optimize unnecessary require operation in write_ascii_slow

benchmarks/src/main/java/com/esotericsoftware/kryo/benchmarks/io/HugeStringBenchmark.java

@@ -0,0 +1,52 @@
+/* Copyright (c) 2008-2020, Nathan Sweet
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following
+ * conditions are met:
+ * 
+ * - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided with the distribution.
+ * - Neither the name of Esoteric Software nor the names of its contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
+
+package com.esotericsoftware.kryo.benchmarks.io;
+
+import com.esotericsoftware.kryo.io.Output;
+import org.openjdk.jmh.annotations.*;
+
+
+
+
+/*
+ * this benchmark is used to test serialize huge string when not reuse the buffer
+ * */
+@BenchmarkMode(Mode.SingleShotTime)
+@Measurement(batchSize = 120000)
+public class HugeStringBenchmark {
+	static String hugeString = "";
+	static {
+		for(int i = 0; i < 256; i++){
+			hugeString += "abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz0123456789";
+		}
+	}
+
+	/**
+	 * 1. not reuse the output
+	 * 2. the initial bufferSize will be smaller than hugeString size
+	 * ***/
+	@Benchmark
+	public void writeAsciiHuge (InputOutputState state) {
+		Output output = new Output(1024, 1024 * 512);
+		output.writeAscii(hugeString);
+	}
+
+}
+￿

src/com/esotericsoftware/kryo/io/ByteBufferOutput.java

@@ -649,7 +649,7 @@ private void writeAscii_slow (String value, int charCount) throws KryoException
 			buffer.put(tmp, 0, charsToWrite);
 			charIndex += charsToWrite;
 			position += charsToWrite;
-			charsToWrite = Math.min(charCount - charIndex, capacity);
+			charsToWrite = Math.min(charCount - charIndex, maxAvailableRequired());
 			if (require(charsToWrite)) buffer = this.byteBuffer;
 		}
 	}

src/com/esotericsoftware/kryo/io/Output.java

@@ -173,7 +173,13 @@ public void reset () {
 		position = 0;
 		total = 0;
 	}
-
+
+	/**how much space can be allocated when call require **/
+	public int maxAvailableRequired(){
+		if(outputStream != null){return maxCapacity;}
+		else{return maxCapacity - position;}
+	}
+
 	/** Ensures the buffer is large enough to read the specified number of bytes.
 	 * @return true if the buffer has been resized. */
 	protected boolean require (int required) throws KryoException {
@@ -637,7 +643,7 @@ public void writeBoolean (boolean value) throws KryoException {
 	}
 
 	// String:
-
+	
 	/** Writes the length and string, or null. Short strings are checked and if ASCII they are written more efficiently, else they
 	 * are written as UTF8. If a string is known to be ASCII, {@link #writeAscii(String)} may be used. The string can be read using
 	 * {@link Input#readString()} or {@link Input#readStringBuilder()}.
@@ -657,6 +663,8 @@ public void writeString (String value) throws KryoException {
 		if (charCount > 1 && charCount <= 32) {
 			for (int i = 0; i < charCount; i++)
 				if (value.charAt(i) > 127) break outer;
+
+				// todo can combine
 			if (capacity - position < charCount)
 				writeAscii_slow(value, charCount);
 			else {
@@ -686,7 +694,7 @@ public void writeString (String value) throws KryoException {
 		}
 		if (charIndex < charCount) writeUtf8_slow(value, charCount, charIndex);
 	}
-
+	
 	/** Writes a string that is known to contain only ASCII characters. Non-ASCII strings passed to this method will be corrupted.
 	 * Each byte is a 7 bit character with the remaining byte denoting if another character is available. This is slightly more
 	 * efficient than {@link #writeString(String)}. The string can be read using {@link Input#readString()} or
@@ -735,7 +743,7 @@ else if (c > 0x07FF) {
 			}
 		}
 	}
-
+	
 	private void writeAscii_slow (String value, int charCount) throws KryoException {
 		if (charCount == 0) return;
 		if (position == capacity) require(1); // Must be able to write at least one character.
@@ -746,13 +754,11 @@ private void writeAscii_slow (String value, int charCount) throws KryoException
 			value.getBytes(charIndex, charIndex + charsToWrite, buffer, position);
 			charIndex += charsToWrite;
 			position += charsToWrite;
-			charsToWrite = Math.min(charCount - charIndex, capacity);
+			charsToWrite = Math.min(charCount - charIndex, maxAvailableRequired());
 			if (require(charsToWrite)) buffer = this.buffer;
 		}
 	}
-
-	// Primitive arrays:
-
+
 	/** Writes an int array in bulk. This may be more efficient than writing them individually. */
 	public void writeInts (int[] array, int offset, int count) throws KryoException {
 		if (capacity >= count << 2) {