gdb/filename-seen-cache.h

   1 /* Filename-seen cache for the GNU debugger, GDB.
   2
   3    Copyright (C) 1986-2019 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 #ifndef FILENAME_SEEN_CACHE_H
  21 #define FILENAME_SEEN_CACHE_H
  22
  23 #include "defs.h"
  24 #include "common/function-view.h"
  25
  26 /* Cache to watch for file names already seen.  */
  27
  28 class filename_seen_cache
  29 {
  30 public:
  31   filename_seen_cache ();
  32   ~filename_seen_cache ();
  33
  34   DISABLE_COPY_AND_ASSIGN (filename_seen_cache);
  35
  36   /* Empty the cache, but do not delete it.  */
  37   void clear ();
  38
  39   /* If FILE is not already in the table of files in CACHE, add it and
  40      return false; otherwise return true.
  41
  42      NOTE: We don't manage space for FILE, we assume FILE lives as
  43      long as the caller needs.  */
  44   bool seen (const char *file);
  45
  46   /* Traverse all cache entries, calling CALLBACK on each.  The
  47      filename is passed as argument to CALLBACK.  */
  48   void traverse (gdb::function_view<void (const char *filename)> callback)
  49   {
  50     auto erased_cb = [] (void **slot, void *info) -> int
  51       {
  52         auto filename = (const char *) *slot;
  53         auto restored_cb = (decltype (callback) *) info;
  54         (*restored_cb) (filename);
  55         return 1;
  56       };
  57
  58     htab_traverse_noresize (m_tab, erased_cb, &callback);
  59   }
  60
  61 private:
  62   /* Table of files seen so far.  */
  63   htab_t m_tab;
  64 };
  65
  66 #endif /* FILENAME_SEEN_CACHE_H */