core: Support for committing from any libarchive-supported format

We really want the ability to take a .tar.gz and directly import
it into a repository, without creating a temporary filesystem tree.

First, doing it this way is significantly faster.  Also, this allows
us to handle importing tar files with e.g. uid 0 files into packed
repositories as non-root, which is very useful for tests and builds.

src/libostree/ostree-libarchive-input-stream.c

@@ -0,0 +1,186 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ * 
+ * Copyright (C) 2011 Colin Walters <walters@verbum.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General
+ * Public License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+
+#include <archive.h>
+#include <gio/gio.h>
+#include "ostree-libarchive-input-stream.h"
+
+enum {
+  PROP_0,
+  PROP_ARCHIVE
+};
+
+G_DEFINE_TYPE (OstreeLibarchiveInputStream, ostree_libarchive_input_stream, G_TYPE_INPUT_STREAM)
+
+struct _OstreeLibarchiveInputStreamPrivate {
+  struct archive *archive;
+};
+
+static void     ostree_libarchive_input_stream_set_property (GObject              *object,
+						  guint                 prop_id,
+						  const GValue         *value,
+						  GParamSpec           *pspec);
+static void     ostree_libarchive_input_stream_get_property (GObject              *object,
+						  guint                 prop_id,
+						  GValue               *value,
+						  GParamSpec           *pspec);
+static gssize   ostree_libarchive_input_stream_read         (GInputStream         *stream,
+						  void                 *buffer,
+						  gsize                 count,
+						  GCancellable         *cancellable,
+						  GError              **error);
+static gboolean ostree_libarchive_input_stream_close        (GInputStream         *stream,
+						  GCancellable         *cancellable,
+						  GError              **error);
+
+static void
+ostree_libarchive_input_stream_finalize (GObject *object)
+{
+  G_OBJECT_CLASS (ostree_libarchive_input_stream_parent_class)->finalize (object);
+}
+
+static void
+ostree_libarchive_input_stream_class_init (OstreeLibarchiveInputStreamClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
+  
+  g_type_class_add_private (klass, sizeof (OstreeLibarchiveInputStreamPrivate));
+
+  gobject_class->get_property = ostree_libarchive_input_stream_get_property;
+  gobject_class->set_property = ostree_libarchive_input_stream_set_property;
+  gobject_class->finalize = ostree_libarchive_input_stream_finalize;
+
+  stream_class->read_fn = ostree_libarchive_input_stream_read;
+  stream_class->close_fn = ostree_libarchive_input_stream_close;
+
+  /**
+   * OstreeLibarchiveInputStream:archive:
+   *
+   * The archive that the stream reads from.
+   */
+  g_object_class_install_property (gobject_class,
+				   PROP_ARCHIVE,
+				   g_param_spec_pointer ("archive",
+							 "", "",
+							 G_PARAM_READWRITE |
+							 G_PARAM_CONSTRUCT_ONLY |
+							 G_PARAM_STATIC_STRINGS));
+
+}
+
+static void
+ostree_libarchive_input_stream_set_property (GObject         *object,
+					     guint            prop_id,
+					     const GValue    *value,
+					     GParamSpec      *pspec)
+{
+  OstreeLibarchiveInputStream *self;
+  
+  self = OSTREE_LIBARCHIVE_INPUT_STREAM (object);
+
+  switch (prop_id)
+    {
+    case PROP_ARCHIVE:
+      self->priv->archive = g_value_get_pointer (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+ostree_libarchive_input_stream_get_property (GObject    *object,
+					     guint       prop_id,
+					     GValue     *value,
+					     GParamSpec *pspec)
+{
+  OstreeLibarchiveInputStream *self;
+
+  self = OSTREE_LIBARCHIVE_INPUT_STREAM (object);
+
+  switch (prop_id)
+    {
+    case PROP_ARCHIVE:
+      g_value_set_pointer (value, self->priv->archive);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+    }
+}
+
+static void
+ostree_libarchive_input_stream_init (OstreeLibarchiveInputStream *self)
+{
+  self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
+					    OSTREE_TYPE_LIBARCHIVE_INPUT_STREAM,
+					    OstreeLibarchiveInputStreamPrivate);
+
+}
+
+GInputStream *
+ostree_libarchive_input_stream_new (struct archive *a)
+{
+  OstreeLibarchiveInputStream *stream;
+
+  stream = g_object_new (OSTREE_TYPE_LIBARCHIVE_INPUT_STREAM,
+			 "archive", a,
+			 NULL);
+
+  return G_INPUT_STREAM (stream);
+}
+
+static gssize
+ostree_libarchive_input_stream_read (GInputStream  *stream,
+				     void          *buffer,
+				     gsize          count,
+				     GCancellable  *cancellable,
+				     GError       **error)
+{
+  OstreeLibarchiveInputStream *self;
+  gssize res = -1;
+
+  self = OSTREE_LIBARCHIVE_INPUT_STREAM (stream);
+
+  if (g_cancellable_set_error_if_cancelled (cancellable, error))
+    return -1;
+
+  res = archive_read_data (self->priv->archive, buffer, count);
+  if (res < 0)
+    {
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "%s", archive_error_string (self->priv->archive));
+    }
+
+  return res;
+}
+
+static gboolean
+ostree_libarchive_input_stream_close (GInputStream  *stream,
+				      GCancellable  *cancellable,
+				      GError       **error)
+{
+  return TRUE;
+}
+