+/* Generates a DUMP-format representation of the object 'o', adding it to the
+ * io stream pointed by 'rio'. This function can't fail. */
+void createDumpPayload(rio *payload, robj *o) {
+ unsigned char buf[2];
+ uint64_t crc;
+
+ /* Serialize the object in a RDB-like format. It consist of an object type
+ * byte followed by the serialized object. This is understood by RESTORE. */
+ rioInitWithBuffer(payload,sdsempty());
+ redisAssert(rdbSaveObjectType(payload,o));
+ redisAssert(rdbSaveObject(payload,o));
+
+ /* Write the footer, this is how it looks like:
+ * ----------------+---------------------+---------------+
+ * ... RDB payload | 2 bytes RDB version | 8 bytes CRC64 |
+ * ----------------+---------------------+---------------+
+ * RDB version and CRC are both in little endian.
+ */
+
+ /* RDB version */
+ buf[0] = REDIS_RDB_VERSION & 0xff;
+ buf[1] = (REDIS_RDB_VERSION >> 8) & 0xff;
+ payload->io.buffer.ptr = sdscatlen(payload->io.buffer.ptr,buf,2);
+
+ /* CRC64 */
+ crc = crc64(0,(unsigned char*)payload->io.buffer.ptr,
+ sdslen(payload->io.buffer.ptr));
+ memrev64ifbe(&crc);
+ payload->io.buffer.ptr = sdscatlen(payload->io.buffer.ptr,&crc,8);
+}
+
+/* Verify that the RDB version of the dump payload matches the one of this Redis
+ * instance and that the checksum is ok.
+ * If the DUMP payload looks valid REDIS_OK is returned, otherwise REDIS_ERR
+ * is returned. */
+int verifyDumpPayload(unsigned char *p, size_t len) {
+ unsigned char *footer;
+ uint16_t rdbver;
+ uint64_t crc;
+
+ /* At least 2 bytes of RDB version and 8 of CRC64 should be present. */
+ if (len < 10) return REDIS_ERR;
+ footer = p+(len-10);
+
+ /* Verify RDB version */
+ rdbver = (footer[1] << 8) | footer[0];
+ if (rdbver != REDIS_RDB_VERSION) return REDIS_ERR;
+
+ /* Verify CRC64 */
+ crc = crc64(0,p,len-8);
+ memrev64ifbe(&crc);
+ return (memcmp(&crc,footer+2,8) == 0) ? REDIS_OK : REDIS_ERR;
+}
+
+/* DUMP keyname
+ * DUMP is actually not used by Redis Cluster but it is the obvious
+ * complement of RESTORE and can be useful for different applications. */
+void dumpCommand(redisClient *c) {
+ robj *o, *dumpobj;
+ rio payload;
+
+ /* Check if the key is here. */
+ if ((o = lookupKeyRead(c->db,c->argv[1])) == NULL) {
+ addReply(c,shared.nullbulk);
+ return;
+ }
+
+ /* Create the DUMP encoded representation. */
+ createDumpPayload(&payload,o);
+
+ /* Transfer to the client */
+ dumpobj = createObject(REDIS_STRING,payload.io.buffer.ptr);
+ addReplyBulk(c,dumpobj);
+ decrRefCount(dumpobj);
+ return;
+}
+
projects / redis.git / blobdiff