From 3568b12529e6da52edffe99a818b6d3940d98e11 Mon Sep 17 00:00:00 2001
From: Megh Bhatt <meghb@juniper.net>
Date: Thu, 17 Sep 2015 10:20:54 -0700
Subject: [PATCH] Remove GetDiffStats() and instead iterate through the current
 map to send the accumulated counter and then clear it so that only new keys
 are sent in the statistics. Closes-Bug: #1494473

Change-Id: Ice58e1761a4200f8ad7b82bce81aba929a744950
---
 src/analytics/collector.cc             |  4 +-
 src/analytics/db_handler.cc            |  2 +-
 src/analytics/diffstats.h              | 38 ----------------
 src/analytics/generator.cc             |  6 +--
 src/analytics/generator.h              |  4 +-
 src/analytics/protobuf_server.cc       | 56 +++++++++--------------
 src/analytics/test/viz_message_test.cc | 33 ++++++--------
 src/analytics/viz_message.cc           | 63 +++++++++++---------------
 src/analytics/viz_message.h            | 11 ++---
 src/gendb/cdb_if.cc                    |  1 -
 src/gendb/gendb_statistics.cc          | 48 ++++++--------------
 src/gendb/gendb_statistics.h           | 10 +---
 src/gendb/test/gendb_if_test.cc        |  1 -
 13 files changed, 88 insertions(+), 189 deletions(-)
 delete mode 100644 src/analytics/diffstats.h

diff --git a/src/analytics/collector.cc b/src/analytics/collector.cc
index deaf754e7d3..d8b94daf6d3 100644
--- a/src/analytics/collector.cc
+++ b/src/analytics/collector.cc
@@ -394,9 +394,9 @@ void Collector::GetGeneratorUVEInfo(vector<ModuleServerState> &genlist) {
         const SandeshGenerator * const gen = gm_it->second;
 
         vector<SandeshStats> ssv;
-        gen->GetStatistics(ssv);
+        gen->GetStatistics(&ssv);
         vector<SandeshLogLevelStats> lsv;
-        gen->GetStatistics(lsv);
+        gen->GetStatistics(&lsv);
         vector<SandeshStatsInfo> ssiv;
         SandeshStatsInfo ssi;
         ssi.set_hostname(Sandesh::source());
diff --git a/src/analytics/db_handler.cc b/src/analytics/db_handler.cc
index f5cc90ddf93..36ac21d5a20 100644
--- a/src/analytics/db_handler.cc
+++ b/src/analytics/db_handler.cc
@@ -307,7 +307,7 @@ void DbHandler::GetSandeshStats(std::string *drop_level,
     *drop_level = Sandesh::LevelToString(drop_level_);
     if (vdropmstats) {
         tbb::mutex::scoped_lock lock(smutex_);
-        dropped_msg_stats_.Get(*vdropmstats);
+        dropped_msg_stats_.Get(vdropmstats);
     }
 }
 
diff --git a/src/analytics/diffstats.h b/src/analytics/diffstats.h
deleted file mode 100644
index aee6c130557..00000000000
--- a/src/analytics/diffstats.h
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright (c) 2013 Juniper Networks, Inc. All rights reserved.
- */
-
-#ifndef ANALYTICS_DIFFSTATS_H__
-#define ANALYTICS_DIFFSTATS_H__
-
-#include <vector>
-
-template<typename PtrMapType, typename KeyType, typename ValueStatsType,
-    typename OutputStatsType>
-void GetDiffStats(PtrMapType &stats_map, PtrMapType &old_stats_map,
-    std::vector<OutputStatsType> &v_output_stats) {
-    // Send diffs 
-    for (typename PtrMapType::const_iterator it = stats_map.begin();
-         it != stats_map.end(); it++) {
-         // Get new stats
-         const ValueStatsType *nstats(it->second);
-         KeyType key(it->first);
-         typename PtrMapType::iterator oit = old_stats_map.find(key);
-         // If entry does not exist in old map, insert it
-         if (oit == old_stats_map.end()) {
-             oit = (old_stats_map.insert(key, new ValueStatsType)).first;
-         }
-         // Get old stats
-         ValueStatsType *ostats(oit->second);
-         // Subtract the old from new
-         ValueStatsType dstats(*nstats - *ostats);
-         // Update old
-         *ostats = *nstats;
-         // Populate diff stats
-         OutputStatsType output_stats;
-         dstats.Get(key, output_stats);
-         v_output_stats.push_back(output_stats);
-    }
-}
-
-#endif  // ANALYTICS_DIFFSTATS_H__
diff --git a/src/analytics/generator.cc b/src/analytics/generator.cc
index be8faa93328..a34c00e510b 100644
--- a/src/analytics/generator.cc
+++ b/src/analytics/generator.cc
@@ -54,12 +54,12 @@ void Generator::UpdateStatistics(const VizMsg *vmsg) {
     statistics_.Update(vmsg);
 }
 
-void Generator::GetStatistics(vector<SandeshStats> &ssv) const {
+void Generator::GetStatistics(vector<SandeshStats> *ssv) const {
     tbb::mutex::scoped_lock lock(smutex_);
     statistics_.Get(ssv);
 }
 
-void Generator::GetStatistics(vector<SandeshLogLevelStats> &lsv) const {
+void Generator::GetStatistics(vector<SandeshLogLevelStats> *lsv) const {
     tbb::mutex::scoped_lock lock(smutex_);
     statistics_.Get(lsv);
 }
@@ -68,7 +68,7 @@ void Generator::SendSandeshMessageStatistics() {
     vector<SandeshMessageInfo> smv;
     {
         tbb::mutex::scoped_lock lock(smutex_);
-        statistics_.Get(smv);
+        statistics_.Get(&smv);
     }
     SandeshMessageStat sms;
     sms.set_name(ToString());
diff --git a/src/analytics/generator.h b/src/analytics/generator.h
index e06b9c891b5..dffd21bdbfa 100644
--- a/src/analytics/generator.h
+++ b/src/analytics/generator.h
@@ -33,8 +33,8 @@ class Generator {
     
     bool ReceiveSandeshMsg(const VizMsg *vmsg, bool rsc);
     void SendSandeshMessageStatistics();
-    void GetStatistics(std::vector<SandeshStats> &ssv) const;
-    void GetStatistics(std::vector<SandeshLogLevelStats> &lsv) const;
+    void GetStatistics(std::vector<SandeshStats> *ssv) const;
+    void GetStatistics(std::vector<SandeshLogLevelStats> *lsv) const;
 
 private:
     void UpdateStatistics(const VizMsg *vmsg);
diff --git a/src/analytics/protobuf_server.cc b/src/analytics/protobuf_server.cc
index 3ec18cceada..b6a2d84d148 100644
--- a/src/analytics/protobuf_server.cc
+++ b/src/analytics/protobuf_server.cc
@@ -20,7 +20,6 @@
 #include <io/io_types.h>
 #include <io/udp_server.h>
 
-#include "analytics/diffstats.h"
 #include "analytics/self_describing_message.pb.h"
 #include "analytics/protobuf_server.h"
 #include "analytics/protobuf_server_impl.h"
@@ -491,15 +490,18 @@ class ProtobufServer::ProtobufServerImpl {
             }
             void GetRxDiff(
                 std::vector<SocketEndpointMessageStats> *semsv) {
-                tbb::mutex::scoped_lock lock(mutex_);
-                // Send diffs
-                GetDiffStats<EndpointStatsMessageMap,
-                    EndpointMessageKey, MessageInfo,
-                    SocketEndpointMessageStats>(rx_stats_map_, o_rx_stats_map_,
-                    *semsv);
+                GetRxInternal(semsv, true);
             }
             void GetRx(
                 std::vector<SocketEndpointMessageStats> *semsv) {
+                GetRxInternal(semsv, false);
+            }
+         private:
+            class MessageInfo;
+
+            void GetRxInternal(
+                std::vector<SocketEndpointMessageStats> *semsv,
+                bool clear_stats) {
                 tbb::mutex::scoped_lock lock(mutex_);
                 BOOST_FOREACH(
                     const EndpointStatsMessageMap::value_type &esmm_value,
@@ -507,12 +509,13 @@ class ProtobufServer::ProtobufServerImpl {
                     const EndpointMessageKey &key(esmm_value.first);
                     const MessageInfo *msg_info(esmm_value.second);
                     SocketEndpointMessageStats sems;
-                    msg_info->Get(key, sems);
+                    msg_info->Get(key, &sems);
                     semsv->push_back(sems); 
                 }
+                if (clear_stats) {
+                    rx_stats_map_.clear();
+                }
             }
-         private:
-            class MessageInfo;
 
             void Update(const boost::asio::ip::udp::endpoint &remote_endpoint,
                 const std::string &message_name, uint64_t bytes,
@@ -534,7 +537,7 @@ class ProtobufServer::ProtobufServerImpl {
                 std::string> EndpointMessageKey;
             typedef boost::ptr_map<EndpointMessageKey,
                 MessageInfo> EndpointStatsMessageMap;
-            EndpointStatsMessageMap rx_stats_map_, o_rx_stats_map_;
+            EndpointStatsMessageMap rx_stats_map_;
             tbb::mutex mutex_;
 
             //
@@ -558,38 +561,21 @@ class ProtobufServer::ProtobufServerImpl {
                     last_timestamp_ = UTCTimestampUsec();
                 }
                 void Get(const EndpointMessageKey &key,
-                    SocketEndpointMessageStats &sems) const {
+                    SocketEndpointMessageStats *sems) const {
                     const boost::asio::ip::udp::endpoint remote_endpoint(
                         key.first);
                     const std::string &message_name(key.second);
                     std::stringstream ss;
                     ss << remote_endpoint;
-                    sems.set_endpoint_name(ss.str());
-                    sems.set_message_name(message_name);
-                    sems.set_messages(messages_);
-                    sems.set_bytes(bytes_);
-                    sems.set_errors(errors_);
-                    sems.set_last_timestamp(last_timestamp_);
+                    sems->set_endpoint_name(ss.str());
+                    sems->set_message_name(message_name);
+                    sems->set_messages(messages_);
+                    sems->set_bytes(bytes_);
+                    sems->set_errors(errors_);
+                    sems->set_last_timestamp(last_timestamp_);
                 }
 
              private:
-                friend MessageInfo operator+(const MessageInfo &a,
-                    const MessageInfo &b) {
-                    MessageInfo sum;
-                    sum.messages_ = a.messages_ + b.messages_;
-                    sum.bytes_ = a.bytes_ + b.bytes_;
-                    sum.errors_ = a.errors_ + b.errors_;
-                    return sum;
-                }
-                friend MessageInfo operator-(const MessageInfo &a,
-                    const MessageInfo &b) {
-                    MessageInfo diff;
-                    diff.messages_ = a.messages_ - b.messages_;
-                    diff.bytes_ = a.bytes_ - b.bytes_;
-                    diff.errors_ = a.errors_ - b.errors_;
-                    diff.last_timestamp_ = a.last_timestamp_ - b.last_timestamp_;
-                    return diff;
-                }
                 uint64_t messages_;
                 uint64_t bytes_;
                 uint64_t errors_;
diff --git a/src/analytics/test/viz_message_test.cc b/src/analytics/test/viz_message_test.cc
index 7f5f418cf30..1ea917e8f9c 100644
--- a/src/analytics/test/viz_message_test.cc
+++ b/src/analytics/test/viz_message_test.cc
@@ -132,21 +132,21 @@ TEST_F(VizMessageTest, Stats) {
     stats_.Update(&vmsgp);
     // Verify Gets - SandeshStats, SandeshLogLevelStats, SandeshMessageInfo 
     std::vector<SandeshStats> vsstats;
-    stats_.Get(vsstats);
+    stats_.Get(&vsstats);
     ASSERT_EQ(1, vsstats.size());
     EXPECT_STREQ("VNSwitchErrorMsg", vsstats[0].get_message_type().c_str());
     EXPECT_EQ(1, vsstats[0].get_messages());
     EXPECT_EQ(xmlmessage.size(), vsstats[0].get_bytes());
     vsstats.clear();
     std::vector<SandeshLogLevelStats> vsllstats;
-    stats_.Get(vsllstats);
+    stats_.Get(&vsllstats);
     ASSERT_EQ(1, vsllstats.size());
     EXPECT_STREQ("SYS_DEBUG", vsllstats[0].get_level().c_str());
     EXPECT_EQ(1, vsllstats[0].get_messages());
     EXPECT_EQ(xmlmessage.size(), vsllstats[0].get_bytes());
     vsllstats.clear();
     std::vector<SandeshMessageInfo> vsmi;
-    stats_.Get(vsmi);
+    stats_.Get(&vsmi);
     ASSERT_EQ(1, vsmi.size());
     EXPECT_STREQ("VNSwitchErrorMsg", vsmi[0].get_type().c_str());
     EXPECT_STREQ("SYS_DEBUG", vsmi[0].get_level().c_str());
@@ -156,19 +156,19 @@ TEST_F(VizMessageTest, Stats) {
     // Send same message, update stats
     stats_.Update(&vmsgp);
     // Verify updates
-    stats_.Get(vsstats);
+    stats_.Get(&vsstats);
     ASSERT_EQ(1, vsstats.size());
     EXPECT_STREQ("VNSwitchErrorMsg", vsstats[0].get_message_type().c_str());
     EXPECT_EQ(2, vsstats[0].get_messages());
     EXPECT_EQ(xmlmessage.size() * 2, vsstats[0].get_bytes());
     vsstats.clear();
-    stats_.Get(vsllstats);
+    stats_.Get(&vsllstats);
     ASSERT_EQ(1, vsllstats.size());
     EXPECT_STREQ("SYS_DEBUG", vsllstats[0].get_level().c_str());
     EXPECT_EQ(2, vsllstats[0].get_messages());
     EXPECT_EQ(xmlmessage.size() * 2, vsllstats[0].get_bytes());
     vsllstats.clear();
-    stats_.Get(vsmi);
+    stats_.Get(&vsmi);
     ASSERT_EQ(1, vsmi.size());
     EXPECT_STREQ("VNSwitchErrorMsg", vsmi[0].get_type().c_str());
     EXPECT_STREQ("SYS_DEBUG", vsmi[0].get_level().c_str());
@@ -194,7 +194,7 @@ TEST_F(VizMessageTest, Stats) {
     // Update stats
     stats_.Update(&vmsgp_object);
     // Verify Gets - SandeshStats, SandeshLogLevelStats, SandeshMessageInfo 
-    stats_.Get(vsstats);
+    stats_.Get(&vsstats);
     ASSERT_EQ(2, vsstats.size());
     EXPECT_STREQ("VNSwitchErrorMsg", vsstats[0].get_message_type().c_str());
     EXPECT_STREQ("VNSwitchErrorMsgObject", vsstats[1].get_message_type().c_str());
@@ -204,23 +204,18 @@ TEST_F(VizMessageTest, Stats) {
     EXPECT_EQ(xmlmessage_object.size(), vsstats[1].get_bytes());
     vsstats.clear();
     // Only SYSTEM and SYSLOG have level
-    stats_.Get(vsllstats);
+    stats_.Get(&vsllstats);
     ASSERT_EQ(1, vsllstats.size());
     EXPECT_STREQ("SYS_DEBUG", vsllstats[0].get_level().c_str());
     EXPECT_EQ(2, vsllstats[0].get_messages());
     EXPECT_EQ(xmlmessage.size() * 2, vsllstats[0].get_bytes());
     vsllstats.clear();
-    stats_.Get(vsmi);
-    ASSERT_EQ(2, vsmi.size());
-    EXPECT_STREQ("VNSwitchErrorMsg", vsmi[0].get_type().c_str());
-    EXPECT_STREQ("SYS_DEBUG", vsmi[0].get_level().c_str());
-    // Diffs
-    EXPECT_EQ(0, vsmi[0].get_messages());
-    EXPECT_EQ(0, vsmi[0].get_bytes());
-    EXPECT_STREQ("VNSwitchErrorMsgObject", vsmi[1].get_type().c_str());
-    EXPECT_STREQ("INVALID", vsmi[1].get_level().c_str());
-    EXPECT_EQ(1, vsmi[1].get_messages());
-    EXPECT_EQ(xmlmessage_object.size(), vsmi[1].get_bytes());
+    stats_.Get(&vsmi);
+    ASSERT_EQ(1, vsmi.size());
+    EXPECT_STREQ("VNSwitchErrorMsgObject", vsmi[0].get_type().c_str());
+    EXPECT_STREQ("INVALID", vsmi[0].get_level().c_str());
+    EXPECT_EQ(1, vsmi[0].get_messages());
+    EXPECT_EQ(xmlmessage_object.size(), vsmi[0].get_bytes());
     vsmi.clear();
     // Delete message
     vmsgp_object.msg = NULL;
diff --git a/src/analytics/viz_message.cc b/src/analytics/viz_message.cc
index fa2e67fe58c..6673f831fdd 100644
--- a/src/analytics/viz_message.cc
+++ b/src/analytics/viz_message.cc
@@ -8,7 +8,6 @@
 #include <base/util.h>
 #include <sandesh/sandesh_message_builder.h>
 #include "collector_uve_types.h"
-#include "analytics/diffstats.h"
 
 RuleMsg::RuleMsg(const VizMsg* vmsgp) : 
     hdr(vmsgp->msg->GetHeader()),
@@ -56,21 +55,6 @@ int RuleMsg::field_value(const std::string& field_id, std::string& type, std::st
     return field_value_recur(field_id, type, value, message_node_);
 }
 
-// VizMsgStatistics
-VizMsgStats operator+(const VizMsgStats &a, const VizMsgStats &b) {
-    VizMsgStats sum;
-    sum.messages = a.messages + b.messages;
-    sum.bytes = a.bytes + b.bytes;
-    return sum;
-}
- 
-VizMsgStats operator-(const VizMsgStats &a, const VizMsgStats &b) {
-    VizMsgStats diff;
-    diff.messages = a.messages - b.messages;
-    diff.bytes = a.bytes - b.bytes;
-    return diff;
-}
-
 void VizMsgStats::Update(const VizMsg *vmsg) {
     const SandeshHeader &header(vmsg->msg->GetHeader());
     messages++;
@@ -79,23 +63,23 @@ void VizMsgStats::Update(const VizMsg *vmsg) {
 }
 
 template <typename T, typename K>
-void GetStats(T &stats, const VizMsgStats *vmstats, K &key) {
-    stats.set_messages(vmstats->messages);
-    stats.set_bytes(vmstats->bytes);
-    stats.set_last_msg_timestamp(vmstats->last_msg_timestamp);
+void GetStats(T *stats, const VizMsgStats *vmstats, const K &key) {
+    stats->set_messages(vmstats->messages);
+    stats->set_bytes(vmstats->bytes);
+    stats->set_last_msg_timestamp(vmstats->last_msg_timestamp);
 }
 
 template <>
-void GetStats<>(SandeshMessageInfo &sminfo,
-    const VizMsgStats *vmstats, VizMsgStatistics::TypeLevelKey &key) {
-    sminfo.set_type(key.first);
-    sminfo.set_level(key.second); 
-    sminfo.set_messages(vmstats->messages);
-    sminfo.set_bytes(vmstats->bytes);
+void GetStats<>(SandeshMessageInfo *sminfo,
+    const VizMsgStats *vmstats, const VizMsgStatistics::TypeLevelKey &key) {
+    sminfo->set_type(key.first);
+    sminfo->set_level(key.second);
+    sminfo->set_messages(vmstats->messages);
+    sminfo->set_bytes(vmstats->bytes);
 }
 
 template <typename K, typename T>
-void VizMsgStats::Get(K &key, T &stats) const {
+void VizMsgStats::Get(const K &key, T *stats) const {
     GetStats<T>(stats, this, key);
 }
 
@@ -130,32 +114,37 @@ void VizMsgStatistics::Update(const VizMsg *vmsg) {
 }
 
 // TypeMap
-void VizMsgStatistics::Get(std::vector<SandeshStats> &ssv) const {
+void VizMsgStatistics::Get(std::vector<SandeshStats> *ssv) const {
     for (TypeMap::const_iterator it = type_map.begin();
          it != type_map.end(); it++) {
         SandeshStats sstats;
         sstats.set_message_type(it->first);
         const VizMsgStats *vmstats(it->second);
-        vmstats->Get(it->first, sstats);
-        ssv.push_back(sstats);
+        vmstats->Get(it->first, &sstats);
+        ssv->push_back(sstats);
     }
 }
 
 // LogLevelMap
-void VizMsgStatistics::Get(std::vector<SandeshLogLevelStats> &lsv) const {
+void VizMsgStatistics::Get(std::vector<SandeshLogLevelStats> *lsv) const {
     for (LevelMap::const_iterator it = level_map.begin();
          it != level_map.end(); it++) {
         SandeshLogLevelStats lstats;
         lstats.set_level(it->first);
         const VizMsgStats *vmstats(it->second);
-        vmstats->Get(it->first, lstats);
-        lsv.push_back(lstats);
+        vmstats->Get(it->first, &lstats);
+        lsv->push_back(lstats);
     }
 }
 
 // TypeLevelMap
-void VizMsgStatistics::Get(std::vector<SandeshMessageInfo> &smv) {
-    // Send diffs 
-   GetDiffStats<TypeLevelMap, TypeLevelKey, VizMsgStats, SandeshMessageInfo>(
-       type_level_map, otype_level_map, smv);
+void VizMsgStatistics::Get(std::vector<SandeshMessageInfo> *smv) {
+    for (TypeLevelMap::const_iterator it = type_level_map.begin();
+         it != type_level_map.end(); it++) {
+        const VizMsgStats *vmstats(it->second);
+        SandeshMessageInfo smi;
+        vmstats->Get(it->first, &smi);
+        smv->push_back(smi);
+    }
+    type_level_map.clear();
 }
diff --git a/src/analytics/viz_message.h b/src/analytics/viz_message.h
index 1d8c466b204..c795bb92716 100644
--- a/src/analytics/viz_message.h
+++ b/src/analytics/viz_message.h
@@ -37,9 +37,7 @@ struct VizMsgStats {
     VizMsgStats() : messages(0), bytes(0), last_msg_timestamp(0) {}
 
     void Update(const VizMsg *vmsg);
-    template <typename K, typename T> void Get(K &key, T &stats) const;
-    friend VizMsgStats operator+(const VizMsgStats &a, const VizMsgStats &b);
-    friend VizMsgStats operator-(const VizMsgStats &a, const VizMsgStats &b);
+    template <typename K, typename T> void Get(const K &key, T *stats) const;
 
     uint64_t messages;
     uint64_t bytes;
@@ -50,9 +48,9 @@ struct VizMsgStatistics {
     VizMsgStatistics() {}
 
     void Update(const VizMsg *vmsg);
-    void Get(std::vector<SandeshStats> &ssv) const;
-    void Get(std::vector<SandeshLogLevelStats> &lsv) const;
-    void Get(std::vector<SandeshMessageInfo> &sms);
+    void Get(std::vector<SandeshStats> *ssv) const;
+    void Get(std::vector<SandeshLogLevelStats> *lsv) const;
+    void Get(std::vector<SandeshMessageInfo> *sms);
 
     typedef boost::ptr_map<std::string, VizMsgStats> TypeMap;
     TypeMap type_map;
@@ -63,7 +61,6 @@ struct VizMsgStatistics {
     typedef std::pair<std::string, std::string> TypeLevelKey;
     typedef boost::ptr_map<TypeLevelKey, VizMsgStats> TypeLevelMap;
     TypeLevelMap type_level_map;
-    TypeLevelMap otype_level_map;
 };
 
 /* generic message for ruleeng processing */
diff --git a/src/gendb/cdb_if.cc b/src/gendb/cdb_if.cc
index 58f2cb5fbe6..fdadd964c08 100644
--- a/src/gendb/cdb_if.cc
+++ b/src/gendb/cdb_if.cc
@@ -6,7 +6,6 @@
 #include <boost/assign/list_of.hpp>
 #include <boost/pointer_cast.hpp>
 
-#include "analytics/diffstats.h"
 #include <base/parse_object.h>
 #include <sandesh/sandesh_constants.h>
 #include <sandesh/sandesh_types.h>
diff --git a/src/gendb/gendb_statistics.cc b/src/gendb/gendb_statistics.cc
index 83e858eea7e..93ea3d3cbe9 100644
--- a/src/gendb/gendb_statistics.cc
+++ b/src/gendb/gendb_statistics.cc
@@ -2,34 +2,10 @@
 // Copyright (c) 2014 Juniper Networks, Inc. All rights reserved.
 //
 
-#include <analytics/diffstats.h>
 #include "gendb_statistics.h"
 
 namespace GenDb {
 
-// TableStats
-GenDb::DbTableStatistics::TableStats operator+(
-    const GenDb::DbTableStatistics::TableStats &a,
-    const GenDb::DbTableStatistics::TableStats &b) {
-    GenDb::DbTableStatistics::TableStats sum;
-    sum.num_reads_ = a.num_reads_ + b.num_reads_;
-    sum.num_read_fails_ = a.num_read_fails_ + b.num_read_fails_;
-    sum.num_writes_ = a.num_writes_ + b.num_writes_;
-    sum.num_write_fails_ = a.num_write_fails_ + b.num_write_fails_;
-    return sum;
-}
-
-GenDb::DbTableStatistics::TableStats operator-(
-    const GenDb::DbTableStatistics::TableStats &a,
-    const GenDb::DbTableStatistics::TableStats &b) {
-    GenDb::DbTableStatistics::TableStats diff;
-    diff.num_reads_ = a.num_reads_ - b.num_reads_;
-    diff.num_read_fails_ = a.num_read_fails_ - b.num_read_fails_;
-    diff.num_writes_ = a.num_writes_ - b.num_writes_;
-    diff.num_write_fails_ = a.num_write_fails_ - b.num_write_fails_;
-    return diff;
-}
-
 void GenDb::DbTableStatistics::TableStats::Update(bool write, bool fail) {
     if (write) {
         if (fail) {
@@ -47,12 +23,12 @@ void GenDb::DbTableStatistics::TableStats::Update(bool write, bool fail) {
 }
 
 void GenDb::DbTableStatistics::TableStats::Get(const std::string &table_name,
-    DbTableInfo &info) const {
-    info.set_table_name(table_name);
-    info.set_reads(num_reads_);
-    info.set_read_fails(num_read_fails_);
-    info.set_writes(num_writes_);
-    info.set_write_fails(num_write_fails_);
+    DbTableInfo *info) const {
+    info->set_table_name(table_name);
+    info->set_reads(num_reads_);
+    info->set_read_fails(num_read_fails_);
+    info->set_writes(num_writes_);
+    info->set_write_fails(num_write_fails_);
 }
 
 // DbTableStatistics
@@ -67,10 +43,14 @@ void GenDb::DbTableStatistics::Update(const std::string &table_name,
 }
 
 void GenDb::DbTableStatistics::Get(std::vector<GenDb::DbTableInfo> *vdbti) {
-    // Send diffs
-    GetDiffStats<GenDb::DbTableStatistics::TableStatsMap, const std::string,
-        GenDb::DbTableStatistics::TableStats, DbTableInfo>(
-        table_stats_map_, otable_stats_map_, *vdbti);
+    for (TableStatsMap::const_iterator it = table_stats_map_.begin();
+         it != table_stats_map_.end(); it++) {
+        const TableStats *table_stats(it->second);
+        GenDb::DbTableInfo dbti;
+        table_stats->Get(it->first, &dbti);
+        vdbti->push_back(dbti);
+    }
+    table_stats_map_.clear();
 }
 
 }  // namespace GenDb
diff --git a/src/gendb/gendb_statistics.h b/src/gendb/gendb_statistics.h
index acf7543ed3d..bb53546848e 100644
--- a/src/gendb/gendb_statistics.h
+++ b/src/gendb/gendb_statistics.h
@@ -27,7 +27,7 @@ class DbTableStatistics {
         }
         void Update(bool write, bool fail);
         void Get(const std::string &table_name,
-            GenDb::DbTableInfo &dbti) const;
+            GenDb::DbTableInfo *dbti) const;
 
         uint64_t num_reads_;
         uint64_t num_read_fails_;
@@ -35,16 +35,8 @@ class DbTableStatistics {
         uint64_t num_write_fails_;
     };
 
-    friend DbTableStatistics::TableStats operator+(
-        const DbTableStatistics::TableStats &a,
-        const DbTableStatistics::TableStats &b);
-    friend DbTableStatistics::TableStats operator-(
-        const DbTableStatistics::TableStats &a,
-        const DbTableStatistics::TableStats &b);
-
     typedef boost::ptr_map<const std::string, TableStats> TableStatsMap;
     TableStatsMap table_stats_map_;
-    TableStatsMap otable_stats_map_;
 };
 
 }  // namespace GenDb
diff --git a/src/gendb/test/gendb_if_test.cc b/src/gendb/test/gendb_if_test.cc
index f3875333e85..9b64101649d 100644
--- a/src/gendb/test/gendb_if_test.cc
+++ b/src/gendb/test/gendb_if_test.cc
@@ -580,7 +580,6 @@ static void PopulateDbDataValueVec(GenDb::DbDataValueVec *dbv, size_t *vsize) {
 }
 
 static GenDb::NewCol* CreateNewColNoSql(size_t *csize) {
-    size_t size(0);
     GenDb::DbDataValueVec *name(new GenDb::DbDataValueVec);
     PopulateDbDataValueVec(name, csize);
     GenDb::DbDataValueVec *value(new GenDb::DbDataValueVec);