lib: Add a lighter weight internal checksum wrapper

The faster (OpenSSL/GnuTLS) code lived in a `GInputStream` wrapper, and that
adds a lot of weight (GObject + vtable calls). Move it into a simple
autoptr-struct wrapper, and use it in the metadata path, so we're
now using the faster checksums there too.

This also drops a malloc there as the new API does hexdigest in place to a
buffer.

Prep for more work in the commit path to avoid `GInputStream` for local file
commits, and ["adopting" files](https://github.com/ostreedev/ostree/pull/1255).

Closes: #1256
Approved by: jlebon

1 files changed, 34 insertions, 3 deletions

diff --git a/src/libotutil/ot-checksum-utils.h b/src/libotutil/ot-checksum-utils.h
index a0e72dbc..abf3c6db 100644
--- a/src/libotutil/ot-checksum-utils.h
+++ b/src/libotutil/ot-checksum-utils.h
@@ -21,7 +21,7 @@
 
 #pragma once
 
-#include <gio/gio.h>
+#include "libglnx.h"
 
 G_BEGIN_DECLS
 
@@ -29,11 +29,42 @@ void ot_bin2hex (char *out_buf, const guint8 *inbuf, gsize len);
 
 guchar *ot_csum_from_gchecksum (GChecksum *checksum);
 
+struct OtChecksum {
+  gboolean initialized;
+  guint uints[2];
+  gpointer data[2];
+};
+typedef struct OtChecksum OtChecksum;
+
+/* Same as OSTREE_SHA256_DIGEST_LEN, but this header can't depend on that */
+#define _OSTREE_SHA256_DIGEST_LEN (32)
+#if defined(OSTREE_SHA256_DIGEST_LEN) && _OSTREE_SHA256_DIGEST_LEN != OSTREE_SHA256_DIGEST_LEN
+#error Mismatched OSTREE_SHA256_DIGEST_LEN
+#endif
+/* See above */
+#define _OSTREE_SHA256_STRING_LEN (64)
+#if defined(OSTREE_SHA256_STRING_LEN) && _OSTREE_SHA256_STRING_LEN != OSTREE_SHA256_STRING_LEN
+#error Mismatched OSTREE_SHA256_STRING_LEN
+#endif
+
+void ot_checksum_init (OtChecksum *checksum);
+void ot_checksum_update (OtChecksum *checksum,
+                         const guint8   *buf,
+                         size_t          len);
+void ot_checksum_get_digest (OtChecksum *checksum,
+                             guint8      *buf,
+                             size_t       buflen);
+void ot_checksum_get_hexdigest (OtChecksum *checksum,
+                                char           *buf,
+                                size_t          buflen);
+void ot_checksum_clear (OtChecksum *checksum);
+G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(OtChecksum, ot_checksum_clear)
+
 gboolean ot_gio_write_update_checksum (GOutputStream  *out,
                                        gconstpointer   data,
                                        gsize           len,
                                        gsize          *out_bytes_written,
-                                       GChecksum      *checksum,
+                                       OtChecksum     *checksum,
                                        GCancellable   *cancellable,
                                        GError        **error);
 
@@ -45,7 +76,7 @@ gboolean ot_gio_splice_get_checksum (GOutputStream  *out,
 
 gboolean ot_gio_splice_update_checksum (GOutputStream  *out,
                                         GInputStream   *in,
-                                        GChecksum      *checksum,
+                                        OtChecksum     *checksum,
                                         GCancellable   *cancellable,
                                         GError        **error);