// Copyright (c) 2011 The LevelDB Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. See the AUTHORS file for names of contributors. #include <ctype.h> #include <stdio.h> #include "db/filename.h" #include "db/dbformat.h" #include "leveldb/env.h" #include "util/logging.h" namespace leveldb { // A utility routine: write "data" to the named file and Sync() it. extern Status WriteStringToFileSync(Env* env, const Slice& data, const std::string& fname); static std::string MakeFileName(const std::string& name, uint64_t number, const char* suffix) { char buf[100]; snprintf(buf, sizeof(buf), "/%06llu.%s", static_cast<unsigned long long>(number), suffix); return name + buf; } std::string LogFileName(const std::string& name, uint64_t number) { assert(number > 0); return MakeFileName(name, number, "log"); } std::string TableFileName(const std::string& name, uint64_t number) { assert(number > 0); return MakeFileName(name, number, "ldb"); } std::string SSTTableFileName(const std::string& name, uint64_t number) { assert(number > 0); return MakeFileName(name, number, "sst"); } std::string DescriptorFileName(const std::string& dbname, uint64_t number) { assert(number > 0); char buf[100]; snprintf(buf, sizeof(buf), "/MANIFEST-%06llu", static_cast<unsigned long long>(number)); return dbname + buf; } std::string CurrentFileName(const std::string& dbname) { return dbname + "/CURRENT"; } std::string LockFileName(const std::string& dbname) { return dbname + "/LOCK"; } std::string TempFileName(const std::string& dbname, uint64_t number) { assert(number > 0); return MakeFileName(dbname, number, "dbtmp"); } std::string InfoLogFileName(const std::string& dbname) { return dbname + "/LOG"; } // Return the name of the old info log file for "dbname". std::string OldInfoLogFileName(const std::string& dbname) { return dbname + "/LOG.old"; } // Owned filenames have the form: // dbname/CURRENT // dbname/LOCK // dbname/LOG // dbname/LOG.old // dbname/MANIFEST-[0-9]+ // dbname/[0-9]+.(log|sst|ldb) bool ParseFileName(const std::string& fname, uint64_t* number, FileType* type) { Slice rest(fname); if (rest == "CURRENT") { *number = 0; *type = kCurrentFile; } else if (rest == "LOCK") { *number = 0; *type = kDBLockFile; } else if (rest == "LOG" || rest == "LOG.old") { *number = 0; *type = kInfoLogFile; } else if (rest.starts_with("MANIFEST-")) { rest.remove_prefix(strlen("MANIFEST-")); uint64_t num; if (!ConsumeDecimalNumber(&rest, &num)) { return false; } if (!rest.empty()) { return false; } *type = kDescriptorFile; *number = num; } else { // Avoid strtoull() to keep filename format independent of the // current locale uint64_t num; if (!ConsumeDecimalNumber(&rest, &num)) { return false; } Slice suffix = rest; if (suffix == Slice(".log")) { *type = kLogFile; } else if (suffix == Slice(".sst") || suffix == Slice(".ldb")) { *type = kTableFile; } else if (suffix == Slice(".dbtmp")) { *type = kTempFile; } else { return false; } *number = num; } return true; } Status SetCurrentFile(Env* env, const std::string& dbname, uint64_t descriptor_number) { // Remove leading "dbname/" and add newline to manifest file name std::string manifest = DescriptorFileName(dbname, descriptor_number); Slice contents = manifest; assert(contents.starts_with(dbname + "/")); contents.remove_prefix(dbname.size() + 1); std::string tmp = TempFileName(dbname, descriptor_number); Status s = WriteStringToFileSync(env, contents.ToString() + "\n", tmp); if (s.ok()) { s = env->RenameFile(tmp, CurrentFileName(dbname)); } if (!s.ok()) { env->DeleteFile(tmp); } return s; } } // namespace leveldb