/***********************************************************************
* setPagePosition
*
* Move cursor position to page id provided in query.
* 1. Find item "_id" which is equal to page id iteratively.
* 2. If found, set begin/last position and next page.
***********************************************************************/
MojErr MojDbSearchCursor::setPagePosition()
{
LOG_TRACE("Entering function %s", __FUNCTION__);
MojErr err;
MojDbStorageItem* item;
m_pos = m_items.begin();
ItemVec::ConstIterator last = m_items.end();
m_limitPos = last;
// retrieve page id from query
MojObject pageKey;
err = m_page.toObject(pageKey);
MojErrCheck(err);
while (m_pos != last) {
// retrieve id from query
item = m_pos->get();
const MojObject id = item->id();
// If match, set begin/last position and next page
if(pageKey.compare(id) == 0) {
if (m_limit >= (last-m_pos)) {
m_limitPos = m_items.end();
m_page.clear();
} else {
m_limitPos = m_pos + m_limit;
// set next page
MojDbStorageItem* nextItem = m_limitPos->get();
const MojObject nextId = nextItem->id();
m_page.fromObject(nextId);
// print log for nextId
MojString strOut;
err = nextId.toJson(strOut);
MojErrCheck(err);
LOG_DEBUG("[db_mojodb] nextId : %s \n", strOut.data());
}
break;
}
++m_pos;
}
return MojErrNone;
}
MojErr MojDb::merge(const MojDbQuery& query, const MojObject& props, MojUInt32& countOut, MojUInt32 flags, MojDbReqRef req)
{
MojLogTrace(s_log);
countOut = 0;
MojErr err = beginReq(req);
MojErrCheck(err);
MojDbCursor cursor;
err = findImpl(query, cursor, NULL, req, OpUpdate);
MojErrCheck(err);
MojAssert(cursor.txn());
MojUInt32 count = 0;
MojUInt32 warns = 0;
bool found = false;
MojObject prev;
for (;;) {
// get prev rev from cursor
MojDbStorageItem* prevItem = NULL;
err = cursor.get(prevItem, found);
if (err == MojErrInternalIndexOnFind) {
warns++;
continue;
}
MojErrCheck(err);
if (!found)
break;
err = prevItem->toObject(prev, m_kindEngine);
MojErrCheck(err);
// merge obj into prev
MojObject merged;
err = mergeInto(merged, props, prev);
MojErrCheck(err);
// and update the db
const MojObject& id = prevItem->id();
err = putObj(id, merged, &prev, prevItem, req, OpUpdate);
MojErrCheck(err);
++count;
}
if (warns > 0)
MojLogWarning(s_log, _T("Merge index_warnings: %s; count: %d\n"), query.from().data(), warns);
err = cursor.close();
MojErrCheck(err);
err = req->end();
MojErrCheck(err);
countOut = count;
return MojErrNone;
}
MojErr MojDbSearchCursor::load()
{
LOG_TRACE("Entering function %s", __FUNCTION__);
// pull unique ids from index
ObjectSet ids;
MojErr err = loadIds(ids);
MojErrCheck(err);
// load objects into memory
err = loadObjects(ids);
MojErrCheck(err);
// sort results
if (!m_orderProp.empty()) {
err = sort();
MojErrCheck(err);
}
// distinct
if (!m_distinct.empty()) {
distinct();
}
// reverse for desc
if (m_query.desc()) {
err = m_items.reverse();
MojErrCheck(err);
}
// next page
if (!m_page.empty()) {
err = setPagePosition();
MojErrCheck(err);
} else {
// set begin/last position.
m_pos = m_items.begin();
if (m_limit >= m_items.size()) {
m_limitPos = m_items.end();
} else {
// if item size is bigger than limit, set next page.
m_limitPos = m_items.begin() + m_limit;
MojDbStorageItem* nextItem = m_limitPos->get();
const MojObject nextId = nextItem->id();
m_page.fromObject(nextId);
}
}
// set remainder count
m_count = m_items.end() - m_pos;
return MojErrNone;
}
MojErr MojDb::delImpl(const MojDbQuery& quer, MojUInt32& countOut, MojDbReq& req, MojUInt32 flags)
{
MojLogTrace(s_log);
countOut = 0;
MojInt32 warns = 0;
MojDbQuery newQuery = quer;
MojUInt32 queryLimit = newQuery.limit();
if(newQuery.limit() == MojDbQuery::LimitDefault)
newQuery.limit(AutoBatchSize);
while(queryLimit > 0)
{
MojDbCursor cursor;
MojErr err = findImpl(newQuery, cursor, NULL, req, OpDelete);
MojErrCheck(err);
MojAssert(cursor.txn());
MojUInt32 count = 0;
MojUInt32 numberInBatch = 0;
bool found = false;
MojObject obj;
for (;;) {
MojDbStorageItem* item = NULL;
err = cursor.get(item, found);
// We simply skip ghost keys and continue; A warning is already written to the system log earlier
if (err == MojErrInternalIndexOnFind) {
warns++;
numberInBatch++;
continue;
}
MojErrCheck(err);
if (!found)
break;
err = item->toObject(obj, m_kindEngine);
MojErrCheck(err);
const MojObject& id = item->id();
MojObject deleted;
err = delObj(id, obj, item, deleted, req, flags);
MojErrCheck(err);
++count;
numberInBatch++;
}
if (warns > 0)
MojLogInfo(s_log, _T("delquery index_warnings: %s, count: %d\n"), newQuery.from().data(), warns);
countOut += count;
err = cursor.close();
MojErrCheck(err);
if(numberInBatch >= AutoBatchSize) // sing > - just in case something messed up
{
err = commitBatch(req);
MojErrCheck(err);
}
if(count == 0)
break;
queryLimit -= newQuery.limit();
if(queryLimit > AutoBatchSize)
newQuery.limit(AutoBatchSize);
else
newQuery.limit(queryLimit);
}
return MojErrNone;
}
