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server.c
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server.c
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#include "server.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>
#include "third_party/log.h"
#define THREAD_MAX 3
#define BUF_MAX 1024
#define GUESS_MAX 6
void acceptor_new(acceptor *self) {
memset(self, 0, sizeof(acceptor));
}
void acceptor_destructor(acceptor *self) {
if (self->destructor != NULL && self->p != NULL) {
self->destructor(self->p);
}
}
void listener_new(listener *self) {
memset(self, 0, sizeof(listener));
}
void listener_destructor(listener *self) {
if (self->destructor != NULL && self->p != NULL) {
self->destructor(self->p);
}
}
// Contains protocol-agnostic logic of `server` and `server_stateless`.
// e.g. Input serialization, server response parsing, error handling.
typedef struct server_impl_t {
char buf[BUF_MAX];
} server_impl;
// Creates a new `server_impl`.
// Returns 0 on success, -1 on failure.
int server_impl_new(server_impl *self) {
memset(self->buf, 0, BUF_MAX);
return 0;
}
void server_impl_destructor(__attribute__((unused)) server_impl *self) {
// do nothing
}
// Handle the client's request.
char *server_impl_handle(server_impl *self, const char msg) {
return NULL;
}
server *server_new(listener l) {
server_impl *p = malloc(sizeof(server_impl));
if (p == NULL) return NULL;
server_impl_new(p);
server *self = malloc(sizeof(server));
if (self == NULL) {
free(p);
return NULL;
}
self->l = l;
self->p = p;
return self;
}
void server_destructor(server *self) {
listener_destructor(&self->l);
if (self->p == NULL) return;
server_impl_destructor(self->p);
free(self->p);
self->p = NULL;
}
typedef struct client_msg_t {
char msg_flag;
char *msg;
} client_msg;
int server_recv_msg(
acceptor *c,
client_msg *ret
) {
char msg_flag;
{
const char *msg = c->recv_func(c->p, 1); // msg flag
if (msg == NULL) {
log_error("recv msg flag failed");
return -1;
}
msg_flag = msg[0];
}
ret->msg_flag = msg_flag;
if (msg_flag < 1) return 0; // received nothing
char *msg_str = NULL;
{
msg_str = malloc(msg_flag + 1);
const char *msg = c->recv_func(c->p, msg_flag); // announcement
if (msg == NULL) {
log_error("recv msg content failed");
return -1;
}
strcpy(msg_str, msg);
msg_str[msg_flag] = 0;
}
ret->msg = msg_str;
return 0;
}
int server_send_control_msg(
acceptor *c,
const char *word,
char word_len,
const char *wrong_guesses,
char wrong_guesses_len
) {
char msg_flag = 0;
if (c->send_func(c->p, &msg_flag, 1)) return -1; // msg flag
if (c->send_func(c->p, &word_len, 1)) return -1; // word len
if (c->send_func(c->p, &wrong_guesses_len, 1)) return -1; // incorrect
if (word_len > 0) {
if (c->send_func(c->p, word, word_len)) return -1; // word
}
if (wrong_guesses_len > 0) {
if (c->send_func(c->p, wrong_guesses, wrong_guesses_len)) return -1; // wrong_guesses
}
return 0;
}
int server_send_announcement(
acceptor *c,
const char *msg,
char msg_len
) {
if (c->send_func(c->p, &msg_len, 1)) return -1; // msg flag
if (c->send_func(c->p, msg, msg_len)) return -1; // msg
return 0;
}
int server_run_p(acceptor *c, const char *word) {
const char word_len = strlen(word);
{
char *msg = c->recv_func(c->p, 1);
if (msg == NULL) {
log_error("recv msg failed");
return -1;
}
const char msg_len = msg[0];
if (msg_len != 0) {
log_error("initial message should be empty");
return -1;
}
}
// Start the game
char *word_buf;
{
word_buf = malloc(sizeof(char) * (word_len + 1));
if (word_buf == NULL) {
log_error("malloc failed");
return -1;
}
memset(word_buf, '_', word_len);
word_buf[word_len] = '\0';
}
char wrong_guesses[GUESS_MAX] = {0};
size_t wrong_guesses_len = 0;
while (wrong_guesses_len < GUESS_MAX) {
if (server_send_control_msg(
c,
word_buf, word_len,
wrong_guesses, wrong_guesses_len
)) {
log_error("send msg failed");
return -1;
}
client_msg msg;
while (1) {
if (server_recv_msg(c, &msg)) {
log_error("recv response failed");
return -1;
}
if (msg.msg_flag < 1) { // client exit
log_info("client exited");
return 0;
}
if (msg.msg_flag == 1) {
break; // received a valid guess
}
}
const char guess = msg.msg[0];
// printf("recv guess: %c\n", guess);
int found = 0;
for (int i = 0; i < word_len; i += 1) {
if (word[i] == guess) {
word_buf[i] = guess;
found = 1;
}
}
if (strcmp(word_buf, word) == 0) {
break; // word is found
}
if (found) {
continue; // guess is correct
}
for (int i = 0; i < GUESS_MAX; i += 1) {
if (wrong_guesses[i] == guess) {
break;
}
if (wrong_guesses[i] == 0) {
wrong_guesses[i] = guess;
wrong_guesses_len += 1;
break;
}
}
}
log_info("game finished");
if (server_send_control_msg(
c,
word, word_len,
wrong_guesses, wrong_guesses_len
)) {
log_error("send final control msg failed");
return -1;
}
if (wrong_guesses_len == GUESS_MAX) {
if (server_send_announcement(c, "You Lose!", 9)) {
log_error("send msg failed");
return -1;
}
} else {
if (server_send_announcement(c, "You Win!", 8)) {
log_error("send msg failed");
return -1;
}
}
if (server_send_announcement(c, "Game Over!", 10)) {
log_error("send msg failed");
return -1;
}
return 0;
}
typedef struct thread_arg_t {
acceptor *c;
const char *word;
size_t *thread_count;
} thread_arg;
void server_thread_handler(thread_arg* arg) {
acceptor *c = arg->c;
const char *word = arg->word;
size_t *thread_count = arg->thread_count;
free(arg);
int ret = server_run_p(c, word);
if (ret < -1) {
(*thread_count) -= 1;
return; // fatal error
}
acceptor_destructor(c);
(*thread_count) -= 1;
}
char* server_rand_word() {
char* words[20] = {0};
FILE *fd = fopen("hangman_words.txt", "r");
if (!fd) return NULL;
size_t words_len = 0;
for (int i = 0; i < 16; i += 1) {
char *buf = malloc(128); /* allocate a memory slot of 128 chars */
if (fscanf(fd, "%127s", buf) > 0) {
words[i] = buf;
words_len += 1;
} else {
free(buf);
break;
}
}
fclose(fd);
return words[rand() % words_len];
}
void server_run(server *self) {
size_t thread_count = 0;
pthread_t thread[THREAD_MAX];
while (1) {
acceptor* c = malloc(sizeof(acceptor));
acceptor_new(c);
int res = self->l.next_client(self->l.p, c);
if (res) {
log_error("accept failed");
free(c);
return;
}
if (thread_count < THREAD_MAX) {
server_send_announcement(c, "welcome", 7);
const char* word = server_rand_word();
if (!word) word = "default"; // default case
log_info("chosen word: %s", word);
thread_arg *arg = malloc(sizeof(thread_arg));
arg->word = word;
arg->c = c;
arg->thread_count = &thread_count;
pthread_create(
&thread[thread_count],
NULL,
(void *(*)(void *)) &server_thread_handler,
arg
);
thread_count += 1;
continue;
}
log_warn("too many threads\n");
server_send_announcement(c, "server-overloaded", 17);
acceptor_destructor(c);
free(c);
}
}