gdb/filename-seen-cache.h

   1 /* Filename-seen cache for the GNU debugger, GDB.
   2
   3    Copyright (C) 1986-2018 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "common/function-view.h"
  22
  23 /* Cache to watch for file names already seen.  */
  24
  25 class filename_seen_cache
  26 {
  27 public:
  28   filename_seen_cache ();
  29   ~filename_seen_cache ();
  30
  31   DISABLE_COPY_AND_ASSIGN (filename_seen_cache);
  32
  33   /* Empty the cache, but do not delete it.  */
  34   void clear ();
  35
  36   /* If FILE is not already in the table of files in CACHE, add it and
  37      return false; otherwise return true.
  38
  39      NOTE: We don't manage space for FILE, we assume FILE lives as
  40      long as the caller needs.  */
  41   bool seen (const char *file);
  42
  43   /* Traverse all cache entries, calling CALLBACK on each.  The
  44      filename is passed as argument to CALLBACK.  */
  45   void traverse (gdb::function_view<void (const char *filename)> callback)
  46   {
  47     auto erased_cb = [] (void **slot, void *info) -> int
  48       {
  49         auto filename = (const char *) *slot;
  50         auto restored_cb = (decltype (callback) *) info;
  51         (*restored_cb) (filename);
  52         return 1;
  53       };
  54
  55     htab_traverse_noresize (m_tab, erased_cb, &callback);
  56   }
  57
  58 private:
  59   /* Table of files seen so far.  */
  60   htab_t m_tab;
  61 };