Refactoring: ByteInputStream little/big endian reading

exxeleron · Nov 16, 2015 · f67447a · f67447a
1 parent 8997c3b
commit f67447a
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Showing 3 changed files with 85 additions and 19 deletions.
diff --git a/src/main/java/com/exxeleron/qjava/ByteInputStream.java b/src/main/java/com/exxeleron/qjava/ByteInputStream.java
@@ -2,28 +2,35 @@
 
 import java.io.UnsupportedEncodingException;
 import java.nio.ByteOrder;
+import java.util.UUID;
 
 /**
  * Convenience class for converting wrapped byte buffer to primitive types.
  */
 public final class ByteInputStream {
 
     private byte[] buffer;
-    private ByteOrder endianess;
     private int position;
     private String encoding;
 
+    private ByteInputStreamReader reader;
+    private ByteInputStreamReader readerLittleEndian;
+    private ByteInputStreamReader readerBigEndian;
+
     /**
      * Creates new {@link ByteInputStream}.
      * 
      * @param encoding
-     *            encoding for symbols convertion
+     *            encoding for symbols conversion
      * @param endianess
      *            byte order of the input stream
      */
     public ByteInputStream(final String encoding, final ByteOrder endianess) {
         this.encoding = encoding;
-        this.endianess = endianess;
+        this.readerLittleEndian = new ByteLittleEndianInputStream();
+        this.readerBigEndian = new ByteBigEndianInputStream();
+
+        setOrder(endianess);
     }
 
     /**
@@ -67,8 +74,7 @@ public byte get() {
      * @return the <code>short</code>
      */
     public short getShort() {
-        final int x = buffer[position++], y = buffer[position++];
-        return (short) (endianess == ByteOrder.LITTLE_ENDIAN ? x & 0xff | y << 8 : x << 8 | y & 0xff);
+        return reader.getShort();
     }
 
     /**
@@ -77,8 +83,7 @@ public short getShort() {
      * @return the <code>int</code>
      */
     public int getInt() {
-        final int x = getShort(), y = getShort();
-        return endianess == ByteOrder.LITTLE_ENDIAN ? x & 0xffff | y << 16 : x << 16 | y & 0xffff;
+        return reader.getInt();
     }
 
     /**
@@ -87,8 +92,7 @@ public int getInt() {
      * @return the <code>long</code>
      */
     public long getLong() {
-        final int x = getInt(), y = getInt();
-        return endianess == ByteOrder.LITTLE_ENDIAN ? x & 0xffffffffL | (long) y << 32 : (long) x << 32 | y & 0xffffffffL;
+        return reader.getLong();
     }
 
     /**
@@ -125,13 +129,24 @@ public String getSymbol() throws UnsupportedEncodingException {
         return (p == position - 1) ? "" : new String(buffer, p, position - 1 - p, encoding);
     }
 
+    /**
+     * Retrieves single {@link UUID} from the byte buffer.
+     * 
+     * @return {@link UUID}
+     */
+    public UUID getUUID() {
+        final long l1 = readerBigEndian.getLong();
+        final long l2 = readerBigEndian.getLong();
+        return new UUID(l1, l2);
+    }
+
     /**
      * Retrieves byte order for the wrapped buffer.
      * 
      * @return {@link ByteOrder}
      */
     public ByteOrder getOrder() {
-        return endianess;
+        return reader.getOrder();
     }
 
     /**
@@ -141,7 +156,65 @@ public ByteOrder getOrder() {
      *            byte order
      */
     public void setOrder( final ByteOrder endianess ) {
-        this.endianess = endianess;
+        this.reader = endianess.equals(ByteOrder.LITTLE_ENDIAN) ? readerLittleEndian : readerBigEndian;
+    }
+
+    private interface ByteInputStreamReader {
+
+        public abstract short getShort();
+
+        public abstract int getInt();
+
+        public abstract long getLong();
+
+        public abstract ByteOrder getOrder();
+
+    }
+
+    private class ByteBigEndianInputStream implements ByteInputStreamReader {
+
+        public short getShort() {
+            final int x = buffer[position++], y = buffer[position++];
+            return (short) (x << 8 | y & 0xff);
+        }
+
+        public int getInt() {
+            final int x = getShort(), y = getShort();
+            return x << 16 | y & 0xffff;
+        }
+
+        public long getLong() {
+            final int x = getInt(), y = getInt();
+            return (long) x << 32 | y & 0xffffffffL;
+        }
+
+        public ByteOrder getOrder() {
+            return ByteOrder.BIG_ENDIAN;
+        }
+
+    }
+
+    private class ByteLittleEndianInputStream implements ByteInputStreamReader {
+
+        public short getShort() {
+            final int x = buffer[position++], y = buffer[position++];
+            return (short) (x & 0xff | y << 8);
+        }
+
+        public int getInt() {
+            final int x = getShort(), y = getShort();
+            return (x & 0xffff | y << 16);
+        }
+
+        public long getLong() {
+            final int x = getInt(), y = getInt();
+            return (x & 0xffffffffL | (long) y << 32);
+        }
+
+        public ByteOrder getOrder() {
+            return ByteOrder.BIG_ENDIAN;
+        }
+
     }
 
 }
diff --git a/src/main/java/com/exxeleron/qjava/DefaultQReader.java b/src/main/java/com/exxeleron/qjava/DefaultQReader.java
@@ -17,7 +17,6 @@
 
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
-import java.nio.ByteOrder;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
@@ -235,12 +234,7 @@ protected Object readList( final QType qtype ) throws QException, UnsupportedEnc
     }
 
     protected UUID readGuid() {
-        final ByteOrder currentOrder = reader.getOrder();
-        reader.setOrder(ByteOrder.BIG_ENDIAN);
-        final long l1 = reader.getLong();
-        final long l2 = reader.getLong();
-        reader.setOrder(currentOrder);
-        return new UUID(l1, l2);
+        return reader.getUUID();
     }
 
     protected Object[] readGeneralList() throws QException, IOException {

diff --git a/src/main/java/com/exxeleron/qjava/QReader.java b/src/main/java/com/exxeleron/qjava/QReader.java
@@ -84,7 +84,6 @@ public QMessage read( final boolean raw ) throws IOException, QException {
         stream.readFully(header, 0, 8);
         reader.wrap(header);
 
-        // TODO: create 2 instances per each endian and select one based on a flag
         final ByteOrder endianess = reader.get() == 0 ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN;
         final QConnection.MessageType messageType = QConnection.MessageType.getMessageType(reader.get());
         final boolean compressed = reader.get() == 1;