/** * Create a blook pool slice * * @param bpid Block pool Id * @param volume {@link FsVolumeImpl} to which this BlockPool belongs to * @param bpDir directory corresponding to the BlockPool * @param conf configuration * @throws IOException */ BlockPoolSlice(String bpid, FsVolumeImpl volume, File bpDir, Configuration conf) throws IOException { this.bpid = bpid; this.volume = volume; this.currentDir = new File(bpDir, DataStorage.STORAGE_DIR_CURRENT); this.finalizedDir = new File(currentDir, DataStorage.STORAGE_DIR_FINALIZED); this.lazypersistDir = new File(currentDir, DataStorage.STORAGE_DIR_LAZY_PERSIST); if (!this.finalizedDir.exists()) { if (!this.finalizedDir.mkdirs()) { throw new IOException("Failed to mkdirs " + this.finalizedDir); } } this.tmpDir = new File(bpDir, DataStorage.STORAGE_DIR_TMP); if (tmpDir.exists()) { FileUtil.fullyDelete(tmpDir); } this.rbwDir = new File(currentDir, DataStorage.STORAGE_DIR_RBW); final boolean supportAppends = conf.getBoolean( DFSConfigKeys.DFS_SUPPORT_APPEND_KEY, DFSConfigKeys.DFS_SUPPORT_APPEND_DEFAULT); if (rbwDir.exists() && !supportAppends) { FileUtil.fullyDelete(rbwDir); } if (!rbwDir.mkdirs()) { // create rbw directory if not exist if (!rbwDir.isDirectory()) { throw new IOException("Mkdirs failed to create " + rbwDir.toString()); } } if (!tmpDir.mkdirs()) { if (!tmpDir.isDirectory()) { throw new IOException("Mkdirs failed to create " + tmpDir.toString()); } } // 循环的获取BP目录的大小 this.dfsUsage = new DU(bpDir, conf, loadDfsUsed()); this.dfsUsage.start(); // 注册一个JVM关闭的钩子 ShutdownHookManager.get() .addShutdownHook( new Runnable() { @Override public void run() { if (!dfsUsedSaved) { saveDfsUsed(); } } }, SHUTDOWN_HOOK_PRIORITY); }