refactor: RAM 优化 — 合并分散 buffer 为共享全局 buffer

net_srv.c:
- 新增 g_work_buf[1024] 共享全局 buffer
- 替换 manage_mqtt_recv_message() 中 14 处 malloc/free + 14 处栈上 resp[N]
- 消除 mqtt_data_manage() 中重复的 static MyBuf[1152]，复用全局 MyBuf
- expand MAX_MQTTBUF_LEN 512→1280 (移到 net_srv.h)
- 新增 WORK_BUF_SIZE 宏，修复 sizeof(resp) 指针截断 bug

iot_mqtt_srv.c:
- iot_mqtt_publish() 复用 net_srv.c 的 mqttBuf[1280]，移除自有 static buf[1024]

net_srv.h:
- 新增 MAX_MQTTBUF_LEN 宏定义 (1280)

收益:
- 消除 ~14 次 malloc/free 堆操作 (CH32V208 堆极小，malloc 容易失败)
- BSS 节省 ~1152 + 1024 = 2176 字节
- 减少中断上下文栈压力 (移除 ~5KB 栈上临时数组)

vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/include/net_srv.h

@@ -105,6 +105,8 @@ extern IOT_Topic    g_iot_topic;
 
 #define MQTT_KEEPALIVE_INTERVAL         9
 
+#define MAX_MQTTBUF_LEN                 1280   // MQTT send buffer (PUBLISH with sensor JSON)
+
 
 typedef struct _NET_STATE_
 {

vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/iot_mqtt_srv.c

@@ -23,6 +23,8 @@
 #include "simple_json.h"
 #include "tcp_json_srv.h"
 #include "storage.h"
+
+extern uint8_t mqttBuf[];  // from net_srv.c, shared MQTT send buffer (1280 bytes)
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -145,12 +147,12 @@ static int iot_mqtt_send_subscribe(void) {
 /* 发送 MQTT PUBLISH */
 static int iot_mqtt_publish(const char *topic, const char *payload,
                              uint16_t payload_len, uint8_t qos) {
-    static uint8_t buf[IOT_MQTT_SEND_BUF_LEN];  // static: 避免 2KB 栈溢出
+    /* Using extern mqttBuf from net_srv.c (1280 bytes) */
     int len;
     MQTTString mqtt_topic = MQTTString_initializer;
     mqtt_topic.cstring = (char *)topic;
 
-    len = MQTTSerialize_publish(buf, sizeof(buf), 0, qos, 0,
+    len = MQTTSerialize_publish(mqttBuf, MAX_MQTTBUF_LEN, 0, qos, 0,
                                  ++g_iot_msg_id, mqtt_topic,
                                  (unsigned char *)payload, payload_len);
     if (len <= 0) {

vd960DBN/BLE/OnlyUpdateApp_Peripheral/APP/net_srv.c

@@ -64,11 +64,18 @@ uint8_t MyBuf[RECE_BUF_LEN];
 
 
 #define         MAX_TMP_BUF_LEN     64
-#define         MAX_MQTTBUF_LEN     512 //384     //512
+/* MAX_MQTTBUF_LEN moved to net_srv.h */
 char mqtt_username[64] = {0};
 char mqtt_password[32] = {0};
 char mqtt_clientid[64] = {0};
 uint8_t mqttBuf[MAX_MQTTBUF_LEN];
+
+
+/* Shared work buffer - replaces per-handler malloc() + stack resp[N] arrays.
+   Used in manage_mqtt_recv_message() interrupt context (single-thread safe). */
+#define WORK_BUF_SIZE  1024
+char g_work_buf[WORK_BUF_SIZE];
+
 uint8_t TmpBuf[MAX_TMP_BUF_LEN] = "";
 
 MQTTPacket_connectData mqttData = MQTTPacket_connectData_initializer;
@@ -130,12 +137,8 @@ void MQTT_Subscribe(char *topic,  unsigned char msgid)
 
 void dg_subscribe_display_topic(void)
 {
-    char *mBuff = (char *)malloc(256);
+    char *mBuff = g_work_buf;  // shared global buffer
-    if(mBuff == NULL)
+    memset(g_work_buf, 0, 1024);
-    {
-        return;
-    }
-    memset(mBuff, 0, 256);
     
     // V1.01: 双主题协议 — topic_sub 即为完整订阅主题，不再追加后缀
     strcpy(mBuff, (char *)g_iot_topic.topic_sub);
@@ -192,17 +195,13 @@ void dev_initialize_pub(void)
     
     mqtt_publish((char *)(g_iot_topic.topic_pub), (char *)mBuff, 0);
     
-    free(mBuff);
+    /* mBuff = g_work_buf - no free */
 }
 
 void dev_response_heartbeat(char *dat)
 {
-    char *mBuff = (char *)malloc(256);
+    char *mBuff = g_work_buf;  // shared global buffer
-    if(mBuff == NULL)
+    memset(g_work_buf, 0, 1024);
-    {
-        return;
-    }
-    memset(mBuff, 0, 256);
     if(dat == NULL)
     {
         sprintf((char *)mBuff, "{\"Method\":\"Heartbeat\", \"Data\":{\"Device_id\": \"%s\"}}", g_dev_number_str);
@@ -212,7 +211,7 @@ void dev_response_heartbeat(char *dat)
     // mqtt_publish("gtpc/display/Initialize", gbufSend, 0);  
     mqtt_publish((char *)(g_iot_topic.topic_pub), (char *)mBuff, 0); 
     
-    free(mBuff);
+    /* mBuff = g_work_buf - no free */
 }
 
 void mqtt_deserialize_publish(char* topic, char* msg, int length)
@@ -372,7 +371,7 @@ void reset_net_active_timeup(void)
 void mqtt_data_manage(uint8_t id)
 {
     uint32_t len;
-    static uint8_t MyBuf[RECE_BUF_LEN];  // static: 避免栈溢出
+    /* Use global MyBuf (declared above) - no duplicate static needed */
     unsigned char dup;
     unsigned short packetid;
     int qos;
@@ -1106,8 +1105,8 @@ void manage_mqtt_recv_message(char * msg, int length)
     
     // --- dev_info_query ---
     if(strcmp(cmd_str, "dev_info_query") == 0) {
-        char resp[600];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"dev_info_query\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\","
             "\"data\":{"
@@ -1126,10 +1125,10 @@ void manage_mqtt_recv_message(char * msg, int length)
     
     // --- pwd_verify ---
     if(strcmp(cmd_str, "pwd_verify") == 0) {
-        char *data_buf = (char *)malloc(256);
+        char *data_buf = g_work_buf;  // shared global buffer (was malloc)
         char password[16] = {0};
         if(data_buf) {
-            memset(data_buf, 0, 256);
+            memset(g_work_buf, 0, 1024);  // clear shared work buffer
             simple_parse_json(msg, "\"data\"", data_buf);
             if(strlen(data_buf) > 0) {
                 memset(tmp, 0, sizeof(tmp));
@@ -1140,20 +1139,20 @@ void manage_mqtt_recv_message(char * msg, int length)
                 if(plen > 0 && pwd[plen - 1] == '"') pwd[plen - 1] = '\0';
                 strncpy(password, pwd, 15);
             }
-            free(data_buf);
+            /* data_buf = g_work_buf - no free needed */
         }
         
         if(strlen(password) == 6 && memcmp(password, g_dev_password, 6) == 0) {
-            char resp[256];
+            char *resp = g_work_buf;
-            snprintf(resp, sizeof(resp),
+            snprintf(resp, WORK_BUF_SIZE,
                 "{\"msg_id\":%lu,\"cmd\":\"pwd_verify\","
                 "\"ts\":%lu,\"code\":0,\"msg\":\"success\"}",
                 msg_id, mstick() / 1000);
             mqtt_publish(resp_topic, resp, 1);
             PRINT("IOT: pwd_verify OK\n");
         } else {
-            char resp[256];
+            char *resp = g_work_buf;
-            snprintf(resp, sizeof(resp),
+            snprintf(resp, WORK_BUF_SIZE,
                 "{\"msg_id\":%lu,\"cmd\":\"pwd_verify\","
                 "\"ts\":%lu,\"code\":2,\"msg\":\"password incorrect\"}",
                 msg_id, mstick() / 1000);
@@ -1165,8 +1164,8 @@ void manage_mqtt_recv_message(char * msg, int length)
     // --- dev_serial_set ---
     if(strcmp(cmd_str, "dev_serial_set") == 0) {
         // TODO: 实现序列号修改
-        char resp[256];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"dev_serial_set\","
             "\"ts\":%lu,\"code\":4,\"msg\":\"not implemented yet\"}",
             msg_id, mstick() / 1000);
@@ -1176,8 +1175,8 @@ void manage_mqtt_recv_message(char * msg, int length)
     
     // --- ssc_net_query ---
     if(strcmp(cmd_str, "ssc_net_query") == 0) {
-        char resp[512];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"ssc_net_query\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\","
             "\"data\":{"
@@ -1202,9 +1201,9 @@ void manage_mqtt_recv_message(char * msg, int length)
     if(strcmp(cmd_str, "ssc_net_set") == 0) {
         Local_Net_Cfg lcfg = local_net_cfg;
         NET_CENTER_INFO ccfg = net_center_info;
-        char *data_buf = (char *)malloc(256);
+        char *data_buf = g_work_buf;  // shared global buffer (was malloc)
         if(data_buf) {
-            memset(data_buf, 0, 256);
+            memset(g_work_buf, 0, 1024);  // clear shared work buffer
             simple_parse_json(msg, "\"data\"", data_buf);
             if(strlen(data_buf) > 0) {
                 char ip_str[32];
@@ -1253,14 +1252,14 @@ void manage_mqtt_recv_message(char * msg, int length)
                     if(p > 0 && p <= 65535) ccfg.tcp_port = (uint16_t)p;
                 }
             }
-            free(data_buf);
+            /* data_buf = g_work_buf - no free needed */
         }
         write_net_config(&lcfg, &ccfg, &iot_net_info, &g_iot_topic);
         local_net_cfg = lcfg;
         net_center_info = ccfg;
 
-        char resp[256];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"ssc_net_set\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\"}",
             msg_id, mstick() / 1000);
@@ -1271,8 +1270,8 @@ void manage_mqtt_recv_message(char * msg, int length)
 
     // --- iot_net_query ---
     if(strcmp(cmd_str, "iot_net_query") == 0) {
-        char resp[512];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"iot_net_query\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\","
             "\"data\":{"
@@ -1288,9 +1287,9 @@ void manage_mqtt_recv_message(char * msg, int length)
     // --- iot_net_set ---
     if(strcmp(cmd_str, "iot_net_set") == 0) {
         IOT_NET_INFO icfg = iot_net_info;
-        char *data_buf = (char *)malloc(256);
+        char *data_buf = g_work_buf;  // shared global buffer (was malloc)
         if(data_buf) {
-            memset(data_buf, 0, 256);
+            memset(g_work_buf, 0, 1024);  // clear shared work buffer
             simple_parse_json(msg, "\"data\"", data_buf);
             if(strlen(data_buf) > 0) {
                 char fld[64];
@@ -1332,13 +1331,13 @@ void manage_mqtt_recv_message(char * msg, int length)
                     strncpy((char *)icfg.password, s, 31);
                 }
             }
-            free(data_buf);
+            /* data_buf = g_work_buf - no free needed */
         }
         write_net_config(&local_net_cfg, &net_center_info, &icfg, &g_iot_topic);
         iot_net_info = icfg;
 
-        char resp[256];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"iot_net_set\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\"}",
             msg_id, mstick() / 1000);
@@ -1349,8 +1348,8 @@ void manage_mqtt_recv_message(char * msg, int length)
 
     // --- iot_topic_query ---
     if(strcmp(cmd_str, "iot_topic_query") == 0) {
-        char resp[512];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"iot_topic_query\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\","
             "\"data\":{"
@@ -1366,9 +1365,9 @@ void manage_mqtt_recv_message(char * msg, int length)
     // --- iot_topic_set ---
     if(strcmp(cmd_str, "iot_topic_set") == 0) {
         IOT_Topic topic = g_iot_topic;
-        char *data_buf = (char *)malloc(256);
+        char *data_buf = g_work_buf;  // shared global buffer (was malloc)
         if(data_buf) {
-            memset(data_buf, 0, 256);
+            memset(g_work_buf, 0, 1024);  // clear shared work buffer
             simple_parse_json(msg, "\"data\"", data_buf);
             if(strlen(data_buf) > 0) {
                 char fld[64];
@@ -1394,13 +1393,13 @@ void manage_mqtt_recv_message(char * msg, int length)
                     strncpy((char *)topic.topic_sub, s, 63);
                 }
             }
-            free(data_buf);
+            /* data_buf = g_work_buf - no free needed */
         }
         write_net_config(&local_net_cfg, &net_center_info, &iot_net_info, &topic);
         g_iot_topic = topic;
 
-        char resp[256];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"iot_topic_set\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\"}",
             msg_id, mstick() / 1000);
@@ -1411,8 +1410,8 @@ void manage_mqtt_recv_message(char * msg, int length)
 
     // --- pwd_set ---
     if(strcmp(cmd_str, "pwd_set") == 0) {
-        char resp[256];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"pwd_set\","
             "\"ts\":%lu,\"code\":4,\"msg\":\"not implemented yet\"}",
             msg_id, mstick() / 1000);
@@ -1422,8 +1421,8 @@ void manage_mqtt_recv_message(char * msg, int length)
     
     // --- factory_reset ---
     if(strcmp(cmd_str, "factory_reset") == 0) {
-        char resp[256];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"factory_reset\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\"}",
             msg_id, mstick() / 1000);
@@ -1443,9 +1442,9 @@ void manage_mqtt_recv_message(char * msg, int length)
 
     // --- report_config ---
     if(strcmp(cmd_str, "report_config") == 0) {
-        char *data_buf = (char *)malloc(512);
+        char *data_buf = g_work_buf;  // shared global buffer (was malloc)
         if(data_buf) {
-            memset(data_buf, 0, 512);
+            memset(g_work_buf, 0, 1024);  // clear shared work buffer
             simple_parse_json(msg, "\"data\"", data_buf);
 
             if(strlen(data_buf) > 0) {
@@ -1484,11 +1483,11 @@ void manage_mqtt_recv_message(char * msg, int length)
                 simple_parse_json(data_buf, "\"timeout\"", tmp);
                 if(strlen(tmp) > 0) g_report_cfg.timeout = (uint16_t)strtoul(tmp, NULL, 10);
             }
-            free(data_buf);
+            /* data_buf = g_work_buf - no free needed */
         }
 
-        char resp[400];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"report_config\","
             "\"ts\":%lu,\"code\":0,\"msg\":\"success\","
             "\"data\":{"
@@ -1510,8 +1509,8 @@ void manage_mqtt_recv_message(char * msg, int length)
 
     // --- 未支持的命令 ---
     {
-        char resp[256];
+        char *resp = g_work_buf;
-        snprintf(resp, sizeof(resp),
+        snprintf(resp, WORK_BUF_SIZE,
             "{\"msg_id\":%lu,\"cmd\":\"%s\","
             "\"ts\":%lu,\"code\":4,\"msg\":\"unsupported command\"}",
             msg_id, cmd_str, mstick() / 1000);