Rewrite openwrite(v)nclose using mkstemp

1 files changed, 39 insertions, 0 deletions

diff --git a/src/libstddjb/openwritevnclose.c b/src/libstddjb/openwritevnclose.c
new file mode 100644
index 0000000..01df3e3
--- /dev/null
+++ b/src/libstddjb/openwritevnclose.c
@@ -0,0 +1,39 @@
+/* ISC license. */
+
+#include <sys/uio.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <skalibs/djbunix.h>
+
+#define SUFFIX ":skalibs-openwritevnclose:XXXXXX"
+
+int openwritevnclose_internal (char const *fn, struct iovec const *v, unsigned int vlen, dev_t *dev, ino_t *ino, int dosync)
+{
+  dev_t tmpdev ;
+  ino_t tmpino ;
+  size_t fnlen = strlen(fn) ;
+  int fd ;
+  char tmp[fnlen + sizeof(SUFFIX)] ;
+  memcpy(tmp, fn, fnlen) ;
+  memcpy(tmp + fnlen, SUFFIX, sizeof(SUFFIX)) ;
+  fd = mkstemp(tmp) ;
+  if (fd < 0) return 0 ;
+  if (!writevnclose_unsafe_internal(fd, v, vlen, dev ? &tmpdev : 0, ino ? &tmpino : 0, dosync)) goto failclose ;
+  if (rename(tmp, fn) < 0) goto fail ;
+  if (dev) *dev = tmpdev ;
+  if (ino) *ino = tmpino ;
+  return 1 ;
+
+ failclose:
+  fd_close(fd) ;
+ fail:
+  {
+    int e = errno ;
+    unlink(tmp) ;
+    errno = e ;
+  }
+  return 0 ;
+}