feat(c-client): 实现完整的 C 客户端 SDK

核心功能： - JSON 解析：使用 cJSON 解析服务端返回的配置 - 配置缓存：自动保存到本地 .kenaito-config-cache.json 文件 - 定时同步：后台线程定时拉取配置变更（默认 10 秒） - 配置变更回调：配置变更时自动触发回调函数 - 全量/增量拉取：首次全量拉取，后续通过 lastTime 增量拉取 - 优雅退出：支持信号处理，Ctrl+C 优雅关闭 API： - config_client_init() - 初始化客户端 - config_client_start() - 启动客户端（全量拉取 + 后台同步） - config_client_get() - 获取配置值 - config_client_stop() - 停止客户端并保存缓存依赖： - libcurl（HTTP 请求） - cJSON（JSON 解析） - pthread（后台同步线程）编译： - SDK: gcc -c main.c -o kenaito_conf.o -lcurl -lcjson - Demo: gcc -o demo main.c ../kenaito-conf-c-client/main.c -lcurl -lcjson -lpthread
2026-04-15 21:02:16 +08:00
parent 102c62b64b
commit 7bf1dff3ce
3 changed files with 531 additions and 78 deletions
@@ -1,8 +1,119 @@
+/**
+ * Kenaito Config Center C Client Demo
+ * 
+ * 演示如何使用 C 客户端 SDK：
+ *   - 初始化客户端
+ *   - 注册配置变更回调
+ *   - 启动/停止客户端
+ *   - 读取配置
+ * 
+ * 编译：
+ *   gcc -o demo main.c -I../kenaito-conf-c-client -L../kenaito-conf-c-client -lkenaito_conf -lcurl -lcjson -lpthread
+ * 
+ * 或直接编译所有源文件：
+ *   gcc -o demo main.c ../kenaito-conf-c-client/main.c -lcurl -lcjson -lpthread
+ * 
+ * 运行：
+ *   ./demo
+ */
+
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include "../kenaito-conf-c-client/main.c"
+
+/* 全局客户端实例，用于信号处理 */
+static ConfigClient *g_demo_client = NULL;
+
+/**
+ * 配置变更回调示例
+ */
+void on_config_change(const char *key, const char *value) {
+    printf("\n[Callback] Config changed: %s = %s\n", key, value);
+    
+    /* 示例：根据配置键执行不同操作 */
+    if (strcmp(key, "log.level") == 0) {
+        printf("  -> Log level changed to: %s\n", value);
+    } else if (strcmp(key, "database.host") == 0) {
+        printf("  -> Database host changed to: %s\n", value);
+        /* 实际应用中可在此重新初始化数据库连接 */
+    } else if (strcmp(key, "database.port") == 0) {
+        printf("  -> Database port changed to: %s\n", value);
+    } else if (strcmp(key, "feature.enabled") == 0) {
+        printf("  -> Feature flag changed: %s\n", value);
+    }
+}
+
+/**
+ * 信号处理 - 优雅退出
+ */
+static void signal_handler(int sig) {
+    printf("\n[Signal] Received signal %d, shutting down...\n", sig);
+    if (g_demo_client) {
+        g_demo_client->running = 0;
+    }
+}

 int main() {
-    printf("Kenaito Config Center C Client Demo\n");
-    printf("AppName: kenaito-springboot-demo, Env: daily\n");
-    printf("See ../kenaito-conf-c-client/main.c for full implementation\n");
+    printf("========================================\n");
+    printf("  Kenaito Config Center C Client Demo\n");
+    printf("========================================\n\n");
+    
+    /* 注册信号处理 */
+    signal(SIGINT, signal_handler);
+    signal(SIGTERM, signal_handler);
+    
+    /* 初始化 CURL */
+    curl_global_init(CURL_GLOBAL_DEFAULT);
+    
+    /* 配置客户端 */
+    Config config = {
+        .baseUrl = "http://localhost:8080",
+        .appName = "kenaito-springboot-demo",
+        .env = "daily",
+        .version = "latest",
+        .token = "",
+        .syncInterval = 10,
+        .ignoreGlobal = 0,
+        .cacheDir = "."
+    };
+    
+    ConfigClient client;
+    config_client_init(&client, &config);
+    client.onChange = on_config_change;
+    
+    g_demo_client = &client;
+    
+    /* 启动客户端 */
+    config_client_start(&client);
+    
+    /* 主循环：演示配置读取 */
+    printf("\n[Demo] Running... Press Ctrl+C to stop\n\n");
+    
+    int iterations = 0;
+    while (client.running && iterations < 10) {
+        sleep(5);
+        
+        /* 演示：定期读取并打印配置 */
+        const char *dbHost = config_client_get(&client, "database.host");
+        const char *dbPort = config_client_get(&client, "database.port");
+        const char *logLevel = config_client_get(&client, "log.level");
+        const char *featureEnabled = config_client_get(&client, "feature.enabled");
+        
+        printf("\n[Current Configs @ %ld]\n", time(NULL));
+        printf("  database.host    = %s\n", dbHost ? dbHost : "(not set)");
+        printf("  database.port    = %s\n", dbPort ? dbPort : "(not set)");
+        printf("  log.level        = %s\n", logLevel ? logLevel : "(not set)");
+        printf("  feature.enabled  = %s\n", featureEnabled ? featureEnabled : "(not set)");
+        printf("  Total configs: %d\n\n", client.configs.count);
+        
+        iterations++;
+    }
+    
+    /* 停止客户端 */
+    config_client_stop(&client);
+    
+    printf("\n[Demo] Finished\n");
    return 0;
 }