Rewrite MIGRATE as DEL for AOF/replication. Also increment the dirty counter to both...

[redis.git] / src / rdb.h

diff --git a/src/rdb.h b/src/rdb.h
index 93185fc3784842833786c509709a4ab5e69f4d13..fec16ffb13df93bf49651608369d0bb3e605b32e 100644 (file)
--- a/src/rdb.h
+++ b/src/rdb.h
@@ -7,6 +7,33 @@
 /* TBD: include only necessary headers. */
 #include "redis.h"
 
+/* Defines related to the dump file format. To store 32 bits lengths for short
+ * keys requires a lot of space, so we check the most significant 2 bits of
+ * the first byte to interpreter the length:
+ *
+ * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
+ * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
+ * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
+ * 11|000000 this means: specially encoded object will follow. The six bits
+ *           number specify the kind of object that follows.
+ *           See the REDIS_RDB_ENC_* defines.
+ *
+ * Lenghts up to 63 are stored using a single byte, most DB keys, and may
+ * values, will fit inside. */
+#define REDIS_RDB_6BITLEN 0
+#define REDIS_RDB_14BITLEN 1
+#define REDIS_RDB_32BITLEN 2
+#define REDIS_RDB_ENCVAL 3
+#define REDIS_RDB_LENERR UINT_MAX
+
+/* When a length of a string object stored on disk has the first two bits
+ * set, the remaining two bits specify a special encoding for the object
+ * accordingly to the following defines: */
+#define REDIS_RDB_ENC_INT8 0        /* 8 bit signed integer */
+#define REDIS_RDB_ENC_INT16 1       /* 16 bit signed integer */
+#define REDIS_RDB_ENC_INT32 2       /* 32 bit signed integer */
+#define REDIS_RDB_ENC_LZF 3         /* string compressed with FASTLZ */
+
 /* Dup object types to RDB object types. Only reason is readability (are we
  * dealing with RDB types or with in-memory object types?). */
 #define REDIS_RDB_TYPE_STRING 0
@@ -32,6 +59,14 @@
 /* Test if a type is an opcode. */
 #define rdbIsOpcode(t) (t >= 253 && t <= 255)
 
+int rdbSaveType(rio *rdb, unsigned char type);
+int rdbLoadType(rio *rdb);
+int rdbSaveTime(rio *rdb, time_t t);
+time_t rdbLoadTime(rio *rdb);
+int rdbSaveLen(rio *rdb, uint32_t len);
+uint32_t rdbLoadLen(rio *rdb, int *isencoded);
+int rdbSaveObjectType(rio *rdb, robj *o);
+int rdbLoadObjectType(rio *rdb);
 int rdbLoad(char *filename);
 int rdbSaveBackground(char *filename);
 void rdbRemoveTempFile(pid_t childpid);
@@ -42,12 +77,6 @@ off_t rdbSavedObjectPages(robj *o);
 robj *rdbLoadObject(int type, rio *rdb);
 void backgroundSaveDoneHandler(int exitcode, int bysignal);
 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, time_t expireitme, time_t now);
-int rdbLoadType(rio *rdb);
-time_t rdbLoadTime(rio *rdb);
 robj *rdbLoadStringObject(rio *rdb);
-int rdbSaveType(rio *rdb, unsigned char type);
-int rdbSaveLen(rio *rdb, uint32_t len);
-int rdbSaveObjectType(rio *rdb, robj *o);
-int rdbLoadObjectType(rio *rdb);
 
 #endif