com.alibaba.nacos.client.naming.cache.DiskCache Maven / Gradle / Ivy
/*
* 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.naming.cache;
import com.alibaba.nacos.api.common.Constants;
import com.alibaba.nacos.api.naming.pojo.Instance;
import com.alibaba.nacos.api.naming.pojo.ServiceInfo;
import com.alibaba.nacos.client.naming.utils.CollectionUtils;
import com.alibaba.nacos.client.utils.ConcurrentDiskUtil;
import com.alibaba.nacos.common.utils.JacksonUtils;
import com.alibaba.nacos.common.utils.StringUtils;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import static com.alibaba.nacos.client.utils.LogUtils.NAMING_LOGGER;
/**
* Disk cache.
*
* @author xuanyin
*/
public class DiskCache {
/**
* Write service info to dir.
*
* @param dom service info
* @param dir directory
*/
public static void write(ServiceInfo dom, String dir) {
try {
makeSureCacheDirExists(dir);
File file = new File(dir, dom.getKeyEncoded());
createFileIfAbsent(file, false);
StringBuilder keyContentBuffer = new StringBuilder();
String json = dom.getJsonFromServer();
if (StringUtils.isEmpty(json)) {
json = JacksonUtils.toJson(dom);
}
keyContentBuffer.append(json);
//Use the concurrent API to ensure the consistency.
ConcurrentDiskUtil.writeFileContent(file, keyContentBuffer.toString(), Charset.defaultCharset().toString());
} catch (Throwable e) {
NAMING_LOGGER.error("[NA] failed to write cache for dom:" + dom.getName(), e);
}
}
public static String getLineSeparator() {
return System.getProperty("line.separator");
}
/**
* Read service info from disk.
*
* @param cacheDir cache file dir
* @return service infos
*/
public static Map read(String cacheDir) {
Map domMap = new HashMap<>(16);
try {
File[] files = makeSureCacheDirExists(cacheDir).listFiles();
if (files == null || files.length == 0) {
return domMap;
}
for (File file : files) {
if (!file.isFile()) {
continue;
}
domMap.putAll(parseServiceInfoFromCache(file));
}
} catch (Throwable e) {
NAMING_LOGGER.error("[NA] failed to read cache file", e);
}
return domMap;
}
/**
* Parse Service info from cache file or failover file.
*
* @param file cache file or failover file
* @return Service info
* @throws UnsupportedEncodingException if the file is not encoded in UTF-8
*/
@SuppressWarnings("PMD.UndefineMagicConstantRule")
public static Map parseServiceInfoFromCache(File file) throws UnsupportedEncodingException {
Map result = new HashMap<>(1);
String fileName = URLDecoder.decode(file.getName(), "UTF-8");
if (!(fileName.endsWith(Constants.SERVICE_INFO_SPLITER + "meta") || fileName
.endsWith(Constants.SERVICE_INFO_SPLITER + "special-url"))) {
ServiceInfo dom = new ServiceInfo(fileName);
List ips = new ArrayList<>();
dom.setHosts(ips);
ServiceInfo newFormat = null;
try (BufferedReader reader = new BufferedReader(
new StringReader(ConcurrentDiskUtil.getFileContent(file, Charset.defaultCharset().toString())))) {
String json;
while ((json = reader.readLine()) != null) {
try {
if (!json.startsWith("{")) {
continue;
}
newFormat = JacksonUtils.toObj(json, ServiceInfo.class);
if (StringUtils.isEmpty(newFormat.getName())) {
ips.add(JacksonUtils.toObj(json, Instance.class));
}
} catch (Throwable e) {
NAMING_LOGGER.error("[NA] error while parsing cache file: " + json, e);
}
}
} catch (Exception e) {
NAMING_LOGGER.error("[NA] failed to read cache for dom: " + file.getName(), e);
}
if (newFormat != null && !StringUtils.isEmpty(newFormat.getName()) && !CollectionUtils
.isEmpty(newFormat.getHosts())) {
result.put(dom.getKey(), newFormat);
} else if (!CollectionUtils.isEmpty(dom.getHosts())) {
result.put(dom.getKey(), dom);
}
}
return result;
}
/**
* Create file if absent.
*
* @param file file
* @param isDir is dir
* @throws IOException if any io exception during create.
*/
public static void createFileIfAbsent(File file, boolean isDir) throws IOException {
if (file.exists()) {
return;
}
boolean createResult = isDir ? file.mkdirs() : file.createNewFile();
if (!createResult && !file.exists()) {
throw new IllegalStateException("failed to create cache : " + (isDir ? "dir" : file) + file.getPath());
}
}
private static File makeSureCacheDirExists(String dir) throws IOException {
File cacheDir = new File(dir);
createFileIfAbsent(cacheDir, true);
return cacheDir;
}
}