* [saidump]

•	Saidump for DNX-SAI sonic-net/sonic-buildimage#13561

Solution and modification:
To use the redis-db SAVE option to save the snapshot of DB each time and recover later, instead of looping through each entry in the table and saving it.

(1) Updated sonic-buildimage/build_debian.sh, to install Python library rdbtools into the host.
(2) Updated sonic-buildimage/src/sonic-sairedis/saidump/saidump.cpp, add a new option -r, which updates the rdbtools's output-JSON files' format.
(3) Add a new script file: files/scripts/saidump.sh, to do the below steps
  For each ASIC0, such as ASIC0,

  #1. Save the Redis data.
  sudo sonic-db-cli -n asic$1 SAVE > /dev/null

  #2. Move dump files to /var/run/redisX/
  docker exec database$1 sh -c "mv /var/lib/redis/dump.rdb /var/run/redis$1/"

  sonic-net#3. Run rdb command to convert the dump files into JSON files
  sudo python /usr/local/bin/rdb --command json  /var/run/redis$1/dump.rdb | sudo tee /var/run/redis$1/dump.json > /dev/null

  sonic-net#4. Run saidump -r to update the JSON files' format as same as the saidump before. Then we can get the saidump result in standard output.
  docker exec syncd$1 sh -c "saidump -r /var/run/redis$1/dump.json"

  sonic-net#5. clear
  sudo rm -f /var/run/redis$1/dump.rdb
  sudo rm -f /var/run/redis$1/dump.json

(4) Update sonic-buildimage/src/sonic-utilities/scripts/generate_dump, replace saidump with saidump.sh

saidump/saidump.cpp

@@ -2,6 +2,9 @@
 #include <string>
 #include <set>
 #include <sstream>
+#include <iostream>
+#include <fstream>
+#include <regex>
 
 extern "C" {
 #include <sai.h>
@@ -10,18 +13,26 @@ extern "C" {
 #include "swss/table.h"
 #include "meta/sai_serialize.h"
 #include "sairediscommon.h"
+#include "swss/json.h"
+#include "swss/json.hpp"
 
 #include <getopt.h>
 
 // TODO split to multiple cpp
 
 using namespace swss;
+using namespace std;
+using json = nlohmann::json;
+
+// 100 MB
+const int64_t RDB_FILE_MAX_SIZE = 1024 * 1024 * 100;
 
 struct CmdOptions
 {
     bool skipAttributes;
     bool dumpTempView;
     bool dumpGraph;
+    string rdb_file;
 };
 
 CmdOptions g_cmdOptions;
@@ -31,11 +42,13 @@ void printUsage()
 {
     SWSS_LOG_ENTER();
 
-    std::cout << "Usage: saidump [-t] [-g] [-h]" << std::endl;
+    std::cout << "Usage: saidump [-t] [-g] [-r] [-h]" << std::endl;
     std::cout << "    -t --tempView:" << std::endl;
     std::cout << "        Dump temp view" << std::endl;
     std::cout << "    -g --dumpGraph:" << std::endl;
     std::cout << "        Dump current graph" << std::endl;
+    std::cout << "    -r --rdb:" << std::endl;
+    std::cout << "        Dump by parsing the Redis persistence file dump.rdb that is generated by SAVE command." << std::endl;
     std::cout << "    -h --help:" << std::endl;
     std::cout << "        Print out this message" << std::endl;
 }
@@ -49,14 +62,15 @@ CmdOptions handleCmdLine(int argc, char **argv)
     options.dumpTempView = false;
     options.dumpGraph = false;
 
-    const char* const optstring = "gth";
+    const char* const optstring = "gtr:h";
 
     while (true)
     {
         static struct option long_options[] =
         {
             { "dumpGraph",      no_argument,       0, 'g' },
             { "tempView",       no_argument,       0, 't' },
+            {  "rdb",           required_argument, 0, 'r' },
             { "help",           no_argument,       0, 'h' },
             { 0,                0,                 0,  0  }
         };
@@ -82,6 +96,11 @@ CmdOptions handleCmdLine(int argc, char **argv)
                 options.dumpTempView = true;
                 break;
 
+            case 'r':
+                SWSS_LOG_WARN("Dumping from dump.rdb");
+                options.rdb_file = string(optarg);                
+                break;
+
             case 'h':
                 printUsage();
                 exit(EXIT_SUCCESS);
@@ -399,7 +418,159 @@ void dumpGraph(const TableDump& td)
     std::cout << "}" << std::endl;
 }
 
-int main(int argc, char ** argv)
+/*
+ preprocess the input json file to make make sure it's a valid json file.
+*/
+int pre_process_file(string file_name)
+{
+    ifstream input_file(file_name);
+
+    if (!input_file.is_open())
+    {
+        cerr << "Failed to open the input file." << endl;
+        return SAI_STATUS_FAILURE;
+    }
+
+    input_file.seekg(0, ios::end);     // Move to the end of the file
+    int64_t file_size = input_file.tellg(); // Get the current position
+
+    if (file_size >= RDB_FILE_MAX_SIZE)
+    {
+        SWSS_LOG_ERROR("Get %s's size failure or its size %ld  >= %ld MB.\n", file_name.c_str(), file_size, RDB_FILE_MAX_SIZE / 1024 / 1024);
+
+        // Close the input file
+        input_file.close();
+        return SAI_STATUS_FAILURE;
+    }
+    input_file.seekg(0, ios::beg);     // Move to the begin of the file
+
+    // Read the content of the input file into a string
+    string content((istreambuf_iterator<char>(input_file)),
+                   istreambuf_iterator<char>());
+
+
+    input_file.close();
+
+    content = regex_replace(content,  regex("\\},\\{\\r"), ",");
+
+    //erase the 1st and last char.
+    if (content.length() >= 2 && content[0] == '[' && content[content.length()-1] == ']')  {
+        content.erase(0, 1);
+        content.erase(content.length() - 1);
+    }
+
+    ofstream outputFile(file_name);
+
+    if (!outputFile.is_open())
+    {
+        cerr << "Failed to open the output file." << endl;
+        return SAI_STATUS_FAILURE;
+    }
+
+    outputFile << content;
+    outputFile.close();
+
+    return SAI_STATUS_SUCCESS;
+}
+
+int dump_from_redis_rdb_file(string file_name)
+{
+    ifstream input_file(file_name);
+    if (!input_file.is_open())
+    {
+        SWSS_LOG_NOTICE("The file %s is not exsisted for dumping from redis dump.rdb file", file_name);
+        return SAI_STATUS_FAILURE;
+    }
+
+    input_file.seekg(0, ios::end);     // Move to the end of the file
+    int64_t file_size = input_file.tellg(); // Get the current position
+    if (file_size >= RDB_FILE_MAX_SIZE)
+    {
+        SWSS_LOG_ERROR("Get %s's size failure or its size %ld  >= %ld MB.\n", file_name.c_str(), file_size, RDB_FILE_MAX_SIZE / 1024 / 1024);
+
+        // Close the input file
+        input_file.close();
+        return SAI_STATUS_FAILURE;
+    }
+    input_file.seekg(0, ios::beg);     // Move to the begin of the file
+
+    try
+    {
+        // Parse the JSON data from the file (validation)
+        nlohmann::json jsonData;
+        input_file >> jsonData;
+        input_file.close();
+
+        SWSS_LOG_DEBUG("%s\n","JSON file is valid.\n");
+
+        for (json::iterator it = jsonData.begin(); it != jsonData.end(); ++it)
+        {
+            json jj_key = it.key();
+
+            string keystr = jj_key;
+            string item_name = keystr;
+            size_t pos = keystr.find_first_of(":");
+            if (pos != string::npos)
+            {
+                if("ASIC_STATE" != keystr.substr(0, pos))  // filter out non ASIC_STATE
+                {
+                    continue;
+                }
+                item_name = keystr.substr(pos + 1);
+                if (item_name.find(":") != string::npos)
+                {
+                    item_name.replace(item_name.find_first_of(":"), 1, " ");
+                }
+            }
+            else
+            {
+                continue;
+            }
+
+            cout << item_name << " " << endl;
+
+            json jj = it.value();
+
+            if (!(*it).is_object())
+            {
+                continue;
+            }
+
+            TableMap map;
+            for (json::iterator itt = jj.begin(); itt != jj.end(); ++itt)
+            {
+                if (itt.key() == "NULL")
+                {
+                    continue;
+                }
+                map[itt.key()] = itt.value();
+            }
+
+            size_t indent = 4;
+            size_t max_len = get_max_attr_len(map);
+            string str_indent = pad_string("", indent);
+
+            for (const auto&field: map)
+            {
+                stringstream ss;
+                ss << str_indent << pad_string(field.first, max_len) << " : ";
+                ss << field.second;
+                cout << ss.str() << std::endl;
+            }
+            cout << endl;
+        }
+        return SAI_STATUS_SUCCESS;    
+    }  
+    catch (exception &ex)
+    {
+        input_file.close();
+        cerr << "JSON file:" << file_name << " is invalid." << endl;
+        cerr << "JSON parsing error: " << ex.what() << endl;
+    }
+    return SAI_STATUS_FAILURE;
+}
+
+int main(int argc, char **argv)
 {
     swss::Logger::getInstance().setMinPrio(swss::Logger::SWSS_DEBUG);
 
@@ -411,6 +582,16 @@ int main(int argc, char ** argv)
 
     g_cmdOptions = handleCmdLine(argc, argv);
 
+    if (g_cmdOptions.rdb_file.size() > 0)
+    {
+        if (SAI_STATUS_FAILURE == pre_process_file(g_cmdOptions.rdb_file))
+        {
+            return EXIT_FAILURE;
+        }        
+        dump_from_redis_rdb_file(g_cmdOptions.rdb_file);
+        return EXIT_SUCCESS;
+    }
+
     swss::DBConnector db("ASIC_DB", 0);
 
     std::string table = ASIC_STATE_TABLE;