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#include "pch.hpp"
#include "rdbmsDataSource.h"
#include "connectionLoader.h"
#include <sys/utsname.h>
#include "logger.h"
#include "scripts.h"
#include <errno.h>
#include <boost/foreach.hpp>
SimpleMessageException(UnknownConnectionProvider);
/// Specialized ElementLoader for instances of RdbmsDataSource; handles persistent DB connections
class RdbmsDataSourceLoader : public ElementLoader::For<RdbmsDataSource> {
public:
void onIdle()
{
// Disconnect all cached database connections
RdbmsDataSource::dbhosts.clear();
}
static bool isConnectionExpired(const RdbmsDataSource::DBHosts::value_type & con)
{
return con.second->isExpired();
}
void onPeriodic()
{
// Disconnect expired database connections
RdbmsDataSource::DBHosts::iterator i;
while ((i = std::find_if(RdbmsDataSource::dbhosts.begin(), RdbmsDataSource::dbhosts.end(), isConnectionExpired)) != RdbmsDataSource::dbhosts.end()) {
RdbmsDataSource::dbhosts.erase(i);
}
}
void onIteration()
{
RdbmsDataSource::changedDSNs.clear();
}
};
DECLARE_CUSTOM_LOADER("rdbmsdatasource", RdbmsDataSourceLoader);
RdbmsDataSource::DBHosts RdbmsDataSource::dbhosts;
RdbmsDataSource::FailedHosts RdbmsDataSource::failedhosts;
RdbmsDataSource::DSNSet RdbmsDataSource::changedDSNs;
RdbmsDataSource::RdbmsDataSource(ScriptNodePtr p) :
DataSource(p),
masterDsn(p->child("masterdsn")),
preferLocal(p->value("preferlocal", true))
{
BOOST_FOREACH(ScriptNodePtr node, p->childrenIn("readonly")) {
roDSNs.insert(ReadonlyDSNs::value_type(node->value("host").as<std::string>(), node));
}
}
RdbmsDataSource::~RdbmsDataSource()
{
}
const DB::Connection &
RdbmsDataSource::getWritable() const
{
ConnectionPtr master = connectTo(masterDsn);
if (!master->txOpen) {
master->connection->beginTx();
master->txOpen = true;
}
changedDSNs.insert(name);
return *master->connection;
}
const DB::Connection &
RdbmsDataSource::getReadonly() const
{
if (changedDSNs.find(name) != changedDSNs.end()) {
return *connectTo(masterDsn)->connection;
}
if (localhost.length() == 0 && preferLocal) {
struct utsname name;
if (uname(&name)) {
Logger()->messagef(LOG_WARNING, "%s: Unable to determine local host name (%d:%s)",
__PRETTY_FUNCTION__, errno, strerror(errno));
localhost = "unknown";
}
else {
localhost = name.nodename;
}
}
if (preferLocal) {
ReadonlyDSNs::const_iterator ro = roDSNs.find(localhost);
try {
if (ro == roDSNs.end()) {
Logger()->messagef(LOG_INFO, "%s: No database host matches local host name (%s) Will use master DSN",
__PRETTY_FUNCTION__, localhost.c_str());
return *connectTo(masterDsn)->connection;
}
return *connectTo(ro->second)->connection;
}
catch (...) {
// Failed to connect to a preferred DB... carry on and try the others...
}
}
BOOST_FOREACH(ReadonlyDSNs::value_type db, roDSNs) {
try {
return *connectTo(db.second)->connection;
}
catch (...) {
}
}
return *connectTo(masterDsn)->connection;
}
void
RdbmsDataSource::commit()
{
DBHosts::const_iterator m = dbhosts.find(masterDsn);
if (m != dbhosts.end() && m->second->txOpen) {
m->second->connection->commitTx();
m->second->txOpen = false;
}
}
void
RdbmsDataSource::rollback()
{
DBHosts::const_iterator m = dbhosts.find(masterDsn);
if (m != dbhosts.end() && m->second->txOpen) {
m->second->connection->rollbackTx();
m->second->txOpen = false;
}
changedDSNs.erase(name);
}
RdbmsDataSource::ConnectionPtr
RdbmsDataSource::connectTo(const ConnectionInfo & dsn)
{
FailedHosts::iterator dbf = failedhosts.find(dsn);
if (dbf != failedhosts.end()) {
if (time(NULL) - 20 > dbf->second.FailureTime) {
failedhosts.erase(dbf);
}
else {
throw dbf->second;
}
}
DBHosts::const_iterator dbi = dbhosts.find(dsn);
if (dbi != dbhosts.end()) {
try {
dbi->second->connection->ping();
dbi->second->touch();
return dbi->second;
}
catch (...) {
// Connection in failed state
Logger()->messagef(LOG_DEBUG, "%s: Cached connection failed", __PRETTY_FUNCTION__);
}
}
try {
ConnectionPtr db = ConnectionPtr(new RdbmsConnection(dsn.connect(), 300));
dbhosts[dsn] = db;
db->touch();
return db;
}
catch (const DB::ConnectionError & e) {
Logger()->messagef(LOG_NOTICE, "%s: connection error message to '%s' -> %s",
__PRETTY_FUNCTION__, dsn.dsn.c_str(), e.what());
failedhosts.insert(FailedHosts::value_type(dsn, e));
throw;
}
}
RdbmsDataSource::RdbmsConnection::RdbmsConnection(const DB::Connection * con, time_t kat) :
connection(con),
txOpen(false),
lastUsedTime(0),
keepAliveTime(kat)
{
}
RdbmsDataSource::RdbmsConnection::~RdbmsConnection()
{
connection->finish();
delete connection;
}
void
RdbmsDataSource::RdbmsConnection::touch() const
{
time(&lastUsedTime);
}
bool
RdbmsDataSource::RdbmsConnection::isExpired() const
{
return (time(NULL) > lastUsedTime + keepAliveTime);
}
RdbmsDataSource::ConnectionInfo::ConnectionInfo(ScriptNodePtr node) :
dsn(node->value("dsn").as<std::string>()),
typeId(Plugable::getLoader<ConnectionLoader, UnknownConnectionProvider>(node->value("provider")))
{
}
DB::Connection *
RdbmsDataSource::ConnectionInfo::connect() const
{
return typeId->create(dsn);
}
bool
RdbmsDataSource::ConnectionInfo::operator<(const RdbmsDataSource::ConnectionInfo & other) const
{
return ((typeId < other.typeId) || ((typeId == other.typeId) && (dsn < other.dsn)));
}
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