Convert the XRef to a "normal" class

src/core/xref.js

@@ -39,9 +39,8 @@ import {
 } from "./core_utils.js";
 import { CipherTransformFactory } from "./crypto.js";
 
-var XRef = (function XRefClosure() {
+class XRef {
-  // eslint-disable-next-line no-shadow
+  constructor(stream, pdfManager) {
-  function XRef(stream, pdfManager) {
     this.stream = stream;
     this.pdfManager = pdfManager;
     this.entries = [];
@@ -54,25 +53,24 @@ var XRef = (function XRefClosure() {
     this._newRefNum = null;
   }
 
-  XRef.prototype = {
+  getNewRef() {
-    getNewRef: function XRef_getNewRef() {
     if (this._newRefNum === null) {
       this._newRefNum = this.entries.length;
     }
     return Ref.get(this._newRefNum++, 0);
-    },
+  }
 
-    resetNewRef: function XRef_resetNewRef() {
+  resetNewRef() {
     this._newRefNum = null;
-    },
+  }
 
-    setStartXRef: function XRef_setStartXRef(startXRef) {
+  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) {
+  parse(recoveryMode = false) {
     var trailerDict;
     if (!recoveryMode) {
       trailerDict = this.readXRef();
@@ -125,9 +123,9 @@ var XRef = (function XRefClosure() {
       }
       throw new FormatError("Invalid root reference");
     }
-    },
+  }
 
-    processXRefTable: function XRef_processXRefTable(parser) {
+  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
@@ -170,9 +168,9 @@ var XRef = (function XRefClosure() {
     delete this.tableState;
 
     return dict;
-    },
+  }
 
-    readXRefTable: function XRef_readXRefTable(parser) {
+  readXRefTable(parser) {
     // Example of cross-reference table:
     // xref
     // 0 1                    <-- subsection header (first obj #, obj count)
@@ -266,9 +264,9 @@ var XRef = (function XRefClosure() {
       throw new FormatError("Invalid XRef table: unexpected first object");
     }
     return obj;
-    },
+  }
 
-    processXRefStream: function XRef_processXRefStream(stream) {
+  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
@@ -290,9 +288,9 @@ var XRef = (function XRefClosure() {
     delete this.streamState;
 
     return stream.dict;
-    },
+  }
 
-    readXRefStream: function XRef_readXRefStream(stream) {
+  readXRefStream(stream) {
     var i, j;
     var streamState = this.streamState;
     stream.pos = streamState.streamPos;
@@ -363,9 +361,9 @@ var XRef = (function XRefClosure() {
       streamState.streamPos = stream.pos;
       entryRanges.splice(0, 2);
     }
-    },
+  }
 
-    indexObjects: function XRef_indexObjects() {
+  indexObjects() {
     // Simple scan through the PDF content to find objects,
     // trailers and XRef streams.
     var TAB = 0x9,
@@ -500,10 +498,7 @@ var XRef = (function XRefClosure() {
         // checking XRef stream suspect
         // (it shall have '/XRef' and next char is not a letter)
         var xrefTagOffset = skipUntil(content, 0, xrefBytes);
-          if (
+        if (xrefTagOffset < contentLength && content[xrefTagOffset + 5] < 64) {
-            xrefTagOffset < contentLength &&
-            content[xrefTagOffset + 5] < 64
-          ) {
           xrefStms.push(position - stream.start);
           this.xrefstms[position - stream.start] = 1; // Avoid recursion
         }
@@ -574,9 +569,9 @@ var XRef = (function XRefClosure() {
     }
     // nothing helps
     throw new InvalidPDFException("Invalid PDF structure.");
-    },
+  }
 
-    readXRef: function XRef_readXRef(recoveryMode) {
+  readXRef(recoveryMode = false) {
     var stream = this.stream;
     // Keep track of already parsed XRef tables, to prevent an infinite loop
     // when parsing corrupt PDF files where e.g. the /Prev entries create a
@@ -668,24 +663,24 @@ var XRef = (function XRefClosure() {
       return undefined;
     }
     throw new XRefParseException();
-    },
+  }
 
-    getEntry: function XRef_getEntry(i) {
+  getEntry(i) {
     var xrefEntry = this.entries[i];
     if (xrefEntry && !xrefEntry.free && xrefEntry.offset) {
       return xrefEntry;
     }
     return null;
-    },
+  }
 
-    fetchIfRef: function XRef_fetchIfRef(obj, suppressEncryption) {
+  fetchIfRef(obj, suppressEncryption = false) {
     if (obj instanceof Ref) {
       return this.fetch(obj, suppressEncryption);
     }
     return obj;
-    },
+  }
 
-    fetch: function XRef_fetch(ref, suppressEncryption) {
+  fetch(ref, suppressEncryption = false) {
     if (!(ref instanceof Ref)) {
       throw new Error("ref object is not a reference");
     }
@@ -722,7 +717,7 @@ var XRef = (function XRefClosure() {
       xrefEntry.dict.objId = ref.toString();
     }
     return xrefEntry;
-    },
+  }
 
   fetchUncompressed(ref, xrefEntry, suppressEncryption = false) {
     var gen = ref.gen;
@@ -773,7 +768,7 @@ var XRef = (function XRefClosure() {
       this._cacheMap.set(num, xrefEntry);
     }
     return xrefEntry;
-    },
+  }
 
   fetchCompressed(ref, xrefEntry, suppressEncryption = false) {
     const tableOffset = xrefEntry.offset;
@@ -784,9 +779,7 @@ var XRef = (function XRefClosure() {
     const first = stream.dict.get("First");
     const n = stream.dict.get("N");
     if (!Number.isInteger(first) || !Number.isInteger(n)) {
-        throw new FormatError(
+      throw new FormatError("invalid first and n parameters for ObjStm stream");
-          "invalid first and n parameters for ObjStm stream"
-        );
     }
     let parser = new Parser({
       lexer: new Lexer(stream),
@@ -854,14 +847,14 @@ var XRef = (function XRefClosure() {
       throw new XRefEntryException(`Bad (compressed) XRef entry: ${ref}`);
     }
     return xrefEntry;
-    },
+  }
 
   async fetchIfRefAsync(obj, suppressEncryption) {
     if (obj instanceof Ref) {
       return this.fetchAsync(obj, suppressEncryption);
     }
     return obj;
-    },
+  }
 
   async fetchAsync(ref, suppressEncryption) {
     try {
@@ -873,14 +866,11 @@ var XRef = (function XRefClosure() {
       await this.pdfManager.requestRange(ex.begin, ex.end);
       return this.fetchAsync(ref, suppressEncryption);
     }
-    },
+  }
 
-    getCatalogObj: function XRef_getCatalogObj() {
+  getCatalogObj() {
     return this.root;
-    },
+  }
-  };
+}
-
-  return XRef;
-})();
 
 export { XRef };