buf.h

/*
 *  buf.h
 *  XBolo
 *
 *  Created by Robert Chrzanowski on 10/15/09.
 *  Copyright 2009 Robert Chrzanowski. All rights reserved.
 *
 */

#ifndef __BUF__
#define __BUF__

#include "errchk.h"

#include <unistd.h>

struct Buf {
  void *ptr;
  size_t nbytes;
  size_t size;
} ;

/* Initializes and allocates a buffer.  Returns -1 on error and sets errno. */
int initbuf(struct Buf *buf);

/* Frees a buffer. */
void freebuf(struct Buf *buf);

/* Writes to the end of a buffer and returns the number of bytes written.  Returns -1 on error and sets errno. */
ssize_t writebuf(struct Buf *buf, const void *data, size_t nbytes);

/* Writes the first nbytes from the buffer to data and shifts the remaining bytes.  If data is NULL no bytes are written.
   Returns the number of bytes removed.  Returns -1 on error and sets errno. */
ssize_t readbuf(struct Buf *buf, void *data, size_t nbytes);

/* Attempts nonblocking send() of buf to descriptor d.  Returns the number of bytes written or 0 if no bytes are sent.
   Returns -1 on error and sets errno. */
ssize_t sendbuf(struct Buf *buf, int d);

/* Attempts nonblocking recv() of descriptor d to the end of the buffer.  Returns the number of bytes received or 0 if
   no data is ready or if the socket has been closed by the distent end.  Select() returns with it ready for reading in that case.
   Returns -1 on error and sets errno. */
ssize_t recvbuf(struct Buf *buf, int d);

int selectreadwrite(int readsock, int writesock);
int selectreadread(int readsock1, int readsock2);
int cntlsend(int cntlsock, int sock, struct Buf *buf);
int cntlrecv(int cntlsock, int sock, struct Buf *buf, size_t nbytes);

#endif  /* __BUF__ */