Changing Buffer Sizes for JSON List Command (#159)

sashi-cli/cli-manager.cpp

@@ -162,19 +162,38 @@ namespace cli
             return -1;
         }
 
-        // Resize the message to max length and resize to original read length after reading.
-        message.resize(BUFFER_SIZE);
-        const int res = read(ctx.socket_fd, message.data(), message.length());
+        // Read the length of the message to a buffer
+        uint8_t  length_buffer[8];
+        int res = read(ctx.socket_fd, length_buffer, 8);
         if (res == -1)
         {
-            std::cerr << errno << " :Error while reading from the sashimono socket.\n";
+            std::cerr << errno << " :Error while reading message length from the sashimono socket.\n";
+            return -1;
+        }
+
+        const uint32_t message_length = uint32_from_bytes(length_buffer);   
+
+        // Resize the message buffer to fit to the message length
+        message.resize(message_length);
+        res = read(ctx.socket_fd, message.data(), message_length);
+        if (res == -1)
+        {
+            std::cerr << errno << " :Error while reading the message from the sashimono socket.\n";
             return -1;
         }
-        message.resize(res);
 
         return res;
     }
 
+    // Convert byte buffer to uint32_t
+    uint32_t uint32_from_bytes(const uint8_t *data)
+    {
+        return ((uint32_t)data[0] << 24) +
+               ((uint32_t)data[1] << 16) +
+               ((uint32_t)data[2] << 8) +
+               ((uint32_t)data[3]);
+    }
+
     int get_json_output(std::string_view json_msg, std::string &output)
     {
         if (write_to_socket(json_msg) == -1 || read_from_socket(output) == -1)
@@ -229,7 +248,7 @@ namespace cli
                 return -1;
             }
 
-            jsoncons::json content = jsoncons::json::parse(d["content"].as<std::string>(), jsoncons::strict_json_parsing());
+            jsoncons::json content = d["content"];
             std::cout << jsoncons::pretty_print(content) << std::endl;
         }
         catch (const std::exception &e)

sashi-cli/cli-manager.hpp

@@ -38,6 +38,8 @@ namespace cli
     const std::string value_to_string(const jsoncons::json &val);
 
     void deinit();
+    
+    uint32_t uint32_from_bytes(const uint8_t *data);
 }
 
 #endif

src/comm/comm_handler.cpp

@@ -91,7 +91,7 @@ namespace comm
      * This accepts connections to the socket.
      * This only gets called whithin the comm handler thread.
      * @return 0 on success -1 on error.
-    */
+     */
     int connect()
     {
         ctx.data_socket = accept(ctx.connection_socket, NULL, NULL);
@@ -106,7 +106,7 @@ namespace comm
     /**
      * Disconnect the session.
      * This only gets called whithin the comm handler thread.
-    */
+     */
     void disconnect()
     {
         close(ctx.data_socket);
@@ -178,7 +178,7 @@ namespace comm
      * Handles the received message.
      * @param message_size Message size.
      * @return 0 on success -1 on error.
-    */
+     */
     int handle_message(const int message_size)
     {
         std::string_view msg((char *)read_buffer.data(), message_size);
@@ -283,7 +283,7 @@ namespace comm
         }
         else
             __HANDLE_RESPONSE("error", TYPE_ERROR, -1);
-
+        
         return 0;
     }
 
@@ -297,10 +297,35 @@ namespace comm
         if (ctx.data_socket == -1)
             return -1;
 
-        const int ret = write(ctx.data_socket, message.data(), message.length());
+        uint8_t length_buffer[8];
+        // Convert message length to a byte array
+        uint32_to_bytes(length_buffer, message.length());
+
+        int res = write(ctx.data_socket, length_buffer, 8);
+        if (res == -1) {
+            disconnect();
+            return -1;
+        }
+
+        res = write(ctx.data_socket, message.data(), message.length());
         // Close connection after sending the response to the client.
         disconnect();
-        return ret == -1 ? -1 : 0;
+        
+        return res ==  -1 ? -1 : 0;
+    }
+
+
+    /**
+     * Convert the given uint32_t number to bytes in big endian format.
+     * @param dest Byte array pointer.
+     * @param x Number to be converted.
+    */
+    void uint32_to_bytes(uint8_t *dest, const uint32_t x)
+    {
+        dest[0] = (uint8_t)((x >> 24) & 0xff);
+        dest[1] = (uint8_t)((x >> 16) & 0xff);
+        dest[2] = (uint8_t)((x >> 8) & 0xff);
+        dest[3] = (uint8_t)((x >> 0) & 0xff);
     }
 
     /**

src/comm/comm_handler.hpp

@@ -34,6 +34,8 @@ namespace comm
 
     int read_socket();
 
+    void uint32_to_bytes(uint8_t *dest, const uint32_t x);
+
 } // namespace comm
 
 #endif

src/msg/json/msg_json.cpp

@@ -11,6 +11,7 @@ namespace msg::json
     constexpr const char *DOUBLE_QUOTE = "\"";
     constexpr uint16_t MOMENT_SIZE = 900;         // XRP ledgers per Moment.
     constexpr uint16_t LEDGER_TIME_APPROX = 4000; // Approx. milliseconds per XRP ledger.
+    constexpr uint16_t INSTANCE_INFO_SIZE = 488;  // Size of a single instance info
     /**
      * Parses a json message sent by the message board.
      * @param d Jsoncons document to which the parsed json should be loaded.
@@ -576,7 +577,8 @@ namespace msg::json
      */
     void build_response(std::string &msg, std::string_view response_type, std::string_view content, const bool json_content)
     {
-        msg.reserve(1024);
+        // Extra 40 bytes added for the other data included, in addition to the content here
+        msg.reserve(content.length() + 40);
         msg += "{\"";
         msg += msg::FLD_TYPE;
         msg += SEP_COLON;
@@ -663,7 +665,9 @@ namespace msg::json
      */
     void build_list_response(std::string &msg, const std::vector<hp::instance_info> &instances, const std::vector<hp::lease_info> &leases)
     {
-        msg.reserve(1024);
+        const uint32_t message_size = (INSTANCE_INFO_SIZE * instances.size()) + 3;
+        msg.reserve(message_size);
+
         msg += "[";
         for (size_t i = 0; i < instances.size(); i++)
         {
@@ -775,4 +779,4 @@ namespace msg::json
         msg += std::to_string(instance.assigned_ports.user_port);
         msg += "}";
     }
-} // namespace msg::json
+} // namespace msg::json