Merge pull request #911 from MonsieurNicolas/scpVerbose

scp info endpoint improvements

Reviewed-by: jedmccaleb

docs/learn/commands.md

@@ -97,7 +97,8 @@ debugging purpose).
   The actual deletion is performed by invoking the `maintenance` endpoint.
 
 * **scp**
-  Returns a JSON object with the internal state of the SCP engine.
+  `/scp?[limit=n]
+  Returns a JSON object with the internal state of the SCP engine for the last n (default 2) ledgers.
 
 * **tx**
   `/tx?blob=Base64`<br>

src/herder/Herder.h

@@ -118,7 +118,7 @@ class Herder
     {
     }
 
-    virtual void dumpInfo(Json::Value& ret) = 0;
+    virtual void dumpInfo(Json::Value& ret, size_t limit) = 0;
     virtual void dumpQuorumInfo(Json::Value& ret, NodeID const& id,
                                 bool summary, uint64 index = 0) = 0;
 };

src/herder/HerderImpl.cpp

@@ -1473,11 +1473,11 @@ HerderImpl::acceptedCommit(uint64 slotIndex, SCPBallot const& ballot)
 }
 
 void
-HerderImpl::dumpInfo(Json::Value& ret)
+HerderImpl::dumpInfo(Json::Value& ret, size_t limit)
 {
     ret["you"] = mApp.getConfig().toStrKey(mSCP.getSecretKey().getPublicKey());
 
-    mSCP.dumpInfo(ret);
+    mSCP.dumpInfo(ret, limit);
 
     mPendingEnvelopes.dumpInfo(ret);
 }

src/herder/HerderImpl.h

@@ -122,7 +122,7 @@ class HerderImpl : public Herder, public SCPDriver
 
     bool resolveNodeID(std::string const& s, PublicKey& retKey) override;
 
-    void dumpInfo(Json::Value& ret) override;
+    void dumpInfo(Json::Value& ret, size_t limit) override;
     void dumpQuorumInfo(Json::Value& ret, NodeID const& id, bool summary,
                         uint64 index) override;
 

src/main/CommandHandler.cpp

@@ -281,8 +281,9 @@ CommandHandler::fileNotFound(std::string const& params, std::string& retStr)
         " default). NODE_ID is either a full key (`GABCD...`), an alias "
         "(`$name`) or an abbreviated ID(`@GABCD`)."
         "If compact is set, only returns a summary version."
-        "</p><p><h1> /scp</h1>"
-        "returns a JSON object with the internal state of the SCP engine"
+        "</p><p><h1> /scp?[limit=n]</h1>"
+        "returns a JSON object with the internal state of the SCP engine for "
+        "the last n (default 2) ledgers."
         "</p><p><h1> /tx?blob=HEX</h1>"
         "submit a transaction to the network.<br>"
         "blob is a hex encoded XDR serialized 'TransactionEnvelope'<br>"
@@ -632,7 +633,21 @@ CommandHandler::scpInfo(std::string const& params, std::string& retStr)
 {
     Json::Value root;
 
-    mApp.getHerder().dumpInfo(root);
+    std::map<std::string, std::string> retMap;
+    http::server::server::parseParams(params, retMap);
+
+    size_t lim = 2;
+    std::string limStr = retMap["limit"];
+    if (!limStr.empty())
+    {
+        size_t n = strtoul(limStr.c_str(), NULL, 0);
+        if (n != 0)
+        {
+            lim = n;
+        }
+    }
+
+    mApp.getHerder().dumpInfo(root, lim);
 
     retStr = root.toStyledString();
 }

src/scp/SCP.cpp

@@ -126,11 +126,13 @@ SCP::getSlot(uint64 slotIndex, bool create)
 }
 
 void
-SCP::dumpInfo(Json::Value& ret)
+SCP::dumpInfo(Json::Value& ret, size_t limit)
 {
-    for (auto& item : mKnownSlots)
+    auto it = mKnownSlots.rbegin();
+    while (it != mKnownSlots.rend() && limit-- != 0)
     {
-        item.second->dumpInfo(ret);
+        it->second->dumpInfo(ret);
+        it++;
     }
 }
 

src/scp/SCP.h

@@ -74,7 +74,7 @@ class SCP
     // returns the local node descriptor
     std::shared_ptr<LocalNode> getLocalNode();
 
-    void dumpInfo(Json::Value& ret);
+    void dumpInfo(Json::Value& ret, size_t limit);
 
     // summary: only return object counts
     // index = 0 for returning information for all slots

src/scp/Slot.cpp

@@ -265,12 +265,26 @@ Slot::dumpInfo(Json::Value& ret)
 
     Json::Value& slotValue = slots[std::to_string(mSlotIndex)];
 
+    std::map<Hash, SCPQuorumSetPtr> qSetsUsed;
+
     int count = 0;
     for (auto const& item : mStatementsHistory)
     {
         Json::Value& v = slotValue["statements"][count++];
         v.append(envToStr(item.first));
         v.append(item.second);
+
+        Hash const& qSetHash =
+            getCompanionQuorumSetHashFromStatement(item.first);
+        auto qSet = getSCPDriver().getQSet(qSetHash);
+        qSetsUsed.insert(std::make_pair(qSetHash, qSet));
+    }
+
+    auto& qSets = slotValue["quorum_sets"];
+    for (auto const& q : qSetsUsed)
+    {
+        auto& qs = qSets[hexAbbrev(q.first)];
+        getLocalNode()->toJson(*q.second, qs);
     }
 
     slotValue["validated"] = mFullyValidated;
@@ -326,7 +340,7 @@ Slot::envToStr(SCPStatement const& st) const
 {
     std::ostringstream oss;
 
-    Hash qSetHash = getCompanionQuorumSetHashFromStatement(st);
+    Hash const& qSetHash = getCompanionQuorumSetHashFromStatement(st);
 
     oss << "{ENV@" << getSCPDriver().toShortString(st.nodeID) << " | "
         << " i: " << st.slotIndex;