/* Simple binding of nanopb streams to TCP sockets.
 */

#include <sys/socket.h>
#include <sys/types.h>
#include <pb_encode.h>
#include <pb_decode.h>

#include "common.h"

static bool write_callback(pb_ostream_t *stream, const uint8_t *buf, size_t count)
{
    int fd = (int)stream->state;
    return send(fd, buf, count, 0) == count;
}

static bool read_callback(pb_istream_t *stream, uint8_t *buf, size_t count)
{
    int fd = (int)stream->state;
    int result;
    
    if (buf == NULL)
    {
        /* Well, this is a really inefficient way to skip input. */
        /* It is only used when there are unknown fields. */
        char dummy;
        while (count-- && recv(fd, &dummy, 1, 0) == 1);
        return count == 0;
    }
    
    result = recv(fd, buf, count, MSG_WAITALL);
    
    if (result == 0)
        stream->bytes_left = 0; /* EOF */
    
    return result == count;
}

pb_ostream_t pb_ostream_from_socket(int fd)
{
    pb_ostream_t stream = {&write_callback, (void*)fd, SIZE_MAX, 0};
    return stream;
}

pb_istream_t pb_istream_from_socket(int fd)
{
    pb_istream_t stream = {&read_callback, (void*)fd, SIZE_MAX};
    return stream;
}