fluencelabs/redis
1
0
Fork 0
mirror of https://github.com/fluencelabs/redis synced 2025-06-17 19:21:21 +00:00
Code Issues Projects Releases Wiki Activity

Integer encoding implemented in dump file. Doc updated

Browse Source
This commit is contained in:
antirez
2009-03-28 10:58:19 +01:00
parent e9a9afd35e
commit e3566d4b46
3 changed files with 118 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

113
redis.c
View File

@ -1509,6 +1509,7 @@ static int rdbSaveType(FILE *fp, unsigned char type) {
return 0;
}
/* check rdbLoadLen() comments for more info */
static int rdbSaveLen(FILE *fp, uint32_t len) {
unsigned char buf[2];
@ -1531,9 +1532,57 @@ static int rdbSaveLen(FILE *fp, uint32_t len) {
return 0;
}
/* String objects in the form "2391" "-100" without any space and with a
* range of values that can fit in an 8, 16 or 32 bit signed value can be
* encoded as integers to save space */
int rdbTryIntegerEncoding(sds s, unsigned char *enc) {
long long value;
char *endptr, buf[32];
/* Check if it's possible to encode this value as a number */
value = strtoll(s, &endptr, 10);
if (endptr[0] != '\0') return 0;
snprintf(buf,32,"%lld",value);
/* If the number converted back into a string is not identical
* then it's not possible to encode the string as integer */
if (strlen(buf) != sdslen(s) || memcmp(buf,s,sdslen(s))) return 0;
/* Finally check if it fits in our ranges */
if (value >= -(1<<7) && value <= (1<<7)-1) {
enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT8;
enc[1] = value&0xFF;
return 2;
} else if (value >= -(1<<15) && value <= (1<<15)-1) {
enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT16;
enc[1] = value&0xFF;
enc[2] = (value>>8)&0xFF;
return 3;
} else if (value >= -((long long)1<<31) && value <= ((long long)1<<31)-1) {
enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT32;
enc[1] = value&0xFF;
enc[2] = (value>>8)&0xFF;
enc[3] = (value>>16)&0xFF;
enc[4] = (value>>24)&0xFF;
return 5;
} else {
return 0;
}
}
/* Save a string objet as [len][data] on disk. If the object is a string
* representation of an integer value we try to safe it in a special form */
static int rdbSaveStringObject(FILE *fp, robj *obj) {
size_t len = sdslen(obj->ptr);
int enclen;
if (len <= 11) {
unsigned char buf[5];
if ((enclen = rdbTryIntegerEncoding(obj->ptr,buf)) > 0) {
if (fwrite(buf,enclen,1,fp) == 0) return -1;
return 0;
}
}
if (rdbSaveLen(fp,len) == -1) return -1;
if (len && fwrite(obj->ptr,len,1,fp) == 0) return -1;
return 0;
@ -1664,10 +1713,16 @@ static int rdbLoadType(FILE *fp) {
return type;
}
static uint32_t rdbLoadLen(FILE *fp, int rdbver) {
/* Load an encoded length from the DB, see the REDIS_RDB_* defines on the top
* of this file for a description of how this are stored on disk.
*
* isencoded is set to 1 if the readed length is not actually a length but
* an "encoding type", check the above comments for more info */
static uint32_t rdbLoadLen(FILE *fp, int rdbver, int *isencoded) {
unsigned char buf[2];
uint32_t len;
if (isencoded) *isencoded = 0;
if (rdbver == 0) {
if (fread(&len,4,1,fp) == 0) return REDIS_RDB_LENERR;
return ntohl(len);
@ -1678,7 +1733,11 @@ static uint32_t rdbLoadLen(FILE *fp, int rdbver) {
type = (buf[0]&0xC0)>>6;
if (type == REDIS_RDB_6BITLEN) {
/* Read a 6 bit len */
return buf[0];
return buf[0]&0x3F;
} else if (type == REDIS_RDB_ENCVAL) {
/* Read a 6 bit len encoding type */
if (isencoded) *isencoded = 1;
return buf[0]&0x3F;
} else if (type == REDIS_RDB_14BITLEN) {
/* Read a 14 bit len */
if (fread(buf+1,1,1,fp) == 0) return REDIS_RDB_LENERR;
@ -1691,10 +1750,47 @@ static uint32_t rdbLoadLen(FILE *fp, int rdbver) {
}
}
static robj *rdbLoadStringObject(FILE*fp,int rdbver) {
uint32_t len = rdbLoadLen(fp,rdbver);
static robj *rdbLoadIntegerObject(FILE *fp, int enctype) {
unsigned char enc[4];
long long val;
if (enctype == REDIS_RDB_ENC_INT8) {
if (fread(enc,1,1,fp) == 0) return NULL;
val = (signed char)enc[0];
} else if (enctype == REDIS_RDB_ENC_INT16) {
uint16_t v;
if (fread(enc,2,1,fp) == 0) return NULL;
v = enc[0]|(enc[1]<<8);
val = (int16_t)v;
} else if (enctype == REDIS_RDB_ENC_INT32) {
uint32_t v;
if (fread(enc,4,1,fp) == 0) return NULL;
v = enc[0]|(enc[1]<<8)|(enc[2]<<16)|(enc[3]<<24);
val = (int32_t)v;
} else {
val = 0; /* anti-warning */
assert(0!=0);
}
return createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",val));
}
static robj *rdbLoadStringObject(FILE*fp, int rdbver) {
int isencoded;
uint32_t len;
sds val;
len = rdbLoadLen(fp,rdbver,&isencoded);
if (isencoded) {
switch(len) {
case REDIS_RDB_ENC_INT8:
case REDIS_RDB_ENC_INT16:
case REDIS_RDB_ENC_INT32:
return rdbLoadIntegerObject(fp,len);
default:
assert(0!=0);
}
}
if (len == REDIS_RDB_LENERR) return NULL;
val = sdsnewlen(NULL,len);
if (len && fread(val,len,1,fp) == 0) {
@ -1736,7 +1832,8 @@ static int rdbLoad(char *filename) {
if (type == REDIS_EOF) break;
/* Handle SELECT DB opcode as a special case */
if (type == REDIS_SELECTDB) {
if ((dbid = rdbLoadLen(fp,rdbver)) == REDIS_RDB_LENERR) goto eoferr;
if ((dbid = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR)
goto eoferr;
if (dbid >= (unsigned)server.dbnum) {
redisLog(REDIS_WARNING,"FATAL: Data file was created with a Redis server configured to handle more than %d databases. Exiting\n", server.dbnum);
exit(1);
@ -1754,7 +1851,7 @@ static int rdbLoad(char *filename) {
/* Read list/set value */
uint32_t listlen;
if ((listlen = rdbLoadLen(fp,rdbver)) == REDIS_RDB_LENERR)
if ((listlen = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR)
goto eoferr;
o = (type == REDIS_LIST) ? createListObject() : createSetObject();
/* Load every single element of the list/set */
@ -1785,8 +1882,8 @@ static int rdbLoad(char *filename) {
return REDIS_OK;
eoferr: /* unexpected end of file is handled here with a fatal exit */
decrRefCount(keyobj);
redisLog(REDIS_WARNING,"Short read loading DB. Unrecoverable error, exiting now.");
if (keyobj) decrRefCount(keyobj);
redisLog(REDIS_WARNING,"Short read or OOM loading DB. Unrecoverable error, exiting now.");
exit(1);
return REDIS_ERR; /* Just to avoid warning */
}