path: root/src/lib/content.cc

/*
    Copyright (C) 2013-2015 Carl Hetherington <cth@carlh.net>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

/** @file  src/lib/content.cc
 *  @brief Content class.
 */

#include "content.h"
#include "util.h"
#include "content_factory.h"
#include "exceptions.h"
#include "film.h"
#include "safe_stringstream.h"
#include "job.h"
#include "compose.hpp"
#include "raw_convert.h"
#include <libcxml/cxml.h>
#include <libxml++/libxml++.h>
#include <boost/thread/mutex.hpp>
#include <iostream>

#include "i18n.h"

using std::string;
using std::list;
using std::cout;
using std::vector;
using std::max;
using std::pair;
using boost::shared_ptr;

int const ContentProperty::PATH = 400;
int const ContentProperty::POSITION = 401;
int const ContentProperty::LENGTH = 402;
int const ContentProperty::TRIM_START = 403;
int const ContentProperty::TRIM_END = 404;

Content::Content (shared_ptr<const Film> film)
	: _film (film)
	, _position (0)
	, _trim_start (0)
	, _trim_end (0)
	, _change_signals_frequent (false)
{

}

Content::Content (shared_ptr<const Film> film, DCPTime p)
	: _film (film)
	, _position (p)
	, _trim_start (0)
	, _trim_end (0)
	, _change_signals_frequent (false)
{

}

Content::Content (shared_ptr<const Film> film, boost::filesystem::path p)
	: _film (film)
	, _position (0)
	, _trim_start (0)
	, _trim_end (0)
	, _change_signals_frequent (false)
{
	_paths.push_back (p);
}

Content::Content (shared_ptr<const Film> film, cxml::ConstNodePtr node)
	: _film (film)
	, _change_signals_frequent (false)
{
	list<cxml::NodePtr> path_children = node->node_children ("Path");
	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").get_value_or ("X");
	_position = DCPTime (node->number_child<DCPTime::Type> ("Position"));
	_trim_start = ContentTime (node->number_child<ContentTime::Type> ("TrimStart"));
	_trim_end = ContentTime (node->number_child<ContentTime::Type> ("TrimEnd"));
}

Content::Content (shared_ptr<const Film> film, vector<shared_ptr<Content> > c)
	: _film (film)
	, _position (c.front()->position ())
	, _trim_start (c.front()->trim_start ())
	, _trim_end (c.back()->trim_end ())
	, _change_signals_frequent (false)
{
	for (size_t i = 0; i < c.size(); ++i) {
		if (i > 0 && c[i]->trim_start() > ContentTime ()) {
			throw JoinError (_("Only the first piece of content to be joined can have a start trim."));
		}

		if (i < (c.size() - 1) && c[i]->trim_end () > ContentTime ()) {
			throw JoinError (_("Only the last piece of content to be joined can have an end trim."));
		}

		for (size_t j = 0; j < c[i]->number_of_paths(); ++j) {
			_paths.push_back (c[i]->path (j));
		}
	}
}

void
Content::as_xml (xmlpp::Node* node) const
{
	boost::mutex::scoped_lock lm (_mutex);

	for (vector<boost::filesystem::path>::const_iterator i = _paths.begin(); i != _paths.end(); ++i) {
		node->add_child("Path")->add_child_text (i->string ());
	}
	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)
{
	if (job) {
		job->sub (_("Computing digest"));
	}

	boost::mutex::scoped_lock lm (_mutex);
	vector<boost::filesystem::path> p = _paths;
	lm.unlock ();

	/* Some content files are very big, so we use a poor man'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) + raw_convert<string> (boost::filesystem::file_size (p.front ()));

	lm.lock ();
	_digest = d;
}

void
Content::signal_changed (int p)
{
	emit (boost::bind (boost::ref (Changed), shared_from_this (), p, _change_signals_frequent));
}

void
Content::set_position (DCPTime p)
{
	{
		boost::mutex::scoped_lock lm (_mutex);
		if (p == _position) {
			return;
		}

		_position = p;
	}

	signal_changed (ContentProperty::POSITION);
}

void
Content::set_trim_start (ContentTime t)
{
	{
		boost::mutex::scoped_lock lm (_mutex);
		_trim_start = t;
	}

	signal_changed (ContentProperty::TRIM_START);
}

void
Content::set_trim_end (ContentTime t)
{
	{
		boost::mutex::scoped_lock lm (_mutex);
		_trim_end = t;
	}

	signal_changed (ContentProperty::TRIM_END);
}


shared_ptr<Content>
Content::clone () const
{
	shared_ptr<const Film> film = _film.lock ();
	if (!film) {
		return shared_ptr<Content> ();
	}

	/* This is a bit naughty, but I can't think of a compelling reason not to do it ... */
	xmlpp::Document doc;
	xmlpp::Node* node = doc.create_root_node ("Content");
	as_xml (node);

	/* notes is unused here (we assume) */
	list<string> notes;
	return content_factory (film, cxml::NodePtr (new cxml::Node (node)), Film::current_state_version, notes);
}

string
Content::technical_summary () const
{
	return String::compose ("%1 %2 %3", path_summary(), digest(), position().seconds());
}

DCPTime
Content::length_after_trim () const
{
	shared_ptr<const Film> film = _film.lock ();
	DCPOMATIC_ASSERT (film);
	return max (DCPTime (), full_length() - DCPTime (trim_start() + trim_end(), film->active_frame_rate_change (position ())));
}

/** @return string which includes everything about how this content affects
 *  its playlist.
 */
string
Content::identifier () const
{
	SafeStringStream s;

	s << Content::digest()
	  << "_" << position().get()
	  << "_" << trim_start().get()
	  << "_" << trim_end().get();

	return s.str ();
}

bool
Content::paths_valid () const
{
	for (vector<boost::filesystem::path>::const_iterator i = _paths.begin(); i != _paths.end(); ++i) {
		if (!boost::filesystem::exists (*i)) {
			return false;
		}
	}

	return true;
}

void
Content::set_path (boost::filesystem::path path)
{
	_paths.clear ();
	_paths.push_back (path);
	signal_changed (ContentProperty::PATH);
}

string
Content::path_summary () const
{
	/* XXX: should handle multiple paths more gracefully */

	DCPOMATIC_ASSERT (number_of_paths ());

	string s = path(0).filename().string ();
	if (number_of_paths() > 1) {
		s += " ...";
	}

	return s;
}

/** @return a list of properties that might be interesting to the user; first string is the property name,
 *  second is the value.
 */
list<pair<string, string> >
Content::properties () const
{
	list<pair<string, string> > p;
	add_properties (p);
	return p;
}