lyx_mirror/src/ConverterCache.cpp
Richard Heck b90919e48b Revert r26683 and add some comments making it a little clearer what
is going on here.


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@26814 a592a061-630c-0410-9148-cb99ea01b6c8
2008-10-08 15:07:09 +00:00

443 lines
12 KiB
C++

/**
* \file ConverterCache.cpp
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Baruch Even
* \author Angus Leeming
* \author Georg Baum
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "ConverterCache.h"
#include "Format.h"
#include "Lexer.h"
#include "LyXRC.h"
#include "Mover.h"
#include "support/convert.h"
#include "support/debug.h"
#include "support/filetools.h"
#include "support/lyxtime.h"
#include "support/Package.h"
#include "support/lassert.h"
#include <boost/crc.hpp>
#include <algorithm>
#include <fstream>
#include <iomanip>
#include <map>
#include <sstream>
using namespace std;
using namespace lyx::support;
namespace lyx {
namespace {
unsigned long do_crc(string const & s)
{
boost::crc_32_type crc;
crc = for_each(s.begin(), s.end(), crc);
return crc.checksum();
}
static FileName cache_dir;
class CacheItem {
public:
CacheItem() {}
CacheItem(FileName const & orig_from, string const & to_format,
time_t t, unsigned long c)
: timestamp(t), checksum(c)
{
ostringstream os;
os << setw(10) << setfill('0') << do_crc(orig_from.absFilename())
<< '-' << to_format;
cache_name = FileName(addName(cache_dir.absFilename(), os.str()));
LYXERR(Debug::FILES, "Add file cache item " << orig_from
<< ' ' << to_format << ' ' << cache_name
<< ' ' << long(timestamp) << ' ' << checksum << '.');
}
~CacheItem() {}
FileName cache_name;
time_t timestamp;
unsigned long checksum;
};
}
/** The cache contains one item per orig file and target format, so use a
* nested map to find the cache item quickly by filename and format.
*/
typedef map<string, CacheItem> FormatCacheType;
class FormatCache {
public:
/// Format of the source file
string from_format;
/// Cache target format -> item to quickly find the item by format
FormatCacheType cache;
};
typedef map<FileName, FormatCache> CacheType;
class ConverterCache::Impl {
public:
///
void readIndex();
///
void writeIndex();
///
CacheItem * find(FileName const & from, string const & format);
CacheType cache;
};
void ConverterCache::Impl::readIndex()
{
time_t const now = current_time();
FileName const index(addName(cache_dir.absFilename(), "index"));
ifstream is(index.toFilesystemEncoding().c_str());
Lexer lex;
lex.setStream(is);
while (lex.isOK()) {
if (!lex.next(true))
break;
string const orig_from = lex.getString();
if (!lex.next())
break;
string const to_format = lex.getString();
if (!lex.next())
break;
time_t const timestamp =
convert<unsigned long>(lex.getString());
if (!lex.next())
break;
unsigned long const checksum =
convert<unsigned long>(lex.getString());
FileName const orig_from_name(orig_from);
CacheItem item(orig_from_name, to_format, timestamp, checksum);
// Don't cache files that do not exist anymore
if (!orig_from_name.exists()) {
LYXERR(Debug::FILES, "Not caching file `"
<< orig_from << "' (does not exist anymore).");
item.cache_name.removeFile();
continue;
}
// Don't add items that are not in the cache anymore
// This can happen if two instances of LyX are running
// at the same time and update the index file independantly.
if (!item.cache_name.exists()) {
LYXERR(Debug::FILES, "Not caching file `" << orig_from
<< "' (cached copy does not exist anymore).");
continue;
}
// Delete the cached file if it is too old
if (difftime(now, item.cache_name.lastModified())
> lyxrc.converter_cache_maxage) {
LYXERR(Debug::FILES, "Not caching file `"
<< orig_from << "' (too old).");
item.cache_name.removeFile();
continue;
}
FormatCache & format_cache = cache[orig_from_name];
if (format_cache.from_format.empty())
format_cache.from_format =
formats.getFormatFromFile(orig_from_name);
format_cache.cache[to_format] = item;
}
is.close();
}
void ConverterCache::Impl::writeIndex()
{
FileName const index(addName(cache_dir.absFilename(), "index"));
ofstream os(index.toFilesystemEncoding().c_str());
os.close();
if (!index.changePermission(0600))
return;
os.open(index.toFilesystemEncoding().c_str());
CacheType::iterator it1 = cache.begin();
CacheType::iterator const end1 = cache.end();
for (; it1 != end1; ++it1) {
FormatCacheType const & format_cache = it1->second.cache;
FormatCacheType::const_iterator it2 = format_cache.begin();
FormatCacheType::const_iterator const end2 = format_cache.end();
for (; it2 != end2; ++it2)
os << Lexer::quoteString(it1->first.absFilename())
<< ' ' << it2->first << ' '
<< it2->second.timestamp << ' '
<< it2->second.checksum << '\n';
}
os.close();
}
CacheItem * ConverterCache::Impl::find(FileName const & from,
string const & format)
{
if (!lyxrc.use_converter_cache)
return 0;
CacheType::iterator const it1 = cache.find(from);
if (it1 == cache.end())
return 0;
FormatCacheType & format_cache = it1->second.cache;
FormatCacheType::iterator const it2 = format_cache.find(format);
if (it2 == format_cache.end())
return 0;
return &(it2->second);
}
/////////////////////////////////////////////////////////////////////
//
// ConverterCache
//
/////////////////////////////////////////////////////////////////////
ConverterCache::ConverterCache()
: pimpl_(new Impl)
{}
ConverterCache::~ConverterCache()
{
if (!lyxrc.use_converter_cache)
return;
pimpl_->writeIndex();
delete pimpl_;
}
ConverterCache & ConverterCache::get()
{
// Now return the cache
static ConverterCache singleton;
return singleton;
}
void ConverterCache::init()
{
if (!lyxrc.use_converter_cache)
return;
// We do this here and not in the constructor because package() gets
// initialized after all static variables.
cache_dir = FileName(addName(package().user_support().absFilename(), "cache"));
if (!cache_dir.exists())
if (!cache_dir.createDirectory(0700)) {
lyxerr << "Could not create cache directory `"
<< cache_dir << "'." << endl;
exit(EXIT_FAILURE);
}
get().pimpl_->readIndex();
}
void ConverterCache::add(FileName const & orig_from, string const & to_format,
FileName const & converted_file) const
{
if (!lyxrc.use_converter_cache || orig_from.empty() ||
converted_file.empty())
return;
LYXERR(Debug::FILES, ' ' << orig_from
<< ' ' << to_format << ' ' << converted_file);
// FIXME: Should not hardcode this (see bug 3819 for details)
if (to_format == "pstex") {
FileName const converted_eps(changeExtension(converted_file.absFilename(), "eps"));
add(orig_from, "eps", converted_eps);
} else if (to_format == "pdftex") {
FileName const converted_pdf(changeExtension(converted_file.absFilename(), "pdf"));
add(orig_from, "pdf", converted_pdf);
}
// Is the file in the cache already?
CacheItem * item = pimpl_->find(orig_from, to_format);
time_t const timestamp = orig_from.lastModified();
Mover const & mover = getMover(to_format);
if (item) {
LYXERR(Debug::FILES, "ConverterCache::add(" << orig_from << "):\n"
"The file is already in the cache.");
// First test for timestamp
if (timestamp == item->timestamp) {
LYXERR(Debug::FILES, "Same timestamp.");
return;
}
// Maybe the contents is still the same?
item->timestamp = timestamp;
unsigned long const checksum = orig_from.checksum();
if (checksum == item->checksum) {
LYXERR(Debug::FILES, "Same checksum.");
return;
}
item->checksum = checksum;
if (!mover.copy(converted_file, item->cache_name,
onlyFilename(item->cache_name.absFilename()))) {
LYXERR(Debug::FILES, "Could not copy file " << orig_from << " to "
<< item->cache_name);
} else if (!item->cache_name.changePermission(0600)) {
LYXERR(Debug::FILES, "Could not change file mode"
<< item->cache_name);
}
} else {
CacheItem new_item(orig_from, to_format, timestamp,
orig_from.checksum());
if (mover.copy(converted_file, new_item.cache_name,
onlyFilename(new_item.cache_name.absFilename()))) {
if (!new_item.cache_name.changePermission(0600)) {
LYXERR(Debug::FILES, "Could not change file mode"
<< new_item.cache_name);
}
FormatCache & format_cache = pimpl_->cache[orig_from];
if (format_cache.from_format.empty())
format_cache.from_format =
formats.getFormatFromFile(orig_from);
format_cache.cache[to_format] = new_item;
} else
LYXERR(Debug::FILES, "ConverterCache::add(" << orig_from << "):\n"
"Could not copy file.");
}
}
void ConverterCache::remove(FileName const & orig_from,
string const & to_format) const
{
if (!lyxrc.use_converter_cache || orig_from.empty())
return;
LYXERR(Debug::FILES, orig_from << ' ' << to_format);
CacheType::iterator const it1 = pimpl_->cache.find(orig_from);
if (it1 == pimpl_->cache.end())
return;
FormatCacheType & format_cache = it1->second.cache;
FormatCacheType::iterator const it2 = format_cache.find(to_format);
if (it2 == format_cache.end())
return;
format_cache.erase(it2);
if (format_cache.empty())
pimpl_->cache.erase(it1);
}
void ConverterCache::remove_all(string const & from_format,
string const & to_format) const
{
if (!lyxrc.use_converter_cache)
return;
CacheType::iterator it1 = pimpl_->cache.begin();
while (it1 != pimpl_->cache.end()) {
if (it1->second.from_format != from_format) {
++it1;
continue;
}
FormatCacheType & format_cache = it1->second.cache;
FormatCacheType::iterator it2 = format_cache.begin();
while (it2 != format_cache.end()) {
if (it2->first == to_format) {
LYXERR(Debug::FILES, "Removing file cache item "
<< it1->first << ' ' << to_format);
it2->second.cache_name.removeFile();
format_cache.erase(it2);
// Have to start over again since items in a
// map are not ordered
it2 = format_cache.begin();
} else {
++it2;
}
}
if (format_cache.empty()) {
pimpl_->cache.erase(it1);
// Have to start over again since items in a map are
// not ordered
it1 = pimpl_->cache.begin();
} else {
++it1;
}
}
pimpl_->writeIndex();
}
bool ConverterCache::inCache(FileName const & orig_from,
string const & to_format) const
{
if (!lyxrc.use_converter_cache || orig_from.empty())
return false;
LYXERR(Debug::FILES, orig_from << ' ' << to_format);
CacheItem * const item = pimpl_->find(orig_from, to_format);
if (!item) {
LYXERR(Debug::FILES, "not in cache.");
return false;
}
time_t const timestamp = orig_from.lastModified();
if (item->timestamp == timestamp) {
LYXERR(Debug::FILES, "identical timestamp.");
return true;
}
if (item->checksum == orig_from.checksum()) {
item->timestamp = timestamp;
LYXERR(Debug::FILES, "identical checksum.");
return true;
}
LYXERR(Debug::FILES, "in cache, but too old.");
return false;
}
FileName const & ConverterCache::cacheName(FileName const & orig_from,
string const & to_format) const
{
LYXERR(Debug::FILES, orig_from << ' ' << to_format);
CacheItem * const item = pimpl_->find(orig_from, to_format);
LASSERT(item, /**/);
return item->cache_name;
}
bool ConverterCache::copy(FileName const & orig_from, string const & to_format,
FileName const & dest) const
{
if (!lyxrc.use_converter_cache || orig_from.empty() || dest.empty())
return false;
LYXERR(Debug::FILES, orig_from << ' ' << to_format << ' ' << dest);
// FIXME: Should not hardcode this (see bug 3819 for details)
if (to_format == "pstex") {
FileName const dest_eps(changeExtension(dest.absFilename(), "eps"));
if (!copy(orig_from, "eps", dest_eps))
return false;
} else if (to_format == "pdftex") {
FileName const dest_pdf(changeExtension(dest.absFilename(), "pdf"));
if (!copy(orig_from, "pdf", dest_pdf))
return false;
}
CacheItem * const item = pimpl_->find(orig_from, to_format);
LASSERT(item, /**/);
Mover const & mover = getMover(to_format);
return mover.copy(item->cache_name, dest,
onlyFilename(dest.absFilename()));
}
} // namespace lyx