sendrecv.c

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

    default:
        trailerlen = 0;
        for (i = 0; i < hdtr->numtrailers; i++) {
            trailerlen += hdtr->trailers[i].iov_len;
        }

        /* XXX:  BUHHH? wow, what a memory leak! */
        trailerbuf = hdtrarray[1].iov_base = apr_palloc(sock->pool, trailerlen);
        hdtrarray[1].iov_len = trailerlen;

        for (i = 0; i < hdtr->numtrailers; i++) {
            memcpy(trailerbuf, hdtr->trailers[i].iov_base,
                   hdtr->trailers[i].iov_len);
            trailerbuf += hdtr->trailers[i].iov_len;
        }
    }

    do {
        if (nbytes) {       /* any bytes to send from the file? */
            rc = sendfile(sock->socketdes,      /* socket  */
                          file->filedes,        /* file descriptor to send */
                          off,                  /* where in the file to start */
                          nbytes,               /* number of bytes to send from file */
                          hdtrarray,            /* Headers/footers */
                          flags);               /* undefined, set to 0 */
        }
        else {              /* we can't call sendfile() with no bytes to send from the file */
            rc = writev(sock->socketdes, hdtrarray, 2);
        }
    } while (rc == -1 && errno == EINTR);

    while ((rc == -1) && (errno == EAGAIN || errno == EWOULDBLOCK) 
                      && (sock->timeout > 0)) {
        apr_status_t arv = apr_wait_for_io_or_timeout(NULL, sock, 0);

        if (arv != APR_SUCCESS) {
            *len = 0;
            return arv;
        }
        else {
            do {
                if (nbytes) {
                    rc = sendfile(sock->socketdes,    /* socket  */
                                  file->filedes,      /* file descriptor to send */
                                  off,                /* where in the file to start */
                                  nbytes,             /* number of bytes to send from file */
                                  hdtrarray,          /* Headers/footers */
                                  flags);             /* undefined, set to 0 */
                }
                else {      /* we can't call sendfile() with no bytes to send from the file */
                    rc = writev(sock->socketdes, hdtrarray, 2);
                }
            } while (rc == -1 && errno == EINTR);
        }
    }

    if (rc == -1) {
        *len = 0;
        return errno;
    }

    /* Set len to the number of bytes written */
    *len = rc;
    return APR_SUCCESS;
}
#elif defined(_AIX) || defined(__MVS__)
/* AIX and OS/390 have the same send_file() interface.
 *
 * subtle differences:
 *   AIX doesn't update the file ptr but OS/390 does
 *
 * availability (correctly determined by autoconf):
 *
 * AIX -  version 4.3.2 with APAR IX85388, or version 4.3.3 and above
 * OS/390 - V2R7 and above
 */
apr_status_t apr_socket_sendfile(apr_socket_t * sock, apr_file_t * file,
                                 apr_hdtr_t * hdtr, apr_off_t * offset,
                                 apr_size_t * len, apr_int32_t flags)
{
    int i, ptr, rv = 0;
    void * hbuf=NULL, * tbuf=NULL;
    apr_status_t arv;
    struct sf_parms parms;

    if (!hdtr) {
        hdtr = &no_hdtr;
    }

    /* Ignore flags for now. */
    flags = 0;

    /* word to the wise: by default, AIX stores files sent by send_file()
     * in the network buffer cache...  there are supposedly scenarios
     * where the most recent copy of the file won't be sent, but I can't
     * recreate the potential problem, perhaps because of the way we
     * use send_file()...  if you suspect such a problem, try turning
     * on the SF_SYNC_CACHE flag
     */

    /* AIX can also send the headers/footers as part of the system call */
    parms.header_length = 0;
    if (hdtr && hdtr->numheaders) {
        if (hdtr->numheaders == 1) {
            parms.header_data = hdtr->headers[0].iov_base;
            parms.header_length = hdtr->headers[0].iov_len;
        }
        else {
            for (i = 0; i < hdtr->numheaders; i++) {
                parms.header_length += hdtr->headers[i].iov_len;
            }
#if 0
            /* Keepalives make apr_palloc a bad idea */
            hbuf = malloc(parms.header_length);
#else
            /* but headers are small, so maybe we can hold on to the
             * memory for the life of the socket...
             */
            hbuf = apr_palloc(sock->pool, parms.header_length);
#endif
            ptr = 0;
            for (i = 0; i < hdtr->numheaders; i++) {
                memcpy((char *)hbuf + ptr, hdtr->headers[i].iov_base,
                       hdtr->headers[i].iov_len);
                ptr += hdtr->headers[i].iov_len;
            }
            parms.header_data = hbuf;
        }
    }
    else parms.header_data = NULL;
    parms.trailer_length = 0;
    if (hdtr && hdtr->numtrailers) {
        if (hdtr->numtrailers == 1) {
            parms.trailer_data = hdtr->trailers[0].iov_base;
            parms.trailer_length = hdtr->trailers[0].iov_len;
        }
        else {
            for (i = 0; i < hdtr->numtrailers; i++) {
                parms.trailer_length += hdtr->trailers[i].iov_len;
            }
#if 0
            /* Keepalives make apr_palloc a bad idea */
            tbuf = malloc(parms.trailer_length);
#else
            tbuf = apr_palloc(sock->pool, parms.trailer_length);
#endif
            ptr = 0;
            for (i = 0; i < hdtr->numtrailers; i++) {
                memcpy((char *)tbuf + ptr, hdtr->trailers[i].iov_base,
                       hdtr->trailers[i].iov_len);
                ptr += hdtr->trailers[i].iov_len;
            }
            parms.trailer_data = tbuf;
        }
    }
    else {
        parms.trailer_data = NULL;
    }

    /* Whew! Headers and trailers set up. Now for the file data */

    parms.file_descriptor = file->filedes;
    parms.file_offset = *offset;
    parms.file_bytes = *len;

    /* O.K. All set up now. Let's go to town */

    if (sock->options & APR_INCOMPLETE_WRITE) {
        sock->options &= ~APR_INCOMPLETE_WRITE;
        goto do_select;
    }

    do {
        rv = send_file(&(sock->socketdes), /* socket */
                       &(parms),           /* all data */
                       flags);             /* flags */
    } while (rv == -1 && errno == EINTR);

    while ((rv == -1) && (errno == EAGAIN || errno == EWOULDBLOCK) 
                      && (sock->timeout > 0)) {
do_select:
        arv = apr_wait_for_io_or_timeout(NULL, sock, 0);
        if (arv != APR_SUCCESS) {
            *len = 0;
            return arv;
        }
        else {
            do {
                rv = send_file(&(sock->socketdes), /* socket */
                               &(parms),           /* all data */
                               flags);             /* flags */
            } while (rv == -1 && errno == EINTR);
        }
    }

    (*len) = parms.bytes_sent;

#if 0
    /* Clean up after ourselves */
    if(hbuf) free(hbuf);
    if(tbuf) free(tbuf);
#endif

    if (rv == -1) {
        return errno;
    }

    if ((sock->timeout > 0)
          && (parms.bytes_sent 
                < (parms.file_bytes + parms.header_length + parms.trailer_length))) {
        sock->options |= APR_INCOMPLETE_WRITE;
    }

    return APR_SUCCESS;
}
#elif defined(__osf__) && defined (__alpha)
/* Tru64's sendfile implementation doesn't work, and we need to make sure that
 * we don't use it until it is fixed.  If it is used as it is now, it will
 * hang the machine and the only way to fix it is a reboot.
 */
#elif defined(HAVE_SENDFILEV)
/* Solaris 8's sendfilev() interface 
 *
 * SFV_FD_SELF refers to our memory space.
 *
 * Required Sparc patches (or newer):
 * 111297-01, 108528-09, 109472-06, 109234-03, 108995-02, 111295-01, 109025-03,
 * 108991-13
 * Required x86 patches (or newer):
 * 111298-01, 108529-09, 109473-06, 109235-04, 108996-02, 111296-01, 109026-04,
 * 108992-13
 */

#if APR_HAS_LARGE_FILES && defined(HAVE_SENDFILEV64)
#define sendfilevec_t sendfilevec64_t
#define sendfilev sendfilev64
#endif

apr_status_t apr_socket_sendfile(apr_socket_t *sock, apr_file_t *file,
                                 apr_hdtr_t *hdtr, apr_off_t *offset,
                                 apr_size_t *len, apr_int32_t flags)
{
    apr_status_t rv, arv;
    apr_size_t nbytes;
    sendfilevec_t *sfv;
    int vecs, curvec, i, repeat;
    apr_size_t requested_len = 0;

    if (!hdtr) {
        hdtr = &no_hdtr;
    }

    /* Ignore flags for now. */
    flags = 0;

    /* Calculate how much space we need. */
    vecs = hdtr->numheaders + hdtr->numtrailers + 1;
    sfv = apr_palloc(sock->pool, sizeof(sendfilevec_t) * vecs);

    curvec = 0;

    /* Add the headers */
    for (i = 0; i < hdtr->numheaders; i++, curvec++) {
        sfv[curvec].sfv_fd = SFV_FD_SELF;
        sfv[curvec].sfv_flag = 0;
        /* Cast to unsigned long to prevent sign extension of the
         * pointer value for the LFS case; see PR 39463. */
        sfv[curvec].sfv_off = (unsigned long)hdtr->headers[i].iov_base;
        sfv[curvec].sfv_len = hdtr->headers[i].iov_len;
        requested_len += sfv[curvec].sfv_len;
    }

    /* If the len is 0, we skip the file. */
    if (*len)
    {
        sfv[curvec].sfv_fd = file->filedes;
        sfv[curvec].sfv_flag = 0;
        sfv[curvec].sfv_off = *offset;
        sfv[curvec].sfv_len = *len; 
        requested_len += sfv[curvec].sfv_len;

        curvec++;
    }
    else {
        vecs--;
    }

    /* Add the footers */
    for (i = 0; i < hdtr->numtrailers; i++, curvec++) {
        sfv[curvec].sfv_fd = SFV_FD_SELF;
        sfv[curvec].sfv_flag = 0;
        sfv[curvec].sfv_off = (unsigned long)hdtr->trailers[i].iov_base;
        sfv[curvec].sfv_len = hdtr->trailers[i].iov_len;
        requested_len += sfv[curvec].sfv_len;
    }

    /* If the last write couldn't send all the requested data,
     * wait for the socket to become writable before proceeding
     */
    if (sock->options & APR_INCOMPLETE_WRITE) {
        sock->options &= ~APR_INCOMPLETE_WRITE;
        arv = apr_wait_for_io_or_timeout(NULL, sock, 0);
        if (arv != APR_SUCCESS) {
            *len = 0;
            return arv;
        }
    }
 
    /* Actually do the sendfilev
     *
     * Solaris may return -1/EAGAIN even if it sent bytes on a non-block sock.
     *
     * If no bytes were originally sent (nbytes == 0) and we are on a TIMEOUT 
     * socket (which as far as the OS is concerned is a non-blocking socket), 
     * we want to retry after waiting for the other side to read the data (as 
     * determined by poll).  Once it is clear to send, we want to retry
     * sending the sendfilevec_t once more.
     */
    arv = 0;
    do {
        /* Clear out the repeat */
        repeat = 0;

        /* socket, vecs, number of vecs, bytes written */
        rv = sendfilev(sock->socketdes, sfv, vecs, &nbytes);

        if (rv == -1 && errno == EAGAIN) {
            if (nbytes) {
                rv = 0;
            }
            else if (!arv && (sock->timeout > 0)) {
                apr_status_t t = apr_wait_for_io_or_timeout(NULL, sock, 0);

                if (t != APR_SUCCESS) {
                    *len = 0;
                    return t;
                }

                arv = 1; 
                repeat = 1;
            }
        }
    } while ((rv == -1 && errno == EINTR) || repeat);

    if (rv == -1) {
        *len = 0;
        return errno;
    }

    /* Update how much we sent */
    *len = nbytes;
    if ((sock->timeout > 0) && (*len < requested_len)) {
        sock->options |= APR_INCOMPLETE_WRITE;
    }
    return APR_SUCCESS;
}
#else
#error APR has detected sendfile on your system, but nobody has written a
#error version of it for APR yet.  To get past this, either write 
#error apr_socket_sendfile or change APR_HAS_SENDFILE in apr.h to 0.
#endif /* __linux__, __FreeBSD__, __DragonFly__, __HPUX__, _AIX, __MVS__,
	  Tru64/OSF1 */

#endif /* APR_HAS_SENDFILE */