C 语言服务器处理客户端请求函数 - handleClientRequests

"#ifndef HANDLE_H\n#define HANDLE_H\n\n#include "string.h"\n#include "stdlib.h"\n#include "sys/socket.h"\n#include "netinet/in.h"\n#include "sqlite3.h"\n#include "server.h"\n#define MAX_BUFFER_SIZE 1024\n\nvoid handleClientRequests(ServerContext *context,int sockfd);// 处理客户端请求\nvoid handleClientRequest(ServerContext context);// 处理单个客户端请求\nint receiveUserId(int sockfd);// 接收客户端发送的userid\nsqlite3_stmt prepareStatement(sqlite3 *db, int userid); // 准备数据库查询语句\nvoid initializeStatus(Status *status);// 初始化设备状态\nvoid updateAcStatus(Status *acStatus, int uid, const unsigned char *device_state, const unsigned char *value) ;// 更新设备状态\nvoid generateAcSuggestion(const Status *acStatus, char *suggestion);// 生成空调建议\nvoid generateHumidifierSuggestion(const Status *humidifierStatus, char suggestion);//生成加湿器建议\nchar combineSuggestions(const char *suggestion, const char *humidifierSuggestion); // 合并建议\nvoid sendSuggestion(int sockfd,char suggestion) ;// 发送建议\n\n#endif\n#include "stdio.h"\n#include "unistd.h"\n#include "sys/socket.h"\n#include "arpa/inet.h"\n#include "handle.h"\n\nint receiveUserId(int sockfd) {\n int userid;\n ssize_t recvSize = recv(sockfd, &userid, sizeof(int), 0);\n if (recvSize == -1 || recvSize == 0 || recvSize != sizeof(int)) {\n perror("接收userid失败");\n return -1;\n }\n return ntohl(userid);\n}\n\nsqlite3_stmt prepareStatement(sqlite3 *db, int userid) {\n char sql[100];\n snprintf(sql, sizeof(sql), "SELECT * FROM Status WHERE uid = %d", userid);\n sqlite3_stmt *stmt = NULL;\n int rc = sqlite3_prepare_v2(db, sql, -1, &stmt, NULL);\n if (rc != SQLITE_OK) {\n fprintf(stderr, "无法执行的语句: %s\n", sqlite3_errmsg(db));\n return NULL;\n }\n return stmt;\n}\n\nvoid initializeStatus(Status *status) {\n memset(status, 0, sizeof(Status));\n status->uid = 0;\n status->device_name[0] = '\0';\n}\n\nvoid updateAcStatus(Status *acStatus, int uid, const unsigned char *device_state, const unsigned char *value) {\n acStatus->uid = uid;\n strncpy(acStatus->device_state, device_state, sizeof(acStatus->device_state) - 1);\n acStatus->device_state[sizeof(acStatus->device_state) - 1] = '\0';\n strncpy(acStatus->value, value, sizeof(acStatus->value) - 1);\n acStatus->value[sizeof(acStatus->value) - 1] = '\0';\n\n}\n\nvoid generateAcSuggestion(const Status *acStatus, char *suggestion) {\n int temperature = atoi(acStatus->value);\n \n if (temperature < 24) {\n snprintf(suggestion, MAX_BUFFER_SIZE, "空调温度过低，建议提高温度至26℃");\n } else if(temperature>35){\n snprintf(suggestion, MAX_BUFFER_SIZE, "空调温度过高，建议降低温度至26℃");\n }\n else{\n snprintf(suggestion, MAX_BUFFER_SIZE, "空调温度适宜");\n }\n}\n\nvoid generateHumidifierSuggestion(const Status *humidifierStatus, char suggestion) {\n int humidity = atoi(humidifierStatus->value);\n if (humidity < 40) {\n snprintf(suggestion, MAX_BUFFER_SIZE, "加湿器湿度过低，建议调整加湿器湿度");\n } else if (humidity > 70) {\n snprintf(suggestion, MAX_BUFFER_SIZE, "加湿器湿度过高，建议调整加湿器湿度");\n } else {\n snprintf(suggestion, MAX_BUFFER_SIZE, "加湿器湿度适宜");\n }\n}\n\nchar combineSuggestions(const char *suggestion, const char *humidifierSuggestion) {\n int combinedSuggestionSize = strlen(suggestion) + strlen(humidifierSuggestion) + 2;\n char *combinedSuggestion = malloc(combinedSuggestionSize);\n snprintf(combinedSuggestion, combinedSuggestionSize, "%s\n%s", suggestion, humidifierSuggestion);\n return combinedSuggestion;\n}\n\nvoid sendSuggestion(int sockfd, char *suggestion) {\n ssize_t sendSize = send(sockfd, suggestion, strlen(suggestion)+1, 0);\n if (sendSize == -1) {\n perror("发送失败\nsend");\n free(suggestion);\n return;\n } else {\n printf("建议已发送\n");\n }\n}\n\nvoid handleClientRequest(ServerContext *context) {\n int userid = receiveUserId(context->sockfd);\n if (userid == -1) {\n perror("接收userid失败");\n return;\n }\n\n printf("客户端已连接\n");\n printf("userid:%d\n", userid);\n\n sqlite3_stmt *stmt = prepareStatement(context->db, userid);\n if (stmt == NULL) {\n fprintf(stderr, "无法执行的语句: %s\n", sqlite3_errmsg(context->db));\n return;\n }\n\n Status acStatus, humidifierStatus;\n initializeStatus(&acStatus);\n initializeStatus(&humidifierStatus);\n\n char suggestion[MAX_BUFFER_SIZE] = "";\n char humidifierSuggestion[MAX_BUFFER_SIZE] = "";\n\n int acOpened = 0;\n int humidifierOpened = 0;\n\n while (sqlite3_step(stmt) == SQLITE_ROW) {\n int uid = sqlite3_column_int(stmt, 1);\n const unsigned char *device_name = sqlite3_column_text(stmt, 2);\n const unsigned char *device_state = sqlite3_column_text(stmt, 3);\n const unsigned char *value = sqlite3_column_text(stmt, 4);\n\n if (strcmp(device_name, "空调" == 0) {\n if (strcmp(device_state, "开启" == 0){\n updateAcStatus(&acStatus, uid, device_state, value);\n generateAcSuggestion(&acStatus, suggestion);\n acOpened = 1;\n } else if (strcmp(device_state, "关闭" == 0) {\n updateAcStatus(&acStatus, uid, device_state, value);\n // 更新设备状态为关闭\n acOpened = 0;\n }\n } else if (strcmp(device_name, "加湿器" == 0) {\n if (strcmp(device_state, "开启" == 0){\n updateAcStatus(&humidifierStatus, uid, device_state, value);\n generateHumidifierSuggestion(&humidifierStatus, humidifierSuggestion);\n humidifierOpened = 1;\n } else if (strcmp(device_state, "关闭" == 0) {\n updateAcStatus(&humidifierStatus, uid, device_state, value);\n // 更新设备状态为关闭\n humidifierOpened = 0;\n }\n }\n }\n\n sqlite3_finalize(stmt);\n\n if (!acOpened) {\n snprintf(suggestion, MAX_BUFFER_SIZE, "空调未开启");\n }\n\n if (!humidifierOpened) {\n snprintf(humidifierSuggestion, MAX_BUFFER_SIZE, "加湿器未开启");\n }\n\n char *combinedSuggestion = combineSuggestions(suggestion, humidifierSuggestion);\n sendSuggestion(context->sockfd, combinedSuggestion);\n printf("建议为：\n%s\n", combinedSuggestion);\n\n free(combinedSuggestion);\n\n // 关闭连接\n shutdown(context->sockfd, SHUT_RDWR);\n printf("按下Ctrl + Z登出...\n");\n}\n\nvoid handleClientRequests(ServerContext *context, int sockfd) {\n fd_set readfds;\n int maxfd = sockfd;\n\n while (1) {\n FD_ZERO(&readfds);\n FD_SET(sockfd, &readfds);\n\n int activity = select(maxfd + 1, &readfds, NULL, NULL, NULL);\n if (activity == -1) {\n perror("select");\n break;\n }\n\n if (FD_ISSET(sockfd, &readfds)) {\n int clientSockfd = accept(sockfd, (struct sockaddr *)&context->client_addr, &context->client_addr_len);\n if (clientSockfd == -1) {\n perror("套接字接收失败\naccept");\n break;\n }\n\n context->sockfd = clientSockfd;\n handleClientRequest(context);\n\n close(clientSockfd);\n }\n }\n}