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 /* 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
  51 /* Test if a type is an object type. */
  52 #define rdbIsObjectType(t) ((t >= 0 && t <= 4) || (t >= 9 && t <= 12))
  53
  54 /* Special RDB opcodes (saved/loaded with rdbSaveType/rdbLoadType). */
  55 #define REDIS_RDB_OPCODE_EXPIRETIME 253
  56 #define REDIS_RDB_OPCODE_SELECTDB   254
  57 #define REDIS_RDB_OPCODE_EOF        255
  58
  59 /* Test if a type is an opcode. */
  60 #define rdbIsOpcode(t) (t >= 253 && t <= 255)
  61
  62 int rdbSaveType(rio *rdb, unsigned char type);
  63 int rdbLoadType(rio *rdb);
  64 int rdbSaveTime(rio *rdb, time_t t);
  65 time_t rdbLoadTime(rio *rdb);
  66 int rdbSaveLen(rio *rdb, uint32_t len);
  67 uint32_t rdbLoadLen(rio *rdb, int *isencoded);
  68 int rdbSaveObjectType(rio *rdb, robj *o);
  69 int rdbLoadObjectType(rio *rdb);
  70 int rdbLoad(char *filename);
  71 int rdbSaveBackground(char *filename);
  72 void rdbRemoveTempFile(pid_t childpid);
  73 int rdbSave(char *filename);
  74 int rdbSaveObject(rio *rdb, robj *o);
  75 off_t rdbSavedObjectLen(robj *o);
  76 off_t rdbSavedObjectPages(robj *o);
  77 robj *rdbLoadObject(int type, rio *rdb);
  78 void backgroundSaveDoneHandler(int exitcode, int bysignal);
  79 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, time_t expireitme, time_t now);
  80 robj *rdbLoadStringObject(rio *rdb);
  81
  82 #endif