Fixed BufferedSocketInputStream::read(byte[], ...) reading "past the buffer"

Author: shyiko

src/main/java/com/github/shyiko/mysql/binlog/io/BufferedSocketInputStream.java

@@ -52,4 +52,19 @@ public int read() throws IOException {
         return limit != -1 ? buffer[offset++] & 0xff : -1;
     }
 
+    @Override
+    public int read(byte[] b, int off, int len) throws IOException {
+        if (offset >= limit) {
+            if (len >= buffer.length) {
+                return in.read(b, off, len);
+            }
+            offset = 0;
+            limit = in.read(buffer, 0, buffer.length);
+        }
+        int bytesRemainingInBuffer = Math.min(len, limit - offset);
+        System.arraycopy(buffer, offset, b, off, bytesRemainingInBuffer);
+        offset += bytesRemainingInBuffer;
+        return bytesRemainingInBuffer;
+    }
+
 }

src/test/java/com/github/shyiko/mysql/binlog/io/BufferedSocketInputStreamTest.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2015 Stanley Shyiko
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.github.shyiko.mysql.binlog.io;
+
+import org.testng.annotations.Test;
+
+import java.io.ByteArrayInputStream;
+import java.util.Arrays;
+
+import static org.testng.Assert.assertEquals;
+
+/**
+ * @author <a href="mailto:stanley.shyiko@gmail.com">Stanley Shyiko</a>
+ */
+public class BufferedSocketInputStreamTest {
+
+    @Test
+    public void testCorrectness() throws Exception {
+        BufferedSocketInputStream in = new BufferedSocketInputStream(new ByteArrayInputStream(new byte[]{
+            0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}), 5);
+        assertEquals(in.read(), 0);
+        assertEquals(in.read(), 1);
+        byte[] buf = new byte[6];
+        assertEquals(in.read(buf, 0, buf.length), 3); // data remaining in BSIS buffer
+        assertEquals(Arrays.copyOf(buf, 3), new byte[] {2, 3, 4});
+        assertEquals(in.read(buf, 0, buf.length), 6);
+        assertEquals(buf, new byte[] {5, 6, 7, 8, 9, 10});
+        assertEquals(in.read(buf, 0, 3), 3);
+        assertEquals(Arrays.copyOf(buf, 3), new byte[] {11, 12, 13});
+        assertEquals(in.read(buf, 0, 3), 2); // data remaining in BSIS buffer
+        assertEquals(Arrays.copyOf(buf, 2), new byte[] {14, 15});
+        assertEquals(in.read(), 16);
+        assertEquals(in.read(), (byte) -1);
+    }
+}