//根据表达式计算id
set<int> ExprCache::Expr2Ids(string & inputExpr, int actor) {
//删除空格
if (inputExpr.find(" ") != inputExpr.npos) {
MCE_WARN("ExprCache::Expr2Ids --> The expression contains whitespace: " << inputExpr);
inputExpr.erase(remove(inputExpr.begin(), inputExpr.end(), ' '),
inputExpr.end());
}
set<int> result;
bool in_cache = false;
{
IceUtil::Mutex::Lock lock(mutex_);
ExprIndex & index = expr_evictor_.get<1> ();
ExprIndex::iterator eit = index.find(inputExpr);//用表达式来查找
if (eit != index.end()) {
in_cache = true;
SeqIndex::iterator sit = expr_evictor_.project<0> (eit);//转换到顺序排序
expr_evictor_.relocate(expr_evictor_.get<0> ().begin(), sit);
++hit_count_;
++find_count_;
result = (*eit)->ids();
MCE_DEBUG("ExprCache::Expr2Ids --> this expression = " << inputExpr << " is in expression-cache. ids size = " << result.size() );
}
MCE_DEBUG("ExprCache::Expr2Ids --> this expression = " << inputExpr << " is Not in expression-cache");
}
if(in_cache && result.size()>0){
FiltFriend(actor, result);//过滤不接受的id
return result;
}
//cache中没有这个表达式，计算id。
Parser parser;
parser.Init(inputExpr);
vector<FactorPtr> factors = parser.Tokenize(); //解析成Factor
result = parser.CalculateIds(); //计算表达式
MCE_DEBUG("ExprCache::Expr2Ids --> After parser.CalculatedIds, the target size = " << result.size());
//将表达式和因子加入各自的cache
{
IceUtil::Mutex::Lock lock(mutex_);
//判断表达式含有的factor是否全部是user factor
bool AllU = true;
for (vector<FactorPtr>::iterator itr = factors.begin(); itr
!= factors.end(); ++itr) {
if ((*itr)->type() != 'u') {
AllU = false;
}
}
if (AllU == false) {//不全为user，要cache
++expr_total_count;
ExprEntryPtr exprEntry = new ExprEntry(inputExpr, result); //构造表达式entry
for (vector<FactorPtr>::iterator itr = factors.begin(); itr
!= factors.end(); ++itr) {
if ((*itr)->type() != 'u') { //如果不是ufactor，则存入cache
FactorEntryPtr fp = FactorFactory(*itr);//由factor构造factorEntry,这个factorEntry有可能已经存在
fp->AddExprEntry(exprEntry);//在factor中加入对应的表达式entry
exprEntry->AddFactorEntry(fp); //将因子entry的引用加入其属于的表达式entry
}
}
AddExprToEvictor(exprEntry);//将计算的新表达式放入Evictor
++find_count_;
}
}
FiltFriend(actor, result);//过滤不接受的id
return result;
}
