epan: Add binary search to introspection API

debian/libwireshark0.symbols

@@ -587,6 +587,8 @@ libwireshark.so.0 libwireshark0 #MINVER#
  epan_get_version_number@Base 2.5.0
  epan_init@Base 2.9.0
  epan_inspect_enums@Base 3.7.0
+ epan_inspect_enums_bsearch@Base 3.7.0
+ epan_inspect_enums_count@Base 3.7.0
  epan_load_settings@Base 2.3.0
  epan_memmem@Base 1.9.1
  epan_new@Base 1.12.0~rc1

epan/CMakeLists.txt

@@ -211,7 +211,7 @@ set(LIBWIRESHARK_NONGENERATED_FILES
 	guid-utils.c
 	iana_charsets.c
 	in_cksum.c
-	introspection-enums.c
+	introspection.c
 	ipproto.c
 	maxmind_db.c
 	media_params.c

epan/introspection-enums.c

@@ -14,8 +14,6 @@
  * requirement to re-run the generator script.
  *
  */
-#include "config.h"
-#include "introspection.h"
 #include <epan/address.h>
 #include <epan/ipproto.h>
 #include <epan/proto.h>
@@ -428,8 +426,3 @@ static ws_enum_t all_enums[] = {
     ENUM(STR_UNICODE),
     { NULL, 0 },
 };
-
-const ws_enum_t *epan_inspect_enums(void)
-{
-    return all_enums;
-}

epan/introspection.c

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2021, João Valverde <j@v6e.pt>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include "config.h"
+#include "introspection.h"
+#include <string.h>
+#include <stdlib.h>
+
+#include "introspection-enums.c"
+
+const ws_enum_t *epan_inspect_enums(void)
+{
+    return all_enums;
+}
+
+static int compare_enum(const void *needle, const void *memb)
+{
+    return strcmp(needle, ((const ws_enum_t *)memb)->symbol);
+}
+
+size_t epan_inspect_enums_count(void)
+{
+    /* Exclude null terminator */
+    return sizeof(all_enums)/sizeof(ws_enum_t) - 1;
+}
+
+const ws_enum_t *epan_inspect_enums_bsearch(const char *needle)
+{
+    return bsearch(needle, all_enums, epan_inspect_enums_count(),
+                        sizeof(ws_enum_t), compare_enum);
+}

epan/introspection.h

@@ -11,6 +11,7 @@
 #ifndef _INTROSPECTION_H_
 #define _INTROSPECTION_H_
 
+#include <stddef.h>
 #include <ws_symbol_export.h>
 
 typedef struct {
@@ -28,4 +29,12 @@ typedef struct {
 WS_DLL_PUBLIC
 const ws_enum_t *epan_inspect_enums(void);
 
+/** Returns size of enums array not including null terminator. */
+WS_DLL_PUBLIC
+size_t epan_inspect_enums_count(void);
+
+/** Performs a binary search for the magic constant "needle". */
+WS_DLL_PUBLIC
+const ws_enum_t *epan_inspect_enums_bsearch(const char *needle);
+
 #endif

tools/make-enums.py

@@ -44,8 +44,6 @@ source = """\
  * requirement to re-run the generator script.
  *
  */
-#include "config.h"
-#include "introspection.h"
 """ % (os.path.basename(sys.argv[0]))
 
 for f in args.infiles:
@@ -68,11 +66,6 @@ for s in symbols:
 source += """\
     { NULL, 0 },
 };
-
-const ws_enum_t *epan_inspect_enums(void)
-{
-    return all_enums;
-}
 """
 
 try: