Add unixmessage_unput, for transaction cancellation

2 files changed, 27 insertions, 0 deletions

diff --git a/src/include/skalibs/unixmessage.h b/src/include/skalibs/unixmessage.h
index 3252a50..5451a05 100644
--- a/src/include/skalibs/unixmessage.h
+++ b/src/include/skalibs/unixmessage.h
@@ -75,6 +75,10 @@ extern int unixmessage_put_and_close (unixmessage_sender_t *, unixmessage_t cons
 extern int unixmessage_putv_and_close (unixmessage_sender_t *, unixmessage_v_t const *, unsigned char const *) ;
 #define unixmessage_putv(b, m) unixmessage_putv_and_close(b, m, unixmessage_bits_closenone)
 
+extern int unixmessage_unput_and_maybe_drop (unixmessage_sender_t *, int) ;
+#define unixmessage_unput(b) unixmessage_unput_and_maybe_drop((b), 0)
+#define unixmessage_unput_and_drop(b) unixmessage_unput_and_maybe_drop((b), 1)
+
 extern unsigned char const *const unixmessage_bits_closenone ;
 extern unsigned char const *const unixmessage_bits_closeall ;
 
diff --git a/src/libunixonacid/unixmessage_unput.c b/src/libunixonacid/unixmessage_unput.c
new file mode 100644
index 0000000..48d46b5
--- /dev/null
+++ b/src/libunixonacid/unixmessage_unput.c
@@ -0,0 +1,23 @@
+ /* ISC license. */
+
+#include <skalibs/genalloc.h>
+#include <skalibs/diuint.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/unixmessage.h>
+
+int unixmessage_unput_and_maybe_drop (unixmessage_sender_t *b, int drop)
+{
+  diuint *start ;
+  unsigned int n = genalloc_len(diuint, &b->offsets) ;
+  if (!n) return 0 ;
+  start = genalloc_s(diuint, &b->offsets) + n - 1 ;
+  if (drop)
+  {
+    register int *fds = genalloc_s(int, &b->fds) + start->right ;
+    register unsigned int i = genalloc_len(int, &b->fds) - start->right ;
+    while (i--) fd_close(fds[i] < 0 ? -(fds[i]+1) : fds[i]) ;
+  }
+  b->data.len = start->left ;
+  genalloc_setlen(int, &b->fds, start->right) ;
+  return 1 ;
+}