fredia commented on code in PR #25818: URL: https://github.com/apache/flink/pull/25818#discussion_r1900645484
########## flink-state-backends/flink-statebackend-forst/src/main/java/org/apache/flink/state/forst/fs/filemapping/FileMappingManager.java: ########## @@ -0,0 +1,252 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 org.apache.flink.state.forst.fs.filemapping; + +import org.apache.flink.annotation.VisibleForTesting; +import org.apache.flink.core.fs.FileSystem; +import org.apache.flink.core.fs.Path; +import org.apache.flink.util.Preconditions; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +/** + * A manager to manage file mapping of forst file system, including misc file mapping (remote file + * -> local file) and linked mapping (remote file -> remote file). Note, the key/value of mapping + * table must be a file path, directories are maintained by file system itself, directories wouldn't + * be the key/value of mapping table. + */ +public class FileMappingManager { + + private static final Logger LOG = LoggerFactory.getLogger(FileMappingManager.class); + + public static final String SST_SUFFIX = ".sst"; + + private final FileSystem fileSystem; + + private final FileSystem localFileSystem; + + private final HashMap<String, MappingEntry> mappingTable; + + private final String remoteBase; + + private final String localBase; + + public FileMappingManager( + FileSystem fileSystem, + FileSystem localFileSystem, + String remoteBase, + String localBase) { + this.fileSystem = fileSystem; + this.localFileSystem = localFileSystem; + this.mappingTable = new HashMap<>(); + this.remoteBase = remoteBase; + this.localBase = localBase; + } + + /** Create a mapping entry for a file. */ + public RealPath createFile(Path file) { + String fileName = file.toString(); + Preconditions.checkState(!mappingTable.containsKey(fileName)); + if (!fileName.endsWith(SST_SUFFIX) && fileName.startsWith(remoteBase)) { + Path localFile = new Path(localBase, file.getName()); + mappingTable.put( + fileName, new MappingEntry(1, localFileSystem, localFile.toString(), false)); + return new RealPath(localFile, true); + } else { + mappingTable.put(fileName, new MappingEntry(1, fileSystem, fileName, false)); + return new RealPath(file, false); + } + } + + /** Called by link/copy. Directory link is not supported now. */ + public int link(String src, String dst) { + if (src.equals(dst)) { + return -1; + } + // if dst already exist, not allow + if (mappingTable.containsKey(dst)) { + return -1; + } + MappingEntry sourceEntry = mappingTable.get(src); + if (sourceEntry != null) { + sourceEntry.retain(); + mappingTable.putIfAbsent(dst, sourceEntry); + } else { + sourceEntry = new MappingEntry(0, fileSystem, src, false); + sourceEntry.retain(); + mappingTable.put(src, sourceEntry); + sourceEntry.retain(); + mappingTable.put(dst, sourceEntry); + } + LOG.trace("link: {} -> {}", dst, src); + return 0; + } + + /** Get the real path of a file, the real path maybe a local file or a remote file/dir. */ + public RealPath realPath(Path file) { + String fileName = file.toString(); + MappingEntry entry = mappingTable.getOrDefault(fileName, null); + if (!fileName.endsWith(SST_SUFFIX) && fileName.startsWith(remoteBase)) { + if (entry != null) { + return new RealPath(new Path(entry.sourcePath), true); + } + Path localFile = new Path(localBase, file.getName()); + return new RealPath(localFile, true); + } + if (entry != null) { + return new RealPath(new Path(entry.sourcePath), false); + } + return new RealPath(file, false); + } + + public List<String> listByPrefix(String path) { + List<String> linkedPaths = new ArrayList<>(); + for (Map.Entry<String, MappingEntry> entry : mappingTable.entrySet()) { + if (entry.getKey().startsWith(path) && !entry.getValue().isDirectory) { + linkedPaths.add(entry.getKey()); + } + } + return linkedPaths; + } + + /** + * 1. If src can match any key, we only `mark rename`, no physical file would be renamed. 2. If + * src is a directory, all files under src will be renamed, including linked files and local + * files, the directory also would be renamed in file system physically. + * + * @param src the source path + * @param dst the destination path + * @return always return true except for IOException + */ + public boolean renameFile(String src, String dst) throws IOException { + MappingEntry srcEntry = mappingTable.get(src); + if (srcEntry != null) { // rename file + if (mappingTable.containsKey(dst)) { + MappingEntry dstEntry = mappingTable.remove(dst); + dstEntry.release(); + } + mappingTable.remove(src); + mappingTable.put(dst, srcEntry); + } else { // rename directory + // 1. rename file in old directory + List<String> toRename = new ArrayList<>(); + for (String key : mappingTable.keySet()) { + if (isParentDir(key, src) || key.equals(src)) { + toRename.add(key); + } + } + if (!toRename.isEmpty()) { + for (String key : toRename) { + MappingEntry sourceEntry = mappingTable.remove(key); + String renamedDst = key.replace(src, dst); + LOG.trace("rename: {} -> {}", key, renamedDst); + sourceEntry.sourcePath = sourceEntry.sourcePath.replace(src, dst); + mappingTable.put(renamedDst, sourceEntry); + } + } + // 2. rename directory in file system physically + Path srcPath = new Path(src); + Path dstPath = new Path(dst); + + // The rename is not atomic for ForSt. Some FileSystems e.g. HDFS, OSS does not allow a + // renaming if the target already exists. So, we delete the target before attempting the + // rename. + if (fileSystem.exists(dstPath)) { + boolean deleted = fileSystem.delete(dstPath, true); + if (!deleted) { + throw new IOException("Fail to rename path, src:" + src + ", dst:" + dst); + } + } + fileSystem.rename(srcPath, dstPath); + } + return true; + } + + /** + * Delete a file or directory from mapping table and file system, the directory deletion may be + * deferred. + * + * @param file to be deleted + * @param recursive whether to delete recursively + * @return true if the file or directory is deleted successfully, false otherwise. + * @throws IOException + */ + public boolean deleteFile(Path file, boolean recursive) throws IOException { + String fileStr = file.toString(); + MappingEntry entry = mappingTable.getOrDefault(fileStr, null); + LOG.trace("delete: {}, source:{}", file, entry == null ? "null" : entry.sourcePath); + if (entry != null) { // delete file + mappingTable.remove(fileStr); + if (!entry.isDirectory) { + entry.release(); + return true; + } + } + + // delete directory + MappingEntry parentEntry = new MappingEntry(0, fileSystem, fileStr, true); + + boolean matched = false; + for (MappingEntry mappingEntry : mappingTable.values()) { + if (isParentDir(mappingEntry.sourcePath, fileStr)) { + parentEntry.retain(); + mappingEntry.parentDir = parentEntry; Review Comment: If the new directory is the parent of old `parent dir`, the old `parent dir` is replaced by base dir now. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
