Hand-apply bbfb370d7de28ec1e8f307865cc6253bb5d4366e from master; quicker digest calcu...

[dcpomatic.git] / src / lib / content.cc

diff --git a/src/lib/content.cc b/src/lib/content.cc
index a8d058cc19cd2c8d3e1ef0b765520ea07777287d..550a8cd0577333d88844ea014d2f41b60299c7f7 100644 (file)
--- a/src/lib/content.cc
+++ b/src/lib/content.cc
@@ -88,7 +88,7 @@ Content::Content (shared_ptr<const Film> f, cxml::ConstNodePtr node)
        for (list<cxml::NodePtr>::const_iterator i = path_children.begin(); i != path_children.end(); ++i) {
                _paths.push_back ((*i)->content ());
        }
-       _digest = node->optional_string_child ("Digest");
+       _digest = node->optional_string_child ("Digest").get_value_or ("X");
        _position = DCPTime (node->number_child<double> ("Position"));
        _trim_start = DCPTime (node->number_child<double> ("TrimStart"));
        _trim_end = DCPTime (node->number_child<double> ("TrimEnd"));
@@ -124,21 +124,15 @@ Content::as_xml (xmlpp::Node* node) const
        for (vector<boost::filesystem::path>::const_iterator i = _paths.begin(); i != _paths.end(); ++i) {
                node->add_child("Path")->add_child_text (i->string ());
        }
-       if (_digest) {
-               node->add_child("Digest")->add_child_text (_digest.get ());
-       }
+       node->add_child("Digest")->add_child_text (_digest);
        node->add_child("Position")->add_child_text (raw_convert<string> (_position.get ()));
        node->add_child("TrimStart")->add_child_text (raw_convert<string> (_trim_start.get ()));
        node->add_child("TrimEnd")->add_child_text (raw_convert<string> (_trim_end.get ()));
 }
 
 void
-Content::examine (shared_ptr<Job> job, bool calculate_digest)
+Content::examine (shared_ptr<Job> job)
 {
-       if (!calculate_digest) {
-               return;
-       }
-
        if (job) {
                job->sub (_("Computing digest"));
        }
@@ -146,8 +140,12 @@ Content::examine (shared_ptr<Job> job, bool calculate_digest)
        boost::mutex::scoped_lock lm (_mutex);
        vector<boost::filesystem::path> p = _paths;
        lm.unlock ();
-       
-       string const d = md5_digest (p, job);
+
+       /* Some content files are very big, so we use a poor's
+          digest here: a MD5 of the first and last 1e6 bytes with the
+          size of the first file tacked on the end as a string.
+       */
+       string const d = md5_digest_head_tail (p, 1000000) + dcp::raw_convert<string> (boost::filesystem::file_size (p.front ()));
 
        lm.lock ();
        _digest = d;
@@ -220,7 +218,7 @@ Content::clone () const
 string
 Content::technical_summary () const
 {
-       return String::compose ("%1 %2 %3", path_summary(), digest().get_value_or("X"), position().seconds());
+       return String::compose ("%1 %2 %3", path_summary(), digest(), position().seconds());
 }
 
 DCPTime
@@ -237,7 +235,7 @@ Content::identifier () const
 {
        SafeStringStream s;
        
-       s << Content::digest().get_value_or("X")
+       s << Content::digest()
          << "_" << position().get()
          << "_" << trim_start().get()
          << "_" << trim_end().get();