/*
- * Copyright (C) 2006-2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2013 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
#include "fd.h"
/**
- * Write a buffer to a file descriptor, re-writing on short writes.
+ * Write an array of buffers to a file descriptor.
*
* \param fd The file descriptor.
- * \param buf The buffer to write.
- * \param len The number of bytes to write.
+ * \param iov Pointer to one or more buffers.
+ * \param iovcnt The number of buffers.
*
* EAGAIN/EWOULDBLOCK is not considered a fatal error condition. For example
* DCCP CCID3 has a sending wait queue which fills up and is emptied
* asynchronously. The EAGAIN case means that there is currently no space in
* the wait queue, but this can change at any moment.
*
- * \return Negative on fatal errors, number of bytes written else. For blocking
- * file descriptors this function returns either \a len or the error code of
- * the fatal error that caused the last write call to fail. For nonblocking
- * file descriptors there is a third possibility: A positive return value < \a
- * len indicates that some bytes have been written but the next write would
- * block.
+ * \return Negative on fatal errors, number of bytes written else.
+ *
+ * For blocking file descriptors, this function returns either the sum of all
+ * buffer sizes, or the error code of the fatal error that caused the last
+ * write call to fail.
+ *
+ * For nonblocking file descriptors there is a third possibility: Any positive
+ * return value less than the sum of the buffer sizes indicates that some bytes
+ * have been written but the next write would block.
+ *
+ * \sa writev(2), \ref xwrite().
*/
-int xwrite(int fd, const char *buf, size_t len)
+int xwritev(int fd, struct iovec *iov, int iovcnt)
{
size_t written = 0;
-
- while (written < len) {
- ssize_t ret = write(fd, buf + written, len - written);
+ int i;
+ struct iovec saved_iov, *curiov;
+
+ i = 0;
+ curiov = iov;
+ saved_iov = *curiov;
+ while (i < iovcnt && curiov->iov_len > 0) {
+ ssize_t ret = writev(fd, curiov, iovcnt - i);
if (ret >= 0) {
written += ret;
+ while (ret > 0) {
+ if (ret < curiov->iov_len) {
+ curiov->iov_base += ret;
+ curiov->iov_len -= ret;
+ break;
+ }
+ ret -= curiov->iov_len;
+ *curiov = saved_iov;
+ i++;
+ if (i >= iovcnt)
+ return written;
+ curiov++;
+ saved_iov = *curiov;
+ }
continue;
}
if (errno == EINTR)
return written;
}
+/**
+ * Write a buffer to a file descriptor, re-writing on short writes.
+ *
+ * \param fd The file descriptor.
+ * \param buf The buffer to write.
+ * \param len The number of bytes to write.
+ *
+ * This is a simple wrapper for \ref xwritev().
+ *
+ * \return The return value of the underlying call to \ref xwritev().
+ */
+int xwrite(int fd, const char *buf, size_t len)
+{
+ struct iovec iov = {.iov_base = (void *)buf, .iov_len = len};
+ return xwritev(fd, &iov, 1);
+}
+
/**
* Write all data to a file descriptor.
*
{
char *msg;
int ret;
+ va_list ap;
- PARA_VSPRINTF(fmt, msg);
- ret = write_buffer(fd, msg);
+ va_start(ap, fmt);
+ ret = xvasprintf(&msg, fmt, ap);
+ ret = write_all(fd, msg, ret);
free(msg);
return ret;
}
*
* If \a rfds is not \p NULL and the (non-blocking) file descriptor \a fd is
* not set in \a rfds, this function returns early without doing anything.
- * Otherwise The function tries to read up to \a sz bytes from \a fd. As for
- * xwrite(), EAGAIN is not considered an error condition. However, EOF
- * is.
+ * Otherwise The function tries to read up to \a sz bytes from \a fd, where \a
+ * sz is the sum of the lengths of all vectors in \a iov. As for xwrite(),
+ * \p EAGAIN is not considered an error condition. However, \p EOF is.
*
* \return Zero or a negative error code. If the underlying call to readv(2)
* returned zero (indicating an end of file condition) or failed for some
{
int ret;
+ *dir = NULL;
if (cwd) {
ret = para_open(".", O_RDONLY, 0);
if (ret < 0)
goto out;
}
*size = file_status.st_size;
+ /*
+ * If the file is empty, *size is zero and mmap() would return EINVAL
+ * (Invalid argument). This error is common enough to spend an extra
+ * error code which explicitly states the problem.
+ */
+ ret = -E_EMPTY;
+ if (*size == 0)
+ goto out;
+ /*
+ * If fd refers to a directory, mmap() returns ENODEV (No such device),
+ * at least on Linux. "Is a directory" seems to be more to the point.
+ */
+ ret = -ERRNO_TO_PARA_ERROR(EISDIR);
+ if (S_ISDIR(file_status.st_mode))
+ goto out;
+
ret = para_mmap(*size, mmap_prot, mmap_flags, fd, 0, map);
out:
if (ret < 0 || !fd_ptr)
projects / paraslash.git / blobdiff