command: use MaCommand object

1 files changed, 417 insertions, 0 deletions

diff --git a/command/ma-command.c b/command/ma-command.c
new file mode 100644
index 00000000..da0e8795
--- /dev/null
+++ b/command/ma-command.c
@@ -0,0 +1,417 @@
+/*
+ * Copyright (C) 2018 Alberts Muktupāvels
+ *
+ * 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 2 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/>.
+ */
+
+#include <config.h>
+#include "ma-command.h"
+
+#define BUFFER_SIZE 64
+
+struct _MaCommand
+{
+  GObject   parent;
+
+  gchar    *command;
+  gchar   **argv;
+};
+
+typedef struct
+{
+  GPid        pid;
+
+  GIOChannel *channel;
+
+  GString    *input;
+
+  guint       io_watch_id;
+  guint       child_watch_id;
+} CommandData;
+
+enum
+{
+  PROP_0,
+
+  PROP_COMMAND,
+
+  LAST_PROP
+};
+
+static GParamSpec *command_properties[LAST_PROP] = { NULL };
+
+static void initable_iface_init (GInitableIface *iface);
+
+G_DEFINE_TYPE_WITH_CODE (MaCommand, ma_command, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,
+                                                initable_iface_init))
+
+static gboolean
+read_cb (GIOChannel   *source,
+         GIOCondition  condition,
+         gpointer      user_data)
+{
+  GTask *task;
+  CommandData *data;
+  gchar buffer[BUFFER_SIZE];
+  gsize bytes_read;
+  GError *error;
+  GIOStatus status;
+
+  task = (GTask *) user_data;
+  data = g_task_get_task_data (task);
+
+  if (g_task_return_error_if_cancelled (task))
+    {
+      g_object_unref (task);
+
+      data->io_watch_id = 0;
+
+      return G_SOURCE_REMOVE;
+    }
+
+  error = NULL;
+  status = g_io_channel_read_chars (source, buffer, BUFFER_SIZE,
+                                    &bytes_read, &error);
+
+  if (status == G_IO_STATUS_AGAIN)
+    {
+      g_clear_error (&error);
+
+      return G_SOURCE_CONTINUE;
+    }
+  else if (status != G_IO_STATUS_NORMAL)
+    {
+      if (error != NULL)
+        {
+          g_task_return_error (task, error);
+          g_object_unref (task);
+        }
+
+      data->io_watch_id = 0;
+
+      return G_SOURCE_REMOVE;
+    }
+
+  g_string_append_len (data->input, buffer, bytes_read);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static void
+child_watch_cb (GPid     pid,
+                gint     status,
+                gpointer user_data)
+{
+  GTask *task;
+  CommandData *data;
+
+  task = (GTask *) user_data;
+  data = g_task_get_task_data (task);
+
+  g_task_return_pointer (task, g_strdup (data->input->str), g_free);
+  g_object_unref (task);
+}
+
+static void
+cancelled_cb (GCancellable *cancellable,
+              gpointer      user_data)
+{
+  GTask *task;
+
+  task = G_TASK (user_data);
+
+  g_object_unref (task);
+}
+
+static void
+command_data_free (gpointer user_data)
+{
+  CommandData *data;
+
+  data = (CommandData *) user_data;
+
+  if (data->pid != 0)
+    {
+      g_spawn_close_pid (data->pid);
+      data->pid = 0;
+    }
+
+  if (data->channel != NULL)
+    {
+      g_io_channel_unref (data->channel);
+      data->channel = NULL;
+    }
+
+  if (data->input != NULL)
+    {
+      g_string_free (data->input, TRUE);
+      data->input = NULL;
+    }
+
+  if (data->io_watch_id != 0)
+    {
+      g_source_remove (data->io_watch_id);
+      data->io_watch_id = 0;
+    }
+
+  if (data->child_watch_id != 0)
+    {
+      g_source_remove (data->child_watch_id);
+      data->child_watch_id = 0;
+    }
+
+  g_free (data);
+}
+
+static gboolean
+ma_command_initable_init (GInitable     *initable,
+                          GCancellable  *cancellable,
+                          GError       **error)
+{
+  MaCommand *command;
+
+  command = MA_COMMAND (initable);
+
+  if (command->command == NULL || *command->command == '\0')
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_DATA,
+                   "Empty command");
+
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+static void
+initable_iface_init (GInitableIface *iface)
+{
+  iface->init = ma_command_initable_init;
+}
+
+static void
+ma_command_finalize (GObject *object)
+{
+  MaCommand *command;
+
+  command = MA_COMMAND (object);
+
+  g_clear_pointer (&command->command, g_free);
+  g_clear_pointer (&command->argv, g_strfreev);
+
+  G_OBJECT_CLASS (ma_command_parent_class)->finalize (object);
+}
+
+static void
+ma_command_set_property (GObject      *object,
+                         guint         property_id,
+                         const GValue *value,
+                         GParamSpec   *pspec)
+{
+  MaCommand *command;
+
+  command = MA_COMMAND (object);
+
+  switch (property_id)
+    {
+      case PROP_COMMAND:
+          //g_assert (command->command == NULL);
+          command->command = g_value_dup_string (value);
+          if (command->argv && *command->argv != NULL) {
+              g_strfreev(command->argv);
+          }
+          g_shell_parse_argv (command->command, NULL, &command->argv, NULL);
+        break;
+
+      default:
+        G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+        break;
+    }
+}
+
+static void
+ma_command_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
+{
+    MaCommand *command;
+
+    command = MA_COMMAND (object);
+
+    switch (prop_id)
+    {
+        case PROP_COMMAND:
+            g_value_set_string (value, command->command);
+        default:
+            G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+            break;
+    }
+}
+
+static void
+install_properties (GObjectClass *object_class)
+{
+  command_properties[PROP_COMMAND] =
+    g_param_spec_string ("command", "command", "command",
+                         NULL,
+                         G_PARAM_READWRITE);
+
+  g_object_class_install_properties (object_class, LAST_PROP,
+                                     command_properties);
+}
+
+static void
+ma_command_class_init (MaCommandClass *command_class)
+{
+  GObjectClass *object_class;
+
+  object_class = G_OBJECT_CLASS (command_class);
+
+  object_class->finalize = ma_command_finalize;
+  object_class->set_property = ma_command_set_property;
+  object_class->get_property = ma_command_get_property;
+
+  install_properties (object_class);
+}
+
+static void
+ma_command_init (MaCommand *command)
+{
+}
+
+/**
+ * ma_command_new:
+ * @command: a command
+ * @error: (nullable): return location for an error, or %NULL
+ *
+ * Creates a new #MaCommand.
+ *
+ * Returns: (nullable): a newly allocated #MaCommand
+ */
+MaCommand *
+ma_command_new (const gchar  *command,
+                GError      **error)
+{
+  return g_initable_new (MA_TYPE_COMMAND, NULL, error,
+                         "command", command,
+                         NULL);
+}
+
+/**
+ * ma_command_run_async:
+ * @command: a #MaCommand
+ * @cancellable: (nullable): a #GCancellable or %NULL
+ * @callback: a #GAsyncReadyCallback to call when the request is satisfied
+ * @user_data: the data to pass to @callback
+ *
+ * Request an asynchronous read of output from command that was passed
+ * to ma_command_new().
+ */
+void
+ma_command_run_async (MaCommand           *command,
+                      GCancellable        *cancellable,
+                      GAsyncReadyCallback  callback,
+                      gpointer             user_data)
+{
+  GTask *task;
+  CommandData *data;
+  GSpawnFlags spawn_flags;
+  gint command_stdout;
+  GError *error;
+  GIOChannel *channel;
+  GIOStatus status;
+  GIOCondition condition;
+
+  g_return_if_fail (MA_IS_COMMAND (command));
+  g_return_if_fail (callback != NULL);
+
+  task = g_task_new (command, cancellable, callback, user_data);
+  g_task_set_source_tag (task, ma_command_run_async);
+
+  if (cancellable)
+    {
+      g_signal_connect_object (cancellable, "cancelled",
+                               G_CALLBACK (cancelled_cb), task,
+                               G_CONNECT_AFTER);
+    }
+
+  data = g_new0 (CommandData, 1);
+  g_task_set_task_data (task, data, command_data_free);
+
+  spawn_flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD;
+  error = NULL;
+
+  if (!g_spawn_async_with_pipes (NULL, command->argv, NULL, spawn_flags,
+                                 NULL, NULL, &data->pid, NULL, &command_stdout,
+                                 NULL, &error))
+    {
+      g_task_return_error (task, error);
+      g_object_unref (task);
+
+      return;
+    }
+
+  channel = data->channel = g_io_channel_unix_new (command_stdout);
+  g_io_channel_set_close_on_unref (channel, TRUE);
+
+  g_assert (error == NULL);
+  status = g_io_channel_set_encoding (channel, NULL, &error);
+
+  if (status != G_IO_STATUS_NORMAL)
+    {
+      g_task_return_error (task, error);
+      g_object_unref (task);
+
+      return;
+    }
+
+  g_assert (error == NULL);
+  status = g_io_channel_set_flags (channel, G_IO_FLAG_NONBLOCK, &error);
+
+  if (status != G_IO_STATUS_NORMAL)
+    {
+      g_task_return_error (task, error);
+      g_object_unref (task);
+
+      return;
+    }
+
+  data->input = g_string_new (NULL);
+
+  condition = G_IO_IN | G_IO_PRI | G_IO_ERR | G_IO_HUP;
+  data->io_watch_id = g_io_add_watch (channel, condition, read_cb, task);
+
+  data->child_watch_id = g_child_watch_add (data->pid, child_watch_cb, task);
+}
+
+/**
+ * ma_command_run_finish:
+ * @command: a #MaCommand
+ * @result: a #GAsyncResult
+ * @error: (nullable): return location for an error, or %NULL
+ *
+ * Finishes an operation started with ma_command_run_async().
+ *
+ * Returns: %NULL if @error is set, otherwise output from command
+ */
+gchar *
+ma_command_run_finish (MaCommand     *command,
+                       GAsyncResult  *result,
+                       GError       **error)
+{
+  g_return_val_if_fail (MA_IS_COMMAND (command), NULL);
+  g_return_val_if_fail (g_task_is_valid (result, command), NULL);
+  g_return_val_if_fail (error == NULL || *error == NULL, NULL);
+
+  return g_task_propagate_pointer (G_TASK (result), error);
+}