From ec4ec48fb8c5c2b8d29560be14c490beddd0a60f Mon Sep 17 00:00:00 2001
From: Mark Travis <mtravis@ripple.com>
Date: Sat, 27 Sep 2014 17:18:58 -0700
Subject: [PATCH] Add counters to track nodestore read and write activities.

---
 src/ripple/nodestore/Database.h         |  9 ++++
 src/ripple/nodestore/impl/DatabaseImp.h | 57 +++++++++++++++++++++++++
 src/ripple/rpc/handlers/GetCounts.cpp   |  6 +++
 3 files changed, 72 insertions(+)

diff --git a/src/ripple/nodestore/Database.h b/src/ripple/nodestore/Database.h
index 2b67dd31c..c10096b40 100644
--- a/src/ripple/nodestore/Database.h
+++ b/src/ripple/nodestore/Database.h
@@ -132,6 +132,15 @@ public:
 
     /** Remove expired entries from the positive and negative caches. */
     virtual void sweep () = 0;
+
+    /** Gather statistics pertaining to read and write activities.
+        Return the reads and writes, and total read and written bytes.
+     */
+    virtual std::uint32_t getStoreCount () const = 0;
+    virtual std::uint32_t getFetchTotalCount () const = 0;
+    virtual std::uint32_t getFetchHitCount () const = 0;
+    virtual std::uint32_t getStoreSize () const = 0;
+    virtual std::uint32_t getFetchSize () const = 0;
 };
 
 }
diff --git a/src/ripple/nodestore/impl/DatabaseImp.h b/src/ripple/nodestore/impl/DatabaseImp.h
index 6dc2c6114..1bf34df11 100644
--- a/src/ripple/nodestore/impl/DatabaseImp.h
+++ b/src/ripple/nodestore/impl/DatabaseImp.h
@@ -74,6 +74,11 @@ public:
             cacheTargetSize, cacheTargetSeconds)
         , m_readShut (false)
         , m_readGen (0)
+        , m_storeCount (0)
+        , m_fetchTotalCount (0)
+        , m_fetchHitCount (0)
+        , m_storeSize (0)
+        , m_fetchSize (0)
     {
         for (int i = 0; i < readThreads; ++i)
             m_readThreads.push_back (std::thread (&DatabaseImp::threadEntry, this));
@@ -222,7 +227,12 @@ public:
                 // If we have a fast back end, store it there for later.
                 //
                 if (m_fastBackend != nullptr)
+                {
                     m_fastBackend->store (obj);
+                    ++m_storeCount;
+                    if (obj.get())
+                        m_storeSize += obj->getData().size();
+                }
 
                 // Since this was a 'hard' fetch, we will log it.
                 //
@@ -240,10 +250,14 @@ public:
         NodeObject::Ptr object;
 
         Status const status = backend.fetch (hash.begin (), &object);
+        ++m_fetchTotalCount;
 
         switch (status)
         {
         case ok:
+            ++m_fetchHitCount;
+            if (object.get())
+                m_fetchSize += object->getData().size();
         case notFound:
             break;
 
@@ -279,11 +293,19 @@ public:
         m_cache.canonicalize (hash, object, true);
 
         m_backend->store (object);
+        ++m_storeCount;
+        if (object.get())
+            m_storeSize += object->getData().size();
 
         m_negCache.erase (hash);
 
         if (m_fastBackend)
+        {
             m_fastBackend->store (object);
+            ++m_storeCount;
+            if (object.get())
+                m_storeSize += object->getData().size();
+        }
     }
 
     //------------------------------------------------------------------------------
@@ -378,11 +400,46 @@ public:
             }
 
             b.push_back (object);
+            ++m_storeCount;
+            if (object.get())
+                m_storeSize += object->getData().size();
         });
 
         if (! b.empty ())
             m_backend->storeBatch (b);
     }
+
+    std::uint32_t getStoreCount () const override
+    {
+        return m_storeCount;
+    }
+
+    std::uint32_t getFetchTotalCount () const override
+    {
+        return m_fetchTotalCount;
+    }
+
+    std::uint32_t getFetchHitCount () const override
+    {
+        return m_fetchHitCount;
+    }
+
+    std::uint32_t getStoreSize () const override
+    {
+        return m_storeSize;
+    }
+
+    std::uint32_t getFetchSize () const override
+    {
+        return m_fetchSize;
+    }
+
+private:
+    std::atomic <std::uint32_t> m_storeCount;
+    std::atomic <std::uint32_t> m_fetchTotalCount;
+    std::atomic <std::uint32_t> m_fetchHitCount;
+    std::atomic <std::uint32_t> m_storeSize;
+    std::atomic <std::uint32_t> m_fetchSize;
 };
 
 }
diff --git a/src/ripple/rpc/handlers/GetCounts.cpp b/src/ripple/rpc/handlers/GetCounts.cpp
index f41e27864..0523efa54 100644
--- a/src/ripple/rpc/handlers/GetCounts.cpp
+++ b/src/ripple/rpc/handlers/GetCounts.cpp
@@ -85,6 +85,12 @@ Json::Value doGetCounts (RPC::Context& context)
     textTime (uptime, s, "minute", 60);
     textTime (uptime, s, "second", 1);
     ret["uptime"] = uptime;
+    
+    ret["node_writes"] = app.getNodeStore().getStoreCount();
+    ret["node_reads_total"] = app.getNodeStore().getFetchTotalCount();
+    ret["node_reads_hit"] = app.getNodeStore().getFetchHitCount();
+    ret["node_written_bytes"] = app.getNodeStore().getStoreSize();
+    ret["node_read_bytes"] = app.getNodeStore().getFetchSize();
 
     return ret;
 }