Split RangeEncoderToBuffer from RangeEncoder.

3 files changed, 64 insertions, 22 deletions

diff --git a/src/org/tukaani/xz/LZMA2OutputStream.java b/src/org/tukaani/xz/LZMA2OutputStream.java
index 5724d10..23341b0 100644
--- a/src/org/tukaani/xz/LZMA2OutputStream.java
+++ b/src/org/tukaani/xz/LZMA2OutputStream.java
@@ -13,7 +13,7 @@ package org.tukaani.xz;
 import java.io.DataOutputStream;
 import java.io.IOException;
 import org.tukaani.xz.lz.LZEncoder;
-import org.tukaani.xz.rangecoder.RangeEncoder;
+import org.tukaani.xz.rangecoder.RangeEncoderToBuffer;
 import org.tukaani.xz.lzma.LZMAEncoder;
 
 class LZMA2OutputStream extends FinishableOutputStream {
@@ -23,7 +23,7 @@ class LZMA2OutputStream extends FinishableOutputStream {
     private final DataOutputStream outData;
 
     private final LZEncoder lz;
-    private final RangeEncoder rc;
+    private final RangeEncoderToBuffer rc;
     private final LZMAEncoder lzma;
 
     private final int props; // Cannot change props on the fly for now.
@@ -57,7 +57,7 @@ class LZMA2OutputStream extends FinishableOutputStream {
 
         this.out = out;
         outData = new DataOutputStream(out);
-        rc = new RangeEncoder(COMPRESSED_SIZE_MAX);
+        rc = new RangeEncoderToBuffer(COMPRESSED_SIZE_MAX);
 
         int dictSize = options.getDictSize();
         int extraSizeBefore = getExtraSizeBefore(dictSize);
diff --git a/src/org/tukaani/xz/rangecoder/RangeEncoder.java b/src/org/tukaani/xz/rangecoder/RangeEncoder.java
index a06fdcc..0472104 100644
--- a/src/org/tukaani/xz/rangecoder/RangeEncoder.java
+++ b/src/org/tukaani/xz/rangecoder/RangeEncoder.java
@@ -10,10 +10,9 @@
 
 package org.tukaani.xz.rangecoder;
 
-import java.io.OutputStream;
 import java.io.IOException;
 
-public final class RangeEncoder extends RangeCoder {
+public abstract class RangeEncoder extends RangeCoder {
     private static final int MOVE_REDUCING_BITS = 4;
     private static final int BIT_PRICE_SHIFT_BITS = 4;
 
@@ -26,13 +25,10 @@ public final class RangeEncoder extends RangeCoder {
     // NOTE: int is OK for LZMA2 because a compressed chunk
     // is not more than 64 KiB, but with LZMA1 there is no chunking
     // so in theory cacheSize can grow very big. To be very safe,
-    // use long instead of int if you adapt this code for LZMA1.
-    private int cacheSize;
+    // use long instead of int since this code is used for LZMA1 too.
+    long cacheSize;
     private byte cache;
 
-    private final byte[] buf;
-    private int bufPos;
-
     static {
         for (int i = (1 << MOVE_REDUCING_BITS) / 2; i < BIT_MODEL_TOTAL;
                 i += (1 << MOVE_REDUCING_BITS)) {
@@ -55,33 +51,32 @@ public final class RangeEncoder extends RangeCoder {
         }
     }
 
-    public RangeEncoder(int bufSize) {
-        buf = new byte[bufSize];
-        reset();
-    }
-
     public void reset() {
         low = 0;
         range = 0xFFFFFFFF;
         cache = 0x00;
         cacheSize = 1;
-        bufPos = 0;
     }
 
     public int getPendingSize() {
-        return bufPos + cacheSize + 5 - 1;
+        // This function is only needed by users of RangeEncoderToBuffer,
+        // but providing a must-be-never-called version here makes
+        // LZMAEncoder simpler.
+        throw new Error();
     }
 
     public int finish() {
         for (int i = 0; i < 5; ++i)
             shiftLow();
 
-        return bufPos;
+        // RangeEncoderToBuffer.finish() needs a return value to tell
+        // how big the finished buffer is. RangeEncoderToStream has no
+        // buffer and thus no return value is needed. Here we use a dummy
+        // value which can be overriden in RangeEncoderToBuffer.finish().
+        return -1;
     }
 
-    public void write(OutputStream out) throws IOException {
-        out.write(buf, 0, bufPos);
-    }
+    abstract void writeByte(byte b) /*throws IOException*/;
 
     private void shiftLow() {
         int lowHi = (int)(low >>> 32);
@@ -90,7 +85,7 @@ public final class RangeEncoder extends RangeCoder {
             int temp = cache;
 
             do {
-                buf[bufPos++] = (byte)(temp + lowHi);
+                writeByte((byte)(temp + lowHi));
                 temp = 0xFF;
             } while (--cacheSize != 0);
 
diff --git a/src/org/tukaani/xz/rangecoder/RangeEncoderToBuffer.java b/src/org/tukaani/xz/rangecoder/RangeEncoderToBuffer.java
new file mode 100644
index 0000000..01fe24e
--- /dev/null
+++ b/src/org/tukaani/xz/rangecoder/RangeEncoderToBuffer.java
@@ -0,0 +1,47 @@
+/*
+ * RangeEncoderToBuffer
+ *
+ * Authors: Lasse Collin <lasse.collin@tukaani.org>
+ *          Igor Pavlov <http://7-zip.org/>
+ *
+ * This file has been put into the public domain.
+ * You can do whatever you want with this file.
+ */
+
+package org.tukaani.xz.rangecoder;
+
+import java.io.OutputStream;
+import java.io.IOException;
+
+public final class RangeEncoderToBuffer extends RangeEncoder {
+    private final byte[] buf;
+    private int bufPos;
+
+    public RangeEncoderToBuffer(int bufSize) {
+        buf = new byte[bufSize];
+        reset();
+    }
+
+    public void reset() {
+        super.reset();
+        bufPos = 0;
+    }
+
+    public int getPendingSize() {
+        // With LZMA2 it is known that cacheSize fits into an int.
+        return bufPos + (int)cacheSize + 5 - 1;
+    }
+
+    public int finish() {
+        super.finish();
+        return bufPos;
+    }
+
+    public void write(OutputStream out) throws IOException {
+        out.write(buf, 0, bufPos);
+    }
+
+    void writeByte(byte b) {
+        buf[bufPos++] = b;
+    }
+}