X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=abad80a86ce368660c1ed3b88a1c0e088488a422;hp=10a3cf608cfbc1f5c9818f38ecc69495e041fbab;hb=bf94a866ee741567b4cf8e35d8e6a0565cdfe9bb;hpb=9ae4e1bcaf7bdcc902b70428afa766ab332a5b23

diff --git a/fd.c b/fd.c
index 10a3cf60..abad80a8 100644
--- a/fd.c
+++ b/fd.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2008 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -60,6 +60,24 @@ int para_select(int n, fd_set *readfds, fd_set *writefds,
 	return ret;
 }
 
+/**
+ * Set a file descriptor to blocking mode.
+ *
+ * \param fd The file descriptor.
+ *
+ * \return Standard.
+ */
+__must_check int mark_fd_blocking(int fd)
+{
+	int flags = fcntl(fd, F_GETFL);
+	if (flags < 0)
+		return -ERRNO_TO_PARA_ERROR(errno);
+	flags = fcntl(fd, F_SETFL, ((long)flags) & ~O_NONBLOCK);
+	if (flags < 0)
+		return -ERRNO_TO_PARA_ERROR(errno);
+	return 1;
+}
+
 /**
  * Set a file descriptor to non-blocking mode.
  *
@@ -67,7 +85,7 @@ int para_select(int n, fd_set *readfds, fd_set *writefds,
  *
  * \return Standard.
  */
-int mark_fd_nonblock(int fd)
+__must_check int mark_fd_nonblocking(int fd)
 {
 	int flags = fcntl(fd, F_GETFL);
 	if (flags < 0)
@@ -243,7 +261,6 @@ int para_opendir(const char *dirname, DIR **dir, int *cwd)
 		return 1;
 	ret = -ERRNO_TO_PARA_ERROR(errno);
 /* Ignore return value of fchdir() and close(). We're busted anyway. */
-change_to_orig_dir:
 	if (cwd)
 		fchdir(*cwd);
 close_cwd:
@@ -280,3 +297,105 @@ int para_mkdir(const char *path, mode_t mode)
 		return 1;
 	return -ERRNO_TO_PARA_ERROR(errno);
 }
+
+/**
+ * Open a file and map it into memory.
+ *
+ * \param path Name of the regular file to map.
+ * \param open_mode Either \p O_RDONLY or \p O_RDWR.
+ * \param map On success, the mapping is returned here.
+ * \param size size of the mapping.
+ * \param fd_ptr The file descriptor of the mapping.
+ *
+ * If \a fd_ptr is \p NULL, the file descriptor resulting from the underlying
+ * open call is closed after mmap().  Otherwise the file is kept open and the
+ * file descriptor is returned in \a fd_ptr.
+ *
+ * \return Standard.
+ *
+ * \sa para_open(), mmap(2).
+ */
+int mmap_full_file(const char *path, int open_mode, void **map,
+		size_t *size, int *fd_ptr)
+{
+	int fd, ret, mmap_prot, mmap_flags;
+	struct stat file_status;
+
+	if (open_mode == O_RDONLY) {
+		mmap_prot = PROT_READ;
+		mmap_flags = MAP_PRIVATE;
+	} else {
+		mmap_prot = PROT_READ | PROT_WRITE;
+		mmap_flags = MAP_SHARED;
+	}
+	ret = para_open(path, open_mode, 0);
+	if (ret < 0)
+		return ret;
+	fd = ret;
+	if (fstat(fd, &file_status) < 0) {
+		ret = -ERRNO_TO_PARA_ERROR(errno);
+		goto out;
+	}
+	*size = file_status.st_size;
+	ret = -E_EMPTY;
+	PARA_DEBUG_LOG("%s: size %zu\n", path, *size);
+	if (!*size)
+		goto out;
+	*map = mmap(NULL, *size, mmap_prot, mmap_flags, fd, 0);
+	if (*map == MAP_FAILED) {
+		*map = NULL;
+		ret = -E_MMAP;
+		goto out;
+	}
+	ret = 1;
+out:
+	if (ret < 0 || !fd_ptr)
+		close(fd);
+	else
+		*fd_ptr = fd;
+	return ret;
+}
+
+/**
+ * A wrapper for munmap(2).
+ *
+ * \param start The start address of the memory mapping.
+ * \param length The size of the mapping.
+ *
+ * \return Positive on success, \p -E_MUNMAP on errors.
+ *
+ * \sa munmap(2), mmap_full_file().
+ */
+int para_munmap(void *start, size_t length)
+{
+	if (munmap(start, length) >= 0)
+		return 1;
+	PARA_ERROR_LOG("munmap (%p/%zu) failed: %s\n", start, length,
+		strerror(errno));
+	return -E_MUNMAP;
+}
+
+/**
+ * check a file descriptor for writability
+ *
+ * \param fd the file descriptor
+ *
+ * \return positive if fd is ready for writing, zero if it isn't, negative if
+ * an error occurred.
+ */
+
+int write_ok(int fd)
+{
+	struct timeval tv = {0, 0};
+	fd_set wfds;
+	int ret;
+again:
+	FD_ZERO(&wfds);
+	FD_SET(fd, &wfds);
+	tv.tv_sec = 0;
+	tv.tv_usec = 0;
+	ret = select(fd + 1, NULL, &wfds, NULL, &tv);
+	if (ret < 0 && errno == EINTR)
+		goto again;
+	return ret;
+}