some improvments

internal/pdf/core/parser.go

@@ -35,10 +35,10 @@ type PdfParser struct {
 	rs               io.ReadSeeker
 	reader           *bufio.Reader
 	fileSize         int64
-	xrefs            XrefTable
+	xrefs            xRefTable
 	objstms          ObjectStreams
 	trailer          *PdfObjectDictionary
-	ObjCache         ObjectCache // TODO: Unexport (v3).
+	ObjCache         objectCache
 	crypter          *PdfCrypt
 	repairsAttempted bool // Avoid multiple attempts for repair.
 
@@ -740,8 +740,8 @@ func (parser *PdfParser) parseXrefTable() (*PdfObjectDictionary, error) {
 				// would be marked as free.  But can still happen!
 				x, ok := parser.xrefs[curObjNum]
 				if !ok || gen > x.generation {
-					obj := XrefObject{objectNumber: curObjNum,
-						xtype:  XREF_TABLE_ENTRY,
+					obj := xRefObject{objectNumber: curObjNum,
+						xtype:  xRefTableEntry,
 						offset: first, generation: gen}
 					parser.xrefs[curObjNum] = obj
 				}
@@ -1000,16 +1000,16 @@ func (parser *PdfParser) parseXrefStream(xstm *PdfObjectInteger) (*PdfObjectDict
 			if xr, ok := parser.xrefs[objNum]; !ok || int(n3) > xr.generation {
 				// Only overload if not already loaded!
 				// or has a newer generation number. (should not happen)
-				obj := XrefObject{objectNumber: objNum,
-					xtype: XREF_TABLE_ENTRY, offset: n2, generation: int(n3)}
+				obj := xRefObject{objectNumber: objNum,
+					xtype: xRefTableEntry, offset: n2, generation: int(n3)}
 				parser.xrefs[objNum] = obj
 			}
 		case 2:
 			// Object type 2: Compressed object.
 			common.Log.Trace("- In use - compressed object")
 			if _, ok := parser.xrefs[objNum]; !ok {
-				obj := XrefObject{objectNumber: objNum,
-					xtype: XREF_OBJECT_STREAM, osObjNumber: int(n2), osObjIndex: int(n3)}
+				obj := xRefObject{objectNumber: objNum,
+					xtype: xRefObjectStream, osObjNumber: int(n2), osObjIndex: int(n3)}
 				parser.xrefs[objNum] = obj
 				common.Log.Trace("entry: %s", parser.xrefs[objNum])
 			}
@@ -1128,7 +1128,7 @@ func (parser *PdfParser) seekToEOFMarker(fSize int64) error {
 // The earlier xrefs have higher precedence.  If objects already
 // loaded will ignore older versions.
 func (parser *PdfParser) loadXrefs() (*PdfObjectDictionary, error) {
-	parser.xrefs = make(XrefTable)
+	parser.xrefs = make(xRefTable)
 	parser.objstms = make(ObjectStreams)
 
 	// Get the file size.
@@ -1482,30 +1482,13 @@ func (parser *PdfParser) ParseIndirectObject() (PdfObject, error) {
 	return &indirect, nil
 }
 
-// For testing purposes.
-// TODO: Unexport (v3) or move to test files, if needed by external test cases.
-func NewParserFromString(txt string) *PdfParser {
-	parser := PdfParser{}
-	buf := []byte(txt)
-
-	bufReader := bytes.NewReader(buf)
-	parser.rs = bufReader
-
-	bufferedReader := bufio.NewReader(bufReader)
-	parser.reader = bufferedReader
-
-	parser.fileSize = int64(len(txt))
-
-	return &parser
-}
-
 // NewParser creates a new parser for a PDF file via ReadSeeker. Loads the cross reference stream and trailer.
 // An error is returned on failure.
 func NewParser(rs io.ReadSeeker) (*PdfParser, error) {
 	parser := &PdfParser{}
 
 	parser.rs = rs
-	parser.ObjCache = make(ObjectCache)
+	parser.ObjCache = make(objectCache)
 	parser.streamLengthReferenceLookupInProgress = map[int64]bool{}
 
 	// Start by reading the xrefs (from bottom).