[SR]: Expand printed details in PassiveDM::operator<<

Include details of the trackedWrites and high prepared/completed
seqnos in debug output of PassiveDM.

Change-Id: Icf9ed52ef5ac911b78b38d9db65c4326452f6bcb
Reviewed-on: http://review.couchbase.org/112698
Tested-by: Build Bot <[email protected]>
Reviewed-by: Ben Huddleston <[email protected]>

Author: daverigby

engines/ep/src/durability/active_durability_monitor.cc

@@ -1134,6 +1134,7 @@ void ActiveDurabilityMonitor::toOStream(std::ostream& os) const {
     } else {
         os << "<null>";
     }
+    os << "\n";
 }
 
 void ActiveDurabilityMonitor::chainToOstream(
@@ -1144,15 +1145,8 @@ void ActiveDurabilityMonitor::chainToOstream(
        << " majority:" << int(rc.majority) << " active:" << rc.active
        << " maxAllowedReplicas:" << rc.maxAllowedReplicas << " positions:[\n";
     for (const auto& pos : rc.positions) {
-        os << "    " << pos.first << ": {lastAck:" << pos.second.lastAckSeqno
-           << " lastWrite:" << pos.second.lastWriteSeqno << " it: @"
-           << &*pos.second.it;
-        if (pos.second.it == trackedWritesEnd) {
-            os << " <end>";
-        } else {
-            os << " seqno:" << pos.second.it->getBySeqno();
-        }
-        os << "\n";
+        os << "    " << pos.first << ": "
+           << to_string(pos.second, trackedWritesEnd) << "\n";
     }
     os << "]";
 }

engines/ep/src/durability/durability_monitor.h

@@ -88,6 +88,16 @@ class DurabilityMonitor {
                                     const DurabilityMonitor& dm);
 
     friend std::ostream& operator<<(std::ostream&, const SyncWrite&);
+
+    /** Return a string representation of the given Position.
+     *
+     * @param pos
+     * @param trackedWritesEnd Iterator pointing at the end() of the
+     *        trackedWrites container this Position references. Used to check
+     *        if Position is at end and print appropiate info.
+     */
+    friend std::string to_string(const DurabilityMonitor::Position& pos,
+                                 Container::const_iterator trackedWritesEnd);
 };
 
 std::string to_string(DurabilityMonitor::ReplicationChainName name);

engines/ep/src/durability/durability_monitor_impl.cc

@@ -298,11 +298,14 @@ DurabilityMonitor::ReplicationChain::ReplicationChain(
             continue;
         }
         // This check ensures that there is no duplicate in the given chain
-        if (!positions.emplace(node, Position(it)).second) {
+        auto result = positions.emplace(node, Position(it));
+        if (!result.second) {
             throw std::invalid_argument(
                     "ReplicationChain::ReplicationChain: Duplicate node: " +
                     node);
         }
+        result.first->second.lastAckSeqno.setLabel(node + "::lastAckSeqno");
+        result.first->second.lastWriteSeqno.setLabel(node + "::lastWriteSeqno");
     }
 }
 
@@ -352,3 +355,20 @@ std::string to_string(const SnapshotEndInfo& snapshotEndInfo) {
     return std::to_string(snapshotEndInfo.seqno) + "{" +
            to_string(snapshotEndInfo.type) + "}";
 }
+
+std::string to_string(
+        const DurabilityMonitor::Position& pos,
+        std::list<DurabilityMonitor::SyncWrite,
+                  std::allocator<DurabilityMonitor::SyncWrite>>::const_iterator
+                trackedWritesEnd) {
+    std::stringstream ss;
+    ss << "{lastAck:" << pos.lastAckSeqno << " lastWrite:" << pos.lastWriteSeqno
+       << " it: @" << &*pos.it;
+    if (pos.it == trackedWritesEnd) {
+        ss << " <end>";
+    } else {
+        ss << " seqno:" << pos.it->getBySeqno();
+    }
+    ss << "}";
+    return ss.str();
+}

engines/ep/src/durability/durability_monitor_impl.h

@@ -361,8 +361,7 @@ struct PassiveDurabilityMonitor::State {
     /**
      * @param pdm The owning PassiveDurabilityMonitor
      */
-    State(const PassiveDurabilityMonitor& pdm) : pdm(pdm) {
-    }
+    State(const PassiveDurabilityMonitor& pdm);
 
     /**
      * Returns the next position for a given Container::iterator.

engines/ep/src/durability/passive_durability_monitor.cc

@@ -36,8 +36,8 @@ PassiveDurabilityMonitor::PassiveDurabilityMonitor(VBucket& vb)
     : vb(vb), state(std::make_unique<State>(*this)) {
     // By design, instances of Container::Position can never be invalid
     auto s = state.wlock();
-    s->highPreparedSeqno = Position(s->trackedWrites.end());
-    s->highCompletedSeqno = Position(s->trackedWrites.end());
+    s->highPreparedSeqno.it = s->trackedWrites.end();
+    s->highCompletedSeqno.it = s->trackedWrites.end();
 }
 
 PassiveDurabilityMonitor::PassiveDurabilityMonitor(VBucket& vb,
@@ -419,14 +419,21 @@ int64_t PassiveDurabilityMonitor::getHighestTrackedSeqno() const {
 }
 
 void PassiveDurabilityMonitor::toOStream(std::ostream& os) const {
-    os << "PassiveDurabilityMonitor[" << this << "]"
-       << " high_prepared_seqno:" << getHighPreparedSeqno()
-       << " trackedWrites:\n";
-    state.withRLock([&os](auto& s) {
-        for (const auto& w : s.trackedWrites) {
-            os << "    " << w << "\n";
-        }
-    });
+    os << "PassiveDurabilityMonitor[" << this << "] " << *state.rlock();
+}
+
+PassiveDurabilityMonitor::State::State(const PassiveDurabilityMonitor& pdm)
+    : pdm(pdm) {
+    const auto prefix =
+            "PassiveDM(" + pdm.vb.getId().to_string() + ")::State::";
+
+    const auto hpsPrefix = prefix + "highPreparedSeqno";
+    highPreparedSeqno.lastWriteSeqno.setLabel(hpsPrefix + ".lastWriteSeqno");
+    highPreparedSeqno.lastAckSeqno.setLabel(hpsPrefix + ".lastAckSeqno");
+
+    const auto hcsPrefix = prefix + "highCompletedSeqno";
+    highCompletedSeqno.lastWriteSeqno.setLabel(hcsPrefix + ".lastWriteSeqno");
+    highCompletedSeqno.lastAckSeqno.setLabel(hcsPrefix + ".lastAckSeqno");
 }
 
 DurabilityMonitor::Container::iterator
@@ -616,3 +623,17 @@ template <class exception>
     throw exception("PassiveDurabilityMonitor::" + thrower + " " +
                     vb.getId().to_string() + " " + error);
 }
+
+std::ostream& operator<<(std::ostream& os,
+                         const PassiveDurabilityMonitor::State& state) {
+    os << "State[" << &state << "] highPreparedSeqno:"
+       << to_string(state.highPreparedSeqno, state.trackedWrites.end())
+       << " highCompletedSeqno:"
+       << to_string(state.highCompletedSeqno, state.trackedWrites.end())
+       << "\ntrackedWrites:[\n";
+    for (const auto& w : state.trackedWrites) {
+        os << "    " << w << "\n";
+    }
+    os << "]\n";
+    return os;
+}

engines/ep/src/durability/passive_durability_monitor.h

@@ -183,4 +183,7 @@ class PassiveDurabilityMonitor : public DurabilityMonitor {
 
     // Necessary for implementing ADM(PDM&&)
     friend class ActiveDurabilityMonitor;
+
+    friend std::ostream& operator<<(
+            std::ostream& os, const PassiveDurabilityMonitor::State& state);
 };