/*
 socket出錯處理封裝函式
 wrap.h*/

#ifndef __WRAP_H_
#define __WRAP_H_

void perr_exit(const char *s);
int Accept(int fd, struct sockaddr* sa, socklen_t *salenptr);
void Bind(int fd, const struct sockaddr* sa, socklen_t salen);
void Connect(int fd, const struct sockaddr* sa, socklen_t salen);
void Listen(int fd, int backlog);
int Socket(int family, int type, int protocol);
ssize_t Read(int fd, void* ptr, size_t nbytes);
ssize_t Write(int fd, const void* ptr, size_t nbytes);
void Close(int fd);
ssize_t Readn(int fd, void* vptr, size_t n);
ssize_t Writen(int fd, const void* vptr, size_t n);
static ssize_t my_read(int fd, char* ptr);
ssize_t Readline(int fd, void* vptr,size_t maxlen);

#endif

/* wrap.c */
#include <stdlib.h>
#include <errno.h>
#include <sys/socket.h>
void perr_exit(const char *s)
{
	perror(s);
  	exit(1);
}
int Accept(int fd, struct sockaddr *sa, socklen_t *salenptr)
{
	int n;
	again:
	if ( (n = accept(fd, sa, salenptr)) < 0) {
		if ((errno == ECONNABORTED) || (errno == EINTR))
			goto again;
		else
			perr_exit("accept error");
	}
	return n;
}
void Bind(int fd, const struct sockaddr *sa, socklen_t salen)
{
	if (bind(fd, sa, salen) < 0)
		perr_exit("bind error");
}
void Connect(int fd, const struct sockaddr *sa, socklen_t salen)
{
	if (connect(fd, sa, salen) < 0)
		perr_exit("connect error");
}
void Listen(int fd, int backlog)
{
	if (listen(fd, backlog) < 0)
		perr_exit("listen error");
}
int Socket(int family, int type, int protocol)
{
	int n;
	if ( (n = socket(family, type, protocol)) < 0)
		perr_exit("socket error");
	return n;
}

ssize_t Read(int fd, void *ptr, size_t nbytes)
{
	ssize_t n;
	again:
		if ( (n = read(fd, ptr, nbytes)) == -1) {
			if (errno == EINTR)
				goto again;
			else
				return -1;
		}
	return n;
}
ssize_t Write(int fd, const void *ptr, size_t nbytes)
{
	ssize_t n;
	again:
		if ( (n = write(fd, ptr, nbytes)) == -1) {
			if (errno == EINTR)
				goto again;
			else
				return -1;
		}
	return n;
}
void Close(int fd)
{
	if (close(fd) == -1)
		perr_exit("close error");
}
ssize_t Readn(int fd, void *vptr, size_t n)
{
	size_t nleft;
	ssize_t nread;
	char *ptr;

	ptr = vptr;
	nleft = n;
	while (nleft > 0) {
		if ( (nread = read(fd, ptr, nleft)) < 0) {
			if (errno == EINTR)//對方中斷
				nread = 0;
			else//其他錯誤
				return -1;
		} else if (nread == 0)//對方關閉
				break;

		nleft -= nread;
		ptr += nread;
	}
	return n - nleft;//返回讀了多少個位元組
}
ssize_t Writen(int fd, const void *vptr, size_t n)
{
	size_t nleft;
	ssize_t nwritten;
	const char *ptr;

	ptr = vptr;
	nleft = n;
	while (nleft > 0) {
		if ( (nwritten = write(fd, ptr, nleft)) <= 0) {
			if (nwritten < 0 && errno == EINTR)
				nwritten = 0;
			else
				return -1;
		}

		nleft -= nwritten;
		ptr += nwritten;
	}
	return n;//返回要求寫的字元數
}
static ssize_t my_read(int fd, char *ptr)
{
	static int read_cnt;
	static char *read_ptr;
	static char read_buf[100];

	if (read_cnt <= 0) {
		again:
			if ( (read_cnt = read(fd, read_buf, sizeof(read_buf))) < 0) {
				if (errno == EINTR)
					goto again;
				return -1;
			} else if (read_cnt == 0)
				return 0;

			read_ptr = read_buf;//成功讀取字元
	}
	read_cnt--;
	*ptr = *read_ptr++;
	return 1;
}
ssize_t Readline(int fd, void *vptr, size_t maxlen)
{
	ssize_t n, rc;
	char c, *ptr;
	
	ptr = vptr;
	for (n = 1; n < maxlen; n++) {
		if ( (rc = my_read(fd, &c)) == 1) {
			*ptr++ = c;
			if (c == '\n')
				break;
		} else if (rc == 0) {
			*ptr = 0;
			return n - 1;
		} else
			return -1;
	}
	*ptr = 0;
	return n;
}