Add support for storing expirations in FLASH

Former-commit-id: 1dca07bd564042fce1b01d275641f35b918ae557

src/db.cpp

@@ -42,6 +42,9 @@
 int keyIsExpired(redisDb *db, robj *key);
 int expireIfNeeded(redisDb *db, robj *key, robj *o);
 
+std::unique_ptr<expireEntry> deserializeExpire(sds key, const char *str, size_t cch, size_t *poffset);
+sds serializeStoredObjectAndExpire(redisDbPersistentData *db, const char *key, robj_roptr o);
+
 /* Update LFU when an object is accessed.
  * Firstly, decrement the counter if the decrement time is reached.
  * Then logarithmically increment the counter, and update the access time. */
@@ -565,6 +568,11 @@ void flushdbCommand(client *c) {
     {
         if (!strcasecmp(szFromObj(c->argv[1]), "cache"))
         {
+            if (g_pserver->m_pstorageFactory == nullptr)
+            {
+                addReplyError(c, "Cannot flush cache without a storage provider set");
+                return;
+            }
             c->db->removeAllCachedValues();
             addReply(c,shared.ok);
             return;
@@ -587,6 +595,11 @@ void flushallCommand(client *c) {
     {
         if (!strcasecmp(szFromObj(c->argv[1]), "cache"))
         {
+            if (g_pserver->m_pstorageFactory == nullptr)
+            {
+                addReplyError(c, "Cannot flush cache without a storage provider set");
+                return;
+            }
             for (int idb = 0; idb < cserver.dbnum; ++idb)
                 g_pserver->db[idb]->removeAllCachedValues();
             addReply(c,shared.ok);
@@ -2100,9 +2113,24 @@ void redisDbPersistentData::ensure(const char *sdsKey, dictEntry **pde)
         if (dictSize(m_pdict) != size())    // if all keys are cached then no point in looking up the database
         {
             m_spstorage->retrieve(sdsKey, sdslen(sdsKey), [&](const char *, size_t, const void *data, size_t cb){
-                robj *o = deserializeStoredObject(this, sdsKey, data, cb);
+                size_t offset = 0;
+                sds sdsNewKey = sdsdupshared(sdsKey);
+                auto spexpire = deserializeExpire((sds)sdsNewKey, (const char*)data, cb, &offset);
+                robj *o = deserializeStoredObject(this, sdsKey, reinterpret_cast<const char*>(data) + offset, cb - offset);
                 serverAssert(o != nullptr);
-                dictAdd(m_pdict, sdsdupshared(sdsKey), o);
+                dictAdd(m_pdict, sdsNewKey, o);
+
+                o->SetFExpires(spexpire != nullptr);
+
+                if (spexpire != nullptr)
+                {
+                    auto itr = m_setexpire->find(sdsKey);
+                    if (itr != m_setexpire->end())
+                        m_setexpire->erase(itr);
+                    m_setexpire->insert(std::move(*spexpire));
+                    serverAssert(m_setexpire->find(sdsKey) != m_setexpire->end());
+                }
+                serverAssert(o->FExpires() == (m_setexpire->find(sdsKey) != m_setexpire->end()));
             });
             *pde = dictFind(m_pdict, sdsKey);
         }
@@ -2117,7 +2145,7 @@ void redisDbPersistentData::ensure(const char *sdsKey, dictEntry **pde)
 
 void redisDbPersistentData::storeKey(const char *szKey, size_t cchKey, robj *o, bool fOverwrite)
 {
-    sds temp = serializeStoredObject(o);
+    sds temp = serializeStoredObjectAndExpire(this, szKey, o);
     m_spstorage->insert(szKey, cchKey, temp, sdslen(temp), fOverwrite);
     sdsfree(temp);
 }
@@ -2162,7 +2190,7 @@ redisDbPersistentData::changelist redisDbPersistentData::processChanges()
                     if (de == nullptr)
                         continue;
                     robj *o = (robj*)dictGetVal(de);
-                    sds temp = serializeStoredObject(o);
+                    sds temp = serializeStoredObjectAndExpire(this, (const char*) dictGetKey(de), o);
                     vecRet.emplace_back(std::move(change), unique_sds_ptr(temp));
                 }
             }
@@ -2274,3 +2302,85 @@ void redisDbPersistentData::trackkey(const char *key, bool fUpdate)
         }
     }
 }
+
+sds serializeExpire(const expireEntry *pexpire)
+{
+    sds str = sdsnewlen(nullptr, sizeof(unsigned));
+
+    if (pexpire == nullptr)
+    {
+        unsigned zero = 0;
+        memcpy(str, &zero, sizeof(unsigned));
+        return str;
+    }
+
+    auto &e = *pexpire;
+    unsigned celem = (unsigned)e.size();
+    memcpy(str, &celem, sizeof(unsigned));
+    
+    for (auto itr = e.begin(); itr != e.end(); ++itr)
+    {
+        unsigned subkeylen = itr.subkey() ? (unsigned)sdslen(itr.subkey()) : 0;
+        size_t strOffset = sdslen(str);
+        str = sdsgrowzero(str, sdslen(str) + sizeof(unsigned) + subkeylen + sizeof(long long));
+        memcpy(str + strOffset, &subkeylen, sizeof(unsigned));
+        if (itr.subkey())
+            memcpy(str + strOffset + sizeof(unsigned), itr.subkey(), subkeylen);
+        long long when = itr.when();
+        memcpy(str + strOffset + sizeof(unsigned) + subkeylen, &when, sizeof(when));
+    }
+    return str;
+}
+
+std::unique_ptr<expireEntry> deserializeExpire(sds key, const char *str, size_t cch, size_t *poffset)
+{
+    unsigned celem;
+    if (cch < sizeof(unsigned))
+        throw "Corrupt expire entry";
+    memcpy(&celem, str, sizeof(unsigned));
+    std::unique_ptr<expireEntry> spexpire;
+
+    size_t offset = sizeof(unsigned);
+    for (; celem > 0; --celem)
+    {
+        serverAssert(cch > (offset+sizeof(unsigned)));
+        
+        unsigned subkeylen;
+        memcpy(&subkeylen, str + offset, sizeof(unsigned));
+        offset += sizeof(unsigned);
+
+        sds subkey = nullptr;
+        if (subkeylen != 0)
+        {
+            serverAssert(cch > (offset + subkeylen));
+            subkey = sdsnewlen(nullptr, subkeylen);
+            memcpy(subkey, str + offset, subkeylen);
+            offset += subkeylen;
+        }
+        
+        long long when;
+        serverAssert(cch >= (offset + sizeof(long long)));
+        memcpy(&when, str + offset, sizeof(long long));
+        offset += sizeof(long long);
+
+        if (spexpire == nullptr)
+            spexpire = std::make_unique<expireEntry>(key, subkey, when);
+        else
+            spexpire->update(subkey, when);
+    }
+
+    *poffset = offset;
+    return spexpire;
+}
+
+sds serializeStoredObjectAndExpire(redisDbPersistentData *db, const char *key, robj_roptr o)
+{
+    auto itrExpire = db->setexpire()->find(key);
+    const expireEntry *pexpire = nullptr;
+    if (itrExpire != db->setexpire()->end())
+        pexpire = &(*itrExpire);
+
+    sds str = serializeExpire(pexpire);
+    str = serializeStoredObject(o, str);
+    return str;
+}

src/object.cpp

@@ -1619,20 +1619,30 @@ robj *deserializeStoredObject(const redisDbPersistentData *db, const char *key,
     return o;
 }
 
-sds serializeStoredObject(robj_roptr o)
+sds serializeStoredObject(robj_roptr o, sds sdsPrefix)
 {
     switch (o->type)
     {
         case OBJ_STRING:
         {
-            sds sdsT = sdsnewlen(nullptr, 1);
+            sds sdsT = nullptr;
-            sdsT[0] = RDB_TYPE_STRING;
+            if (sdsPrefix)
+                sdsT = sdsgrowzero(sdsPrefix, sdslen(sdsPrefix)+1);
+            else
+                sdsT = sdsnewlen(nullptr, 1);
+            sdsT[sdslen(sdsT)-1] = RDB_TYPE_STRING;
             return serializeStoredStringObject(sdsT, o);
         }
             
         default:
             rio rdb;
             createDumpPayload(&rdb,o,nullptr);
+            if (sdsPrefix)
+            {
+                sds rval = sdscatsds(sdsPrefix, (sds)rdb.io.buffer.ptr);
+                sdsfree((sds)rdb.io.buffer.ptr);
+                return rval;
+            }
             return (sds)rdb.io.buffer.ptr;
     }
     serverPanic("Attempting to store unknown object type");

src/sds.c

@@ -234,6 +234,9 @@ void sdsclear(sds s) {
  * Note: this does not change the *length* of the sds string as returned
  * by sdslen(), but only the free buffer space we have. */
 sds sdsMakeRoomFor(sds s, size_t addlen) {
+    if (s == NULL)
+        return sdsnewlen(NULL, addlen);
+    
     void *sh, *newsh;
     size_t avail = sdsavail(s);
     size_t len, newlen;

src/server.h

@@ -1163,6 +1163,13 @@ public:
             pfatentry()->m_vecexpireEntries.begin() + itr.m_idx);
     }
 
+    size_t size() const
+    {
+        if (FFat())
+            return u.m_pfatentry->size();
+        return 1;
+    }
+
     bool FGetPrimaryExpire(long long *pwhen) const
     {
         *pwhen = -1;
@@ -2633,7 +2640,8 @@ unsigned long long estimateObjectIdleTime(robj_roptr o);
 void trimStringObjectIfNeeded(robj *o);
 
 robj *deserializeStoredObject(const redisDbPersistentData *db, const char *key, const void *data, size_t cb);
-sds serializeStoredObject(robj_roptr o);
+std::unique_ptr<expireEntry> deserializeExpire(sds key, const char *str, size_t cch, size_t *poffset);
+sds serializeStoredObject(robj_roptr o, sds sdsPrefix = nullptr);
 
 #define sdsEncodedObject(objptr) (objptr->encoding == OBJ_ENCODING_RAW || objptr->encoding == OBJ_ENCODING_EMBSTR)
 

src/snapshot.cpp

@@ -283,7 +283,13 @@ bool redisDbPersistentDataSnapshot::iterate_threadsafe(std::function<bool(const
             bool fContinue = true;
             if (de == nullptr)
             {
-                robj *o = fKeyOnly ? nullptr : deserializeStoredObject(this, sdsKey, data, cbData);
+                robj *o = nullptr;
+                if (!fKeyOnly)
+                {
+                    size_t offset = 0;
+                    deserializeExpire(sdsKey, (const char*)data, cbData, &offset);
+                    o = deserializeStoredObject(this, sdsKey, reinterpret_cast<const char*>(data)+offset, cbData-offset);
+                }
                 fContinue = fn(sdsKey, o);
                 if (o != nullptr)
                     decrRefCount(o);