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#include "redis.h"
#include "sha1.h" /* SHA1 is used for DEBUG DIGEST */
#include <arpa/inet.h>
/* ================================= Debugging ============================== */
/* Compute the sha1 of string at 's' with 'len' bytes long.
* The SHA1 is then xored againt the string pointed by digest.
* Since xor is commutative, this operation is used in order to
* "add" digests relative to unordered elements.
*
* So digest(a,b,c,d) will be the same of digest(b,a,c,d) */
void xorDigest(unsigned char *digest, void *ptr, size_t len) {
SHA1_CTX ctx;
unsigned char hash[20], *s = ptr;
int j;
SHA1Init(&ctx);
SHA1Update(&ctx,s,len);
SHA1Final(hash,&ctx);
for (j = 0; j < 20; j++)
digest[j] ^= hash[j];
}
void xorObjectDigest(unsigned char *digest, robj *o) {
o = getDecodedObject(o);
xorDigest(digest,o->ptr,sdslen(o->ptr));
decrRefCount(o);
}
/* This function instead of just computing the SHA1 and xoring it
* against diget, also perform the digest of "digest" itself and
* replace the old value with the new one.
*
* So the final digest will be:
*
* digest = SHA1(digest xor SHA1(data))
*
* This function is used every time we want to preserve the order so
* that digest(a,b,c,d) will be different than digest(b,c,d,a)
*
* Also note that mixdigest("foo") followed by mixdigest("bar")
* will lead to a different digest compared to "fo", "obar".
*/
void mixDigest(unsigned char *digest, void *ptr, size_t len) {
SHA1_CTX ctx;
char *s = ptr;
xorDigest(digest,s,len);
SHA1Init(&ctx);
SHA1Update(&ctx,digest,20);
SHA1Final(digest,&ctx);
}
void mixObjectDigest(unsigned char *digest, robj *o) {
o = getDecodedObject(o);
mixDigest(digest,o->ptr,sdslen(o->ptr));
decrRefCount(o);
}
/* Compute the dataset digest. Since keys, sets elements, hashes elements
* are not ordered, we use a trick: every aggregate digest is the xor
* of the digests of their elements. This way the order will not change
* the result. For list instead we use a feedback entering the output digest
* as input in order to ensure that a different ordered list will result in
* a different digest. */
void computeDatasetDigest(unsigned char *final) {
unsigned char digest[20];
char buf[128];
dictIterator *di = NULL;
dictEntry *de;
int j;
uint32_t aux;
memset(final,0,20); /* Start with a clean result */
for (j = 0; j < server.dbnum; j++) {
redisDb *db = server.db+j;
if (dictSize(db->dict) == 0) continue;
di = dictGetSafeIterator(db->dict);
/* hash the DB id, so the same dataset moved in a different
* DB will lead to a different digest */
aux = htonl(j);
mixDigest(final,&aux,sizeof(aux));
/* Iterate this DB writing every entry */
while((de = dictNext(di)) != NULL) {
sds key;
robj *keyobj, *o;
time_t expiretime;
memset(digest,0,20); /* This key-val digest */
key = dictGetEntryKey(de);
keyobj = createStringObject(key,sdslen(key));
mixDigest(digest,key,sdslen(key));
/* Make sure the key is loaded if VM is active */
o = lookupKeyRead(db,keyobj);
if (o == NULL) {
/* Key expired on lookup? Try the next one. */
decrRefCount(keyobj);
continue;
}
aux = htonl(o->type);
mixDigest(digest,&aux,sizeof(aux));
expiretime = getExpire(db,keyobj);
/* Save the key and associated value */
if (o->type == REDIS_STRING) {
mixObjectDigest(digest,o);
} else if (o->type == REDIS_LIST) {
listTypeIterator *li = listTypeInitIterator(o,0,REDIS_TAIL);
listTypeEntry entry;
while(listTypeNext(li,&entry)) {
robj *eleobj = listTypeGet(&entry);
mixObjectDigest(digest,eleobj);
decrRefCount(eleobj);
}
listTypeReleaseIterator(li);
} else if (o->type == REDIS_SET) {
setTypeIterator *si = setTypeInitIterator(o);
robj *ele;
while((ele = setTypeNextObject(si)) != NULL) {
xorObjectDigest(digest,ele);
decrRefCount(ele);
}
setTypeReleaseIterator(si);
} else if (o->type == REDIS_ZSET) {
unsigned char eledigest[20];
if (o->encoding == REDIS_ENCODING_ZIPLIST) {
unsigned char *zl = o->ptr;
unsigned char *eptr, *sptr;
unsigned char *vstr;
unsigned int vlen;
long long vll;
double score;
eptr = ziplistIndex(zl,0);
redisAssert(eptr != NULL);
sptr = ziplistNext(zl,eptr);
redisAssert(sptr != NULL);
while (eptr != NULL) {
redisAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
score = zzlGetScore(sptr);
memset(eledigest,0,20);
if (vstr != NULL) {
mixDigest(eledigest,vstr,vlen);
} else {
ll2string(buf,sizeof(buf),vll);
mixDigest(eledigest,buf,strlen(buf));
}
snprintf(buf,sizeof(buf),"%.17g",score);
mixDigest(eledigest,buf,strlen(buf));
xorDigest(digest,eledigest,20);
zzlNext(zl,&eptr,&sptr);
}
} else if (o->encoding == REDIS_ENCODING_SKIPLIST) {
zset *zs = o->ptr;
dictIterator *di = dictGetIterator(zs->dict);
dictEntry *de;
while((de = dictNext(di)) != NULL) {
robj *eleobj = dictGetEntryKey(de);
double *score = dictGetEntryVal(de);
snprintf(buf,sizeof(buf),"%.17g",*score);
memset(eledigest,0,20);
mixObjectDigest(eledigest,eleobj);
mixDigest(eledigest,buf,strlen(buf));
xorDigest(digest,eledigest,20);
}
dictReleaseIterator(di);
} else {
redisPanic("Unknown sorted set encoding");
}
} else if (o->type == REDIS_HASH) {
hashTypeIterator *hi;
robj *obj;
hi = hashTypeInitIterator(o);
while (hashTypeNext(hi) != REDIS_ERR) {
unsigned char eledigest[20];
memset(eledigest,0,20);
obj = hashTypeCurrentObject(hi,REDIS_HASH_KEY);
mixObjectDigest(eledigest,obj);
decrRefCount(obj);
obj = hashTypeCurrentObject(hi,REDIS_HASH_VALUE);
mixObjectDigest(eledigest,obj);
decrRefCount(obj);
xorDigest(digest,eledigest,20);
}
hashTypeReleaseIterator(hi);
} else {
redisPanic("Unknown object type");
}
/* If the key has an expire, add it to the mix */
if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
/* We can finally xor the key-val digest to the final digest */
xorDigest(final,digest,20);
decrRefCount(keyobj);
}
dictReleaseIterator(di);
}
}
void debugCommand(redisClient *c) {
if (!strcasecmp(c->argv[1]->ptr,"segfault")) {
*((char*)-1) = 'x';
} else if (!strcasecmp(c->argv[1]->ptr,"reload")) {
if (rdbSave(server.dbfilename) != REDIS_OK) {
addReply(c,shared.err);
return;
}
emptyDb();
if (rdbLoad(server.dbfilename) != REDIS_OK) {
addReply(c,shared.err);
return;
}
redisLog(REDIS_WARNING,"DB reloaded by DEBUG RELOAD");
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
emptyDb();
if (loadAppendOnlyFile(server.appendfilename) != REDIS_OK) {
addReply(c,shared.err);
return;
}
redisLog(REDIS_WARNING,"Append Only File loaded by DEBUG LOADAOF");
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"object") && c->argc == 3) {
dictEntry *de = dictFind(c->db->dict,c->argv[2]->ptr);
robj *val;
if (!de) {
addReply(c,shared.nokeyerr);
return;
}
val = dictGetEntryVal(de);
if (!server.vm_enabled || (val->storage == REDIS_VM_MEMORY ||
val->storage == REDIS_VM_SWAPPING)) {
char *strenc;
strenc = strEncoding(val->encoding);
addReplyStatusFormat(c,
"Value at:%p refcount:%d "
"encoding:%s serializedlength:%lld "
"lru:%d lru_seconds_idle:%lu",
(void*)val, val->refcount,
strenc, (long long) rdbSavedObjectLen(val),
val->lru, estimateObjectIdleTime(val));
} else {
vmpointer *vp = (vmpointer*) val;
addReplyStatusFormat(c,
"Value swapped at: page %llu "
"using %llu pages",
(unsigned long long) vp->page,
(unsigned long long) vp->usedpages);
}
} else if (!strcasecmp(c->argv[1]->ptr,"swapin") && c->argc == 3) {
lookupKeyRead(c->db,c->argv[2]);
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"swapout") && c->argc == 3) {
dictEntry *de = dictFind(c->db->dict,c->argv[2]->ptr);
robj *val;
vmpointer *vp;
if (!server.vm_enabled) {
addReplyError(c,"Virtual Memory is disabled");
return;
}
if (!de) {
addReply(c,shared.nokeyerr);
return;
}
val = dictGetEntryVal(de);
/* Swap it */
if (val->storage != REDIS_VM_MEMORY) {
addReplyError(c,"This key is not in memory");
} else if (val->refcount != 1) {
addReplyError(c,"Object is shared");
} else if ((vp = vmSwapObjectBlocking(val)) != NULL) {
dictGetEntryVal(de) = vp;
addReply(c,shared.ok);
} else {
addReply(c,shared.err);
}
} else if (!strcasecmp(c->argv[1]->ptr,"populate") && c->argc == 3) {
long keys, j;
robj *key, *val;
char buf[128];
if (getLongFromObjectOrReply(c, c->argv[2], &keys, NULL) != REDIS_OK)
return;
for (j = 0; j < keys; j++) {
snprintf(buf,sizeof(buf),"key:%lu",j);
key = createStringObject(buf,strlen(buf));
if (lookupKeyRead(c->db,key) != NULL) {
decrRefCount(key);
continue;
}
snprintf(buf,sizeof(buf),"value:%lu",j);
val = createStringObject(buf,strlen(buf));
dbAdd(c->db,key,val);
decrRefCount(key);
}
addReply(c,shared.ok);
} else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
unsigned char digest[20];
sds d = sdsempty();
int j;
computeDatasetDigest(digest);
for (j = 0; j < 20; j++)
d = sdscatprintf(d, "%02x",digest[j]);
addReplyStatus(c,d);
sdsfree(d);
} else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
double dtime = strtod(c->argv[2]->ptr,NULL);
long long utime = dtime*1000000;
usleep(utime);
addReply(c,shared.ok);
} else {
addReplyError(c,
"Syntax error, try DEBUG [SEGFAULT|OBJECT <key>|SWAPIN <key>|SWAPOUT <key>|RELOAD]");
}
}
void _redisAssert(char *estr, char *file, int line) {
redisLog(REDIS_WARNING,"=== ASSERTION FAILED ===");
redisLog(REDIS_WARNING,"==> %s:%d '%s' is not true",file,line,estr);
#ifdef HAVE_BACKTRACE
redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
*((char*)-1) = 'x';
#endif
}
void _redisPanic(char *msg, char *file, int line) {
redisLog(REDIS_WARNING,"!!! Software Failure. Press left mouse button to continue");
redisLog(REDIS_WARNING,"Guru Meditation: %s #%s:%d",msg,file,line);
#ifdef HAVE_BACKTRACE
redisLog(REDIS_WARNING,"(forcing SIGSEGV in order to print the stack trace)");
*((char*)-1) = 'x';
#endif
}
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