Add bsearch_record.

I'm not sure if we need it or not :)


git-svn-id: http://opensvn.csie.org/pttbbs/trunk@5880 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

2 files changed, 29 insertions, 0 deletions

diff --git a/pttbbs/common/sys/record.c b/pttbbs/common/sys/record.c
index df78f699..7d908676 100644
--- a/pttbbs/common/sys/record.c
+++ b/pttbbs/common/sys/record.c
@@ -1,6 +1,8 @@
 /* $Id$ */
 
 #include <sys/stat.h>
+#include <sys/mman.h>
+#include <string.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <assert.h>
@@ -307,3 +309,27 @@ apply_record(const char *fpath, int (*fptr) (void *item, void *optarg),
 
     return 0;
 }
+
+int bsearch_record(const char *fpath, const void *key,
+                   int (*compar)(const void *item1, const void *item2),
+                   size_t size, void *buffer)
+{
+  int fd;
+  size_t sz = dashs(fpath);
+  void *addr = NULL, *found;
+
+  if((fd = open(fpath, O_RDONLY, 0)) < 0)
+    return -1;
+  addr = mmap(NULL, sz, PROT_READ, MAP_SHARED, fd, 0);
+  if (!addr) {
+      close(fd);
+      return -1;
+  }
+  found = bsearch(key, addr, sz / size, size, compar);
+  if (buffer && found)
+      memcpy(buffer, found, size);
+
+  munmap(addr, sz);
+  close(fd);
+  return found ? (found - addr) / size : -1;
+}
diff --git a/pttbbs/include/cmsys.h b/pttbbs/include/cmsys.h
index b9082763..82936638 100644
--- a/pttbbs/include/cmsys.h
+++ b/pttbbs/include/cmsys.h
@@ -175,6 +175,9 @@ int substitute_record2(const char *fpath,
                               record_callback_t cb_can_substitue);
 int delete_record2(const char *fpath, const void *rptr, size_t size,
                           int id, record_callback_t cb_can_substitue);
+int bsearch_record(const char *fpath, const void *key,
+                   int (*compar)(const void *item1, const void *item2),
+                   size_t size, void *buffer);
 
 /* vector.c */
 struct Vector {