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/*
Copyright (C) 2013-2021 Carl Hetherington <cth@carlh.net>
This file is part of DCP-o-matic.
DCP-o-matic 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.
DCP-o-matic 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 DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file src/lib/file_group.cc
* @brief FileGroup class.
*/
#include "compose.hpp"
#include "cross.h"
#include "dcpomatic_assert.h"
#include "exceptions.h"
#include "file_group.h"
#include <dcp/filesystem.h>
#include <sndfile.h>
#include <cstdio>
using std::vector;
/** Construct a FileGroup with no files */
FileGroup::FileGroup ()
{
}
/** Construct a FileGroup with a single file */
FileGroup::FileGroup (boost::filesystem::path p)
{
_paths.push_back (p);
ensure_open_path (0);
seek (0, SEEK_SET);
}
/** Construct a FileGroup with multiple files */
FileGroup::FileGroup (vector<boost::filesystem::path> const & p)
: _paths (p)
{
ensure_open_path (0);
seek (0, SEEK_SET);
}
void
FileGroup::set_paths (vector<boost::filesystem::path> const & p)
{
_paths = p;
ensure_open_path (0);
seek (0, SEEK_SET);
}
/** Ensure that the given path index in the content is the _current_file */
void
FileGroup::ensure_open_path (size_t p) const
{
if (_current_file && _current_path == p) {
/* Already open */
return;
}
if (_current_file) {
_current_file->close();
}
_current_path = p;
_current_file = dcp::File(_paths[_current_path], "rb");
if (!_current_file) {
throw OpenFileError (_paths[_current_path], errno, OpenFileError::READ);
}
_current_size = dcp::filesystem::file_size(_paths[_current_path]);
}
int64_t
FileGroup::seek (int64_t pos, int whence) const
{
switch (whence) {
case SEEK_SET:
_position = pos;
break;
case SEEK_CUR:
_position += pos;
break;
case SEEK_END:
_position = length() - pos;
break;
}
/* Find an offset within one of the files, if _position is within a file */
size_t i = 0;
int64_t sub_pos = _position;
while (i < _paths.size()) {
boost::uintmax_t len = dcp::filesystem::file_size(_paths[i]);
if (sub_pos < int64_t(len)) {
break;
}
sub_pos -= int64_t(len);
++i;
}
if (i < _paths.size()) {
ensure_open_path (i);
_current_file->seek(sub_pos, SEEK_SET);
} else {
ensure_open_path (_paths.size() - 1);
_current_file->seek(_current_size, SEEK_SET);
}
return _position;
}
/** Try to read some data from the current position into a buffer.
* @param buffer Buffer to write data into.
* @param amount Number of bytes to read.
*/
FileGroup::Result
FileGroup::read (uint8_t* buffer, int amount) const
{
DCPOMATIC_ASSERT (_current_file);
int read = 0;
while (true) {
bool eof = false;
size_t to_read = amount - read;
DCPOMATIC_ASSERT (_current_file);
auto const current_position = _current_file->tell();
if (current_position == -1) {
to_read = 0;
eof = true;
} else if ((current_position + to_read) > _current_size) {
to_read = _current_size - current_position;
eof = true;
}
int const this_time = _current_file->read(buffer + read, 1, to_read);
read += this_time;
_position += this_time;
if (read == amount) {
/* Done */
break;
}
if (_current_file->error()) {
throw FileError (String::compose("fread error %1", errno), _paths[_current_path]);
}
if (eof) {
/* See if there is another file to use */
if ((_current_path + 1) >= _paths.size()) {
return { read, true };
}
ensure_open_path (_current_path + 1);
}
}
return { read, false };
}
/** @return Combined length of all the files */
int64_t
FileGroup::length () const
{
int64_t len = 0;
for (size_t i = 0; i < _paths.size(); ++i) {
len += dcp::filesystem::file_size(_paths[i]);
}
return len;
}
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