+/* The current RDB version. When the format changes in a way that is no longer
+ * backward compatible this number gets incremented. */
+#define REDIS_RDB_VERSION 6
+
+/* 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 */
+