core: Clean up checksumming

Don't expose GChecksum in APIs.  Add a new stream class which allows
us to pass an input stream somewhere, but gather a checksum as it's
read.

Move some bits of the internals towards binary csums.

src/libostree/ostree-checksum-input-stream.h

@@ -0,0 +1,68 @@
+/* -*- 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.
+ *
+ */
+
+#ifndef __OSTREE_CHECKSUM_INPUT_STREAM_H__
+#define __OSTREE_CHECKSUM_INPUT_STREAM_H__
+
+#include <gio/gio.h>
+
+G_BEGIN_DECLS
+
+#define OSTREE_TYPE_CHECKSUM_INPUT_STREAM         (ostree_checksum_input_stream_get_type ())
+#define OSTREE_CHECKSUM_INPUT_STREAM(o)           (G_TYPE_CHECK_INSTANCE_CAST ((o), OSTREE_TYPE_CHECKSUM_INPUT_STREAM, OstreeChecksumInputStream))
+#define OSTREE_CHECKSUM_INPUT_STREAM_CLASS(k)     (G_TYPE_CHECK_CLASS_CAST((k), OSTREE_TYPE_CHECKSUM_INPUT_STREAM, OstreeChecksumInputStreamClass))
+#define OSTREE_IS_CHECKSUM_INPUT_STREAM(o)        (G_TYPE_CHECK_INSTANCE_TYPE ((o), OSTREE_TYPE_CHECKSUM_INPUT_STREAM))
+#define OSTREE_IS_CHECKSUM_INPUT_STREAM_CLASS(k)  (G_TYPE_CHECK_CLASS_TYPE ((k), OSTREE_TYPE_CHECKSUM_INPUT_STREAM))
+#define OSTREE_CHECKSUM_INPUT_STREAM_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), OSTREE_TYPE_CHECKSUM_INPUT_STREAM, OstreeChecksumInputStreamClass))
+
+typedef struct _OstreeChecksumInputStream         OstreeChecksumInputStream;
+typedef struct _OstreeChecksumInputStreamClass    OstreeChecksumInputStreamClass;
+typedef struct _OstreeChecksumInputStreamPrivate  OstreeChecksumInputStreamPrivate;
+
+struct _OstreeChecksumInputStream
+{
+  GFilterInputStream parent_instance;
+
+  /*< private >*/
+  OstreeChecksumInputStreamPrivate *priv;
+};
+
+struct _OstreeChecksumInputStreamClass
+{
+  GFilterInputStreamClass parent_class;
+
+  /*< private >*/
+  /* Padding for future expansion */
+  void (*_g_reserved1) (void);
+  void (*_g_reserved2) (void);
+  void (*_g_reserved3) (void);
+  void (*_g_reserved4) (void);
+  void (*_g_reserved5) (void);
+};
+
+GType          ostree_checksum_input_stream_get_type     (void) G_GNUC_CONST;
+
+OstreeChecksumInputStream * ostree_checksum_input_stream_new          (GInputStream   *stream,
+                                                                       GChecksum      *checksum);
+
+G_END_DECLS
+
+#endif /* __OSTREE_CHECKSUM_INPUT_STREAM_H__ */