CppCMS C++ Web Framework Code

#include "thread_cache.h"

#define DEBUG_CACHE

namespace cppcms {

class mutex_lock {
	pthread_mutex_t &m;
public:
	mutex_lock(pthread_mutex_t &p): m(p) { pthread_mutex_lock(&m); };
	~mutex_lock() { pthread_mutex_unlock(&m); };
};

class rwlock_rdlock {
	pthread_rwlock_t &m;
public:
	rwlock_rdlock(pthread_rwlock_t &p): m(p) { pthread_rwlock_rdlock(&m); };
	~rwlock_rdlock() { pthread_rwlock_unlock(&m); };
};

class rwlock_wrlock {
	pthread_rwlock_t &m;
public:
	rwlock_wrlock(pthread_rwlock_t &p): m(p) { pthread_rwlock_wrlock(&m); };
	~rwlock_wrlock() { pthread_rwlock_unlock(&m); };
};

thread_cache::~thread_cache()
{
	pthread_mutex_destroy(&lru_mutex);
	pthread_rwlock_destroy(&access_lock);
}

string *thread_cache::get(string const &key,set<string> *triggers)
{
	pointer p;
	time_t now;
	time(&now);
	if((p=primary.find(key))==primary.end() || p->second.timeout->first < now) {
		return NULL;
	}
	if(triggers) {
		list<triggers_ptr>::iterator tp;
		for(tp=p->second.triggers.begin();tp!=p->second.triggers.end();tp++) {
			triggers->insert((*tp)->first);
		}
	}
	{
		mutex_lock lock(lru_mutex);
		lru.erase(p->second.lru);
		lru.push_front(p);
		p->second.lru=lru.begin();
	}
	return &(p->second.data);
}

bool thread_cache::fetch_page(string const &key,string &out,bool gzip)
{
	rwlock_rdlock lock(access_lock);
	string *r=get(key,NULL);
	if(!r) return false;
	archive a(*r);
	if(!gzip) {
		a>>out;
	}
	else {
		string tmp;
		a>>tmp;
		a>>out;
	}
	return true;
}

bool thread_cache::fetch(string const  &key,archive &a,set<string> &tags)
{
	rwlock_rdlock lock(access_lock);
	string *r=get(key,&tags);
	if(!r) return false;
	a.set(*r);
	return true;
}

void thread_cache::rise(string const &trigger)
{
	rwlock_wrlock lock(access_lock);
	pair<triggers_ptr,triggers_ptr> range=triggers.equal_range(trigger);
	triggers_ptr p;
	list<pointer> kill_list;
	for(p=range.first;p!=range.second;p++) {
		kill_list.push_back(p->second);
	}
	list<pointer>::iterator lptr;
	for(lptr=kill_list.begin();lptr!=kill_list.end();lptr++) {
		delete_node(*lptr);
	}
}

void thread_cache::store(string const &key,set<string> const &triggers_in,time_t timeout_in,archive const &a)
{
	rwlock_wrlock lock(access_lock);
	pointer main;
	main=primary.find(key);
	if(main==primary.end() && primary.size()>=limit && limit>0) {
		time_t now;
		time(&now);
		if(timeout.begin()->first<now) {
			pointer main=timeout.begin()->second;
		}
		else {
			main=lru.back();
		}
	}
	if(main!=primary.end())
		delete_node(main);
	pair<pointer,bool> res=primary.insert(pair<string,container>(key,container()));
	main=res.first;
	container &cont=main->second;
	cont.data=a.get();
	lru.push_front(main);
	cont.lru=lru.begin();
	cont.timeout=timeout.insert(pair<time_t,pointer>(timeout_in,main));
	cont.triggers.push_back(triggers.insert(pair<string,pointer>(key,main)));
	set<string>::const_iterator si;
	for(si=triggers_in.begin();si!=triggers_in.end();si++) {
		cont.triggers.push_back(triggers.insert(pair<string,pointer>(*si,main)));
	}
}

void thread_cache::delete_node(pointer p)
{
	lru.erase(p->second.lru);
	timeout.erase(p->second.timeout);
	list<triggers_ptr>::iterator i;
	for(i=p->second.triggers.begin();i!=p->second.triggers.end();i++) {
		triggers.erase(*i);
	}
	primary.erase(p);
}

};