rocksdb/db/filename.cc
jorlow@chromium.org f67e15e50f Initial checkin.
git-svn-id: https://leveldb.googlecode.com/svn/trunk@2 62dab493-f737-651d-591e-8d6aee1b9529
2011-03-18 22:37:00 +00:00

155 lines
4.2 KiB
C++

// 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 "include/env.h"
#include "util/logging.h"
namespace leveldb {
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, "sst");
}
std::string LargeValueFileName(const std::string& name,
const LargeValueRef& large_ref) {
std::string result = name + "/";
result += LargeValueRefToFilenameString(large_ref);
result += ".val";
return result;
}
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/[0-9a-f]{20}-[0-9]+-[0-9]+.val
// dbname/[0-9]+.(log|sst)
bool ParseFileName(const std::string& fname,
uint64_t* number,
LargeValueRef* large_ref,
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.size() >= 4 &&
Slice(rest.data() + rest.size() - 4, 4) == ".val") {
LargeValueRef h;
if (!FilenameStringToLargeValueRef(Slice(rest.data(), rest.size() - 4),
&h)) {
return false;
}
*large_ref = h;
*type = kLargeValueFile;
} 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")) {
*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 = WriteStringToFile(env, contents.ToString() + "\n", tmp);
if (s.ok()) {
s = env->RenameFile(tmp, CurrentFileName(dbname));
}
if (!s.ok()) {
env->DeleteFile(tmp);
}
return s;
}
}