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8274112: (fc) Tune FileChannel.transferTo()

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Reviewed-by: alanb, lancea, rriggs
This commit is contained in:
Brian Burkhalter 2022-05-04 14:33:16 +00:00
parent 7424f47557
commit 17cc7131ab
3 changed files with 121 additions and 47 deletions
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14
src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java
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@ -574,6 +574,10 @@ public class FileChannelImpl
}
}
// Size threshold above which to use a mapped buffer;
// transferToArbitraryChannel() is faster for smaller transfers
private static final long TRUSTED_TRANSFER_THRESHOLD = 16L*1024L;
// Maximum size to map when using a mapped buffer
private static final long MAPPED_TRANSFER_SIZE = 8L*1024L*1024L;
@ -581,6 +585,9 @@ public class FileChannelImpl
WritableByteChannel target)
throws IOException
{
if (count < TRUSTED_TRANSFER_THRESHOLD)
return IOStatus.UNSUPPORTED_CASE;
boolean isSelChImpl = (target instanceof SelChImpl);
if (!((target instanceof FileChannelImpl) || isSelChImpl))
return IOStatus.UNSUPPORTED;
@ -1372,9 +1379,10 @@ public class FileChannelImpl
// Removes an existing mapping
private static native int unmap0(long address, long length);
// Transfers from src to dst, or returns -2 if kernel can't do that
private native long transferTo0(FileDescriptor src, long position,
long count, FileDescriptor dst);
// Transfers from src to dst, or returns IOStatus.UNSUPPORTED (-4) or
// IOStatus.UNSUPPORTED_CASE (-6) if the kernel does not support it
private static native long transferTo0(FileDescriptor src, long position,
long count, FileDescriptor dst);
// Retrieves the maximum size of a transfer
private static native int maxDirectTransferSize0();

138
test/jdk/java/nio/channels/FileChannel/TransferToChannel.java
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -22,25 +22,47 @@
*/
/* @test
* @bug 4652496
* @bug 4652496 8274112
* @summary Test transferTo with different target channels
* @library /test/lib
* @build jdk.test.lib.RandomFactory
* @run main TransferToChannel
* @run main/othervm -Djdk.nio.enableFastFileTransfer TransferToChannel
* @key randomness
*/
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.WritableByteChannel;
import java.nio.ByteBuffer;
import java.io.*;
import java.nio.file.Files;
import java.util.Arrays;
import java.util.Random;
import jdk.test.lib.RandomFactory;
public class TransferToChannel {
static File file;
static File outFile;
static FileChannel in;
// Chunk size should be larger than FileChannelImpl.TRANSFER_SIZE for good test
static int CHUNK_SIZE = 1024 * 9;
private static final Random RAND = RandomFactory.getRandom();
// Chunk size should be larger than FileChannelImpl.TRANSFER_SIZE (8192)
// for a good test
private static final int CHUNK_SIZE = 9*1024;
// File size should be a value much larger than CHUNK_SIZE
private static final int FILE_SIZE = 1000*1024;
// The minimum direct transfer size should be less than the file size
// but still substantial
private static final int MIN_DIRECT_TRANSFER_SIZE = FILE_SIZE/2;
private static File file;
private static File outFile;
private static FileChannel in;
public static void main(String[] args) throws Exception {
file = File.createTempFile("readingin", null);
@ -52,52 +74,60 @@ public class TransferToChannel {
in = fis.getChannel();
test1();
test2();
test3();
in.close();
file.delete();
outFile.delete();
}
static void test1() throws Exception {
private static void test1() throws Exception {
for (int i=0; i<10; i++) {
transferFileToUserChannel();
System.gc();
System.err.println("Transferred file...");
System.err.println("Transferred file to user channel...");
}
}
static void test2() throws Exception {
private static void test2() throws Exception {
for (int i=0; i<10; i++) {
transferFileToTrustedChannel();
System.gc();
System.err.println("Transferred file...");
System.err.println("Transferred file to trusted channel...");
}
}
static void transferFileToUserChannel() throws Exception {
private static void test3() throws Exception {
for (int i=0; i<10; i++) {
transferFileDirectly();
System.gc();
System.err.println("Transferred file directly...");
}
}
private static void transferFileToUserChannel() throws Exception {
long remainingBytes = in.size();
long size = remainingBytes;
WritableByteChannel wbc = new WritableByteChannel() {
Random rand = new Random(0);
public int write(ByteBuffer src) throws IOException {
int read = src.remaining();
byte[] incoming = new byte[read];
src.get(incoming);
checkData(incoming, read);
return read == 0 ? -1 : read;
}
public boolean isOpen() {
return true;
}
public void close() throws IOException {
}
void checkData(byte[] incoming, int size) {
byte[] expected = new byte[size];
rand.nextBytes(expected);
for (int i=0; i<size; i++)
if (incoming[i] != expected[i])
throw new RuntimeException("Data corrupted");
}
};
Random rand = new Random(0);
public int write(ByteBuffer src) throws IOException {
int read = src.remaining();
byte[] incoming = new byte[read];
src.get(incoming);
checkData(incoming, read);
return read == 0 ? -1 : read;
}
public boolean isOpen() {
return true;
}
public void close() throws IOException {
}
void checkData(byte[] incoming, int size) {
byte[] expected = new byte[size];
rand.nextBytes(expected);
if (!Arrays.equals(incoming, expected))
throw new RuntimeException("Data corrupted");
}
};
while (remainingBytes > 0) {
long bytesTransferred = in.transferTo(size - remainingBytes,
Math.min(CHUNK_SIZE, remainingBytes), wbc);
@ -108,7 +138,7 @@ public class TransferToChannel {
}
}
static void transferFileToTrustedChannel() throws Exception {
private static void transferFileToTrustedChannel() throws Exception {
long remainingBytes = in.size();
long size = remainingBytes;
FileOutputStream fos = new FileOutputStream(outFile);
@ -124,14 +154,44 @@ public class TransferToChannel {
out.close();
}
static void generateBigFile(File file) throws Exception {
private static void transferFileDirectly() throws Exception {
outFile.delete();
final long size = in.size();
final long position = RAND.nextInt((int)size - MIN_DIRECT_TRANSFER_SIZE);
try (FileOutputStream fos = new FileOutputStream(outFile);
FileChannel out = fos.getChannel()) {
assert out.position() == 0;
long pos = position;
while (pos < size) {
long bytesTransferred = in.transferTo(pos, Long.MAX_VALUE, out);
if (bytesTransferred >= 0)
pos += bytesTransferred;
else {
throw new Exception("transfer failed at " + pos +
" / " + size);
}
}
}
byte[] expected = Files.readAllBytes(file.toPath());
byte[] actual = Files.readAllBytes(outFile.toPath());
if (!Arrays.equals(expected, (int)position, (int)size,
actual, 0, (int)(size - position)))
throw new Exception("Actual bytes do not match expected bytes");
}
private static void generateBigFile(File file) throws Exception {
OutputStream out = new BufferedOutputStream(
new FileOutputStream(file));
byte[] randomBytes = new byte[1024];
Random rand = new Random(0);
for (int i = 0; i < 1000; i++) {
int numWritten = 0;
while (numWritten < FILE_SIZE) {
int nwrite = Math.min(randomBytes.length, FILE_SIZE - numWritten);
rand.nextBytes(randomBytes);
out.write(randomBytes);
out.write(randomBytes, 0, nwrite);
numWritten += nwrite;
}
out.flush();
out.close();

16
test/jdk/java/nio/channels/FileChannel/Transfers.java
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2002, 2017, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -432,10 +432,16 @@ public class Transfers {
int pos = (int)seed & 0xfff;
fc.position(pos);
int n = (int)fc.transferTo(off, len, tgt.channel());
if (n != len)
throw new Failure("Incorrect transfer length: " + n
+ " (expected " + len + ")");
long position = off;
long count = len;
while (count > 0) {
long n = (int)fc.transferTo(position, count, tgt.channel());
if (n < 0 || n > count)
throw new Failure("Incorrect transfer length n = : " + n
+ " (expected 0 <= n <= " + len + ")");
position += n;
count -= n;
}
// Check that source wasn't changed
if (fc.position() != pos)