[gnome-builder/wip/libide] libide: enforce file-size max when opening buffers

[Christian Hergert <chergert src gnome org>]

commit f8f37013bff2802cad3421f06f70ded6e38cf712
Author: Christian Hergert <christian hergert me>
Date:   Sat Mar 14 14:58:34 2015 -0700

    libide: enforce file-size max when opening buffers
    
    Enforce maximum file size fo 10 Mb for now. You can disable this by
    setting the IdeBufferManager:file-size-max property to zero in your
    scripting environment if you need larger files.
    
    We can raise this later, but we are not very well suited to open very
    large files like SQL dumps and files of that nature.

 libide/ide-buffer-manager.c |  135 ++++++++++++++++++++++++++++++++++++-------
 libide/ide-buffer-manager.h |    3 +
 2 files changed, 117 insertions(+), 21 deletions(-)
---
diff --git a/libide/ide-buffer-manager.c b/libide/ide-buffer-manager.c
index 144be8f..4dadc96 100644
--- a/libide/ide-buffer-manager.c
+++ b/libide/ide-buffer-manager.c
@@ -33,7 +33,8 @@
 #include "ide-progress.h"
 #include "ide-source-location.h"
 
-#define AUTO_SAVE_TIMEOUT_DEFAULT 60
+#define AUTO_SAVE_TIMEOUT_DEFAULT    60
+#define MAX_FILE_SIZE_BYTES_DEFAULT  (1024UL * 1024UL * 10UL)
 
 struct _IdeBufferManager
 {
@@ -41,11 +42,11 @@ struct _IdeBufferManager
 
   GPtrArray                *buffers;
   GHashTable               *timeouts;
-
   IdeBuffer                *focus_buffer;
-
   GtkSourceCompletionWords *word_completion;
 
+  gsize                     max_file_size;
+
   guint                     auto_save_timeout;
   guint                     auto_save : 1;
 };
@@ -59,10 +60,11 @@ typedef struct
 
 typedef struct
 {
-  IdeBuffer   *buffer;
-  IdeFile     *file;
-  IdeProgress *progress;
-  guint        is_new;
+  IdeBuffer           *buffer;
+  IdeFile             *file;
+  IdeProgress         *progress;
+  GtkSourceFileLoader *loader;
+  guint                is_new : 1;
 } LoadState;
 
 typedef struct
@@ -79,6 +81,7 @@ enum {
   PROP_AUTO_SAVE,
   PROP_AUTO_SAVE_TIMEOUT,
   PROP_FOCUS_BUFFER,
+  PROP_MAX_FILE_SIZE,
   LAST_PROP
 };
 
@@ -127,6 +130,7 @@ load_state_free (gpointer data)
       g_clear_object (&state->buffer);
       g_clear_object (&state->file);
       g_clear_object (&state->progress);
+      g_clear_object (&state->loader);
       g_slice_free (LoadState, state);
     }
 }
@@ -468,18 +472,17 @@ emit_signal:
 }
 
 static void
-ide_buffer_manager__load_file_read_cb (GObject      *object,
-                                       GAsyncResult *result,
-                                       gpointer      user_data)
+ide_buffer_manager__load_file_query_info_cb (GObject      *object,
+                                             GAsyncResult *result,
+                                             gpointer      user_data)
 {
   IdeBufferManager *self;
   GFile *file = (GFile *)object;
-  g_autoptr(GFileInputStream) stream = NULL;
   g_autoptr(GTask) task = user_data;
-  GtkSourceFile *source_file;
-  GtkSourceFileLoader *loader;
+  g_autoptr(GFileInfo) file_info = NULL;
   LoadState *state;
   GError *error = NULL;
+  gsize size;
 
   g_assert (G_IS_FILE (file));
   g_assert (G_IS_TASK (task));
@@ -491,22 +494,28 @@ ide_buffer_manager__load_file_read_cb (GObject      *object,
   g_assert (IDE_IS_BUFFER (state->buffer));
   g_assert (IDE_IS_BUFFER_MANAGER (self));
 
-  stream = g_file_read_finish (file, result, &error);
+  file_info = g_file_query_info_finish (file, result, &error);
 
-  if (!stream)
+  if (!file_info)
     {
       g_task_return_error (task, error);
       return;
     }
 
-  source_file = _ide_file_get_source_file (state->file);
-  loader = gtk_source_file_loader_new_from_stream (GTK_SOURCE_BUFFER (state->buffer),
-                                                   source_file,
-                                                   G_INPUT_STREAM (stream));
+  size = g_file_info_get_attribute_uint64 (file_info, G_FILE_ATTRIBUTE_STANDARD_SIZE);
+
+  if ((self->max_file_size > 0) && (size > self->max_file_size))
+    {
+      g_task_return_new_error (task,
+                               G_IO_ERROR,
+                               G_IO_ERROR_INVALID_DATA,
+                               _("File too large to be opened."));
+      return;
+    }
 
   g_signal_emit (self, gSignals [LOAD_BUFFER], 0, state->buffer);
 
-  gtk_source_file_loader_load_async (loader,
+  gtk_source_file_loader_load_async (state->loader,
                                      G_PRIORITY_DEFAULT,
                                      g_task_get_cancellable (task),
                                      ide_progress_file_progress_callback,
@@ -514,8 +523,48 @@ ide_buffer_manager__load_file_read_cb (GObject      *object,
                                      g_object_unref,
                                      ide_buffer_manager_load_file__load_cb,
                                      g_object_ref (task));
+}
+
+static void
+ide_buffer_manager__load_file_read_cb (GObject      *object,
+                                       GAsyncResult *result,
+                                       gpointer      user_data)
+{
+  GFile *file = (GFile *)object;
+  g_autoptr(GFileInputStream) stream = NULL;
+  g_autoptr(GTask) task = user_data;
+  GtkSourceFile *source_file;
+  LoadState *state;
+  GError *error = NULL;
+
+  g_assert (G_IS_FILE (file));
+  g_assert (G_IS_TASK (task));
 
-  g_clear_object (&loader);
+  state = g_task_get_task_data (task);
+
+  g_assert (state);
+  g_assert (IDE_IS_BUFFER (state->buffer));
+
+  stream = g_file_read_finish (file, result, &error);
+
+  if (!stream)
+    {
+      g_task_return_error (task, error);
+      return;
+    }
+
+  source_file = _ide_file_get_source_file (state->file);
+  state->loader = gtk_source_file_loader_new_from_stream (GTK_SOURCE_BUFFER (state->buffer),
+                                                          source_file,
+                                                          G_INPUT_STREAM (stream));
+
+  g_file_query_info_async (file,
+                           G_FILE_ATTRIBUTE_STANDARD_SIZE,
+                           G_FILE_QUERY_INFO_NONE,
+                           G_PRIORITY_DEFAULT,
+                           g_task_get_cancellable (task),
+                           ide_buffer_manager__load_file_query_info_cb,
+                           g_object_ref (task));
 }
 
 /**
@@ -525,6 +574,10 @@ ide_buffer_manager__load_file_read_cb (GObject      *object,
  * Asynchronously requests that the file represented by @file is loaded. If the file is already
  * loaded, the previously loaded version of the file will be returned, asynchronously.
  *
+ * Before loading the file, #IdeBufferManager will check the file size to help protect itself
+ * from the user accidentally loading very large files. You can change the maximum size of file
+ * that will be loaded with the #IdeBufferManager:max-file-size property.
+ *
  * See ide_buffer_manager_load_file_finish() for how to complete this asynchronous request.
  */
 void
@@ -1059,6 +1112,7 @@ ide_buffer_manager_init (IdeBufferManager *self)
   self->auto_save = TRUE;
   self->auto_save_timeout = AUTO_SAVE_TIMEOUT_DEFAULT;
   self->buffers = g_ptr_array_new ();
+  self->max_file_size = MAX_FILE_SIZE_BYTES_DEFAULT;
   self->timeouts = g_hash_table_new (g_direct_hash, g_direct_equal);
   self->word_completion = gtk_source_completion_words_new (_("Words"), NULL);
 }
@@ -1205,3 +1259,42 @@ ide_buffer_manager_has_file (IdeBufferManager *self,
 {
   return !!ide_buffer_manager_find_buffer (self, file);
 }
+
+/**
+ * ide_buffer_manager_get_max_file_size:
+ * @self: An #IdeBufferManager.
+ *
+ * Gets the #IdeBufferManager:max-file-size property. This contains the maximum file size in bytes
+ * that a file may be to be loaded by the #IdeBufferManager.
+ *
+ * If zero, no size limits will be enforced.
+ *
+ * Returns: A #gsize in bytes or zero.
+ */
+gsize
+ide_buffer_manager_get_max_file_size (IdeBufferManager *self)
+{
+  g_return_val_if_fail (IDE_IS_BUFFER_MANAGER (self), 0);
+
+  return self->max_file_size;
+}
+
+/**
+ * ide_buffer_manager_set_max_file_size:
+ * @self: An #IdeBufferManager.
+ * @max_file_size: The maximum file size in bytes, or zero for no limit.
+ *
+ * Sets the maximum file size in bytes, that will be loaded by the #IdeBufferManager.
+ */
+void
+ide_buffer_manager_set_max_file_size (IdeBufferManager *self,
+                                      gsize             max_file_size)
+{
+  g_return_if_fail (IDE_IS_BUFFER_MANAGER (self));
+
+  if (self->max_file_size != max_file_size)
+    {
+      self->max_file_size = max_file_size;
+      g_object_notify_by_pspec (G_OBJECT (self), gParamSpecs [PROP_MAX_FILE_SIZE]);
+    }
+}
diff --git a/libide/ide-buffer-manager.h b/libide/ide-buffer-manager.h
index d0ec766..bd83976 100644
--- a/libide/ide-buffer-manager.h
+++ b/libide/ide-buffer-manager.h
@@ -59,6 +59,9 @@ gboolean                  ide_buffer_manager_has_file            (IdeBufferManag
                                                                   IdeFile              *file);
 IdeBuffer                *ide_buffer_manager_find_buffer         (IdeBufferManager     *self,
                                                                   IdeFile              *file);
+gsize                     ide_buffer_manager_get_max_file_size   (IdeBufferManager     *self);
+void                      ide_buffer_manager_set_max_file_size   (IdeBufferManager     *self,
+                                                                  gsize                 max_file_size);
 
 G_END_DECLS