Add additional tests

Former-commit-id: e7d2c78e776b8262fd54caeb7b6bd210182e9bdb

src/db.cpp

@@ -556,6 +556,16 @@ int getFlushCommandFlags(client *c, int *flags) {
 void flushdbCommand(client *c) {
     int flags;
 
+    if (c->argc == 2)
+    {
+        if (!strcasecmp(szFromObj(c->argv[1]), "cache"))
+        {
+            c->db->removeAllCachedValues();
+            addReply(c,shared.ok);
+            return;
+        }
+    }
+
     if (getFlushCommandFlags(c,&flags) == C_ERR) return;
     signalFlushedDb(c->db->id);
     g_pserver->dirty += emptyDb(c->db->id,flags,NULL);
@@ -568,6 +578,17 @@ void flushdbCommand(client *c) {
 void flushallCommand(client *c) {
     int flags;
 
+    if (c->argc == 2)
+    {
+        if (!strcasecmp(szFromObj(c->argv[1]), "cache"))
+        {
+            for (int idb = 0; idb < cserver.dbnum; ++idb)
+                g_pserver->db[idb]->removeAllCachedValues();
+            addReply(c,shared.ok);
+            return;
+        }
+    }
+
     if (getFlushCommandFlags(c,&flags) == C_ERR) return;
     signalFlushedDb(-1);
     g_pserver->dirty += emptyDb(-1,flags,NULL);
@@ -2220,3 +2241,16 @@ void redisDbPersistentData::trackChanges()
 {
     m_fTrackingChanges++;
 }
+
+void redisDbPersistentData::removeAllCachedValues()
+{
+    // First we have to flush the tracked changes
+    if (m_fTrackingChanges)
+    {
+        auto vec = processChanges();
+        commitChanges(vec);
+        trackChanges();
+    }
+
+    dictEmpty(m_pdict, nullptr);
+}

src/server.h

@@ -1342,6 +1342,7 @@ public:
 
     bool FStorageProvider() { return m_spstorage != nullptr; }
     bool removeCachedValue(const char *key);
+    void removeAllCachedValues();
 
 private:
     void ensure(const char *key);
@@ -1468,6 +1469,7 @@ typedef struct redisDb : public redisDbPersistentDataSnapshot
     using redisDbPersistentData::createSnapshot;
     using redisDbPersistentData::endSnapshot;
     using redisDbPersistentData::consolidate_snapshot;
+    using redisDbPersistentData::removeAllCachedValues;
 
 public:
     expireset::setiter expireitr;

tests/unit/flash.tcl

@@ -1,15 +1,31 @@
 start_server {tags {"flash"} overrides {"storage-provider flash ./rocks.db"}} {
 
+    test { FLASH - GET works after eviction } {
+        r set testkey foo
+        r flushall cache
+        assert_equal {foo} [r get testkey]
+    }
+
+    test { DEL of nonexistant key returns 0 } {
+        assert_equal {0} [r del foobar]
+    }
+
+   test { SET of existing but flushed key works } {
+        r set testkey foo
+        r flushall cache
+        r set testkey bar
+        assert_equal {bar} [r get testkey]
+    } 
+
+    r flushall
     foreach policy {
         allkeys-random allkeys-lru allkeys-lfu
     } {
         test "FLASH - is eviction working without data loss (successfully stored to flash)? (policy $policy)" {
-            # make sure to start with a blank instance
-            r flushall
             # Get the current memory limit and calculate a new limit.
             # Set limit to 100M.
             set used [s used_memory]
-            set limit [expr {$used+100000*1024}]
+            set limit [expr {$used+50000*1024}]
             r config set maxmemory $limit
             r config set maxmemory-policy $policy
             # Now add keys equivalent to 1024b until the limit is almost reached.
@@ -38,7 +54,9 @@ start_server {tags {"flash"} overrides {"storage-provider flash ./rocks.db"}} {
             assert {$dbsize == $numkeys+10002}
             assert {[r get first] == {val}}
             assert {[r get last] == {val}}
+            r flushall
         }
     }
+
 }