[gnumeric] Recent: don't re-query recent file existance.

[Morten Welinder <mortenw src gnome org>]

commit 4331419882147a0d521d1ed459421692ee40d61e
Author: Morten Welinder <terra gnome org>
Date:   Sun Jan 9 11:19:18 2022 -0500

    Recent: don't re-query recent file existance.

 NEWS              |  1 +
 src/application.c | 34 +++++++++++++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 1 deletion(-)
---
diff --git a/NEWS b/NEWS
index bdafef691..d33c3f3ac 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,7 @@ Morten:
        * Fix MROUND.  [#604]
        * Take evasive action re g_memdup.
        * Fix inter-gnumeric array formula paste crash.  [#606]
+       * Avoid re-querying file existance for recent files.  [Part of #602]
 
 --------------------------------------------------------------------------
 Gnumeric 1.12.50
diff --git a/src/application.c b/src/application.c
index 48d3352fb..2af56754e 100644
--- a/src/application.c
+++ b/src/application.c
@@ -70,6 +70,7 @@ struct _GnmApp {
 
        GtkRecentManager *recent;
        gulong           recent_sig;
+       GHashTable       *file_exists_cache;
 
        gboolean         shutting_down;
        gboolean         initial_open_complete;
@@ -614,6 +615,30 @@ compare_mru (GtkRecentInfo *a, GtkRecentInfo *b)
        return ta < tb;
 }
 
+
+// Test whether a file exists, but cache the result.  We want to avoid
+// repeatedly querying file that may reside on non-responsive network
+// shars.
+static gboolean
+gnm_app_file_exists (const char *filename)
+{
+       gpointer val;
+       gboolean res;
+
+       if (g_hash_table_lookup_extended (app->file_exists_cache,
+                                         (gpointer)filename,
+                                         NULL, &val))
+               res = val != NULL;
+       else {
+               res = g_file_test (filename, G_FILE_TEST_EXISTS);
+               g_hash_table_insert (app->file_exists_cache,
+                                    g_strdup (filename),
+                                    GUINT_TO_POINTER (res));
+       }
+       return res;
+}
+
+
 /**
  * gnm_app_history_get_list:
  *
@@ -662,7 +687,7 @@ gnm_app_history_get_list (int max_elements)
 
                if (want_it) {
                        char *filename = go_filename_from_uri (uri);
-                       if (filename && !g_file_test (filename, G_FILE_TEST_EXISTS))
+                       if (filename && !gnm_app_file_exists (filename))
                                want_it = FALSE;
                        g_free (filename);
                }
@@ -736,6 +761,10 @@ gnm_app_finalize (GObject *obj)
        application->clipboard_cut_range = NULL;
 
        application->recent = NULL;
+       if (application->file_exists_cache) {
+               g_hash_table_destroy (application->file_exists_cache);
+               application->file_exists_cache = NULL;
+       }
 
        if (app == application)
                app = NULL;
@@ -895,6 +924,9 @@ gnm_app_init (GObject *obj)
                                         gnm_app, 0);
        }
 
+       gnm_app->file_exists_cache =
+               g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
+
        app = gnm_app;
 }