1 files changed, 113 insertions, 0 deletions
diff --git a/src/org/tukaani/xz/DeltaOutputStream.java b/src/org/tukaani/xz/DeltaOutputStream.java
new file mode 100644
index 0000000..bd880db
--- /dev/null
+++ b/src/org/tukaani/xz/DeltaOutputStream.java
@@ -0,0 +1,113 @@
+/*
+ * DeltaOutputStream
+ *
+ * Author: Lasse Collin <lasse.collin@tukaani.org>
+ *
+ * This file has been put into the public domain.
+ * You can do whatever you want with this file.
+ */
+
+package org.tukaani.xz;
+
+import java.io.IOException;
+import org.tukaani.xz.delta.DeltaEncoder;
+
+class DeltaOutputStream extends FinishableOutputStream {
+    private static final int FILTER_BUF_SIZE = 4096;
+
+    private FinishableOutputStream out;
+    private final DeltaEncoder delta;
+    private final byte[] filterBuf = new byte[FILTER_BUF_SIZE];
+
+    private boolean finished = false;
+    private IOException exception = null;
+
+    private final byte[] tempBuf = new byte[1];
+
+    static int getMemoryUsage() {
+        return 1 + FILTER_BUF_SIZE / 1024;
+    }
+
+    DeltaOutputStream(FinishableOutputStream out, DeltaOptions options) {
+        this.out = out;
+        delta = new DeltaEncoder(options.getDistance());
+    }
+
+    public void write(int b) throws IOException {
+        tempBuf[0] = (byte)b;
+        write(tempBuf, 0, 1);
+    }
+
+    public void write(byte[] buf, int off, int len) throws IOException {
+        if (off < 0 || len < 0 || off + len < 0 || off + len > buf.length)
+            throw new IndexOutOfBoundsException();
+
+        if (exception != null)
+            throw exception;
+
+        if (finished)
+            throw new XZIOException("Stream finished");
+
+        try {
+            while (len > FILTER_BUF_SIZE) {
+                delta.encode(buf, off, FILTER_BUF_SIZE, filterBuf);
+                out.write(filterBuf);
+                off += FILTER_BUF_SIZE;
+                len -= FILTER_BUF_SIZE;
+            }
+
+            delta.encode(buf, off, len, filterBuf);
+            out.write(filterBuf, 0, len);
+        } catch (IOException e) {
+            exception = e;
+            throw e;
+        }
+    }
+
+    public void flush() throws IOException {
+        if (exception != null)
+            throw exception;
+
+        if (finished)
+            throw new XZIOException("Stream finished or closed");
+
+        try {
+            out.flush();
+        } catch (IOException e) {
+            exception = e;
+            throw e;
+        }
+    }
+
+    public void finish() throws IOException {
+        if (!finished) {
+            if (exception != null)
+                throw exception;
+
+            try {
+                out.finish();
+            } catch (IOException e) {
+                exception = e;
+                throw e;
+            }
+
+            finished = true;
+        }
+    }
+
+    public void close() throws IOException {
+        if (out != null) {
+            try {
+                out.close();
+            } catch (IOException e) {
+                if (exception == null)
+                    exception = e;
+            }
+
+            out = null;
+        }
+
+        if (exception != null)
+            throw exception;
+    }
+}