/* Write a sequence of commands able to fully rebuild the dataset into
* "filename". Used both by REWRITEAOF and BGREWRITEAOF.
*
* In order to minimize the number of commands needed in the rewritten
* log Redis uses variadic commands when possible, such as RPUSH, SADD
* and ZADD. However at max REDIS_AOF_REWRITE_ITEMS_PER_CMD items per time
* are inserted using a single command. */
int rewriteAppendOnlyFile(char *filename) {
dictIterator *di = NULL;
dictEntry *de;
rio aof;
FILE *fp;
char tmpfile[256];
int j;
long long now = mstime();
/* Note that we have to use a different temp name here compared to the
* one used by rewriteAppendOnlyFileBackground() function. */
snprintf(tmpfile,256,"temp-rewriteaof-%d.aof", (int) getpid());
fp = fopen(tmpfile,"w");
if (!fp) {
redisLog(REDIS_WARNING, "Opening the temp file for AOF rewrite in rewriteAppendOnlyFile(): %s", strerror(errno));
return REDIS_ERR;
}
rioInitWithFile(&aof,fp);
for (j = 0; j < server.dbnum; j++) {
char selectcmd[] = "*2\r\n$6\r\nSELECT\r\n";
redisDb *db = server.db+j;
dict *d = db->dict;
if (dictSize(d) == 0) continue;
di = dictGetSafeIterator(d);
if (!di) {
fclose(fp);
return REDIS_ERR;
}
/* SELECT the new DB */
if (rioWrite(&aof,selectcmd,sizeof(selectcmd)-1) == 0) goto werr;
if (rioWriteBulkLongLong(&aof,j) == 0) goto werr;
/* Iterate this DB writing every entry */
while((de = dictNext(di)) != NULL) {
sds keystr;
robj key, *o;
long long expiretime;
keystr = dictGetKey(de);
o = dictGetVal(de);
initStaticStringObject(key,keystr);
expiretime = getExpire(db,&key);
/* Save the key and associated value */
if (o->type == REDIS_STRING) {
/* Emit a SET command */
char cmd[]="*3\r\n$3\r\nSET\r\n";
if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
/* Key and value */
if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
if (rioWriteBulkObject(&aof,o) == 0) goto werr;
} else if (o->type == REDIS_LIST) {
if (rewriteListObject(&aof,&key,o) == 0) goto werr;
} else if (o->type == REDIS_SET) {
if (rewriteSetObject(&aof,&key,o) == 0) goto werr;
} else if (o->type == REDIS_ZSET) {
if (rewriteSortedSetObject(&aof,&key,o) == 0) goto werr;
} else if (o->type == REDIS_HASH) {
if (rewriteHashObject(&aof,&key,o) == 0) goto werr;
} else {
redisPanic("Unknown object type");
}
/* Save the expire time */
if (expiretime != -1) {
char cmd[]="*3\r\n$9\r\nPEXPIREAT\r\n";
/* If this key is already expired skip it */
if (expiretime < now) continue;
if (rioWrite(&aof,cmd,sizeof(cmd)-1) == 0) goto werr;
if (rioWriteBulkObject(&aof,&key) == 0) goto werr;
if (rioWriteBulkLongLong(&aof,expiretime) == 0) goto werr;
}
}
dictReleaseIterator(di);
}
/* Make sure data will not remain on the OS's output buffers */
fflush(fp);
aof_fsync(fileno(fp));
fclose(fp);
/* Use RENAME to make sure the DB file is changed atomically only
* if the generate DB file is ok. */
if (rename(tmpfile,filename) == -1) {
redisLog(REDIS_WARNING,"Error moving temp append only file on the final destination: %s", strerror(errno));
unlink(tmpfile);
return REDIS_ERR;
}
redisLog(REDIS_NOTICE,"SYNC append only file rewrite performed");
return REDIS_OK;
werr:
fclose(fp);
unlink(tmpfile);
redisLog(REDIS_WARNING,"Write error writing append only file on disk: %s", strerror(errno));
if (di) dictReleaseIterator(di);
return REDIS_ERR;
}
/* Check the specified RDB file. Return 0 if the RDB looks sane, otherwise
* 1 is returned. */
int redis_check_rdb(char *rdbfilename) {
uint64_t dbid;
int type, rdbver;
char buf[1024];
long long expiretime, now = mstime();
FILE *fp;
static rio rdb; /* Pointed by global struct riostate. */
if ((fp = fopen(rdbfilename,"r")) == NULL) return 1;
rioInitWithFile(&rdb,fp);
rdbstate.rio = &rdb;
rdb.update_cksum = rdbLoadProgressCallback;
if (rioRead(&rdb,buf,9) == 0) goto eoferr;
buf[9] = '\0';
if (memcmp(buf,"REDIS",5) != 0) {
rdbCheckError("Wrong signature trying to load DB from file");
return 1;
}
rdbver = atoi(buf+5);
if (rdbver < 1 || rdbver > RDB_VERSION) {
rdbCheckError("Can't handle RDB format version %d",rdbver);
return 1;
}
startLoading(fp);
while(1) {
robj *key, *val;
expiretime = -1;
/* Read type. */
rdbstate.doing = RDB_CHECK_DOING_READ_TYPE;
if ((type = rdbLoadType(&rdb)) == -1) goto eoferr;
/* Handle special types. */
if (type == RDB_OPCODE_EXPIRETIME) {
rdbstate.doing = RDB_CHECK_DOING_READ_EXPIRE;
/* EXPIRETIME: load an expire associated with the next key
* to load. Note that after loading an expire we need to
* load the actual type, and continue. */
if ((expiretime = rdbLoadTime(&rdb)) == -1) goto eoferr;
/* We read the time so we need to read the object type again. */
rdbstate.doing = RDB_CHECK_DOING_READ_TYPE;
if ((type = rdbLoadType(&rdb)) == -1) goto eoferr;
/* the EXPIRETIME opcode specifies time in seconds, so convert
* into milliseconds. */
expiretime *= 1000;
} else if (type == RDB_OPCODE_EXPIRETIME_MS) {
/* EXPIRETIME_MS: milliseconds precision expire times introduced
* with RDB v3. Like EXPIRETIME but no with more precision. */
rdbstate.doing = RDB_CHECK_DOING_READ_EXPIRE;
if ((expiretime = rdbLoadMillisecondTime(&rdb)) == -1) goto eoferr;
/* We read the time so we need to read the object type again. */
rdbstate.doing = RDB_CHECK_DOING_READ_TYPE;
if ((type = rdbLoadType(&rdb)) == -1) goto eoferr;
} else if (type == RDB_OPCODE_EOF) {
/* EOF: End of file, exit the main loop. */
break;
} else if (type == RDB_OPCODE_SELECTDB) {
/* SELECTDB: Select the specified database. */
rdbstate.doing = RDB_CHECK_DOING_READ_LEN;
if ((dbid = rdbLoadLen(&rdb,NULL)) == RDB_LENERR)
goto eoferr;
rdbCheckInfo("Selecting DB ID %d", dbid);
continue; /* Read type again. */
} else if (type == RDB_OPCODE_RESIZEDB) {
/* RESIZEDB: Hint about the size of the keys in the currently
* selected data base, in order to avoid useless rehashing. */
uint64_t db_size, expires_size;
rdbstate.doing = RDB_CHECK_DOING_READ_LEN;
if ((db_size = rdbLoadLen(&rdb,NULL)) == RDB_LENERR)
goto eoferr;
if ((expires_size = rdbLoadLen(&rdb,NULL)) == RDB_LENERR)
goto eoferr;
continue; /* Read type again. */
} else if (type == RDB_OPCODE_AUX) {
/* AUX: generic string-string fields. Use to add state to RDB
* which is backward compatible. Implementations of RDB loading
* are requierd to skip AUX fields they don't understand.
*
* An AUX field is composed of two strings: key and value. */
robj *auxkey, *auxval;
rdbstate.doing = RDB_CHECK_DOING_READ_AUX;
if ((auxkey = rdbLoadStringObject(&rdb)) == NULL) goto eoferr;
if ((auxval = rdbLoadStringObject(&rdb)) == NULL) goto eoferr;
rdbCheckInfo("AUX FIELD %s = '%s'",
(char*)auxkey->ptr, (char*)auxval->ptr);
decrRefCount(auxkey);
decrRefCount(auxval);
continue; /* Read type again. */
} else {
if (!rdbIsObjectType(type)) {
rdbCheckError("Invalid object type: %d", type);
return 1;
}
rdbstate.key_type = type;
}
/* Read key */
rdbstate.doing = RDB_CHECK_DOING_READ_KEY;
if ((key = rdbLoadStringObject(&rdb)) == NULL) goto eoferr;
rdbstate.key = key;
rdbstate.keys++;
/* Read value */
rdbstate.doing = RDB_CHECK_DOING_READ_OBJECT_VALUE;
if ((val = rdbLoadObject(type,&rdb)) == NULL) goto eoferr;
/* Check if the key already expired. This function is used when loading
* an RDB file from disk, either at startup, or when an RDB was
* received from the master. In the latter case, the master is
* responsible for key expiry. If we would expire keys here, the
* snapshot taken by the master may not be reflected on the slave. */
if (server.masterhost == NULL && expiretime != -1 && expiretime < now)
rdbstate.already_expired++;
if (expiretime != -1) rdbstate.expires++;
rdbstate.key = NULL;
decrRefCount(key);
decrRefCount(val);
rdbstate.key_type = -1;
}
/* Verify the checksum if RDB version is >= 5 */
if (rdbver >= 5 && server.rdb_checksum) {
uint64_t cksum, expected = rdb.cksum;
rdbstate.doing = RDB_CHECK_DOING_CHECK_SUM;
if (rioRead(&rdb,&cksum,8) == 0) goto eoferr;
memrev64ifbe(&cksum);
if (cksum == 0) {
rdbCheckInfo("RDB file was saved with checksum disabled: no check performed.");
} else if (cksum != expected) {
rdbCheckError("RDB CRC error");
} else {
rdbCheckInfo("Checksum OK");
}
}
fclose(fp);
return 0;
eoferr: /* unexpected end of file is handled here with a fatal exit */
if (rdbstate.error_set) {
rdbCheckError(rdbstate.error);
} else {
rdbCheckError("Unexpected EOF reading RDB file");
}
return 1;
}
