#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/stat.h>
#include <unistd.h>
#include "json.h"
#include "ovsdb.h"
#include "ovsdb-error.h"
#include "sha1.h"
+#include "socket-util.h"
#include "transaction.h"
#include "util.h"
-
-#define THIS_MODULE VLM_ovsdb_log
#include "vlog.h"
+VLOG_DEFINE_THIS_MODULE(ovsdb_log);
+
enum ovsdb_log_mode {
OVSDB_LOG_READ,
OVSDB_LOG_WRITE
enum ovsdb_log_mode mode;
};
+/* Attempts to open 'name' with the specified 'open_mode'. On success, stores
+ * the new log into '*filep' and returns NULL; otherwise returns NULL and
+ * stores NULL into '*filep'.
+ *
+ * Whether the file will be locked using lockfile_lock() depends on 'locking':
+ * use true to lock it, false not to lock it, or -1 to lock it only if
+ * 'open_mode' is a mode that allows writing.
+ */
struct ovsdb_error *
-ovsdb_log_open(const char *name, int flags, struct ovsdb_log **filep)
+ovsdb_log_open(const char *name, enum ovsdb_log_open_mode open_mode,
+ int locking, struct ovsdb_log **filep)
{
struct lockfile *lockfile;
struct ovsdb_error *error;
struct ovsdb_log *file;
struct stat s;
FILE *stream;
- int accmode;
+ int flags;
int fd;
*filep = NULL;
- accmode = flags & O_ACCMODE;
- if (accmode == O_RDWR || accmode == O_WRONLY) {
+ assert(locking == -1 || locking == false || locking == true);
+ if (locking < 0) {
+ locking = open_mode != OVSDB_LOG_READ_ONLY;
+ }
+ if (locking) {
int retval = lockfile_lock(name, 0, &lockfile);
if (retval) {
error = ovsdb_io_error(retval, "%s: failed to lock lockfile",
lockfile = NULL;
}
+ if (open_mode == OVSDB_LOG_READ_ONLY) {
+ flags = O_RDONLY;
+ } else if (open_mode == OVSDB_LOG_READ_WRITE) {
+ flags = O_RDWR;
+ } else if (open_mode == OVSDB_LOG_CREATE) {
+ flags = O_RDWR | O_CREAT | O_EXCL;
+ } else {
+ NOT_REACHED();
+ }
fd = open(name, flags, 0666);
if (fd < 0) {
- const char *op = flags & O_CREAT && flags & O_EXCL ? "create" : "open";
+ const char *op = open_mode == OVSDB_LOG_CREATE ? "create" : "open";
error = ovsdb_io_error(errno, "%s: %s failed", op, name);
goto error_unlock;
}
if (!fstat(fd, &s) && s.st_size == 0) {
/* It's (probably) a new file so fsync() its parent directory to ensure
* that its directory entry is committed to disk. */
- char *dir = dir_name(name);
- int dirfd = open(dir, O_RDONLY);
- if (dirfd >= 0) {
- if (fsync(dirfd) && errno != EINVAL) {
- VLOG_ERR("%s: fsync failed (%s)", dir, strerror(errno));
- }
- close(dirfd);
- } else {
- VLOG_ERR("%s: open failed (%s)", dir, strerror(errno));
- }
- free(dir);
+ fsync_parent_dir(name);
}
- stream = fdopen(fd, (accmode == O_RDONLY ? "rb"
- : accmode == O_WRONLY ? "wb"
- : "w+b"));
+ stream = fdopen(fd, open_mode == OVSDB_LOG_READ_ONLY ? "rb" : "w+b");
if (!stream) {
error = ovsdb_io_error(errno, "%s: fdopen failed", name);
goto error_close;
return 0;
}
+/* Returns the current offset into the file backing 'log', in bytes. This
+ * reflects the number of bytes that have been read or written in the file. If
+ * the whole file has been read, this is the file size. */
+off_t
+ovsdb_log_get_offset(const struct ovsdb_log *log)
+{
+ return log->offset;
+}