readwrite.c

Apache 2.0.63 is the current stable version of the 2.0 series, and is recommended over any previous

        rv = 0;
        while (rv == 0 && size > 0) {
            if (thefile->bufpos == APR_FILE_BUFSIZE)   // write buffer is full
                rv = apr_file_flush(thefile);

            blocksize = size > APR_FILE_BUFSIZE - thefile->bufpos ? APR_FILE_BUFSIZE - thefile->bufpos : size;
            memcpy(thefile->buffer + thefile->bufpos, pos, blocksize);
            thefile->bufpos += blocksize;
            pos += blocksize;
            size -= blocksize;
        }

        apr_thread_mutex_unlock(thefile->mutex);
        return rv;
    } else {
        if (!thefile->pipe) {
            apr_off_t offset = 0;
            apr_status_t rc;
            if (thefile->append) {
                /* apr_file_lock will mutex the file across processes.
                 * The call to apr_thread_mutex_lock is added to avoid
                 * a race condition between LockFile and WriteFile 
                 * that occasionally leads to deadlocked threads.
                 */
                apr_thread_mutex_lock(thefile->mutex);
                rc = apr_file_lock(thefile, APR_FLOCK_EXCLUSIVE);
                if (rc != APR_SUCCESS) {
                    apr_thread_mutex_unlock(thefile->mutex);
                    return rc;
                }
                rc = apr_file_seek(thefile, APR_END, &offset);
                if (rc != APR_SUCCESS) {
                    apr_thread_mutex_unlock(thefile->mutex);
                    return rc;
                }
            }
            if (thefile->pOverlapped) {
                thefile->pOverlapped->Offset     = (DWORD)thefile->filePtr;
                thefile->pOverlapped->OffsetHigh = (DWORD)(thefile->filePtr >> 32);
            }
            rv = WriteFile(thefile->filehand, buf, *nbytes, &bwrote,
                           thefile->pOverlapped);
            if (thefile->append) {
                apr_file_unlock(thefile);
                apr_thread_mutex_unlock(thefile->mutex);
            }
        }
        else {
            rv = WriteFile(thefile->filehand, buf, *nbytes, &bwrote,
                           thefile->pOverlapped);
        }
        if (rv) {
            *nbytes = bwrote;
            rv = APR_SUCCESS;
        }
        else {
            (*nbytes) = 0;
            rv = apr_get_os_error();
            if (rv == APR_FROM_OS_ERROR(ERROR_IO_PENDING)) {
 
                DWORD timeout_ms;

                if (thefile->timeout == 0) {
                    timeout_ms = 0;
                }
                else if (thefile->timeout < 0) {
                    timeout_ms = INFINITE;
                }
                else {
                    timeout_ms = (DWORD)(thefile->timeout / 1000);
                }
	       
                rv = WaitForSingleObject(thefile->pOverlapped->hEvent, timeout_ms);
                switch (rv) {
                    case WAIT_OBJECT_0:
                        GetOverlappedResult(thefile->filehand, thefile->pOverlapped, nbytes, TRUE);
                        rv = APR_SUCCESS;
                        break;
                    case WAIT_TIMEOUT:
                        rv = APR_TIMEUP;
                        break;
                    case WAIT_FAILED:
                        rv = apr_get_os_error();
                        break;
                    default:
                        break;
                }
                if (rv != APR_SUCCESS) {
                    if (apr_os_level >= APR_WIN_98)
                        CancelIo(thefile->filehand);
                }
            }
        }
        if (rv == APR_SUCCESS && thefile->pOverlapped && !thefile->pipe) {
            thefile->filePtr += *nbytes;
        }
    }
    return rv;
}
/* ToDo: Write for it anyway and test the oslevel!
 * Too bad WriteFileGather() is not supported on 95&98 (or NT prior to SP2)
 */
APR_DECLARE(apr_status_t) apr_file_writev(apr_file_t *thefile,
                                     const struct iovec *vec,
                                     apr_size_t nvec, 
                                     apr_size_t *nbytes)
{
    apr_status_t rv = APR_SUCCESS;
    apr_size_t i;
    DWORD bwrote = 0;
    char *buf;

    *nbytes = 0;
    for (i = 0; i < nvec; i++) {
        buf = vec[i].iov_base;
        bwrote = vec[i].iov_len;
        rv = apr_file_write(thefile, buf, &bwrote);
        *nbytes += bwrote;
        if (rv != APR_SUCCESS) {
            break;
        }
    }
    return rv;
}

APR_DECLARE(apr_status_t) apr_file_putc(char ch, apr_file_t *thefile)
{
    DWORD len = 1;

    return apr_file_write(thefile, &ch, &len);
}

APR_DECLARE(apr_status_t) apr_file_ungetc(char ch, apr_file_t *thefile)
{
    thefile->ungetchar = (unsigned char) ch;
    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_file_getc(char *ch, apr_file_t *thefile)
{
    apr_status_t rc;
    int bread;

    bread = 1;
    rc = apr_file_read(thefile, ch, &bread);

    if (rc) {
        return rc;
    }
    
    if (bread == 0) {
        thefile->eof_hit = TRUE;
        return APR_EOF;
    }
    return APR_SUCCESS; 
}

APR_DECLARE(apr_status_t) apr_file_puts(const char *str, apr_file_t *thefile)
{
    DWORD len = strlen(str);

    return apr_file_write(thefile, str, &len);
}

APR_DECLARE(apr_status_t) apr_file_gets(char *str, int len, apr_file_t *thefile)
{
    apr_size_t readlen;
    apr_status_t rv = APR_SUCCESS;
    int i;    

    for (i = 0; i < len-1; i++) {
        readlen = 1;
        rv = apr_file_read(thefile, str+i, &readlen);

        if (rv != APR_SUCCESS && rv != APR_EOF)
            return rv;

        if (readlen == 0) {
            /* If we have bytes, defer APR_EOF to the next call */
            if (i > 0)
                rv = APR_SUCCESS;
            break;
        }
        
        if (str[i] == '\n') {
            i++; /* don't clobber this char below */
            break;
        }
    }
    str[i] = 0;
    return rv;
}

APR_DECLARE(apr_status_t) apr_file_flush(apr_file_t *thefile)
{
    if (thefile->buffered) {
        DWORD written = 0;
        apr_status_t rc = 0;

        if (thefile->direction == 1 && thefile->bufpos) {
            if (!WriteFile(thefile->filehand, thefile->buffer, thefile->bufpos, &written, NULL))
                rc = apr_get_os_error();
            thefile->filePtr += written;

            if (rc == 0)
                thefile->bufpos = 0;
        }

        return rc;
    }

    /* There isn't anything to do if we aren't buffering the output
     * so just return success.
     */
    return APR_SUCCESS; 
}

struct apr_file_printf_data {
    apr_vformatter_buff_t vbuff;
    apr_file_t *fptr;
    char *buf;
};

static int file_printf_flush(apr_vformatter_buff_t *buff)
{
    struct apr_file_printf_data *data = (struct apr_file_printf_data *)buff;

    if (apr_file_write_full(data->fptr, data->buf,
                            data->vbuff.curpos - data->buf, NULL)) {
        return -1;
    }

    data->vbuff.curpos = data->buf;
    return 0;
}

APR_DECLARE_NONSTD(int) apr_file_printf(apr_file_t *fptr, 
                                        const char *format, ...)
{
    struct apr_file_printf_data data;
    va_list ap;
    int count;

    data.buf = malloc(HUGE_STRING_LEN);
    if (data.buf == NULL) {
        return 0;
    }
    data.vbuff.curpos = data.buf;
    data.vbuff.endpos = data.buf + HUGE_STRING_LEN;
    data.fptr = fptr;
    va_start(ap, format);
    count = apr_vformatter(file_printf_flush,
                           (apr_vformatter_buff_t *)&data, format, ap);
    /* apr_vformatter does not call flush for the last bits */
    if (count >= 0) file_printf_flush((apr_vformatter_buff_t *)&data);

    va_end(ap);

    free(data.buf);
    return count;
}