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