Refactor [SR]: Remove the MockDurabilityMonitor class

The mock class was exposing mostly const-methods. We can just expose
those to the DM public interface.
Also, a DM instance is owned by VBucket. Given that in all DM tests we
already have access to VBucket, then there is no much gain in hiding the
DM's services.

Change-Id: I806b18717b715c8d66092f7d0fa955ab165c5c0c
Reviewed-on: http://review.couchbase.org/107933
Tested-by: Build Bot <[email protected]>
Reviewed-by: Dave Rigby <[email protected]>

Author: paolococchi

engines/ep/src/durability/active_durability_monitor.h

@@ -110,11 +110,8 @@ class ActiveDurabilityMonitor : public DurabilityMonitor {
      */
     void addStats(const AddStatFn& addStat, const void* cookie) const override;
 
-protected:
     size_t getNumTracked() const override;
 
-    void toOStream(std::ostream& os) const override;
-
     /**
      * @return the size of FirstChain
      */
@@ -149,6 +146,16 @@ class ActiveDurabilityMonitor : public DurabilityMonitor {
      */
     int64_t getNodeAckSeqno(const std::string& node) const;
 
+    /**
+     * Test only.
+     *
+     * @return the set of seqnos tracked by this DurabilityMonitor
+     */
+    std::unordered_set<int64_t> getTrackedSeqnos() const;
+
+protected:
+    void toOStream(std::ostream& os) const override;
+
     /**
      * Commit the given SyncWrite.
      *
@@ -163,13 +170,6 @@ class ActiveDurabilityMonitor : public DurabilityMonitor {
      */
     void abort(const SyncWrite& sw);
 
-    /**
-     * Test only.
-     *
-     * @return the set of seqnos tracked by this DurabilityMonitor
-     */
-    std::unordered_set<int64_t> getTrackedSeqnos() const;
-
     /**
      * Test only (for now; shortly this will be probably needed at rollback).
      * Removes all SyncWrites from the tracked container. Replication chain
@@ -271,4 +271,7 @@ class ActiveDurabilityMonitor : public DurabilityMonitor {
     folly::Synchronized<State> state;
 
     const size_t maxReplicas = 3;
+
+    // @todo: Try to remove this, currenlty necessary for testing wipeTracked()
+    friend class ActiveDurabilityMonitorTest;
 };

engines/ep/src/durability/durability_monitor.h

@@ -38,18 +38,18 @@ class DurabilityMonitor {
     /// @return the high_prepared_seqno.
     virtual int64_t getHighPreparedSeqno() const = 0;
 
+    /**
+     * @return the number of pending SyncWrite(s) currently tracked
+     */
+    virtual size_t getNumTracked() const = 0;
+
 protected:
     class SyncWrite;
     struct ReplicationChain;
     struct Position;
 
     using Container = std::list<SyncWrite>;
 
-    /**
-     * @return the number of pending SyncWrite(s) currently tracked
-     */
-    virtual size_t getNumTracked() const = 0;
-
     virtual void toOStream(std::ostream& os) const = 0;
 
     friend std::ostream& operator<<(std::ostream& os,

engines/ep/src/vbucket.cc

@@ -577,11 +577,16 @@ void VBucket::setReplicationTopology(const nlohmann::json& topology) {
     }
 }
 
-ActiveDurabilityMonitor& VBucket::getActiveDM() const {
+ActiveDurabilityMonitor& VBucket::getActiveDM() {
     Expects(state == vbucket_state_active);
     return dynamic_cast<ActiveDurabilityMonitor&>(*durabilityMonitor);
 }
 
+PassiveDurabilityMonitor& VBucket::getPassiveDM() {
+    Expects(state == vbucket_state_replica);
+    return dynamic_cast<PassiveDurabilityMonitor&>(*durabilityMonitor);
+}
+
 std::unique_ptr<DurabilityMonitor> VBucket::makeDurabilityMonitor() {
     if (state == vbucket_state_active) {
         return std::make_unique<ActiveDurabilityMonitor>(*this);

engines/ep/src/vbucket.h

@@ -38,15 +38,16 @@
 #include <queue>
 
 class ActiveDurabilityMonitor;
-class EPStats;
 class CheckpointManager;
 class ConflictResolution;
 class Configuration;
+class DCPBackfill;
 class DurabilityMonitor;
+class EPStats;
+class EventuallyPersistentEngine;
 class ItemMetaData;
+class PassiveDurabilityMonitor;
 class PreLinkDocumentContext;
-class EventuallyPersistentEngine;
-class DCPBackfill;
 class RollbackResult;
 class VBucketBGFetchItem;
 struct vbucket_state;
@@ -1844,7 +1845,12 @@ class VBucket : public std::enable_shared_from_this<VBucket> {
     /**
      * @return a reference (if valid, i.e. vbstate=active) to the Active DM
      */
-    ActiveDurabilityMonitor& getActiveDM() const;
+    ActiveDurabilityMonitor& getActiveDM();
+
+    /**
+     * @return a reference (if valid, i.e. vbstate=replica) to the Passive DM
+     */
+    PassiveDurabilityMonitor& getPassiveDM();
 
     /**
      * @return a new instance of DurabilityMonitor, Active or Passive depending
@@ -2185,11 +2191,10 @@ class VBucket : public std::enable_shared_from_this<VBucket> {
 
     static double mutationMemThreshold;
 
-    friend class ActiveDurabilityMonitorTest;
     friend class DurabilityMonitorTest;
-    friend class PassiveDurabilityMonitorTest;
     friend class SingleThreadedActiveStreamTest;
     friend class VBucketTestBase;
+    friend class VBucketTestIntrospector;
     friend class VBucketDurabilityTest;
 
     DISALLOW_COPY_AND_ASSIGN(VBucket);