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/libotutil/ot-checksum-utils.c

@@ -0,0 +1,38 @@
+/* -*- 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.
+ *
+ * Author: Colin Walters <walters@verbum.org>
+ */
+
+#include "config.h"
+
+#include "otutil.h"
+
+#include <string.h>
+
+guchar *
+ot_csum_from_gchecksum (GChecksum  *checksum)
+{
+  guchar *ret = g_malloc (32);
+  gsize len = 32;
+  
+  g_checksum_get_digest (checksum, ret, &len);
+  g_assert (len == 32);
+  return ret;
+}

src/libotutil/ot-checksum-utils.h

@@ -0,0 +1,34 @@
+/* -*- 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.
+ *
+ * Author: Colin Walters <walters@verbum.org>
+ */
+
+#ifndef __OSTREE_CHECKSUM_UTILS_H__
+#define __OSTREE_CHECKSUM_UTILS_H__
+
+#include <gio/gio.h>
+
+G_BEGIN_DECLS
+
+guchar *ot_csum_from_gchecksum (GChecksum *checksum);
+
+G_END_DECLS
+
+#endif

src/libotutil/ot-gio-utils.c

@@ -229,21 +229,17 @@ ot_gfile_get_basename_cached (GFile *file)
 }
 
 gboolean
-ot_gio_splice_and_checksum (GOutputStream  *out,
-                            GInputStream   *in,
-                            GChecksum     **out_checksum,
-                            GCancellable   *cancellable,
-                            GError        **error)
+ot_gio_splice_update_checksum (GOutputStream  *out,
+                               GInputStream   *in,
+                               GChecksum      *checksum,
+                               GCancellable   *cancellable,
+                               GError        **error)
 {
   gboolean ret = FALSE;
-  GChecksum *ret_checksum = NULL;
 
-  g_return_val_if_fail (out != NULL || out_checksum != NULL, FALSE);
+  g_return_val_if_fail (out != NULL || checksum != NULL, FALSE);
 
-  if (out_checksum)
-    ret_checksum = g_checksum_new (G_CHECKSUM_SHA256);
-  
-  if (ret_checksum != NULL)
+  if (checksum != NULL)
     {
       gsize bytes_read, bytes_written;
       char buf[4096];
@@ -251,8 +247,7 @@ ot_gio_splice_and_checksum (GOutputStream  *out,
         {
           if (!g_input_stream_read_all (in, buf, sizeof(buf), &bytes_read, cancellable, error))
             goto out;
-          if (ret_checksum)
-            g_checksum_update (ret_checksum, (guint8*)buf, bytes_read);
+          g_checksum_update (checksum, (guint8*)buf, bytes_read);
           if (out)
             {
               if (!g_output_stream_write_all (out, buf, bytes_read, &bytes_written, cancellable, error))
@@ -268,21 +263,44 @@ ot_gio_splice_and_checksum (GOutputStream  *out,
     }
 
   ret = TRUE;
-  ot_transfer_out_value(out_checksum, &ret_checksum);
  out:
-  ot_clear_checksum (&ret_checksum);
+  return ret;
+}
+
+gboolean
+ot_gio_splice_get_checksum (GOutputStream  *out,
+                            GInputStream   *in,
+                            guchar        **out_csum,
+                            GCancellable   *cancellable,
+                            GError        **error)
+{
+  gboolean ret = FALSE;
+  GChecksum *checksum = NULL;
+  ot_lfree guchar *ret_csum = NULL;
+
+  checksum = g_checksum_new (G_CHECKSUM_SHA256);
+
+  if (!ot_gio_splice_update_checksum (out, in, checksum, cancellable, error))
+    goto out;
+
+  ret_csum = ot_csum_from_gchecksum (checksum);
+
+  ret = TRUE;
+  ot_transfer_out_value (out_csum, &ret_csum);
+ out:
+  ot_clear_checksum (&checksum);
   return ret;
 }
 
 gboolean
 ot_gio_checksum_stream (GInputStream   *in,
-                        GChecksum     **out_checksum,
+                        guchar        **out_csum,
                         GCancellable   *cancellable,
                         GError        **error)
 {
-  if (!out_checksum)
+  if (!out_csum)
     return TRUE;
-  return ot_gio_splice_and_checksum (NULL, in, out_checksum, cancellable, error);
+  return ot_gio_splice_get_checksum (NULL, in, out_csum, cancellable, error);
 }
 
 gboolean

src/libotutil/ot-gio-utils.h

@@ -61,14 +61,20 @@ gboolean ot_gfile_load_contents_utf8 (GFile         *file,
                                       GCancellable  *cancellable,
                                       GError       **error);
 
-gboolean ot_gio_splice_and_checksum (GOutputStream  *out,
+gboolean ot_gio_splice_get_checksum (GOutputStream  *out,
                                      GInputStream   *in,
-                                     GChecksum     **out_checksum,
+                                     guchar        **out_csum,
                                      GCancellable   *cancellable,
                                      GError        **error);
 
+gboolean ot_gio_splice_update_checksum (GOutputStream  *out,
+                                        GInputStream   *in,
+                                        GChecksum      *checksum,
+                                        GCancellable   *cancellable,
+                                        GError        **error);
+
 gboolean ot_gio_checksum_stream (GInputStream   *in,
-                                 GChecksum     **out_checksum,
+                                 guchar        **out_csum,
                                  GCancellable   *cancellable,
                                  GError        **error);
 

src/libotutil/ot-variant-utils.c

@@ -159,9 +159,9 @@ ot_util_variant_from_stream (GInputStream         *src,
 
   data_stream = (GMemoryOutputStream*)g_memory_output_stream_new (NULL, 0, g_realloc, g_free);
 
-  if (!g_output_stream_splice ((GOutputStream*)data_stream, src,
-                               G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE | G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET,
-                               cancellable, error))
+  if (g_output_stream_splice ((GOutputStream*)data_stream, src,
+                              G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE | G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET,
+                              cancellable, error) < 0)
     goto out;
 
   ret_variant = g_variant_new_from_data (type, g_memory_output_stream_get_data (data_stream),

src/libotutil/otutil.h

@@ -47,5 +47,6 @@
 #include <ot-opt-utils.h>
 #include <ot-unix-utils.h>
 #include <ot-variant-utils.h>
+#include <ot-checksum-utils.h>
 
 #endif