Make RandomAccessReader.isMotorolaByteOrder read only.

If the byte order changes during extraction, a new reader is made via WithByteOrder.
That new reader is naturally scoped to the sub-reading operation, and the byte order
does not need to be reverted.

Source/com/drew/imaging/tiff/TiffReader.java

@@ -44,7 +44,7 @@ public class TiffReader
      *                                 ignored or recovered from
      * @throws IOException an error occurred while accessing the required data
      */
-    public void processTiff(@NotNull final RandomAccessReader reader,
+    public void processTiff(@NotNull RandomAccessReader reader,
                             @NotNull final TiffHandler handler) throws TiffProcessingException, IOException
     {
         // Standard TIFF
@@ -67,9 +67,9 @@ public void processTiff(@NotNull final RandomAccessReader reader,
         short byteOrderIdentifier = reader.getInt16(0);
 
         if (byteOrderIdentifier == 0x4d4d) { // "MM"
-            reader.setMotorolaByteOrder(true);
+            reader = reader.withByteOrder(true);
         } else if (byteOrderIdentifier == 0x4949) { // "II"
-            reader.setMotorolaByteOrder(false);
+            reader = reader.withByteOrder(false);
         } else {
             throw new TiffProcessingException("Unclear distinction between Motorola/Intel byte ordering: " + byteOrderIdentifier);
         }
@@ -134,7 +134,7 @@ public void processTiff(@NotNull final RandomAccessReader reader,
      * @throws IOException an error occurred while accessing the required data
      */
     public static void processIfd(@NotNull final TiffHandler handler,
-                                  @NotNull final RandomAccessReader reader,
+                                  @NotNull RandomAccessReader reader,
                                   @NotNull final Set<Integer> processedIfdOffsets,
                                   final int ifdOffset,
                                   final boolean isBigTiff) throws IOException
@@ -161,15 +161,14 @@ public static void processIfd(@NotNull final TiffHandler handler,
         //   - 8 bytes: component count
         //   - 8 bytes: inline value, or offset pointer if too large to fit in eight bytes
 
-        Boolean resetByteOrder = null;
         try {
             // Check for directories we've already visited to avoid stack overflows when recursive/cyclic directory structures exist.
             // Note that we track these offsets in the global frame, not the reader's local frame.
             int globalIfdOffset = reader.toUnshiftedOffset(ifdOffset);
 
             // remember that we've visited this directory so that we don't visit it again later
             if (!processedIfdOffsets.add(globalIfdOffset)) {
-            	return;
+                return;
             }
 
             // Validate IFD offset
@@ -188,9 +187,8 @@ public static void processIfd(@NotNull final TiffHandler handler,
             // Here we detect switched bytes that suggest this problem, and temporarily swap the byte order.
             // This was discussed in GitHub issue #136.
             if (!isBigTiff && dirTagCount > 0xFF && (dirTagCount & 0xFF) == 0) {
-                resetByteOrder = reader.isMotorolaByteOrder();
                 dirTagCount >>= 8;
-                reader.setMotorolaByteOrder(!reader.isMotorolaByteOrder());
+                reader = reader.withByteOrder(!reader.isMotorolaByteOrder());
             }
 
             int dirLength = isBigTiff
@@ -312,8 +310,6 @@ public static void processIfd(@NotNull final TiffHandler handler,
             }
         } finally {
             handler.endingIFD();
-            if (resetByteOrder != null)
-                reader.setMotorolaByteOrder(resetByteOrder);
         }
     }
 

Source/com/drew/lang/ByteArrayReader.java

@@ -51,6 +51,14 @@ public ByteArrayReader(@NotNull byte[] buffer)
     @com.drew.lang.annotations.SuppressWarnings(value = "EI_EXPOSE_REP2", justification = "Design intent")
     public ByteArrayReader(@NotNull byte[] buffer, int baseOffset)
     {
+        this(buffer, baseOffset, true);
+    }
+
+    @SuppressWarnings({ "ConstantConditions" })
+    @com.drew.lang.annotations.SuppressWarnings(value = "EI_EXPOSE_REP2", justification = "Design intent")
+    public ByteArrayReader(@NotNull byte[] buffer, int baseOffset, boolean isMotorolaByteOrder)
+    {
+        super(isMotorolaByteOrder);
         if (buffer == null)
             throw new NullPointerException();
         if (baseOffset < 0)
@@ -61,13 +69,20 @@ public ByteArrayReader(@NotNull byte[] buffer, int baseOffset)
     }
 
     @Override
-    public RandomAccessReader withShiftedBaseOffset(int shift) throws IOException {
+    public ByteArrayReader withByteOrder(boolean isMotorolaByteOrder) {
+        if (isMotorolaByteOrder == isMotorolaByteOrder()) {
+            return this;
+        } else {
+            return new ByteArrayReader(_buffer, _baseOffset, isMotorolaByteOrder);
+        }
+    }
+
+    @Override
+    public ByteArrayReader withShiftedBaseOffset(int shift) throws IOException {
         if (shift == 0) {
             return this;
         } else {
-            RandomAccessReader reader = new ByteArrayReader(_buffer, _baseOffset + shift);
-            reader.setMotorolaByteOrder(isMotorolaByteOrder());
-            return reader;
+            return new ByteArrayReader(_buffer, _baseOffset + shift, isMotorolaByteOrder());
         }
     }
 

Source/com/drew/lang/RandomAccessFileReader.java

@@ -52,6 +52,14 @@ public RandomAccessFileReader(@NotNull RandomAccessFile file) throws IOException
     @com.drew.lang.annotations.SuppressWarnings(value = "EI_EXPOSE_REP2", justification = "Design intent")
     public RandomAccessFileReader(@NotNull RandomAccessFile file, int baseOffset) throws IOException
     {
+        this(file, baseOffset, true);
+    }
+
+    @SuppressWarnings({ "ConstantConditions" })
+    @com.drew.lang.annotations.SuppressWarnings(value = "EI_EXPOSE_REP2", justification = "Design intent")
+    public RandomAccessFileReader(@NotNull RandomAccessFile file, int baseOffset, boolean isMotorolaByteOrder) throws IOException
+    {
+        super(isMotorolaByteOrder);
         if (file == null)
             throw new NullPointerException();
 
@@ -61,13 +69,20 @@ public RandomAccessFileReader(@NotNull RandomAccessFile file, int baseOffset) th
     }
 
     @Override
-    public RandomAccessReader withShiftedBaseOffset(int shift) throws IOException {
+    public RandomAccessFileReader withByteOrder(boolean isMotorolaByteOrder) throws IOException {
+        if (isMotorolaByteOrder == isMotorolaByteOrder()) {
+            return this;
+        } else {
+            return new RandomAccessFileReader(_file, _baseOffset, isMotorolaByteOrder);
+        }
+    }
+
+    @Override
+    public RandomAccessFileReader withShiftedBaseOffset(int shift) throws IOException {
         if (shift == 0) {
             return this;
         } else {
-            RandomAccessReader reader = new RandomAccessFileReader(_file, _baseOffset + shift);
-            reader.setMotorolaByteOrder(isMotorolaByteOrder());
-            return reader;
+            return new RandomAccessFileReader(_file, _baseOffset + shift, isMotorolaByteOrder());
         }
     }
 

Source/com/drew/lang/RandomAccessReader.java

@@ -45,7 +45,14 @@
  */
 public abstract class RandomAccessReader
 {
-    private boolean _isMotorolaByteOrder = true;
+    private final boolean _isMotorolaByteOrder;
+
+    protected RandomAccessReader(boolean isMotorolaByteOrder)
+    {
+        _isMotorolaByteOrder = isMotorolaByteOrder;
+    }
+
+    public abstract RandomAccessReader withByteOrder(boolean isMotorolaByteOrder) throws IOException;
 
     public abstract RandomAccessReader withShiftedBaseOffset(int shift) throws IOException;
 
@@ -106,20 +113,6 @@ public abstract class RandomAccessReader
      */
     public abstract long getLength() throws IOException;
 
-    /**
-     * Sets the endianness of this reader.
-     * <ul>
-     * <li><code>true</code> for Motorola (or big) endianness (also known as network byte order), with MSB before LSB.</li>
-     * <li><code>false</code> for Intel (or little) endianness, with LSB before MSB.</li>
-     * </ul>
-     *
-     * @param motorolaByteOrder <code>true</code> for Motorola/big endian, <code>false</code> for Intel/little endian
-     */
-    public void setMotorolaByteOrder(boolean motorolaByteOrder)
-    {
-        _isMotorolaByteOrder = motorolaByteOrder;
-    }
-
     /**
      * Gets the endianness of this reader.
      * <ul>

Source/com/drew/lang/RandomAccessStreamReader.java

@@ -55,6 +55,12 @@ public RandomAccessStreamReader(@NotNull InputStream stream, int chunkLength)
 
     public RandomAccessStreamReader(@NotNull InputStream stream, int chunkLength, long streamLength)
     {
+        this(stream, chunkLength, streamLength, true);
+    }
+
+    public RandomAccessStreamReader(@NotNull InputStream stream, int chunkLength, long streamLength, boolean isMotorolaByteOrder)
+    {
+        super(isMotorolaByteOrder);
         if (stream == null)
             throw new NullPointerException();
         if (chunkLength <= 0)
@@ -213,14 +219,21 @@ public byte[] getBytes(int index, int count) throws IOException
         return bytes;
     }
 
+    @Override
+    public RandomAccessReader withByteOrder(boolean isMotorolaByteOrder) {
+        if (isMotorolaByteOrder == isMotorolaByteOrder()) {
+            return this;
+        } else {
+            return new ShiftedRandomAccessStreamReader(this, 0, isMotorolaByteOrder);
+        }
+    }
+
     @Override
     public RandomAccessReader withShiftedBaseOffset(int shift) {
         if (shift == 0) {
             return this;
         } else {
-            RandomAccessReader reader = new ShiftedRandomAccessStreamReader(this, shift);
-            reader.setMotorolaByteOrder(isMotorolaByteOrder());
-            return reader;
+            return new ShiftedRandomAccessStreamReader(this, shift, isMotorolaByteOrder());
         }
     }
 
@@ -229,8 +242,9 @@ private static class ShiftedRandomAccessStreamReader extends RandomAccessReader
         private final RandomAccessStreamReader _baseReader;
         private final int _baseOffset;
 
-        public ShiftedRandomAccessStreamReader(RandomAccessStreamReader baseReader, int baseOffset)
+        public ShiftedRandomAccessStreamReader(RandomAccessStreamReader baseReader, int baseOffset, boolean isMotorolaByteOrder)
         {
+            super(isMotorolaByteOrder);
             if (baseOffset < 0)
                 throw new IllegalArgumentException("Must be zero or greater.");
 
@@ -239,13 +253,20 @@ public ShiftedRandomAccessStreamReader(RandomAccessStreamReader baseReader, int
         }
 
         @Override
-        public RandomAccessReader withShiftedBaseOffset(int shift) {
+        public ShiftedRandomAccessStreamReader withByteOrder(boolean isMotorolaByteOrder) throws IOException {
+            if (isMotorolaByteOrder == isMotorolaByteOrder()) {
+                return this;
+            } else {
+                return new ShiftedRandomAccessStreamReader(_baseReader, _baseOffset, isMotorolaByteOrder);
+            }
+        }
+
+        @Override
+        public ShiftedRandomAccessStreamReader withShiftedBaseOffset(int shift) {
             if (shift == 0) {
                 return this;
             } else {
-                RandomAccessReader reader = new ShiftedRandomAccessStreamReader(_baseReader, _baseOffset + shift);
-                reader.setMotorolaByteOrder(isMotorolaByteOrder());
-                return reader;
+                return new ShiftedRandomAccessStreamReader(_baseReader, _baseOffset + shift, isMotorolaByteOrder());
             }
         }
 

Source/com/drew/metadata/avi/AviRiffHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 Drew Noakes and contributors
+ * Copyright 2002-2022 Drew Noakes and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@
 
 import com.drew.imaging.riff.RiffHandler;
 import com.drew.lang.ByteArrayReader;
+import com.drew.lang.RandomAccessReader;
 import com.drew.lang.annotations.NotNull;
 import com.drew.metadata.Metadata;
 
@@ -54,31 +55,34 @@ public AviRiffHandler(@NotNull Metadata metadata)
         metadata.addDirectory(_directory);
     }
 
+    @Override
     public boolean shouldAcceptRiffIdentifier(@NotNull String identifier)
     {
         return identifier.equals(AviDirectory.FORMAT);
     }
 
+    @Override
     public boolean shouldAcceptChunk(@NotNull String fourCC)
     {
         return fourCC.equals(AviDirectory.CHUNK_STREAM_HEADER)
             || fourCC.equals(AviDirectory.CHUNK_MAIN_HEADER)
             || fourCC.equals(AviDirectory.CHUNK_DATETIME_ORIGINAL);
     }
 
+    @Override
     public boolean shouldAcceptList(@NotNull String fourCC)
     {
         return fourCC.equals(AviDirectory.LIST_HEADER)
             || fourCC.equals(AviDirectory.LIST_STREAM_HEADER)
             || fourCC.equals(AviDirectory.FORMAT);
     }
 
+    @Override
     public void processChunk(@NotNull String fourCC, @NotNull byte[] payload)
     {
         try {
             if (fourCC.equals(AviDirectory.CHUNK_STREAM_HEADER)) {
-                ByteArrayReader reader = new ByteArrayReader(payload);
-                reader.setMotorolaByteOrder(false);
+                RandomAccessReader reader = new ByteArrayReader(payload, 0, false);
 
                 String fccType = new String(reader.getBytes(0, 4));
                 String fccHandler = new String(reader.getBytes(4, 4));
@@ -114,8 +118,7 @@ public void processChunk(@NotNull String fourCC, @NotNull byte[] payload)
                     }
                 }
             } else if (fourCC.equals(AviDirectory.CHUNK_MAIN_HEADER)) {
-                ByteArrayReader reader = new ByteArrayReader(payload);
-                reader.setMotorolaByteOrder(false);
+                RandomAccessReader reader = new ByteArrayReader(payload, 0, false);
 
 //                int dwMicroSecPerFrame = reader.getInt32(0);
 //                int dwMaxBytesPerSec = reader.getInt32(4);

Source/com/drew/metadata/eps/EpsReader.java

@@ -53,7 +53,7 @@ public class EpsReader
      */
     public void extract(@NotNull final InputStream inputStream, @NotNull final Metadata metadata) throws IOException
     {
-        RandomAccessStreamReader reader = new RandomAccessStreamReader(inputStream);
+        RandomAccessReader reader = new RandomAccessStreamReader(inputStream);
         EpsDirectory directory = new EpsDirectory();
         metadata.addDirectory(directory);
 
@@ -64,7 +64,7 @@ public void extract(@NotNull final InputStream inputStream, @NotNull final Metad
          */
         switch (reader.getInt32(0)) {
             case 0xC5D0D3C6:
-                reader.setMotorolaByteOrder(false);
+                reader = reader.withByteOrder(false);
                 int postScriptOffset = reader.getInt32(4);
                 int postScriptLength = reader.getInt32(8);
                 int wmfOffset = reader.getInt32(12);

Source/com/drew/metadata/exif/ExifDescriptorBase.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 Drew Noakes and contributors
+ * Copyright 2002-2022 Drew Noakes and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -1158,7 +1158,7 @@ private int[] decodeCfaPattern(int tagType)
             if (end > values.length) // sanity check in case of byte order problems; calculated 'end' should be <= length of the values
             {
                 // try swapping byte order (I have seen this order different than in EXIF)
-                reader.setMotorolaByteOrder(!reader.isMotorolaByteOrder());
+                reader = reader.withByteOrder(!reader.isMotorolaByteOrder());
                 item0 = reader.getInt16(0);
                 item1 = reader.getInt16(2);