Fix TAB-completion + .gdb_index slowness (generalize filename_seen_cache)

[deliverable/binutils-gdb.git] / gdb / filename-seen-cache.c

diff --git a/gdb/filename-seen-cache.c b/gdb/filename-seen-cache.c
new file mode 100644 (file)
index 0000000..6282105
--- /dev/null
+++ b/gdb/filename-seen-cache.c
@@ -0,0 +1,66 @@
+/* Filename-seen cache for the GNU debugger, GDB.
+
+   Copyright (C) 1986-2017 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "defs.h"
+#include "filename-seen-cache.h"
+#include "filenames.h"
+
+  /* Initial size of the table.  It automagically grows from here.  */
+#define INITIAL_FILENAME_SEEN_CACHE_SIZE 100
+
+/* filename_seen_cache constructor.  */
+
+filename_seen_cache::filename_seen_cache ()
+{
+  m_tab = htab_create_alloc (INITIAL_FILENAME_SEEN_CACHE_SIZE,
+                            filename_hash, filename_eq,
+                            NULL, xcalloc, xfree);
+}
+
+/* See filename-seen-cache.h.  */
+
+void
+filename_seen_cache::clear ()
+{
+  htab_empty (m_tab);
+}
+
+/* See filename-seen-cache.h.  */
+
+filename_seen_cache::~filename_seen_cache ()
+{
+  htab_delete (m_tab);
+}
+
+/* See filename-seen-cache.h.  */
+
+bool
+filename_seen_cache::seen (const char *file)
+{
+  void **slot;
+
+  /* Is FILE in tab?  */
+  slot = htab_find_slot (m_tab, file, INSERT);
+  if (*slot != NULL)
+    return true;
+
+  /* No; add it to tab.  */
+  *slot = (char *) file;
+  return false;
+}