client.cpp

/* Copyright (c) 2021 Xie Meiyi(xiemeiyi@hust.edu.cn) and OceanBase and/or its affiliates. All rights reserved.
miniob is licensed under Mulan PSL v2.
You can use this software according to the terms and conditions of the Mulan PSL v2.
You may obtain a copy of Mulan PSL v2 at:
         http://license.coscl.org.cn/MulanPSL2
THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
See the Mulan PSL v2 for more details. */

//
// Created by Longda on 2021
//

#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/un.h>
#include <unistd.h>
#include <termios.h>

#include "common/defs.h"
#include "common/lang/string.h"

#ifdef USE_READLINE
#include "readline/readline.h"
#endif

#define MAX_MEM_BUFFER_SIZE 8192
#define PORT_DEFAULT 6789

using namespace common;

#ifdef USE_READLINE
char *my_readline(const char *prompt) 
{
  return readline(prompt);
}
#else // USE_READLINE
char *my_readline(const char *prompt)
{
  char *buffer = (char *)malloc(MAX_MEM_BUFFER_SIZE);
  if (nullptr == buffer) {
    fprintf(stderr, "failed to alloc line buffer");
    return nullptr;
  }
  fprintf(stdout, prompt);
  char *s = fgets(buffer, MAX_MEM_BUFFER_SIZE, stdin);
  if (nullptr == s) {
    fprintf(stderr, "failed to read message from console");
    free(buffer);
    return nullptr;
  }
  return buffer;
}
#endif // USE_READLINE

/* this function config a exit-cmd list, strncasecmp func truncate the command from terminal according to the number,
   'strncasecmp("exit", cmd, 4)' means that obclient read command string from terminal, truncate it to 4 chars from 
   the beginning, then compare the result with 'exit', if they match, exit the obclient.
*/
bool is_exit_command(const char *cmd) {
  return 0 == strncasecmp("exit", cmd, 4) ||
         0 == strncasecmp("bye", cmd, 3) ||
         0 == strncasecmp("\\q", cmd, 2) ;
}

int init_unix_sock(const char *unix_sock_path)
{
  int sockfd = socket(PF_UNIX, SOCK_STREAM, 0);
  if (sockfd < 0) {
    fprintf(stderr, "failed to create unix socket. %s", strerror(errno));
    return -1;
  }

  struct sockaddr_un sockaddr;
  memset(&sockaddr, 0, sizeof(sockaddr));
  sockaddr.sun_family = PF_UNIX;
  snprintf(sockaddr.sun_path, sizeof(sockaddr.sun_path), "%s", unix_sock_path);

  if (connect(sockfd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)) < 0) {
    fprintf(stderr, "failed to connect to server. unix socket path '%s'. error %s", sockaddr.sun_path, strerror(errno));
    close(sockfd);
    return -1;
  }
  return sockfd;
}

int init_tcp_sock(const char *server_host, int server_port)
{
  struct hostent *host;
  struct sockaddr_in serv_addr;

  if ((host = gethostbyname(server_host)) == NULL) {
    fprintf(stderr, "gethostbyname failed. errmsg=%d:%s\n", errno, strerror(errno));
    return -1;
  }

  int sockfd;
  if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
    fprintf(stderr, "create socket error. errmsg=%d:%s\n", errno, strerror(errno));
    return -1;
  }

  serv_addr.sin_family = AF_INET;
  serv_addr.sin_port = htons(server_port);
  serv_addr.sin_addr = *((struct in_addr *)host->h_addr);
  bzero(&(serv_addr.sin_zero), 8);

  if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(struct sockaddr)) == -1) {
    fprintf(stderr, "Failed to connect. errmsg=%d:%s\n", errno, strerror(errno));
    close(sockfd);
    return -1;
  }
  return sockfd;
}

int main(int argc, char *argv[])
{
  const char *unix_socket_path = nullptr;
  const char *server_host = "127.0.0.1";
  int server_port = PORT_DEFAULT;
  int opt;
  extern char *optarg;
  while ((opt = getopt(argc, argv, "s:h:p:")) > 0) {
    switch (opt) {
      case 's':
        unix_socket_path = optarg;
        break;
      case 'p':
        server_port = atoi(optarg);
        break;
      case 'h':
        server_host = optarg;
        break;
    }
  }

  const char *prompt_str = "miniob > ";

  int sockfd, send_bytes;

  if (unix_socket_path != nullptr) {
    sockfd = init_unix_sock(unix_socket_path);
  } else {
    sockfd = init_tcp_sock(server_host, server_port);
  }
  if (sockfd < 0) {
    return 1;
  }

  char send_buf[MAX_MEM_BUFFER_SIZE];

  char *input_command = nullptr;
  while ((input_command = my_readline(prompt_str)) != nullptr) {
    if (common::is_blank(input_command)) {
      free(input_command);
      continue;
    }

    if (is_exit_command(input_command)) {
      free(input_command);
      break;
    }

    if ((send_bytes = write(sockfd, input_command, strlen(input_command) + 1)) == -1) { // TODO writen
      fprintf(stderr, "send error: %d:%s \n", errno, strerror(errno));
      exit(1);
    }
    free(input_command);
    memset(send_buf, 0, sizeof(send_buf));

    int len = 0;
    while ((len = recv(sockfd, send_buf, MAX_MEM_BUFFER_SIZE, 0)) > 0) {
      bool msg_end = false;
      for (int i = 0; i < len; i++) {
        if (0 == send_buf[i]) {
          msg_end = true;
          break;
        }
        printf("%c", send_buf[i]);
      }
      if (msg_end) {
        break;
      }
      memset(send_buf, 0, MAX_MEM_BUFFER_SIZE);
    }

    if (len < 0) {
      fprintf(stderr, "Connection was broken: %s\n", strerror(errno));
      break;
    }
    if (0 == len) {
      printf("Connection has been closed\n");
      break;
    }
  }
  close(sockfd);

  return 0;
}