Avoid to flush an extra buffer when the string isn't too large in MessagePack#packString

komamitsu · komamitsu · commit af98ae9c7472 · 2015-11-15T17:47:23.000+09:00
diff --git a/msgpack-core/src/main/java/org/msgpack/core/MessagePack.java b/msgpack-core/src/main/java/org/msgpack/core/MessagePack.java
@@ -50,6 +50,7 @@ public static class Config
         private final int stringEncoderBufferSize;
         private final int stringDecoderBufferSize;
         private final int packerBufferSize;
+        private final int packerLargeStringThreshold;
         private final int packerRawDataCopyingThreshold;
 
         public Config(
@@ -61,6 +62,7 @@ public Config(
                 int stringEncoderBufferSize,
                 int stringDecoderBufferSize,
                 int packerBufferSize,
+                int packerLargeStringLengthThreshold,
                 int packerRawDataCopyingThreshold)
         {
             checkArgument(packerBufferSize > 0, "packer buffer size must be larger than 0: " + packerBufferSize);
@@ -75,6 +77,7 @@ public Config(
             this.stringEncoderBufferSize = stringEncoderBufferSize;
             this.stringDecoderBufferSize = stringDecoderBufferSize;
             this.packerBufferSize = packerBufferSize;
+            this.packerLargeStringThreshold = packerLargeStringLengthThreshold;
             this.packerRawDataCopyingThreshold = packerRawDataCopyingThreshold;
         }
 
@@ -133,6 +136,11 @@ public int getPackerBufferSize()
             return packerBufferSize;
         }
 
+        public int getPackerLargeStringLengthThreshold()
+        {
+            return packerLargeStringThreshold;
+        }
+
         public int getPackerRawDataCopyingThreshold()
         {
             return packerRawDataCopyingThreshold;
@@ -154,6 +162,7 @@ public static class ConfigBuilder
         private int stringEncoderBufferSize = 8192;
         private int stringDecoderBufferSize = 8192;
         private int packerBufferSize = 8192;
+        private int packerLargeStringLengthThreshold = 512;
         private int packerRawDataCopyingThreshold = 512;
 
         public Config build()
@@ -167,6 +176,7 @@ public Config build()
                     stringEncoderBufferSize,
                     stringDecoderBufferSize,
                     packerBufferSize,
+                    packerLargeStringLengthThreshold,
                     packerRawDataCopyingThreshold
             );
         }
@@ -219,6 +229,12 @@ public ConfigBuilder packerBufferSize(int size)
             return this;
         }
 
+        public ConfigBuilder packerLargeStringThreshold(int threshold)
+        {
+            this.packerLargeStringLengthThreshold = threshold;
+            return this;
+        }
+
         public ConfigBuilder packerRawDataCopyingThreshold(int threshold)
         {
             this.packerRawDataCopyingThreshold = threshold;
diff --git a/msgpack-core/src/main/java/org/msgpack/core/MessagePacker.java b/msgpack-core/src/main/java/org/msgpack/core/MessagePacker.java
@@ -442,6 +442,14 @@ public MessagePacker packDouble(double v)
         return this;
     }
 
+    private void packSmallString(String s)
+            throws IOException
+    {
+        byte[] bytes = s.getBytes("UTF-8");
+        packRawStringHeader(bytes.length);
+        writePayload(bytes);
+    }
+
     /**
      * Pack the input String in UTF-8 encoding
      *
@@ -457,6 +465,12 @@ public MessagePacker packString(String s)
             return this;
         }
 
+        if (s.length() < config.getPackerLargeStringLengthThreshold()) {
+            // Write the length and payload of small string to the buffer so that it avoids an extra flush of buffer
+            packSmallString(s);
+            return this;
+        }
+
         CharBuffer in = CharBuffer.wrap(s);
         prepareEncoder();
 
diff --git a/msgpack-core/src/test/scala/org/msgpack/core/MessagePackerTest.scala b/msgpack-core/src/test/scala/org/msgpack/core/MessagePackerTest.scala
@@ -22,6 +22,7 @@ import org.msgpack.core.buffer.{ChannelBufferOutput, OutputStreamBufferOutput}
 import org.msgpack.value.ValueFactory
 import xerial.core.io.IOUtil
 
+import scala.compat.Platform
 import scala.util.Random
 
 /**
@@ -235,6 +236,25 @@ class MessagePackerTest
       up1.hasNext shouldBe false
       up1.close
     }
+
+    "pack a lot of String within expected time" in {
+      val count = 500000
+
+      def measureDuration(outputStream: java.io.OutputStream) : Long = {
+        val packer = MessagePack.newDefaultPacker(outputStream)
+        val start = Platform.currentTime
+        for (i <- 0 to count) {
+          packer.packString("0123456789ABCDEF")
+        }
+        packer.close
+        Platform.currentTime - start
+      }
+
+      val baseDuration = measureDuration(new ByteArrayOutputStream())
+      val (_, fileOutput) = createTempFileWithOutputStream
+      val targetDuration = measureDuration(fileOutput)
+      targetDuration shouldBe <= (baseDuration * 3)
+    }
   }
 
   "compute totalWrittenBytes" in {
