xref: /redis-3.2.3/src/rdb.h (revision 32f80e2f)
1 /*
2  * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  *   * Redistributions of source code must retain the above copyright notice,
9  *     this list of conditions and the following disclaimer.
10  *   * Redistributions in binary form must reproduce the above copyright
11  *     notice, this list of conditions and the following disclaimer in the
12  *     documentation and/or other materials provided with the distribution.
13  *   * Neither the name of Redis nor the names of its contributors may be used
14  *     to endorse or promote products derived from this software without
15  *     specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #ifndef __RDB_H
31 #define __RDB_H
32 
33 #include <stdio.h>
34 #include "rio.h"
35 
36 /* TBD: include only necessary headers. */
37 #include "server.h"
38 
39 /* The current RDB version. When the format changes in a way that is no longer
40  * backward compatible this number gets incremented. */
41 #define RDB_VERSION 7
42 
43 /* Defines related to the dump file format. To store 32 bits lengths for short
44  * keys requires a lot of space, so we check the most significant 2 bits of
45  * the first byte to interpreter the length:
46  *
47  * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
48  * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
49  * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
50  * 11|000000 this means: specially encoded object will follow. The six bits
51  *           number specify the kind of object that follows.
52  *           See the RDB_ENC_* defines.
53  *
54  * Lengths up to 63 are stored using a single byte, most DB keys, and may
55  * values, will fit inside. */
56 #define RDB_6BITLEN 0
57 #define RDB_14BITLEN 1
58 #define RDB_32BITLEN 2
59 #define RDB_ENCVAL 3
60 #define RDB_LENERR UINT_MAX
61 
62 /* When a length of a string object stored on disk has the first two bits
63  * set, the remaining two bits specify a special encoding for the object
64  * accordingly to the following defines: */
65 #define RDB_ENC_INT8 0        /* 8 bit signed integer */
66 #define RDB_ENC_INT16 1       /* 16 bit signed integer */
67 #define RDB_ENC_INT32 2       /* 32 bit signed integer */
68 #define RDB_ENC_LZF 3         /* string compressed with FASTLZ */
69 
70 /* Dup object types to RDB object types. Only reason is readability (are we
71  * dealing with RDB types or with in-memory object types?). */
72 #define RDB_TYPE_STRING 0
73 #define RDB_TYPE_LIST   1
74 #define RDB_TYPE_SET    2
75 #define RDB_TYPE_ZSET   3
76 #define RDB_TYPE_HASH   4
77 /* NOTE: WHEN ADDING NEW RDB TYPE, UPDATE rdbIsObjectType() BELOW */
78 
79 /* Object types for encoded objects. */
80 #define RDB_TYPE_HASH_ZIPMAP    9
81 #define RDB_TYPE_LIST_ZIPLIST  10
82 #define RDB_TYPE_SET_INTSET    11
83 #define RDB_TYPE_ZSET_ZIPLIST  12
84 #define RDB_TYPE_HASH_ZIPLIST  13
85 #define RDB_TYPE_LIST_QUICKLIST 14
86 /* NOTE: WHEN ADDING NEW RDB TYPE, UPDATE rdbIsObjectType() BELOW */
87 
88 /* Test if a type is an object type. */
89 #define rdbIsObjectType(t) ((t >= 0 && t <= 4) || (t >= 9 && t <= 14))
90 
91 /* Special RDB opcodes (saved/loaded with rdbSaveType/rdbLoadType). */
92 #define RDB_OPCODE_AUX        250
93 #define RDB_OPCODE_RESIZEDB   251
94 #define RDB_OPCODE_EXPIRETIME_MS 252
95 #define RDB_OPCODE_EXPIRETIME 253
96 #define RDB_OPCODE_SELECTDB   254
97 #define RDB_OPCODE_EOF        255
98 
99 int rdbSaveType(rio *rdb, unsigned char type);
100 int rdbLoadType(rio *rdb);
101 int rdbSaveTime(rio *rdb, time_t t);
102 time_t rdbLoadTime(rio *rdb);
103 int rdbSaveLen(rio *rdb, uint32_t len);
104 uint32_t rdbLoadLen(rio *rdb, int *isencoded);
105 int rdbSaveObjectType(rio *rdb, robj *o);
106 int rdbLoadObjectType(rio *rdb);
107 int rdbLoad(char *filename);
108 int rdbSaveBackground(char *filename);
109 int rdbSaveToSlavesSockets(void);
110 void rdbRemoveTempFile(pid_t childpid);
111 int rdbSave(char *filename);
112 ssize_t rdbSaveObject(rio *rdb, robj *o);
113 size_t rdbSavedObjectLen(robj *o);
114 robj *rdbLoadObject(int type, rio *rdb);
115 void backgroundSaveDoneHandler(int exitcode, int bysignal);
116 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, long long expiretime, long long now);
117 robj *rdbLoadStringObject(rio *rdb);
118 
119 #endif
120