com.alibaba.nacos.client.config.utils.ConcurrentDiskUtil Maven / Gradle / Ivy
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/*
* Copyright 1999-2018 Alibaba Group Holding Ltd.
*
* 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.alibaba.nacos.client.config.utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
/**
* concurrent disk util;op file with file lock
*
* @author configCenter
*/
public class ConcurrentDiskUtil {
/**
* get file content
*
* @param path file path
* @param charsetName charsetName
* @return content
* @throws IOException IOException
*/
public static String getFileContent(String path, String charsetName)
throws IOException {
File file = new File(path);
return getFileContent(file, charsetName);
}
/**
* get file content
*
* @param file file
* @param charsetName charsetName
* @return content
* @throws IOException IOException
*/
public static String getFileContent(File file, String charsetName)
throws IOException {
RandomAccessFile fis = null;
FileLock rlock = null;
try {
fis = new RandomAccessFile(file, "r");
FileChannel fcin = fis.getChannel();
int i = 0;
do {
try {
rlock = fcin.tryLock(0L, Long.MAX_VALUE, true);
} catch (Exception e) {
++i;
if (i > RETRY_COUNT) {
LOGGER.error("read {} fail;retryed time:{}",
file.getName(), i);
throw new IOException("read " + file.getAbsolutePath()
+ " conflict");
}
sleep(SLEEP_BASETIME * i);
LOGGER.warn("read {} conflict;retry time:{}", file.getName(),
i);
}
} while (null == rlock);
int fileSize = (int)fcin.size();
ByteBuffer byteBuffer = ByteBuffer.allocate(fileSize);
fcin.read(byteBuffer);
byteBuffer.flip();
return byteBufferToString(byteBuffer, charsetName);
} finally {
if (rlock != null) {
rlock.release();
rlock = null;
}
if (fis != null) {
fis.close();
fis = null;
}
}
}
/**
* write file content
*
* @param path file path
* @param content content
* @param charsetName charsetName
* @return whether write ok
* @throws IOException IOException
*/
public static Boolean writeFileContent(String path, String content,
String charsetName) throws IOException {
File file = new File(path);
return writeFileContent(file, content, charsetName);
}
/**
* write file content
*
* @param file file
* @param content content
* @param charsetName charsetName
* @return whether write ok
* @throws IOException IOException
*/
public static Boolean writeFileContent(File file, String content,
String charsetName) throws IOException {
if (!file.exists()) {
boolean isCreateOk = file.createNewFile();
if (!isCreateOk) {
return false;
}
}
FileChannel channel = null;
FileLock lock = null;
RandomAccessFile raf = null;
try {
raf = new RandomAccessFile(file, "rw");
channel = raf.getChannel();
int i = 0;
do {
try {
lock = channel.tryLock();
} catch (Exception e) {
++i;
if (i > RETRY_COUNT) {
LOGGER.error("write {} fail;retryed time:{}",
file.getName(), i);
throw new IOException("write " + file.getAbsolutePath()
+ " conflict");
}
sleep(SLEEP_BASETIME * i);
LOGGER.warn("write {} conflict;retry time:{}", file.getName(),
i);
}
} while (null == lock);
ByteBuffer sendBuffer = ByteBuffer.wrap(content
.getBytes(charsetName));
while (sendBuffer.hasRemaining()) {
channel.write(sendBuffer);
}
channel.truncate(content.length());
} catch (FileNotFoundException e) {
throw new IOException("file not exist");
} finally {
if (lock != null) {
try {
lock.release();
lock = null;
} catch (IOException e) {
LOGGER.warn("close wrong", e);
}
}
if (channel != null) {
try {
channel.close();
channel = null;
} catch (IOException e) {
LOGGER.warn("close wrong", e);
}
}
if (raf != null) {
try {
raf.close();
raf = null;
} catch (IOException e) {
LOGGER.warn("close wrong", e);
}
}
}
return true;
}
/**
* transfer ByteBuffer to String
*
* @param buffer buffer
* @param charsetName charsetName
* @return String
* @throws IOException IOException
*/
public static String byteBufferToString(ByteBuffer buffer,
String charsetName) throws IOException {
Charset charset = null;
CharsetDecoder decoder = null;
CharBuffer charBuffer = null;
charset = Charset.forName(charsetName);
decoder = charset.newDecoder();
charBuffer = decoder.decode(buffer.asReadOnlyBuffer());
return charBuffer.toString();
}
private static void sleep(int time) {
try {
Thread.sleep(time);
} catch (InterruptedException e) {
LOGGER.warn("sleep wrong", e);
}
}
private static final Logger LOGGER = LoggerFactory.getLogger(ConcurrentDiskUtil.class);
static final int RETRY_COUNT = 10;
/**
* ms
*/
static final int SLEEP_BASETIME = 10;
}