TechEmpower.FrameworkBenchmarks/cpoll_cppsp/www/db_pg_threadpool

<%!-lpq%><%!-I/usr/include/postgresql%><%@ class mypage %><%#
#include <libpq-fe.h>
#include <postgres.h>
#include <catalog/pg_type.h>
#include <json/json.h>
#include <cpoll/threadpool.H>
#include <list>
#include "connectioninfo.H"
#include "generic_pool.H"
#include "world.H"

using namespace CP;
using namespace cppsp;
using namespace std;

class myStatement
{
public:
	PGconn* db;
	int paramLengths[1];
	int paramFormats[1];
	myStatement() {
		db=doConnect_pg(NULL);
		Oid oid=INT4OID;
		PGresult* res;
		if((res=PQprepare(db, "zxcvb", "SELECT randomnumber FROM World where id=$1", 1, &oid))==NULL)
			goto fail;
		PQclear(res);
		paramLengths[0] = sizeof(int);
		paramFormats[0] = 1; //binary
		return;
	fail:
		doDisconnect_pg(NULL,db);
		throw runtime_error("error preparing statement");
	}
	~myStatement() {
		doDisconnect_pg(NULL,db);
	}
	PGresult* exec(int id) {
		const char *params[1];
		id=htonl(id);
		params[0]=(const char*)&id;
		return PQexecPrepared(db,"zxcvb",1,params,paramLengths,paramFormats,1/*binary*/);
	}
};
myStatement* cStatement(void*) {
	return new myStatement();
}
void dStatement(void*, myStatement* s) {
	delete s;
}
genericPool<myStatement*,64> stmtPool(&cStatement,&dStatement);

ThreadPool tp(32);


%><%$
EventFD efd{0,EFD_SEMAPHORE};
int queries=1;
world* items;
myStatement* stmt;

void tpFunc() {
	for (int i=0;i<queries;i++){
		PGresult* res;
		if((res=stmt->exec(items[i].id=(rand()%10000)))==NULL) throw bad_alloc();
		if(PQntuples(res)>0) {
			items[i].rnd=ntohl(*(const int*)PQgetvalue(res,0,0));
		}
		else items[i].rnd=0;
		PQclear(res);
	}
	efd.sendEvent(1);
}
//asynchronously load the data in the doInit() function, and defer page rendering until data is available
void doInit() override {
	auto it=request->queryString.find("queries");
	if(it!=request->queryString.end()) {
		queries=atoi((*it).second);
	}
	if(queries<1)queries=1;
	if(queries>500)queries=500;
	
	items=(world*)sp->alloc(sizeof(world)*queries);
	stmt=stmtPool.get();
	poll->add(efd);
	tp.invoke({&mypage::tpFunc,this});
	efd.getEvent({&mypage::efdCB,this});
}
void efdCB(eventfd_t efdVal) {
	stmtPool.put(stmt);
	Page::doInit();
}
void waitCB(eventfd_t efdVal) {
	this->doInit();
}

%>[<%
for (int i=0;i<queries;i++){
	if(i>0) output.write(',');
	%>{"id":<%=items[i].id%>,"randomNumber":<%=items[i].rnd%>}<%
}

response->headers["Content-Type"]="application/json";
response->headers["Server"]="cppsp/0.2";
%>]