DEBUG DIGEST refactoring: extract function to digest a value.

1 files changed, 142 insertions, 131 deletions

diff --git a/src/debug.c b/src/debug.c
index 3cb567520..3c2e7fd55 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -74,7 +74,7 @@ void xorDigest(unsigned char *digest, void *ptr, size_t len) {
         digest[j] ^= hash[j];
 }
 
-void xorObjectDigest(unsigned char *digest, robj *o) {
+void xorStringObjectDigest(unsigned char *digest, robj *o) {
     o = getDecodedObject(o);
     xorDigest(digest,o->ptr,sdslen(o->ptr));
     decrRefCount(o);
@@ -104,12 +104,151 @@ void mixDigest(unsigned char *digest, void *ptr, size_t len) {
     SHA1Final(digest,&ctx);
 }
 
-void mixObjectDigest(unsigned char *digest, robj *o) {
+void mixStringObjectDigest(unsigned char *digest, robj *o) {
     o = getDecodedObject(o);
     mixDigest(digest,o->ptr,sdslen(o->ptr));
     decrRefCount(o);
 }
 
+/* This function computes the digest of a data structure stored in the
+ * object 'o'. It is the core of the DEBUG DIGEST command: when taking the
+ * digest of a whole dataset, we take the digest of the key and the value
+ * pair, and xor all those together.
+ *
+ * Note that this function does not reset the initial 'digest' passed, it
+ * will continue mixing this object digest to anything that was already
+ * present. */
+void xorObjectDigest(redisDb *db, robj *keyobj, unsigned char *digest, robj *o) {
+    uint32_t aux = htonl(o->type);
+    mixDigest(digest,&aux,sizeof(aux));
+    long long expiretime = getExpire(db,keyobj);
+    char buf[128];
+
+    /* Save the key and associated value */
+    if (o->type == OBJ_STRING) {
+        mixStringObjectDigest(digest,o);
+    } else if (o->type == OBJ_LIST) {
+        listTypeIterator *li = listTypeInitIterator(o,0,LIST_TAIL);
+        listTypeEntry entry;
+        while(listTypeNext(li,&entry)) {
+            robj *eleobj = listTypeGet(&entry);
+            mixStringObjectDigest(digest,eleobj);
+            decrRefCount(eleobj);
+        }
+        listTypeReleaseIterator(li);
+    } else if (o->type == OBJ_SET) {
+        setTypeIterator *si = setTypeInitIterator(o);
+        sds sdsele;
+        while((sdsele = setTypeNextObject(si)) != NULL) {
+            xorDigest(digest,sdsele,sdslen(sdsele));
+            sdsfree(sdsele);
+        }
+        setTypeReleaseIterator(si);
+    } else if (o->type == OBJ_ZSET) {
+        unsigned char eledigest[20];
+
+        if (o->encoding == OBJ_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);
+            serverAssert(eptr != NULL);
+            sptr = ziplistNext(zl,eptr);
+            serverAssert(sptr != NULL);
+
+            while (eptr != NULL) {
+                serverAssert(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 == OBJ_ENCODING_SKIPLIST) {
+            zset *zs = o->ptr;
+            dictIterator *di = dictGetIterator(zs->dict);
+            dictEntry *de;
+
+            while((de = dictNext(di)) != NULL) {
+                sds sdsele = dictGetKey(de);
+                double *score = dictGetVal(de);
+
+                snprintf(buf,sizeof(buf),"%.17g",*score);
+                memset(eledigest,0,20);
+                mixDigest(eledigest,sdsele,sdslen(sdsele));
+                mixDigest(eledigest,buf,strlen(buf));
+                xorDigest(digest,eledigest,20);
+            }
+            dictReleaseIterator(di);
+        } else {
+            serverPanic("Unknown sorted set encoding");
+        }
+    } else if (o->type == OBJ_HASH) {
+        hashTypeIterator *hi = hashTypeInitIterator(o);
+        while (hashTypeNext(hi) != C_ERR) {
+            unsigned char eledigest[20];
+            sds sdsele;
+
+            memset(eledigest,0,20);
+            sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_KEY);
+            mixDigest(eledigest,sdsele,sdslen(sdsele));
+            sdsfree(sdsele);
+            sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_VALUE);
+            mixDigest(eledigest,sdsele,sdslen(sdsele));
+            sdsfree(sdsele);
+            xorDigest(digest,eledigest,20);
+        }
+        hashTypeReleaseIterator(hi);
+    } else if (o->type == OBJ_STREAM) {
+        streamIterator si;
+        streamIteratorStart(&si,o->ptr,NULL,NULL,0);
+        streamID id;
+        int64_t numfields;
+
+        while(streamIteratorGetID(&si,&id,&numfields)) {
+            sds itemid = sdscatfmt(sdsempty(),"%U.%U",id.ms,id.seq);
+            mixDigest(digest,itemid,sdslen(itemid));
+            sdsfree(itemid);
+
+            while(numfields--) {
+                unsigned char *field, *value;
+                int64_t field_len, value_len;
+                streamIteratorGetField(&si,&field,&value,
+                                           &field_len,&value_len);
+                mixDigest(digest,field,field_len);
+                mixDigest(digest,value,value_len);
+            }
+        }
+        streamIteratorStop(&si);
+    } else if (o->type == OBJ_MODULE) {
+        RedisModuleDigest md;
+        moduleValue *mv = o->ptr;
+        moduleType *mt = mv->type;
+        moduleInitDigestContext(md);
+        if (mt->digest) {
+            mt->digest(&md,mv->value);
+            xorDigest(digest,md.x,sizeof(md.x));
+        }
+    } else {
+        serverPanic("Unknown object type");
+    }
+    /* If the key has an expire, add it to the mix */
+    if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
+}
+
 /* 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
@@ -118,7 +257,6 @@ void mixObjectDigest(unsigned char *digest, robj *o) {
  * a different digest. */
 void computeDatasetDigest(unsigned char *final) {
     unsigned char digest[20];
-    char buf[128];
     dictIterator *di = NULL;
     dictEntry *de;
     int j;
@@ -141,7 +279,6 @@ void computeDatasetDigest(unsigned char *final) {
         while((de = dictNext(di)) != NULL) {
             sds key;
             robj *keyobj, *o;
-            long long expiretime;
 
             memset(digest,0,20); /* This key-val digest */
             key = dictGetKey(de);
@@ -150,134 +287,8 @@ void computeDatasetDigest(unsigned char *final) {
             mixDigest(digest,key,sdslen(key));
 
             o = dictGetVal(de);
+            xorObjectDigest(db,keyobj,digest,o);
 
-            aux = htonl(o->type);
-            mixDigest(digest,&aux,sizeof(aux));
-            expiretime = getExpire(db,keyobj);
-
-            /* Save the key and associated value */
-            if (o->type == OBJ_STRING) {
-                mixObjectDigest(digest,o);
-            } else if (o->type == OBJ_LIST) {
-                listTypeIterator *li = listTypeInitIterator(o,0,LIST_TAIL);
-                listTypeEntry entry;
-                while(listTypeNext(li,&entry)) {
-                    robj *eleobj = listTypeGet(&entry);
-                    mixObjectDigest(digest,eleobj);
-                    decrRefCount(eleobj);
-                }
-                listTypeReleaseIterator(li);
-            } else if (o->type == OBJ_SET) {
-                setTypeIterator *si = setTypeInitIterator(o);
-                sds sdsele;
-                while((sdsele = setTypeNextObject(si)) != NULL) {
-                    xorDigest(digest,sdsele,sdslen(sdsele));
-                    sdsfree(sdsele);
-                }
-                setTypeReleaseIterator(si);
-            } else if (o->type == OBJ_ZSET) {
-                unsigned char eledigest[20];
-
-                if (o->encoding == OBJ_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);
-                    serverAssert(eptr != NULL);
-                    sptr = ziplistNext(zl,eptr);
-                    serverAssert(sptr != NULL);
-
-                    while (eptr != NULL) {
-                        serverAssert(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 == OBJ_ENCODING_SKIPLIST) {
-                    zset *zs = o->ptr;
-                    dictIterator *di = dictGetIterator(zs->dict);
-                    dictEntry *de;
-
-                    while((de = dictNext(di)) != NULL) {
-                        sds sdsele = dictGetKey(de);
-                        double *score = dictGetVal(de);
-
-                        snprintf(buf,sizeof(buf),"%.17g",*score);
-                        memset(eledigest,0,20);
-                        mixDigest(eledigest,sdsele,sdslen(sdsele));
-                        mixDigest(eledigest,buf,strlen(buf));
-                        xorDigest(digest,eledigest,20);
-                    }
-                    dictReleaseIterator(di);
-                } else {
-                    serverPanic("Unknown sorted set encoding");
-                }
-            } else if (o->type == OBJ_HASH) {
-                hashTypeIterator *hi = hashTypeInitIterator(o);
-                while (hashTypeNext(hi) != C_ERR) {
-                    unsigned char eledigest[20];
-                    sds sdsele;
-
-                    memset(eledigest,0,20);
-                    sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_KEY);
-                    mixDigest(eledigest,sdsele,sdslen(sdsele));
-                    sdsfree(sdsele);
-                    sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_VALUE);
-                    mixDigest(eledigest,sdsele,sdslen(sdsele));
-                    sdsfree(sdsele);
-                    xorDigest(digest,eledigest,20);
-                }
-                hashTypeReleaseIterator(hi);
-            } else if (o->type == OBJ_STREAM) {
-                streamIterator si;
-                streamIteratorStart(&si,o->ptr,NULL,NULL,0);
-                streamID id;
-                int64_t numfields;
-
-                while(streamIteratorGetID(&si,&id,&numfields)) {
-                    sds itemid = sdscatfmt(sdsempty(),"%U.%U",id.ms,id.seq);
-                    mixDigest(digest,itemid,sdslen(itemid));
-                    sdsfree(itemid);
-
-                    while(numfields--) {
-                        unsigned char *field, *value;
-                        int64_t field_len, value_len;
-                        streamIteratorGetField(&si,&field,&value,
-                                                   &field_len,&value_len);
-                        mixDigest(digest,field,field_len);
-                        mixDigest(digest,value,value_len);
-                    }
-                }
-                streamIteratorStop(&si);
-            } else if (o->type == OBJ_MODULE) {
-                RedisModuleDigest md;
-                moduleValue *mv = o->ptr;
-                moduleType *mt = mv->type;
-                moduleInitDigestContext(md);
-                if (mt->digest) {
-                    mt->digest(&md,mv->value);
-                    xorDigest(digest,md.x,sizeof(md.x));
-                }
-            } else {
-                serverPanic("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);