1 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file. See the AUTHORS file for names of contributors.
4
5 #include <ctype.h>
6 #include <stdio.h>
7 #include "db/filename.h"
8 #include "db/dbformat.h"
9 #include "leveldb/env.h"
10 #include "util/logging.h"
11
12 namespace leveldb {
13
14 // A utility routine: write "data" to the named file and Sync() it.
15 extern Status WriteStringToFileSync(Env* env, const Slice& data,
16 const std::string& fname);
17
MakeFileName(const std::string & name,uint64_t number,const char * suffix)18 static std::string MakeFileName(const std::string& name, uint64_t number,
19 const char* suffix) {
20 char buf[100];
21 snprintf(buf, sizeof(buf), "/%06llu.%s",
22 static_cast<unsigned long long>(number),
23 suffix);
24 return name + buf;
25 }
26
LogFileName(const std::string & name,uint64_t number)27 std::string LogFileName(const std::string& name, uint64_t number) {
28 assert(number > 0);
29 return MakeFileName(name, number, "log");
30 }
31
TableFileName(const std::string & name,uint64_t number)32 std::string TableFileName(const std::string& name, uint64_t number) {
33 assert(number > 0);
34 return MakeFileName(name, number, "ldb");
35 }
36
SSTTableFileName(const std::string & name,uint64_t number)37 std::string SSTTableFileName(const std::string& name, uint64_t number) {
38 assert(number > 0);
39 return MakeFileName(name, number, "sst");
40 }
41
DescriptorFileName(const std::string & dbname,uint64_t number)42 std::string DescriptorFileName(const std::string& dbname, uint64_t number) {
43 assert(number > 0);
44 char buf[100];
45 snprintf(buf, sizeof(buf), "/MANIFEST-%06llu",
46 static_cast<unsigned long long>(number));
47 return dbname + buf;
48 }
49
CurrentFileName(const std::string & dbname)50 std::string CurrentFileName(const std::string& dbname) {
51 return dbname + "/CURRENT";
52 }
53
LockFileName(const std::string & dbname)54 std::string LockFileName(const std::string& dbname) {
55 return dbname + "/LOCK";
56 }
57
TempFileName(const std::string & dbname,uint64_t number)58 std::string TempFileName(const std::string& dbname, uint64_t number) {
59 assert(number > 0);
60 return MakeFileName(dbname, number, "dbtmp");
61 }
62
InfoLogFileName(const std::string & dbname)63 std::string InfoLogFileName(const std::string& dbname) {
64 return dbname + "/LOG";
65 }
66
67 // Return the name of the old info log file for "dbname".
OldInfoLogFileName(const std::string & dbname)68 std::string OldInfoLogFileName(const std::string& dbname) {
69 return dbname + "/LOG.old";
70 }
71
72
73 // Owned filenames have the form:
74 // dbname/CURRENT
75 // dbname/LOCK
76 // dbname/LOG
77 // dbname/LOG.old
78 // dbname/MANIFEST-[0-9]+
79 // dbname/[0-9]+.(log|sst|ldb)
ParseFileName(const std::string & fname,uint64_t * number,FileType * type)80 bool ParseFileName(const std::string& fname,
81 uint64_t* number,
82 FileType* type) {
83 Slice rest(fname);
84 if (rest == "CURRENT") {
85 *number = 0;
86 *type = kCurrentFile;
87 } else if (rest == "LOCK") {
88 *number = 0;
89 *type = kDBLockFile;
90 } else if (rest == "LOG" || rest == "LOG.old") {
91 *number = 0;
92 *type = kInfoLogFile;
93 } else if (rest.starts_with("MANIFEST-")) {
94 rest.remove_prefix(strlen("MANIFEST-"));
95 uint64_t num;
96 if (!ConsumeDecimalNumber(&rest, &num)) {
97 return false;
98 }
99 if (!rest.empty()) {
100 return false;
101 }
102 *type = kDescriptorFile;
103 *number = num;
104 } else {
105 // Avoid strtoull() to keep filename format independent of the
106 // current locale
107 uint64_t num;
108 if (!ConsumeDecimalNumber(&rest, &num)) {
109 return false;
110 }
111 Slice suffix = rest;
112 if (suffix == Slice(".log")) {
113 *type = kLogFile;
114 } else if (suffix == Slice(".sst") || suffix == Slice(".ldb")) {
115 *type = kTableFile;
116 } else if (suffix == Slice(".dbtmp")) {
117 *type = kTempFile;
118 } else {
119 return false;
120 }
121 *number = num;
122 }
123 return true;
124 }
125
SetCurrentFile(Env * env,const std::string & dbname,uint64_t descriptor_number)126 Status SetCurrentFile(Env* env, const std::string& dbname,
127 uint64_t descriptor_number) {
128 // Remove leading "dbname/" and add newline to manifest file name
129 std::string manifest = DescriptorFileName(dbname, descriptor_number);
130 Slice contents = manifest;
131 assert(contents.starts_with(dbname + "/"));
132 contents.remove_prefix(dbname.size() + 1);
133 std::string tmp = TempFileName(dbname, descriptor_number);
134 Status s = WriteStringToFileSync(env, contents.ToString() + "\n", tmp);
135 if (s.ok()) {
136 s = env->RenameFile(tmp, CurrentFileName(dbname));
137 }
138 if (!s.ok()) {
139 env->DeleteFile(tmp);
140 }
141 return s;
142 }
143
144 } // namespace leveldb
145