try to use less memory for buffers

- fix default 64k max sizes
- start with empty buffers
- simplify Buffer class

4 files changed, 23 insertions, 107 deletions

diff --git a/jrt/src/com/yahoo/jrt/Buffer.java b/jrt/src/com/yahoo/jrt/Buffer.java
index 937666a28ae..06a658740e5 100644
--- a/jrt/src/com/yahoo/jrt/Buffer.java
+++ b/jrt/src/com/yahoo/jrt/Buffer.java
@@ -6,9 +6,6 @@ import java.nio.ByteBuffer;
 
 
 class Buffer {
-
-    static final int MAX_IO = 65000;
-
     private ByteBuffer buf;
     private int        readPos;
     private int        writePos;
@@ -111,20 +108,4 @@ class Buffer {
         ensureFree(minFree);
         return buf;
     }
-
-    public ByteBuffer getChannelReadable() {
-        ByteBuffer bb = getReadable();
-        if (bb.remaining() > MAX_IO) {
-            bb.limit(bb.position() + MAX_IO);
-        }
-        return bb;
-    }
-
-    public ByteBuffer getChannelWritable(int minFree) {
-        ByteBuffer bb = getWritable(minFree);
-        if (bb.remaining() > MAX_IO) {
-            bb.limit(bb.position() + MAX_IO);
-        }
-        return bb;
-    }
 }
diff --git a/jrt/src/com/yahoo/jrt/Connection.java b/jrt/src/com/yahoo/jrt/Connection.java
index 891558684ed..6158576348a 100644
--- a/jrt/src/com/yahoo/jrt/Connection.java
+++ b/jrt/src/com/yahoo/jrt/Connection.java
@@ -19,9 +19,9 @@ class Connection extends Target {
 
     private static final Logger log = Logger.getLogger(Connection.class.getName());
 
-    private static final int READ_SIZE  = 32768;
+    private static final int READ_SIZE  = 16*1024;
     private static final int READ_REDO  = 10;
-    private static final int WRITE_SIZE = 32768;
+    private static final int WRITE_SIZE = 16*1024;
     private static final int WRITE_REDO = 10;
 
     private static final int INITIAL    = 0;
@@ -32,11 +32,11 @@ class Connection extends Target {
     private int state = INITIAL;
     private final Queue  queue   = new Queue();
     private final Queue  myQueue = new Queue();
-    private final Buffer input   = new Buffer(0x1000); // Start off with small buffer.
-    private final Buffer output  = new Buffer(0x1000); // Start off with small buffer.
-    private int maxInputSize  = 64*1024;
-    private int maxOutputSize = 64*1024;
-    private boolean dropEmptyBuffers = false;
+    private final Buffer input   = new Buffer(0); // Start off with empty buffer.
+    private final Buffer output  = new Buffer(0); // Start off with empty buffer.
+    private final int maxInputSize;
+    private final int maxOutputSize;
+    private final boolean dropEmptyBuffers;
     private final boolean tcpNoDelay;
     private final Map<Integer, ReplyHandler> replyMap = new HashMap<>();
     private final Map<TargetWatcher, TargetWatcher> watchers = new IdentityHashMap<>();
@@ -98,6 +98,9 @@ class Connection extends Target {
         this.socket = parent.transport().createServerCryptoSocket(channel);
         this.spec = null;
         this.tcpNoDelay = tcpNoDelay;
+        maxInputSize = owner.getMaxInputBufferSize();
+        maxOutputSize = owner.getMaxOutputBufferSize();
+        dropEmptyBuffers = owner.getDropEmptyBuffers();
         server = true;
         owner.sessionInit(this);
     }
@@ -108,22 +111,13 @@ class Connection extends Target {
         this.owner = owner;
         this.spec = spec;
         this.tcpNoDelay = tcpNoDelay;
+        maxInputSize = owner.getMaxInputBufferSize();
+        maxOutputSize = owner.getMaxOutputBufferSize();
+        dropEmptyBuffers = owner.getDropEmptyBuffers();
         server = false;
         owner.sessionInit(this);
     }
 
-    public void setMaxInputSize(int bytes) {
-        maxInputSize = bytes;
-    }
-
-    public void setMaxOutputSize(int bytes) {
-        maxOutputSize = bytes;
-    }
-
-    public void setDropEmptyBuffers(boolean value) {
-        dropEmptyBuffers = value;
-    }
-
     public TransportThread transportThread() {
         return parent;
     }
@@ -235,7 +229,7 @@ class Connection extends Target {
                 readSize = socket.getMinimumReadBufferSize();
             }
             setState(CONNECTED);
-            while (socket.drain(input.getChannelWritable(readSize)) > 0) {
+            while (socket.drain(input.getWritable(readSize)) > 0) {
                 handlePackets();
             }
             break;
@@ -302,14 +296,14 @@ class Connection extends Target {
     private void read() throws IOException {
         boolean doneRead = false;
         for (int i = 0; !doneRead && i < READ_REDO; i++) {
-            ByteBuffer wb = input.getChannelWritable(readSize);
+            ByteBuffer wb = input.getWritable(readSize);
             if (socket.read(wb) == -1) {
                 throw new IOException("jrt: Connection closed by peer");
             }
             doneRead = (wb.remaining() > 0);
             handlePackets();
         }
-        while (socket.drain(input.getChannelWritable(readSize)) > 0) {
+        while (socket.drain(input.getWritable(readSize)) > 0) {
             handlePackets();
         }
         if (dropEmptyBuffers) {
@@ -346,7 +340,7 @@ class Connection extends Target {
                 owner.writePacket(info);
                 info.encodePacket(packet, wb);
             }
-            ByteBuffer rb = output.getChannelReadable();
+            ByteBuffer rb = output.getReadable();
             if (rb.remaining() == 0) {
                 break;
             }
diff --git a/jrt/src/com/yahoo/jrt/Supervisor.java b/jrt/src/com/yahoo/jrt/Supervisor.java
index 5975e191a5b..b82664b2f56 100644
--- a/jrt/src/com/yahoo/jrt/Supervisor.java
+++ b/jrt/src/com/yahoo/jrt/Supervisor.java
@@ -21,8 +21,8 @@ public class Supervisor {
     private SessionHandler          sessionHandler = null;
     private final Object            methodMapLock = new Object();
     private final AtomicReference<HashMap<String, Method>> methodMap = new AtomicReference<>(new HashMap<>());
-    private int                     maxInputBufferSize  = 0;
-    private int                     maxOutputBufferSize = 0;
+    private int                     maxInputBufferSize  = 64*1024;
+    private int                     maxOutputBufferSize = 64*1024;
     private boolean                 dropEmptyBuffers = false;
 
     /**
@@ -47,6 +47,7 @@ public class Supervisor {
         dropEmptyBuffers = value;
         return this;
     }
+    boolean getDropEmptyBuffers() { return dropEmptyBuffers; }
 
     /**
      * Set maximum input buffer size. This value will only affect
@@ -61,6 +62,7 @@ public class Supervisor {
     public void setMaxInputBufferSize(int bytes) {
         maxInputBufferSize = bytes;
     }
+    int getMaxInputBufferSize() { return maxInputBufferSize; }
 
     /**
      * Set maximum output buffer size. This value will only affect
@@ -75,6 +77,7 @@ public class Supervisor {
     public void setMaxOutputBufferSize(int bytes) {
         maxOutputBufferSize = bytes;
     }
+    int getMaxOutputBufferSize() { return maxOutputBufferSize; }
 
     /**
      * Obtain the method map for this Supervisor
@@ -192,12 +195,6 @@ public class Supervisor {
      * @param target the target
      **/
     void sessionInit(Target target) {
-        if (target instanceof Connection) {
-            Connection conn = (Connection) target;
-            conn.setMaxInputSize(maxInputBufferSize);
-            conn.setMaxOutputSize(maxOutputBufferSize);
-            conn.setDropEmptyBuffers(dropEmptyBuffers);
-        }
         SessionHandler handler = sessionHandler;
         if (handler != null) {
             handler.handleSessionInit(target);
diff --git a/jrt/tests/com/yahoo/jrt/BufferTest.java b/jrt/tests/com/yahoo/jrt/BufferTest.java
index 7f3145365d9..10f1fbc17d3 100644
--- a/jrt/tests/com/yahoo/jrt/BufferTest.java
+++ b/jrt/tests/com/yahoo/jrt/BufferTest.java
@@ -28,7 +28,7 @@ public class BufferTest {
     @org.junit.Test
     public void testBuffer() {
 
-        int        size = Buffer.MAX_IO + (Buffer.MAX_IO / 10);
+        int        size = 70*1024;
         Buffer     buf  = new Buffer(1024);
         ByteBuffer b    = null;
 
@@ -118,62 +118,6 @@ public class BufferTest {
     }
 
     @org.junit.Test
-    public void testBufferMax() {
-        int        size = Buffer.MAX_IO + (Buffer.MAX_IO / 10);
-        Buffer     buf  = new Buffer(1024);
-        ByteBuffer b    = null;
-
-        byte[] x = new byte[size];
-        byte[] y = new byte[size];
-
-        Arrays.fill(x, (byte) 10);
-        Arrays.fill(y, (byte) 55);
-
-        assertEquals(buf.bytes(), 0);
-        assertFalse(Arrays.equals(x, y));
-
-        b = buf.getChannelWritable(size);
-        assertEquals(b.remaining(), Buffer.MAX_IO);
-        assertTrue(b.remaining() < size);
-        assertEquals(buf.bytes(), 0);
-        b.put(x, 0, Buffer.MAX_IO);
-        assertEquals(buf.bytes(), Buffer.MAX_IO);
-        assertEquals(b.remaining(), 0);
-
-        b = buf.getChannelWritable(size - Buffer.MAX_IO);
-        assertTrue(b.remaining() >= size - Buffer.MAX_IO);
-        assertEquals(buf.bytes(), Buffer.MAX_IO);
-        b.put(x, Buffer.MAX_IO, x.length - Buffer.MAX_IO);
-        assertEquals(buf.bytes(), size);
-
-        b = buf.getChannelReadable();
-        assertEquals(buf.bytes(), size);
-
-        b = buf.getChannelWritable(512);
-        assertEquals(buf.bytes(), size);
-        b.put((byte)42);
-        assertEquals(buf.bytes(), size + 1);
-
-        b = buf.getChannelReadable();
-        assertEquals(buf.bytes(), size + 1);
-        assertEquals(b.remaining(), Buffer.MAX_IO);
-        b.get(y, 0, Buffer.MAX_IO);
-        assertEquals(buf.bytes(), size - Buffer.MAX_IO + 1);
-
-        b = buf.getChannelReadable();
-        assertEquals(buf.bytes(), size - Buffer.MAX_IO + 1);
-        assertEquals(b.remaining(), size - Buffer.MAX_IO + 1);
-        b.get(y, Buffer.MAX_IO, y.length - Buffer.MAX_IO);
-        assertEquals(buf.bytes(), 1);
-        assertEquals(b.remaining(), 1);
-        assertEquals(b.get(), 42);
-        assertEquals(buf.bytes(), 0);
-        assertEquals(b.remaining(), 0);
-
-        assertTrue(Arrays.equals(x, y));
-    }
-
-    @org.junit.Test
     public void testBufferShrink() {
         Buffer     buf = new Buffer(500);
         ByteBuffer b   = null;