBuffersToBytes,
collectActions,
encodeToXmlString,
escapePDFName,
escapeString,
getArrayLookupTableFactory,
getInheritableProperty,
getLookupTableFactory,
getNewAnnotationsMap,
getRotationMatrix,
isAscii,
isWhiteSpace,
log2,
MissingDataException,
numberToString,
ParserEOFException,
parseXFAPath,
PDF_VERSION_REGEXP,
readInt8,
readUint16,
readUint32,
recoverJsURL,
stringToUTF16HexString,
stringToUTF16String,
toRomanNumerals,
validateCSSFont,
XRefEntryException,
XRefParseException,
};