Add cdb_init_at and cdb_init_fromfd, rename cdb_reader

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/libstddjb/cdb_init_fromfd.c b/src/libstddjb/cdb_init_fromfd.c
new file mode 100644
index 0000000..7446f4a
--- /dev/null
+++ b/src/libstddjb/cdb_init_fromfd.c
@@ -0,0 +1,23 @@
+/* ISC license. */
+
+#include <skalibs/bsdsnowflake.h>
+
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <stdint.h>
+#include <errno.h>
+
+#include <skalibs/cdb.h>
+
+int cdb_init_fromfd (cdb *c, int fd)
+{
+  char *map ;
+  struct stat st ;
+  if (fstat(fd, &st) < 0) return 0 ;
+  if (st.st_size > UINT32_MAX) return (errno = EOVERFLOW, 0) ;
+  map = mmap(0, st.st_size, PROT_READ, MAP_SHARED, fd, 0) ;
+  if (map == MAP_FAILED) return 0 ;
+  c->map = map ;
+  c->size = st.st_size ;
+  return 1 ;
+}