a bit faster implementation of output stream for Redis

src/main/java/redis/clients/util/RedisOutputStream.java

@@ -0,0 +1,98 @@
+package redis.clients.util;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.CharsetEncoder;
+import java.nio.charset.CoderResult;
+
+/**
+ * The class implements a buffered output stream without synchronization
+ * There are also special operations like in-place string encoding
+ */
+public final class RedisOutputStream extends FilterOutputStream {
+    protected final byte buf[];
+    protected final ByteBuffer outByteBuffer;
+
+    protected int count;
+
+    public RedisOutputStream(OutputStream out) {
+        this(out, 8192);
+    }
+
+    public RedisOutputStream(OutputStream out, int size) {
+        super(out);
+        if (size <= 0) {
+            throw new IllegalArgumentException("Buffer size <= 0");
+        }
+        buf = new byte[size];
+        outByteBuffer = ByteBuffer.wrap(buf);
+    }
+
+    private void flushBuffer() throws IOException {
+        if (count > 0) {
+            out.write(buf, 0, count);
+            outByteBuffer.position(0);
+            count = 0;
+        }
+    }
+
+    public void write(int b) throws IOException {
+        buf[count++] = (byte) b;
+        if (count >= buf.length) {
+            flushBuffer();
+        }
+    }
+
+    public void write(byte b[], int off, int len) throws IOException {
+        if (len >= buf.length) {
+            flushBuffer();
+            out.write(b, off, len);
+        }
+        else {
+            if (len >= buf.length - count) {
+                flushBuffer();
+            }
+
+            System.arraycopy(b, off, buf, count, len);
+            count += len;
+        }
+    }
+
+    public void write(String str, CharsetEncoder encoder) throws IOException {
+        final CharBuffer in = CharBuffer.wrap(str);
+        if (in.remaining() == 0)
+            return;
+
+        outByteBuffer.position(count);
+
+        encoder.reset();
+        for (;;) {
+            CoderResult cr;
+            if (in.hasRemaining())
+                cr = encoder.encode(in, outByteBuffer, true);
+            else
+                cr = encoder.flush(outByteBuffer);
+
+            count = outByteBuffer.position();
+            if(count == buf.length)
+                flushBuffer();
+
+            if (cr.isUnderflow()) {
+                break;
+            }
+            if (cr.isOverflow()) {
+                flushBuffer();
+                continue;
+            }
+            cr.throwException();
+        }
+    }
+
+    public void flush() throws IOException {
+        flushBuffer();
+        out.flush();
+    }
+}