Re-write sonic-db-cli with c++ for sonic startup performance issue (#607)

#### Why I did it
    Fix sonic-db-cli high CPU usage on SONiC startup issue: sonic-net/sonic-buildimage#10218
    ETA of this issue will be 2022/05/31

#### How I did it
    Re-write sonic-cli with c++.

#### How to verify it
    Add c++ unit test to cover all code.
    Pass all E2E test scenario.

#### Which release branch to backport (provide reason below if selected)

<!--
- Note we only backport fixes to a release branch, *not* features!
- Please also provide a reason for the backporting below.
- e.g.
- [x] 202006
-->

- [ ] 201811
- [ ] 201911
- [ ] 202006
- [ ] 202012
- [ ] 202106
- [ ] 202111

#### Description for the changelog
    Re-write sonic-cli with c++ for sonic startup performance issue

Author: liuh-80

Makefile.am

@@ -1,3 +1,3 @@
-SUBDIRS = common pyext tests
+SUBDIRS = common pyext sonic-db-cli tests
 
 ACLOCAL_AMFLAGS = -I m4

common/rediscommand.cpp

@@ -49,6 +49,16 @@ void RedisCommand::formatArgv(int argc, const char **argv, const size_t *argvlen
     }
 }
 
+void RedisCommand::format(const vector<string> &commands)
+{
+    vector<const char*> args;
+    for (auto& command : commands)
+    {
+        args.push_back(command.c_str());
+    }
+    formatArgv(static_cast<int>(args.size()), args.data(), NULL);
+}
+
 /* Format HMSET key multiple field value command */
 void RedisCommand::formatHMSET(const std::string &key,
                                const std::vector<FieldValueTuple> &values)

common/rediscommand.h

@@ -25,6 +25,7 @@ class RedisCommand {
 
     void format(const char *fmt, ...);
     void formatArgv(int argc, const char **argv, const size_t *argvlen);
+    void format(const std::vector<std::string> &commands);
 
     /* Format HMSET key multiple field value command */
 #ifndef SWIG

common/redisreply.cpp

@@ -2,6 +2,7 @@
 #include <stdint.h>
 #include <vector>
 #include <iostream>
+#include <sstream>
 #include <system_error>
 #include <functional>
 
@@ -158,7 +159,7 @@ void RedisReply::checkReplyType(int expectedType)
         const char *err = (m_reply->type == REDIS_REPLY_STRING || m_reply->type == REDIS_REPLY_ERROR) ?
             m_reply->str : "NON-STRING-REPLY";
 
-        string errmsg = "Expected to get redis type " + to_string(expectedType) + " got type " + to_string(m_reply->type) + ", err: " + err;
+        string errmsg = "Expected to get redis type " + std::to_string(expectedType) + " got type " + std::to_string(m_reply->type) + ", err: " + err;
         SWSS_LOG_ERROR("%s", errmsg.c_str());
         throw system_error(make_error_code(errc::io_error), errmsg);
     }
@@ -225,4 +226,44 @@ template<> RedisMessage RedisReply::getReply<RedisMessage>()
     return ret;
 }
 
+
+string RedisReply::to_string()
+{
+    return to_string(getContext());
+}
+
+string RedisReply::to_string(redisReply *reply)
+{
+    switch(reply->type)
+    {
+    case REDIS_REPLY_INTEGER:
+        return std::to_string(reply->integer);
+
+    case REDIS_REPLY_STRING:
+    case REDIS_REPLY_ERROR:
+    case REDIS_REPLY_STATUS:
+    case REDIS_REPLY_NIL:
+        return string(reply->str, reply->len);
+
+    case REDIS_REPLY_ARRAY:
+    {
+        stringstream result;
+        for (size_t i = 0; i < reply->elements; i++)
+        {
+            result << to_string(reply->element[i]);
+
+            if (i < reply->elements - 1)
+            {
+                result << endl;
+            }
+        }
+        return result.str();
+    }
+
+    default:
+        SWSS_LOG_ERROR("invalid type %d for message", reply->type);
+        return string();
+    }
+}
+
 }

common/redisreply.h

@@ -92,6 +92,10 @@ class RedisReply
     /* Check that the status is QUEUED, throw exception otherwise */
     void checkStatusQueued();
 
+    std::string to_string();
+
+    static std::string to_string(redisReply *reply);
+
 private:
     void checkStatus(const char *status);
     void checkReply();

configure.ac

@@ -98,6 +98,7 @@ AC_CONFIG_FILES([
     pyext/Makefile
     pyext/py2/Makefile
     pyext/py3/Makefile
+    sonic-db-cli/Makefile
     tests/Makefile
 ])
 

debian/control

@@ -35,3 +35,9 @@ Architecture: any
 Depends: ${shlibs:Depends}, ${misc:Pre-Depends}
 Section: libs
 Description: This package contains Switch State Service common Python3 library.
+
+Package: sonic-db-cli
+Architecture: any
+Depends: ${shlibs:Depends}, ${misc:Pre-Depends}
+Section: libs
+Description: This package contains SONiC DB cli.

debian/sonic-db-cli.dirs

@@ -0,0 +1 @@
+usr/bin

debian/sonic-db-cli.install

@@ -0,0 +1 @@
+usr/bin/sonic-db-cli

sonic-db-cli/Makefile.am

@@ -0,0 +1,19 @@
+INCLUDES = -I $(top_srcdir)
+
+if DEBUG
+DBGFLAGS = -ggdb -DDEBUG
+else
+DBGFLAGS = -g -DNDEBUG
+endif
+
+lib_LTLIBRARIES = libsonicdbcli.la
+libsonicdbcli_la_SOURCES = sonic-db-cli.cpp
+libsonicdbcli_la_CFLAGS = $(DBGFLAGS) $(AM_CFLAGS) $(CFLAGS_COMMON)
+libsonicdbcli_la_CPPFLAGS = $(DBGFLAGS) $(AM_CPPFLAGS) $(CFLAGS_COMMON)
+libsonicdbcli_la_LDFLAGS = -L$(top_srcdir)/common -lswsscommon -lpthread
+
+bin_PROGRAMS = sonic-db-cli
+sonic_db_cli_SOURCES = sonic-db-cli.cpp main.cpp
+sonic_db_cli_CFLAGS = $(DBGFLAGS) $(AM_CFLAGS) $(CFLAGS_COMMON)
+sonic_db_cli_CPPFLAGS = $(DBGFLAGS) $(AM_CPPFLAGS) $(CFLAGS_COMMON)
+sonic_db_cli_LDFLAGS = -L$(top_srcdir)/common -lswsscommon -lpthread

sonic-db-cli/main.cpp

@@ -0,0 +1,24 @@
+#include "sonic-db-cli.h"
+#include "common/dbconnector.h"
+
+using namespace swss;
+using namespace std;
+
+int main(int argc, char** argv)
+{
+    auto initializeGlobalConfig = []()
+    {
+        SonicDBConfig::initializeGlobalConfig(SonicDBConfig::DEFAULT_SONIC_DB_GLOBAL_CONFIG_FILE);
+    };
+
+    auto initializeConfig = []()
+    {
+        SonicDBConfig::initialize(SonicDBConfig::DEFAULT_SONIC_DB_CONFIG_FILE);
+    };
+
+    return sonic_db_cli(
+                    argc,
+                    argv,
+                    initializeGlobalConfig,
+                    initializeConfig);
+}