src/rdb.h

   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 /* The current RDB version. When the format changes in a way that is no longer
  11  * backward compatible this number gets incremented. */
  12 #define REDIS_RDB_VERSION 4
  13
  14 /* Defines related to the dump file format. To store 32 bits lengths for short
  15  * keys requires a lot of space, so we check the most significant 2 bits of
  16  * the first byte to interpreter the length:
  17  *
  18  * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
  19  * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
  20  * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
  21  * 11|000000 this means: specially encoded object will follow. The six bits
  22  *           number specify the kind of object that follows.
  23  *           See the REDIS_RDB_ENC_* defines.
  24  *
  25  * Lenghts up to 63 are stored using a single byte, most DB keys, and may
  26  * values, will fit inside. */
  27 #define REDIS_RDB_6BITLEN 0
  28 #define REDIS_RDB_14BITLEN 1
  29 #define REDIS_RDB_32BITLEN 2
  30 #define REDIS_RDB_ENCVAL 3
  31 #define REDIS_RDB_LENERR UINT_MAX
  32
  33 /* When a length of a string object stored on disk has the first two bits
  34  * set, the remaining two bits specify a special encoding for the object
  35  * accordingly to the following defines: */
  36 #define REDIS_RDB_ENC_INT8 0        /* 8 bit signed integer */
  37 #define REDIS_RDB_ENC_INT16 1       /* 16 bit signed integer */
  38 #define REDIS_RDB_ENC_INT32 2       /* 32 bit signed integer */
  39 #define REDIS_RDB_ENC_LZF 3         /* string compressed with FASTLZ */
  40
  41 /* Dup object types to RDB object types. Only reason is readability (are we
  42  * dealing with RDB types or with in-memory object types?). */
  43 #define REDIS_RDB_TYPE_STRING 0
  44 #define REDIS_RDB_TYPE_LIST   1
  45 #define REDIS_RDB_TYPE_SET    2
  46 #define REDIS_RDB_TYPE_ZSET   3
  47 #define REDIS_RDB_TYPE_HASH   4
  48
  49 /* Object types for encoded objects. */
  50 #define REDIS_RDB_TYPE_HASH_ZIPMAP    9
  51 #define REDIS_RDB_TYPE_LIST_ZIPLIST  10
  52 #define REDIS_RDB_TYPE_SET_INTSET    11
  53 #define REDIS_RDB_TYPE_ZSET_ZIPLIST  12
  54 #define REDIS_RDB_TYPE_HASH_ZIPLIST  13
  55
  56 /* Test if a type is an object type. */
  57 #define rdbIsObjectType(t) ((t >= 0 && t <= 4) || (t >= 9 && t <= 12))
  58
  59 /* Special RDB opcodes (saved/loaded with rdbSaveType/rdbLoadType). */
  60 #define REDIS_RDB_OPCODE_EXPIRETIME_MS 252
  61 #define REDIS_RDB_OPCODE_EXPIRETIME 253
  62 #define REDIS_RDB_OPCODE_SELECTDB   254
  63 #define REDIS_RDB_OPCODE_EOF        255
  64
  65 /* Test if a type is an opcode. */
  66 #define rdbIsOpcode(t) (t >= 253 && t <= 255)
  67
  68 int rdbSaveType(rio *rdb, unsigned char type);
  69 int rdbLoadType(rio *rdb);
  70 int rdbSaveTime(rio *rdb, time_t t);
  71 time_t rdbLoadTime(rio *rdb);
  72 int rdbSaveLen(rio *rdb, uint32_t len);
  73 uint32_t rdbLoadLen(rio *rdb, int *isencoded);
  74 int rdbSaveObjectType(rio *rdb, robj *o);
  75 int rdbLoadObjectType(rio *rdb);
  76 int rdbLoad(char *filename);
  77 int rdbSaveBackground(char *filename);
  78 void rdbRemoveTempFile(pid_t childpid);
  79 int rdbSave(char *filename);
  80 int rdbSaveObject(rio *rdb, robj *o);
  81 off_t rdbSavedObjectLen(robj *o);
  82 off_t rdbSavedObjectPages(robj *o);
  83 robj *rdbLoadObject(int type, rio *rdb);
  84 void backgroundSaveDoneHandler(int exitcode, int bysignal);
  85 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, long long expiretime, long long now);
  86 robj *rdbLoadStringObject(rio *rdb);
  87
  88 #endif