MojErr MojDbIndex::getKeys(const MojObject& obj, KeySet& keysOut) const
{
LOG_TRACE("Entering function %s", __FUNCTION__);
// build the set of unique keys from object
MojDbKeyBuilder builder;
MojErr err = builder.push(m_idSet);
MojErrCheck(err);
MojSize idx = 0;
for (PropVec::ConstIterator i = m_props.begin();
i != m_props.end();
++i, ++idx) {
KeySet vals;
err = (*i)->vals(obj, vals);
MojErrCheck(err);
err = builder.push(vals);
MojErrCheck(err);
}
err = builder.keys(keysOut);
MojErrCheck(err);
return MojErrNone;
}
MojErr MojDbQueryPlan::buildRanges(const MojDbIndex& index)
{
MojAssert(!index.props().empty());
MojErr err = MojErrNone;
const MojDbQuery::WhereMap& where = m_query.where();
const StringVec& props = index.props();
const MojDbQuery::WhereClause* lastClause = NULL;
MojDbKeyBuilder lowerBuilder;
MojDbKeyBuilder upperBuilder;
MojDbKeyBuilder::KeySet prefixKeys;
err = pushVal(lowerBuilder, index.id(), NULL);
MojErrCheck(err);
err = pushVal(upperBuilder, index.id(), NULL);
MojErrCheck(err);
// push vals for all props in index prop order to create upper and lower bounds
for (StringVec::ConstIterator i = props.begin(); i != props.end(); ++i) {
// get clause for prop
MojDbQuery::WhereMap::ConstIterator clause = where.find(*i);
if (clause == where.end()) {
MojAssert((MojSize)(i - props.begin()) == where.size());
break;
}
// create collator
MojRefCountedPtr<MojDbTextCollator> collator;
MojDbCollationStrength coll = clause->collation();
if (coll != MojDbCollationInvalid) {
collator.reset(new MojDbTextCollator);
MojAllocCheck(collator.get());
err = collator->init(m_locale, coll);
MojErrCheck(err);
}
// push vals for clause
MojDbQuery::CompOp lowerOp = clause->lowerOp();
if (lowerOp == MojDbQuery::OpSearch) {
// tokenize search strings
err = pushSearch(lowerBuilder, upperBuilder, clause->lowerVal(), collator.get());
MojErrCheck(err);
} else {
// copy off prefix before writing an inequality val
if (lowerOp != MojDbQuery::OpEq && lowerOp != MojDbQuery::OpPrefix) {
err = lowerBuilder.keys(prefixKeys);
MojErrCheck(err);
if (prefixKeys.empty()) {
// if there is no prefix yet, put an empty key
err = prefixKeys.put(MojDbKey());
MojErrCheck(err);
}
}
// append lower-value to lower-key
err = pushVal(lowerBuilder, clause->lowerVal(), collator.get());
MojErrCheck(err);
// append appropriate value to upper-key
if (clause->upperOp() == MojDbQuery::OpNone) {
err = pushVal(upperBuilder, clause->lowerVal(), collator.get());
MojErrCheck(err);
} else {
err = pushVal(upperBuilder, clause->upperVal(), collator.get());
MojErrCheck(err);
}
}
lastClause = &clause.value();
}
// go from builders to ranges
KeySet lowerKeys;
err = lowerBuilder.keys(lowerKeys);
MojErrCheck(err);
KeySet upperKeys;
err = upperBuilder.keys(upperKeys);
MojErrCheck(err);
if (prefixKeys.empty()) {
prefixKeys = lowerKeys;
}
err = rangesFromKeySets(lowerKeys, upperKeys, prefixKeys, lastClause);
MojErrCheck(err);
return MojErrNone;
}