Prefer instanceof Dict rather than calling isDict() with one argument

Unless you actually need to check that something is both a `Dict` and also of the *correct* type, using `instanceof Dict` directly should be a tiny bit more efficient since it avoids one function call and an unnecessary `undefined` check.

This patch uses ESLint to enforce this, since we obviously still want to keep the `isDict` helper function for where it makes sense.
This commit is contained in:
Jonas Jenwald 2022-02-21 12:44:56 +01:00
parent 67b658e8d5
commit 4df82ad31e
18 changed files with 83 additions and 93 deletions

View File

@ -183,6 +183,10 @@
"selector": "CallExpression[callee.name='isCmd'][arguments.length<2]",
"message": "Use `instanceof Cmd` rather than `isCmd()` with one argument.",
},
{
"selector": "CallExpression[callee.name='isDict'][arguments.length<2]",
"message": "Use `instanceof Dict` rather than `isDict()` with one argument.",
},
{
"selector": "NewExpression[callee.name='Cmd']",
"message": "Use `Cmd.get()` rather than `new Cmd()`.",

View File

@ -39,7 +39,7 @@ import {
createDefaultAppearance,
parseDefaultAppearance,
} from "./default_appearance.js";
import { Dict, isDict, isName, Name, Ref, RefSet } from "./primitives.js";
import { Dict, isName, Name, Ref, RefSet } from "./primitives.js";
import { BaseStream } from "./base_stream.js";
import { bidi } from "./bidi.js";
import { Catalog } from "./catalog.js";
@ -95,7 +95,7 @@ class AnnotationFactory {
pageIndex = -1
) {
const dict = xref.fetchIfRef(ref);
if (!isDict(dict)) {
if (!(dict instanceof Dict)) {
return undefined;
}
@ -209,7 +209,7 @@ class AnnotationFactory {
static async _getPageIndex(xref, ref, pdfManager) {
try {
const annotDict = await xref.fetchIfRefAsync(ref);
if (!isDict(annotDict)) {
if (!(annotDict instanceof Dict)) {
return -1;
}
const pageRef = annotDict.getRaw("P");
@ -636,7 +636,7 @@ class Annotation {
}
this.borderStyle = new AnnotationBorderStyle();
if (!isDict(borderStyle)) {
if (!(borderStyle instanceof Dict)) {
return;
}
if (borderStyle.has("BS")) {
@ -681,7 +681,7 @@ class Annotation {
this.appearance = null;
const appearanceStates = dict.get("AP");
if (!isDict(appearanceStates)) {
if (!(appearanceStates instanceof Dict)) {
return;
}
@ -691,7 +691,7 @@ class Annotation {
this.appearance = normalAppearanceState;
return;
}
if (!isDict(normalAppearanceState)) {
if (!(normalAppearanceState instanceof Dict)) {
return;
}
@ -1418,7 +1418,7 @@ class WidgetAnnotation extends Annotation {
const { xref } = evaluator;
const dict = xref.fetchIfRef(this.ref);
if (!isDict(dict)) {
if (!(dict instanceof Dict)) {
return null;
}
@ -2085,7 +2085,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
}
const dict = evaluator.xref.fetchIfRef(this.ref);
if (!isDict(dict)) {
if (!(dict instanceof Dict)) {
return null;
}
@ -2131,7 +2131,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
}
const dict = evaluator.xref.fetchIfRef(this.ref);
if (!isDict(dict)) {
if (!(dict instanceof Dict)) {
return null;
}
@ -2158,7 +2158,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
parentBuffer = [`${this.parent.num} ${this.parent.gen} obj\n`];
writeDict(parent, parentBuffer, parentTransform);
parentBuffer.push("\nendobj\n");
} else if (isDict(this.parent)) {
} else if (this.parent instanceof Dict) {
this.parent.set("V", name);
}
}
@ -2250,12 +2250,12 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
_processCheckBox(params) {
const customAppearance = params.dict.get("AP");
if (!isDict(customAppearance)) {
if (!(customAppearance instanceof Dict)) {
return;
}
const normalAppearance = customAppearance.get("N");
if (!isDict(normalAppearance)) {
if (!(normalAppearance instanceof Dict)) {
return;
}
@ -2318,7 +2318,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
// The parent field's `V` entry holds a `Name` object with the appearance
// state of whichever child field is currently in the "on" state.
const fieldParent = params.dict.get("Parent");
if (isDict(fieldParent)) {
if (fieldParent instanceof Dict) {
this.parent = params.dict.getRaw("Parent");
const fieldParentValue = fieldParent.get("V");
if (isName(fieldParentValue)) {
@ -2328,11 +2328,11 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
// The button's value corresponds to its appearance state.
const appearanceStates = params.dict.get("AP");
if (!isDict(appearanceStates)) {
if (!(appearanceStates instanceof Dict)) {
return;
}
const normalAppearance = appearanceStates.get("N");
if (!isDict(normalAppearance)) {
if (!(normalAppearance instanceof Dict)) {
return;
}
for (const key of normalAppearance.getKeys()) {

View File

@ -120,7 +120,7 @@ class Catalog {
let collection = null;
try {
const obj = this._catDict.get("Collection");
if (isDict(obj) && obj.size > 0) {
if (obj instanceof Dict && obj.size > 0) {
collection = obj;
}
} catch (ex) {
@ -136,7 +136,7 @@ class Catalog {
let acroForm = null;
try {
const obj = this._catDict.get("AcroForm");
if (isDict(obj) && obj.size > 0) {
if (obj instanceof Dict && obj.size > 0) {
acroForm = obj;
}
} catch (ex) {
@ -208,7 +208,7 @@ class Catalog {
*/
_readMarkInfo() {
const obj = this._catDict.get("MarkInfo");
if (!isDict(obj)) {
if (!(obj instanceof Dict)) {
return null;
}
@ -249,7 +249,7 @@ class Catalog {
*/
_readStructTreeRoot() {
const obj = this._catDict.get("StructTreeRoot");
if (!isDict(obj)) {
if (!(obj instanceof Dict)) {
return null;
}
const root = new StructTreeRoot(obj);
@ -259,7 +259,7 @@ class Catalog {
get toplevelPagesDict() {
const pagesObj = this._catDict.get("Pages");
if (!isDict(pagesObj)) {
if (!(pagesObj instanceof Dict)) {
throw new FormatError("Invalid top-level pages dictionary.");
}
return shadow(this, "toplevelPagesDict", pagesObj);
@ -283,7 +283,7 @@ class Catalog {
*/
_readDocumentOutline() {
let obj = this._catDict.get("Outlines");
if (!isDict(obj)) {
if (!(obj instanceof Dict)) {
return null;
}
obj = obj.getRaw("First");
@ -376,7 +376,7 @@ class Catalog {
*/
_readPermissions() {
const encrypt = this.xref.trailer.get("Encrypt");
if (!isDict(encrypt)) {
if (!(encrypt instanceof Dict)) {
return null;
}
@ -654,7 +654,7 @@ class Catalog {
const labelDict = nums.get(i);
if (labelDict !== undefined) {
if (!isDict(labelDict)) {
if (!(labelDict instanceof Dict)) {
throw new FormatError("PageLabel is not a dictionary.");
}
@ -799,7 +799,7 @@ class Catalog {
const obj = this._catDict.get("ViewerPreferences");
let prefs = null;
if (isDict(obj)) {
if (obj instanceof Dict) {
for (const key in ViewerPreferencesValidators) {
if (!obj.has(key)) {
continue;
@ -921,7 +921,7 @@ class Catalog {
const obj = this._catDict.get("OpenAction");
const openAction = Object.create(null);
if (isDict(obj)) {
if (obj instanceof Dict) {
// Convert the OpenAction dictionary into a format that works with
// `parseDestDictionary`, to avoid having to re-implement those checks.
const destDict = new Dict(this.xref);
@ -1337,7 +1337,7 @@ class Catalog {
if (
isRefsEqual(kidRef, pageRef) &&
!isDict(node, "Page") &&
!(isDict(node) && !node.has("Type") && node.has("Contents"))
!(node instanceof Dict && !node.has("Type") && node.has("Contents"))
) {
throw new FormatError(
"The reference does not point to a /Page dictionary."
@ -1346,7 +1346,7 @@ class Catalog {
if (!node) {
return null;
}
if (!isDict(node)) {
if (!(node instanceof Dict)) {
throw new FormatError("Node must be a dictionary.");
}
parentRef = node.getRaw("Parent");
@ -1356,7 +1356,7 @@ class Catalog {
if (!parent) {
return null;
}
if (!isDict(parent)) {
if (!(parent instanceof Dict)) {
throw new FormatError("Parent must be a dictionary.");
}
return parent.getAsync("Kids");
@ -1379,7 +1379,7 @@ class Catalog {
}
kidPromises.push(
xref.fetchAsync(kid).then(function (obj) {
if (!isDict(obj)) {
if (!(obj instanceof Dict)) {
throw new FormatError("Kid node must be a dictionary.");
}
if (obj.has("Count")) {
@ -1430,7 +1430,7 @@ class Catalog {
*/
static parseDestDictionary(params) {
const destDict = params.destDict;
if (!isDict(destDict)) {
if (!(destDict instanceof Dict)) {
warn("parseDestDictionary: `destDict` must be a dictionary.");
return;
}
@ -1444,14 +1444,14 @@ class Catalog {
let action = destDict.get("A"),
url,
dest;
if (!isDict(action)) {
if (!(action instanceof Dict)) {
if (destDict.has("Dest")) {
// A /Dest entry should *only* contain a Name or an Array, but some bad
// PDF generators ignore that and treat it as an /A entry.
action = destDict.get("Dest");
} else {
action = destDict.get("AA");
if (isDict(action)) {
if (action instanceof Dict) {
if (action.has("D")) {
// MouseDown
action = action.get("D");
@ -1463,7 +1463,7 @@ class Catalog {
}
}
if (isDict(action)) {
if (action instanceof Dict) {
const actionType = action.get("S");
if (!isName(actionType)) {
warn("parseDestDictionary: Invalid type in Action dictionary.");
@ -1508,7 +1508,7 @@ class Catalog {
case "GoToR":
const urlDict = action.get("F");
if (isDict(urlDict)) {
if (urlDict instanceof Dict) {
// We assume that we found a FileSpec dictionary
// and fetch the URL without checking any further.
url = urlDict.get("F") || null;

View File

@ -13,9 +13,9 @@
* limitations under the License.
*/
import { Dict, isDict } from "./primitives.js";
import { CCITTFaxDecoder } from "./ccitt.js";
import { DecodeStream } from "./decode_stream.js";
import { Dict } from "./primitives.js";
class CCITTFaxStream extends DecodeStream {
constructor(str, maybeLength, params) {
@ -24,7 +24,7 @@ class CCITTFaxStream extends DecodeStream {
this.str = str;
this.dict = str.dict;
if (!isDict(params)) {
if (!(params instanceof Dict)) {
params = Dict.empty;
}

View File

@ -21,7 +21,7 @@ import {
unreachable,
warn,
} from "../shared/util.js";
import { isDict, isName, Name, Ref } from "./primitives.js";
import { Dict, isName, Name, Ref } from "./primitives.js";
import { BaseStream } from "./base_stream.js";
import { MissingDataException } from "./core_utils.js";
@ -392,9 +392,9 @@ class ColorSpace {
case "Pattern":
return new PatternCS(/* baseCS = */ null);
default:
if (isDict(resources)) {
if (resources instanceof Dict) {
const colorSpaces = resources.get("ColorSpace");
if (isDict(colorSpaces)) {
if (colorSpaces instanceof Dict) {
const resourcesCS = colorSpaces.get(cs.name);
if (resourcesCS) {
if (isName(resourcesCS)) {

View File

@ -24,7 +24,7 @@ import {
utf8StringToString,
warn,
} from "../shared/util.js";
import { isDict, isName, Name } from "./primitives.js";
import { Dict, isName, Name } from "./primitives.js";
import { DecryptStream } from "./decrypt_stream.js";
class ARCFourCipher {
@ -1713,7 +1713,7 @@ const CipherTransformFactory = (function CipherTransformFactoryClosure() {
// Trying to find default handler -- it usually has Length.
const cfDict = dict.get("CF");
const streamCryptoName = dict.get("StmF");
if (isDict(cfDict) && isName(streamCryptoName)) {
if (cfDict instanceof Dict && isName(streamCryptoName)) {
cfDict.suppressEncryption = true; // See comment below.
const handlerDict = cfDict.get(streamCryptoName.name);
keyLength = (handlerDict && handlerDict.get("Length")) || 128;
@ -1838,7 +1838,7 @@ const CipherTransformFactory = (function CipherTransformFactoryClosure() {
if (algorithm >= 4) {
const cf = dict.get("CF");
if (isDict(cf)) {
if (cf instanceof Dict) {
// The 'CF' dictionary itself should not be encrypted, and by setting
// `suppressEncryption` we can prevent an infinite loop inside of
// `XRef_fetchUncompressed` if the dictionary contains indirect

View File

@ -44,7 +44,7 @@ import {
XRefEntryException,
XRefParseException,
} from "./core_utils.js";
import { Dict, isDict, isName, Name, Ref } from "./primitives.js";
import { Dict, isName, Name, Ref } from "./primitives.js";
import { getXfaFontDict, getXfaFontName } from "./xfa_fonts.js";
import { NullStream, Stream } from "./stream.js";
import { AnnotationFactory } from "./annotation.js";
@ -120,7 +120,7 @@ class Page {
if (!Array.isArray(value)) {
return value;
}
if (value.length === 1 || !isDict(value[0])) {
if (value.length === 1 || !(value[0] instanceof Dict)) {
return value[0];
}
return Dict.merge({ xref: this.xref, dictArray: value });
@ -1175,7 +1175,7 @@ class PDFDocument {
info("The document information dictionary is invalid.");
}
if (isDict(infoDict)) {
if (infoDict instanceof Dict) {
// Fill the document info with valid entries from the specification,
// as well as any existing well-formed custom entries.
for (const key of infoDict.getKeys()) {

View File

@ -35,16 +35,7 @@ import {
warn,
} from "../shared/util.js";
import { CMapFactory, IdentityCMap } from "./cmap.js";
import {
Cmd,
Dict,
EOF,
isDict,
isName,
Name,
Ref,
RefSet,
} from "./primitives.js";
import { Cmd, Dict, EOF, isName, Name, Ref, RefSet } from "./primitives.js";
import { ErrorFont, Font } from "./fonts.js";
import { FontFlags, getFontType } from "./fonts_utils.js";
import {
@ -1042,7 +1033,7 @@ class PartialEvaluator {
gStateObj.push([key, false]);
break;
}
if (isDict(value)) {
if (value instanceof Dict) {
isSimpleGState = false;
promise = promise.then(() => {
@ -1162,7 +1153,7 @@ class PartialEvaluator {
}
font = xref.fetchIfRef(fontRef);
if (!isDict(font)) {
if (!(font instanceof Dict)) {
return errorFont();
}
@ -1190,7 +1181,7 @@ class PartialEvaluator {
fontID = `f${fontRef.toString()}`;
}
if (hash && isDict(descriptor)) {
if (hash && descriptor instanceof Dict) {
if (!descriptor.fontAliases) {
descriptor.fontAliases = Object.create(null);
}
@ -1493,7 +1484,7 @@ class PartialEvaluator {
if (isName(contentProperties)) {
const properties = resources.get("Properties");
optionalContent = properties.get(contentProperties.name);
} else if (isDict(contentProperties)) {
} else if (contentProperties instanceof Dict) {
optionalContent = contentProperties;
} else {
throw new FormatError("Optional content properties malformed.");
@ -1521,7 +1512,7 @@ class PartialEvaluator {
const optionalContentGroups = optionalContent.get("OCGs");
if (
Array.isArray(optionalContentGroups) ||
isDict(optionalContentGroups)
optionalContentGroups instanceof Dict
) {
const groupIds = [];
if (Array.isArray(optionalContentGroups)) {
@ -3133,7 +3124,7 @@ class PartialEvaluator {
if (includeMarkedContent) {
flushTextContentItem();
let mcid = null;
if (isDict(args[1])) {
if (args[1] instanceof Dict) {
mcid = args[1].get("MCID");
}
textContent.items.push({
@ -3197,7 +3188,7 @@ class PartialEvaluator {
if (properties.composite) {
// CIDSystemInfo helps to match CID to glyphs
const cidSystemInfo = dict.get("CIDSystemInfo");
if (isDict(cidSystemInfo)) {
if (cidSystemInfo instanceof Dict) {
properties.cidSystemInfo = {
registry: stringToPDFString(cidSystemInfo.get("Registry")),
ordering: stringToPDFString(cidSystemInfo.get("Ordering")),
@ -3222,7 +3213,7 @@ class PartialEvaluator {
let encoding;
if (dict.has("Encoding")) {
encoding = dict.get("Encoding");
if (isDict(encoding)) {
if (encoding instanceof Dict) {
baseEncodingName = encoding.get("BaseEncoding");
baseEncodingName = isName(baseEncodingName)
? baseEncodingName.name
@ -3784,7 +3775,7 @@ class PartialEvaluator {
hash.update(encoding.name);
} else if (encoding instanceof Ref) {
hash.update(encoding.toString());
} else if (isDict(encoding)) {
} else if (encoding instanceof Dict) {
for (const entry of encoding.getRawValues()) {
if (isName(entry)) {
hash.update(entry.name);

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@ -15,7 +15,7 @@
import { stringToPDFString, warn } from "../shared/util.js";
import { BaseStream } from "./base_stream.js";
import { isDict } from "./primitives.js";
import { Dict } from "./primitives.js";
function pickPlatformItem(dict) {
// Look for the filename in this order:
@ -43,7 +43,7 @@ function pickPlatformItem(dict) {
*/
class FileSpec {
constructor(root, xref) {
if (!root || !isDict(root)) {
if (!(root instanceof Dict)) {
return;
}
this.xref = xref;

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@ -13,7 +13,7 @@
* limitations under the License.
*/
import { Dict, isDict, Ref } from "./primitives.js";
import { Dict, Ref } from "./primitives.js";
import {
FormatError,
info,
@ -508,7 +508,7 @@ function isPDFFunction(v) {
let fnDict;
if (typeof v !== "object") {
return false;
} else if (isDict(v)) {
} else if (v instanceof Dict) {
fnDict = v;
} else if (v instanceof BaseStream) {
fnDict = v.dict;

View File

@ -15,7 +15,7 @@
import { BaseStream } from "./base_stream.js";
import { DecodeStream } from "./decode_stream.js";
import { isDict } from "./primitives.js";
import { Dict } from "./primitives.js";
import { Jbig2Image } from "./jbig2.js";
import { shadow } from "../shared/util.js";
@ -50,7 +50,7 @@ class Jbig2Stream extends DecodeStream {
const jbig2Image = new Jbig2Image();
const chunks = [];
if (isDict(this.params)) {
if (this.params instanceof Dict) {
const globalsStream = this.params.get("JBIG2Globals");
if (globalsStream instanceof BaseStream) {
const globals = globalsStream.getBytes();

View File

@ -14,7 +14,7 @@
*/
import { DecodeStream } from "./decode_stream.js";
import { isDict } from "./primitives.js";
import { Dict } from "./primitives.js";
import { JpegImage } from "./jpg.js";
import { shadow } from "../shared/util.js";
@ -81,7 +81,7 @@ class JpegStream extends DecodeStream {
}
}
// Fetching the 'ColorTransform' entry, if it exists.
if (isDict(this.params)) {
if (this.params instanceof Dict) {
const colorTransform = this.params.get("ColorTransform");
if (Number.isInteger(colorTransform)) {
jpegOptions.colorTransform = colorTransform;

View File

@ -13,8 +13,8 @@
* limitations under the License.
*/
import { Dict, RefSet } from "./primitives.js";
import { FormatError, unreachable, warn } from "../shared/util.js";
import { isDict, RefSet } from "./primitives.js";
/**
* A NameTree/NumberTree is like a Dict but has some advantageous properties,
@ -43,7 +43,7 @@ class NameOrNumberTree {
const queue = [this.root];
while (queue.length > 0) {
const obj = xref.fetchIfRef(queue.shift());
if (!isDict(obj)) {
if (!(obj instanceof Dict)) {
continue;
}
if (obj.has("Kids")) {

View File

@ -22,16 +22,7 @@ import {
StreamType,
warn,
} from "../shared/util.js";
import {
Cmd,
Dict,
EOF,
isCmd,
isDict,
isName,
Name,
Ref,
} from "./primitives.js";
import { Cmd, Dict, EOF, isCmd, isName, Name, Ref } from "./primitives.js";
import {
isWhiteSpace,
MissingDataException,
@ -1401,7 +1392,7 @@ class Linearization {
Number.isInteger(obj1) &&
Number.isInteger(obj2) &&
isCmd(obj3, "obj") &&
isDict(linDict) &&
linDict instanceof Dict &&
isNum((obj = linDict.get("Linearized"))) &&
obj > 0
)

View File

@ -14,14 +14,14 @@
*/
import { DecodeStream } from "./decode_stream.js";
import { Dict } from "./primitives.js";
import { FormatError } from "../shared/util.js";
import { isDict } from "./primitives.js";
class PredictorStream extends DecodeStream {
constructor(str, maybeLength, params) {
super(maybeLength);
if (!isDict(params)) {
if (!(params instanceof Dict)) {
return str; // no prediction
}
const predictor = (this.predictor = params.get("Predictor") || 1);

View File

@ -13,7 +13,7 @@
* limitations under the License.
*/
import { isDict, isName, Ref } from "./primitives.js";
import { Dict, isName, Ref } from "./primitives.js";
import { isString, stringToPDFString, warn } from "../shared/util.js";
import { NumberTree } from "./name_number_tree.js";
@ -38,7 +38,7 @@ class StructTreeRoot {
readRoleMap() {
const roleMapDict = this.dict.get("RoleMap");
if (!isDict(roleMapDict)) {
if (!(roleMapDict instanceof Dict)) {
return;
}
roleMapDict.forEach((key, value) => {
@ -112,7 +112,7 @@ class StructElementNode {
let kidDict = null;
if (kid instanceof Ref) {
kidDict = this.dict.xref.fetch(kid);
} else if (isDict(kid)) {
} else if (kid instanceof Dict) {
kidDict = kid;
}
if (!kidDict) {
@ -256,7 +256,7 @@ class StructTreePage {
return false;
}
if (isDict(obj)) {
if (obj instanceof Dict) {
if (obj.objId !== dict.objId) {
return false;
}

View File

@ -14,7 +14,7 @@
*/
import { bytesToString, escapeString, warn } from "../shared/util.js";
import { Dict, isDict, isName, Name, Ref } from "./primitives.js";
import { Dict, isName, Name, Ref } from "./primitives.js";
import { escapePDFName, parseXFAPath } from "./core_utils.js";
import { SimpleDOMNode, SimpleXMLParser } from "./xml_parser.js";
import { BaseStream } from "./base_stream.js";
@ -86,7 +86,7 @@ function writeValue(value, buffer, transform) {
buffer.push(numberToString(value));
} else if (typeof value === "boolean") {
buffer.push(value.toString());
} else if (isDict(value)) {
} else if (value instanceof Dict) {
writeDict(value, buffer, transform);
} else if (value instanceof BaseStream) {
writeStream(value, buffer, transform);

View File

@ -518,6 +518,8 @@ describe("primitives", function () {
});
describe("isDict", function () {
/* eslint-disable no-restricted-syntax */
it("handles non-dictionaries", function () {
const nonDict = {};
expect(isDict(nonDict)).toEqual(false);
@ -535,6 +537,8 @@ describe("primitives", function () {
expect(isDict(dict, "Page")).toEqual(true);
expect(isDict(dict, "Contents")).toEqual(false);
});
/* eslint-enable no-restricted-syntax */
});
describe("isRefsEqual", function () {