xref: /redis-3.2.3/src/rdb.h (revision 80586cb8)
1 #ifndef __REDIS_RDB_H
2 #define __REDIS_RDB_H
3 
4 #include <stdio.h>
5 #include "rio.h"
6 
7 /* TBD: include only necessary headers. */
8 #include "redis.h"
9 
10 /* Defines related to the dump file format. To store 32 bits lengths for short
11  * keys requires a lot of space, so we check the most significant 2 bits of
12  * the first byte to interpreter the length:
13  *
14  * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
15  * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
16  * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
17  * 11|000000 this means: specially encoded object will follow. The six bits
18  *           number specify the kind of object that follows.
19  *           See the REDIS_RDB_ENC_* defines.
20  *
21  * Lenghts up to 63 are stored using a single byte, most DB keys, and may
22  * values, will fit inside. */
23 #define REDIS_RDB_6BITLEN 0
24 #define REDIS_RDB_14BITLEN 1
25 #define REDIS_RDB_32BITLEN 2
26 #define REDIS_RDB_ENCVAL 3
27 #define REDIS_RDB_LENERR UINT_MAX
28 
29 /* When a length of a string object stored on disk has the first two bits
30  * set, the remaining two bits specify a special encoding for the object
31  * accordingly to the following defines: */
32 #define REDIS_RDB_ENC_INT8 0        /* 8 bit signed integer */
33 #define REDIS_RDB_ENC_INT16 1       /* 16 bit signed integer */
34 #define REDIS_RDB_ENC_INT32 2       /* 32 bit signed integer */
35 #define REDIS_RDB_ENC_LZF 3         /* string compressed with FASTLZ */
36 
37 /* Dup object types to RDB object types. Only reason is readability (are we
38  * dealing with RDB types or with in-memory object types?). */
39 #define REDIS_RDB_TYPE_STRING 0
40 #define REDIS_RDB_TYPE_LIST   1
41 #define REDIS_RDB_TYPE_SET    2
42 #define REDIS_RDB_TYPE_ZSET   3
43 #define REDIS_RDB_TYPE_HASH   4
44 
45 /* Object types for encoded objects. */
46 #define REDIS_RDB_TYPE_HASH_ZIPMAP    9
47 #define REDIS_RDB_TYPE_LIST_ZIPLIST  10
48 #define REDIS_RDB_TYPE_SET_INTSET    11
49 #define REDIS_RDB_TYPE_ZSET_ZIPLIST  12
50 #define REDIS_RDB_TYPE_HASH_ZIPLIST  13
51 
52 /* Test if a type is an object type. */
53 #define rdbIsObjectType(t) ((t >= 0 && t <= 4) || (t >= 9 && t <= 12))
54 
55 /* Special RDB opcodes (saved/loaded with rdbSaveType/rdbLoadType). */
56 #define REDIS_RDB_OPCODE_EXPIRETIME_MS 252
57 #define REDIS_RDB_OPCODE_EXPIRETIME 253
58 #define REDIS_RDB_OPCODE_SELECTDB   254
59 #define REDIS_RDB_OPCODE_EOF        255
60 
61 /* Test if a type is an opcode. */
62 #define rdbIsOpcode(t) (t >= 253 && t <= 255)
63 
64 int rdbSaveType(rio *rdb, unsigned char type);
65 int rdbLoadType(rio *rdb);
66 int rdbSaveTime(rio *rdb, time_t t);
67 time_t rdbLoadTime(rio *rdb);
68 int rdbSaveLen(rio *rdb, uint32_t len);
69 uint32_t rdbLoadLen(rio *rdb, int *isencoded);
70 int rdbSaveObjectType(rio *rdb, robj *o);
71 int rdbLoadObjectType(rio *rdb);
72 int rdbLoad(char *filename);
73 int rdbSaveBackground(char *filename);
74 void rdbRemoveTempFile(pid_t childpid);
75 int rdbSave(char *filename);
76 int rdbSaveObject(rio *rdb, robj *o);
77 off_t rdbSavedObjectLen(robj *o);
78 off_t rdbSavedObjectPages(robj *o);
79 robj *rdbLoadObject(int type, rio *rdb);
80 void backgroundSaveDoneHandler(int exitcode, int bysignal);
81 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, long long expiretime, long long now);
82 robj *rdbLoadStringObject(rio *rdb);
83 
84 #endif
85