Optional progress reporting when making MXF hashes.

5 files changed, 36 insertions, 6 deletions

diff --git a/src/asset.cc b/src/asset.cc
index fb21580e..06b87953 100644
--- a/src/asset.cc
+++ b/src/asset.cc
@@ -88,12 +88,22 @@ string
 Asset::digest () const
 {
 	if (_digest.empty ()) {
-		_digest = make_digest (path().string());
+		_digest = make_digest (path().string(), 0);
 	}
 
 	return _digest;
 }
 
+void
+Asset::compute_digest (boost::function<void (float)> progress)
+{
+	if (!_digest.empty ()) {
+		return;
+	}
+
+	_digest = make_digest (path().string(), &progress);
+}
+
 bool
 Asset::equals (shared_ptr<const Asset> other, EqualityOptions, boost::function<void (NoteType, string)> note) const
 {
diff --git a/src/asset.h b/src/asset.h
index 44d088a3..c6ff7e83 100644
--- a/src/asset.h
+++ b/src/asset.h
@@ -73,6 +73,14 @@ public:
 	 */
 	void write_to_assetmap (xmlpp::Node *) const;
 
+	/** Compute the digest for this asset.  Calling this is optional: if
+	 *  it is not called, the digest will be computed when required.  However,
+	 *  calling this method allows the caller to see the progress of the
+	 *  computation, which can be long for large assets.
+	 *  @param Called with progress between 0 and 1.
+	 */
+	void compute_digest (boost::function<void (float)> progress);
+
 	std::string uuid () const {
 		return _uuid;
 	}
diff --git a/src/cpl.cc b/src/cpl.cc
index e4f36fed..561cc989 100644
--- a/src/cpl.cc
+++ b/src/cpl.cc
@@ -252,7 +252,7 @@ CPL::write_xml (bool interop, XMLMetadata const & metadata, shared_ptr<Encryptio
 
 	doc.write_to_file_formatted (p.string (), "UTF-8");
 
-	_digest = make_digest (p.string ());
+	_digest = make_digest (p.string (), 0);
 	_length = boost::filesystem::file_size (p.string ());
 }
 
diff --git a/src/util.cc b/src/util.cc
index 875693bf..d7b4f980 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -70,10 +70,12 @@ libdcp::make_uuid ()
 
 /** Create a digest for a file.
  *  @param filename File name.
+ *  @param progress Pointer to a progress reporting function, or 0.  The function will be called
+ *  with a progress value between 0 and 1.
  *  @return Digest.
  */
 string
-libdcp::make_digest (string filename)
+libdcp::make_digest (string filename, boost::function<void (float)>* progress)
 {
 	Kumu::FileReader reader;
 	if (ASDCP_FAILURE (reader.OpenRead (filename.c_str ()))) {
@@ -82,8 +84,12 @@ libdcp::make_digest (string filename)
 	
 	SHA_CTX sha;
 	SHA1_Init (&sha);
-	
-	Kumu::ByteString read_buffer (65536);
+
+	int const buffer_size = 65536;
+	Kumu::ByteString read_buffer (buffer_size);
+
+	Kumu::fsize_t done = 0;
+	Kumu::fsize_t const size = reader.Size ();
 	while (1) {
 		ui32_t read = 0;
 		Kumu::Result_t r = reader.Read (read_buffer.Data(), read_buffer.Capacity(), &read);
@@ -95,6 +101,11 @@ libdcp::make_digest (string filename)
 		}
 		
 		SHA1_Update (&sha, read_buffer.Data(), read);
+
+		if (progress) {
+			(*progress) (float (done) / size);
+			done += read;
+		}
 	}
 
 	byte_t byte_buffer[20];
diff --git a/src/util.h b/src/util.h
index 9153dbda..586d197f 100644
--- a/src/util.h
+++ b/src/util.h
@@ -27,6 +27,7 @@
 #include <string>
 #include <stdint.h>
 #include <boost/shared_ptr.hpp>
+#include <boost/function.hpp>
 #include <openjpeg.h>
 #include "types.h"
 
@@ -60,7 +61,7 @@ extern bool operator== (Size const & a, Size const & b);
 extern bool operator!= (Size const & a, Size const & b);
 
 extern std::string make_uuid ();
-extern std::string make_digest (std::string filename);
+extern std::string make_digest (std::string filename, boost::function<void (float)> *);
 extern std::string content_kind_to_string (ContentKind kind);
 extern ContentKind content_kind_from_string (std::string kind);
 extern bool empty_or_white_space (std::string s);