[gnome-builder] libide-io: add cached list model

[Christian Hergert <chergert src gnome org>]

commit e9362e66381ce82555b82378c2fffddd46154b67
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jul 11 16:39:43 2022 -0700

    libide-io: add cached list model
    
    A GListModel that caches the result from the base layer.

 src/libide/io/ide-cached-list-model.c | 302 ++++++++++++++++++++++++++++++++++
 src/libide/io/ide-cached-list-model.h |  40 +++++
 src/libide/io/libide-io.h             |   1 +
 src/libide/io/meson.build             |   3 +
 4 files changed, 346 insertions(+)
---
diff --git a/src/libide/io/ide-cached-list-model.c b/src/libide/io/ide-cached-list-model.c
new file mode 100644
index 000000000..fe17d3cd2
--- /dev/null
+++ b/src/libide/io/ide-cached-list-model.c
@@ -0,0 +1,302 @@
+/* ide-cached-list-model.c
+ *
+ * Copyright 2022 Christian Hergert <chergert redhat com>
+ *
+ * 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/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#define G_LOG_DOMAIN "ide-cached-list-model"
+
+#include "config.h"
+
+#include "ide-cached-list-model.h"
+
+struct _IdeCachedListModel
+{
+  GObject     parent_instance;
+  GSequence  *items;
+  GListModel *model;
+  gulong      items_changed_handler;
+};
+
+enum {
+  PROP_0,
+  PROP_MODEL,
+  N_PROPS
+};
+
+static GType
+ide_cached_list_model_get_item_type (GListModel *model)
+{
+  IdeCachedListModel *self = IDE_CACHED_LIST_MODEL (model);
+
+  if (self->model == NULL)
+    return G_TYPE_OBJECT;
+
+  return g_list_model_get_item_type (self->model);
+}
+
+static guint
+ide_cached_list_model_get_n_items (GListModel *model)
+{
+  IdeCachedListModel *self = IDE_CACHED_LIST_MODEL (model);
+
+  if (self->model == NULL)
+    return 0;
+
+  return g_list_model_get_n_items (self->model);
+}
+
+static gpointer
+ide_cached_list_model_get_item (GListModel *model,
+                                guint       position)
+{
+  IdeCachedListModel *self = IDE_CACHED_LIST_MODEL (model);
+  GSequenceIter *iter;
+  gpointer item;
+
+  if (self->model == NULL)
+    return NULL;
+
+  iter = g_sequence_get_iter_at_pos (self->items, position);
+  if (g_sequence_iter_is_end (iter))
+    return NULL;
+
+  if (!(item = g_sequence_get (iter)))
+    {
+      item = g_list_model_get_item (self->model, position);
+      g_sequence_set (iter, item);
+    }
+
+  return g_object_ref (item);
+}
+
+static void
+list_model_iface_init (GListModelInterface *iface)
+{
+  iface->get_item_type = ide_cached_list_model_get_item_type;
+  iface->get_n_items = ide_cached_list_model_get_n_items;
+  iface->get_item = ide_cached_list_model_get_item;
+}
+
+G_DEFINE_FINAL_TYPE_WITH_CODE (IdeCachedListModel, ide_cached_list_model, G_TYPE_OBJECT,
+                               G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, list_model_iface_init))
+
+static GParamSpec *properties [N_PROPS];
+
+static void
+_g_object_xunref (gpointer data)
+{
+  if (data)
+    g_object_unref (data);
+}
+
+static void
+ide_cached_list_model_dispose (GObject *object)
+{
+  IdeCachedListModel *self = (IdeCachedListModel *)object;
+
+  ide_cached_list_model_set_model (self, NULL);
+
+  g_assert (self->model == NULL);
+  g_assert (self->items == NULL);
+  g_assert (self->items_changed_handler == 0);
+
+  G_OBJECT_CLASS (ide_cached_list_model_parent_class)->dispose (object);
+}
+
+static void
+ide_cached_list_model_get_property (GObject    *object,
+                                    guint       prop_id,
+                                    GValue     *value,
+                                    GParamSpec *pspec)
+{
+  IdeCachedListModel *self = IDE_CACHED_LIST_MODEL (object);
+
+  switch (prop_id)
+    {
+    case PROP_MODEL:
+      g_value_set_object (value, ide_cached_list_model_get_model (self));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+ide_cached_list_model_set_property (GObject      *object,
+                                    guint         prop_id,
+                                    const GValue *value,
+                                    GParamSpec   *pspec)
+{
+  IdeCachedListModel *self = IDE_CACHED_LIST_MODEL (object);
+
+  switch (prop_id)
+    {
+    case PROP_MODEL:
+      ide_cached_list_model_set_model (self, g_value_get_object (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+ide_cached_list_model_class_init (IdeCachedListModelClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = ide_cached_list_model_dispose;
+  object_class->get_property = ide_cached_list_model_get_property;
+  object_class->set_property = ide_cached_list_model_set_property;
+
+  properties [PROP_MODEL] =
+    g_param_spec_object ("model", NULL, NULL,
+                         G_TYPE_LIST_MODEL,
+                         (G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS));
+
+  g_object_class_install_properties (object_class, N_PROPS, properties);
+}
+
+static void
+ide_cached_list_model_init (IdeCachedListModel *self)
+{
+}
+
+/**
+ * ide_cached_list_model_get_model:
+ * @self: a #IdeCachedListModel
+ *
+ * Gets the underlying model.
+ *
+ * Returns: (transfer none) (nullable): a #GListModel or %NULL
+ */
+GListModel *
+ide_cached_list_model_get_model (IdeCachedListModel *self)
+{
+  g_return_val_if_fail (IDE_IS_CACHED_LIST_MODEL (self), NULL);
+
+  return self->model;
+}
+
+static void
+ide_cached_list_model_items_changed_cb (IdeCachedListModel *self,
+                                        guint               position,
+                                        guint               removed,
+                                        guint               added,
+                                        GListModel         *model)
+{
+  GSequenceIter *iter;
+
+  g_assert (IDE_IS_CACHED_LIST_MODEL (self));
+  g_assert (G_IS_LIST_MODEL (model));
+  g_assert (self->items != NULL);
+
+  iter = g_sequence_get_iter_at_pos (self->items, position);
+
+  if (removed > 0)
+    {
+      GSequenceIter *end;
+
+      if (removed == 1)
+        end = iter;
+      else
+        end = g_sequence_iter_prev (g_sequence_get_iter_at_pos (self->items, position+removed));
+
+      g_sequence_remove_range (iter, end);
+
+      iter = g_sequence_get_iter_at_pos (self->items, position);
+    }
+
+  for (guint i = 0; i < added; i++)
+    g_sequence_insert_before (iter, NULL);
+
+  g_list_model_items_changed (G_LIST_MODEL (self), position, removed, added);
+}
+
+void
+ide_cached_list_model_set_model (IdeCachedListModel *self,
+                                 GListModel         *model)
+{
+  g_autoptr(GSequence) old_items = NULL;
+  guint removed = 0;
+  guint added = 0;
+
+  g_return_if_fail (IDE_IS_CACHED_LIST_MODEL (self));
+  g_return_if_fail (!model || G_IS_LIST_MODEL (model));
+
+  if (self->model == model)
+    return;
+
+  if (self->model != NULL)
+    {
+      removed = g_list_model_get_n_items (self->model);
+      g_clear_signal_handler (&self->items_changed_handler, self->model);
+      old_items = g_steal_pointer (&self->items);
+    }
+
+  if (model != NULL)
+    {
+      GSequenceIter *end;
+
+      added = g_list_model_get_n_items (model);
+      self->items_changed_handler =
+        g_signal_connect_object (model,
+                                 "items-changed",
+                                 G_CALLBACK (ide_cached_list_model_items_changed_cb),
+                                 self,
+                                 G_CONNECT_SWAPPED);
+
+      self->items = g_sequence_new (_g_object_xunref);
+      end = g_sequence_get_end_iter (self->items);
+      for (guint i = 0; i < added; i++)
+        g_sequence_insert_before (end, NULL);
+    }
+
+  g_set_object (&self->model, model);
+
+  if (removed || added)
+    g_list_model_items_changed (G_LIST_MODEL (self), 0, removed, added);
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_MODEL]);
+}
+
+/**
+ * ide_cached_list_model_new:
+ * @model: (nullable) (transfer full): a #GListModel or %NULL
+ *
+ * Creates a new list model that caches the items.
+ *
+ * This might be useful if have a GtkMapListModel which would otherwise discard your
+ * mapped items.
+ *
+ * Returns: (transfer full): an #IdeCachedListModel
+ */
+IdeCachedListModel *
+ide_cached_list_model_new (GListModel *model)
+{
+  IdeCachedListModel *ret;
+
+  g_return_val_if_fail (!model || G_IS_LIST_MODEL (model), NULL);
+
+  ret = g_object_new (IDE_TYPE_CACHED_LIST_MODEL,
+                      "model", model,
+                      NULL);
+  g_clear_object (&model);
+  return ret;
+}
diff --git a/src/libide/io/ide-cached-list-model.h b/src/libide/io/ide-cached-list-model.h
new file mode 100644
index 000000000..1d7ee6b68
--- /dev/null
+++ b/src/libide/io/ide-cached-list-model.h
@@ -0,0 +1,40 @@
+/* ide-cached-list-model.h
+ *
+ * Copyright 2022 Christian Hergert <chergert redhat com>
+ *
+ * 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/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <libide-core.h>
+
+G_BEGIN_DECLS
+
+#define IDE_TYPE_CACHED_LIST_MODEL (ide_cached_list_model_get_type())
+
+IDE_AVAILABLE_IN_ALL
+G_DECLARE_FINAL_TYPE (IdeCachedListModel, ide_cached_list_model, IDE, CACHED_LIST_MODEL, GObject)
+
+IDE_AVAILABLE_IN_ALL
+IdeCachedListModel *ide_cached_list_model_new       (GListModel         *model);
+IDE_AVAILABLE_IN_ALL
+GListModel         *ide_cached_list_model_get_model (IdeCachedListModel *self);
+IDE_AVAILABLE_IN_ALL
+void                ide_cached_list_model_set_model (IdeCachedListModel *self,
+                                                     GListModel         *model);
+
+G_END_DECLS
diff --git a/src/libide/io/libide-io.h b/src/libide/io/libide-io.h
index c83025e7f..1c416b834 100644
--- a/src/libide/io/libide-io.h
+++ b/src/libide/io/libide-io.h
@@ -26,6 +26,7 @@
 G_BEGIN_DECLS
 
 #define IDE_IO_INSIDE
+# include "ide-cached-list-model.h"
 
 #include "ide-content-type.h"
 #include "ide-gfile.h"
diff --git a/src/libide/io/meson.build b/src/libide/io/meson.build
index 8dcddbe89..b98ef3e5f 100644
--- a/src/libide/io/meson.build
+++ b/src/libide/io/meson.build
@@ -6,6 +6,7 @@ libide_include_directories += include_directories('.')
 #
 
 libide_io_public_headers = [
+  'ide-cached-list-model.h',
   'ide-content-type.h',
   'ide-gfile.h',
   'ide-line-reader.h',
@@ -15,6 +16,7 @@ libide_io_public_headers = [
   'ide-persistent-map-builder.h',
   'ide-pkcon-transfer.h',
   'ide-pty-intercept.h',
+  'ide-recursive-file-monitor.h',
   'ide-shell.h',
   'libide-io.h',
 ]
@@ -31,6 +33,7 @@ install_headers(libide_io_public_headers, subdir: libide_io_header_subdir)
 #
 
 libide_io_public_sources = [
+  'ide-cached-list-model.c',
   'ide-content-type.c',
   'ide-gfile.c',
   'ide-line-reader.c',