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// 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 "db/filename.h"
#include <cassert>
#include <cstdio>
#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.
Status WriteStringToFileSync(Env* env, const Slice& data,
const std::string& fname);
static std::string MakeFileName(const std::string& dbname, uint64_t number,
const char* suffix) {
char buf[100];
std::snprintf(buf, sizeof(buf), "/%06llu.%s",
static_cast<unsigned long long>(number), suffix);
return dbname + buf;
}
std::string LogFileName(const std::string& dbname, uint64_t number) {
assert(number > 0);
return MakeFileName(dbname, number, "log");
}
std::string TableFileName(const std::string& dbname, uint64_t number) {
assert(number > 0);
return MakeFileName(dbname, number, "ldb");
}
std::string SSTTableFileName(const std::string& dbname, uint64_t number) {
assert(number > 0);
return MakeFileName(dbname, number, "sst");
}
std::string DescriptorFileName(const std::string& dbname, uint64_t number) {
assert(number > 0);
char buf[100];
std::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& filename, uint64_t* number,
FileType* type) {
Slice rest(filename);
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->RemoveFile(tmp);
}
return s;
}
} // namespace leveldb
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