1 files changed, 67 insertions, 0 deletions
diff --git a/src/libps/s6ps_grcache.c b/src/libps/s6ps_grcache.c
new file mode 100644
index 0000000..189f5ae
--- /dev/null
+++ b/src/libps/s6ps_grcache.c
@@ -0,0 +1,67 @@
+/* ISC license. */
+
+#include <stdint.h>
+
+#include <grp.h>
+#include <errno.h>
+#include <skalibs/types.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/genalloc.h>
+#include <skalibs/skamisc.h>
+#include <skalibs/avltree.h>
+
+#include "s6-ps.h"
+
+static avltree grcache_tree = AVLTREE_ZERO ;
+static genalloc grcache_index = GENALLOC_ZERO ;
+
+int s6ps_grcache_init (void)
+{
+  avltree_init(&grcache_tree, 5, 3, 8, &left_dtok, &uint32_cmp, &grcache_index) ;
+  return 1 ;
+}
+
+void s6ps_grcache_finish (void)
+{
+  avltree_free(&grcache_tree) ;
+  genalloc_free(dius_t, &grcache_index) ;
+}
+
+int s6ps_grcache_lookup (stralloc *sa, gid_t gid)
+{
+  int wasnull = !satmp.s ;
+  dius_t d = { .left = (uint32_t)gid, .right = satmp.len } ;
+  uint32_t i ;
+  if (!avltree_search(&grcache_tree, &d.left, &i))
+  {
+    struct group *gr ;
+    unsigned int n = genalloc_len(dius_t, &grcache_index) ;
+    errno = 0 ;
+    gr = getgrgid(gid) ;
+    if (!gr)
+    {
+      if (errno) return 0 ;
+      if (!stralloc_readyplus(&satmp, UINT_FMT + 2)) return 0 ;
+      stralloc_catb(&satmp, "(", 1) ;
+      satmp.len += uint_fmt(satmp.s + satmp.len, gid) ;
+      stralloc_catb(&satmp, ")", 2) ;
+    }
+    else if (!stralloc_cats(&satmp, gr->gr_name) || !stralloc_0(&satmp)) return 0 ;
+    if (!genalloc_append(dius_t, &grcache_index, &d)) goto err ;
+    if (!avltree_insert(&grcache_tree, n))
+    {
+      genalloc_setlen(dius_t, &grcache_index, n) ;
+      goto err ;
+    }
+    i = n ;
+  }
+  return stralloc_cats(sa, satmp.s + genalloc_s(dius_t, &grcache_index)[i].right) ;
+ err:
+  {
+    int e = errno ;
+    if (wasnull) stralloc_free(&satmp) ;
+    else satmp.len = d.right ;
+    errno = e ;
+  }
+  return 0 ;
+}