/* Copyright (C) 2014 J.F.Dockes
* 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.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <unistd.h>
#include <fcntl.h>
#include <iostream>
using namespace std;
#include "ohmetacache.hxx"
#include "conftree.hxx"
#include "libupnpp/workqueue.hxx"
#include "libupnpp/log.hxx"
#include "base64.hxx"
class SaveCacheTask {
public:
SaveCacheTask(const string& fn, const mcache_type& cache)
: m_fn(fn), m_cache(cache)
{}
string m_fn;
mcache_type m_cache;
};
static WorkQueue<SaveCacheTask*> saveQueue("SaveQueue");
// We use base64 to encode names and value, and need to replace the '='
static const char eqesc = '*';
static void eqtoggle(string& nm)
{
int i = nm.size() - 1;
while (i >= 0) {
if (nm[i] == '=') {
nm[i] = eqesc;
} else if (nm[i] == eqesc) {
nm[i] = '=';
} else {
break;
}
i--;
}
}
bool dmcacheSave(const string& fn, const mcache_type& cache)
{
SaveCacheTask *tsk = new SaveCacheTask(fn, cache);
// Use the flush option to put() so that only the latest version
// stays on the queue, possibly saving writes.
if (!saveQueue.put(tsk, true)) {
LOGERR("dmcacheSave: can't queue save task" << endl);
return false;
}
return true;
}
static void *dmcacheSaveWorker(void *)
{
for (;;) {
SaveCacheTask *tsk = 0;
size_t qsz;
if (!saveQueue.take(&tsk, &qsz)) {
LOGERR("dmcacheSaveWorker: can't get task from queue" << endl);
saveQueue.workerExit();
return (void*)1;
}
LOGDEB("dmcacheSave: got save task: " << tsk->m_cache.size() <<
" entries to " << tsk->m_fn << endl);
// Beware that calling the constructor with a std::string
// would result in a memory-based object...
ConfSimple cs(tsk->m_fn.c_str());
cs.clear();
if (cs.getStatus() != ConfSimple::STATUS_RW) {
LOGERR("dmcacheSave: could not open " << tsk->m_fn
<< " for writing" << endl);
delete tsk;
continue;
}
cs.holdWrites(true);
for (mcache_type::const_iterator it = tsk->m_cache.begin();
it != tsk->m_cache.end(); it++) {
string name = base64_encode(it->first);
eqtoggle(name);
string value = base64_encode(it->second);
//LOGDEB("dmcacheSave: " << name << " -> " << value << endl);
cs.set(name, value);
}
if (!cs.holdWrites(false)) {
LOGERR("dmcacheSave: write error while saving to " <<
tsk->m_fn << endl);
}
delete tsk;
}
}
bool dmcacheRestore(const string& fn, mcache_type& cache)
{
// Restore is called once at startup, so seize the opportunity to start the
// save thread
if (!saveQueue.start(1, dmcacheSaveWorker, 0)) {
LOGERR("dmcacheRestore: could not start save thread" << endl);
return false;
}
// Beware that calling the constructor with a std::string
// would result in a memory-based object...
ConfSimple cs(fn.c_str(), 1);
if (!cs.ok()) {
LOGINF("dmcacheRestore: could not read metadata from " << fn << endl);
return false;
}
vector<string> names = cs.getNames("");
for (auto &name : names) {
string value;
if (!cs.get(name, value)) {
// ??
LOGDEB("dmcacheRestore: no data for found name " << name << endl);
continue;
}
eqtoggle(name);
name = base64_decode(name);
value = base64_decode(value);
LOGDEB("dmcacheRestore: " << name << " -> " <<
value.substr(0, 20) << endl);
cache[name] = value;
}
return true;
}