C++ StringData::compare方法代码示例

 Status basicIsUpdatable(const FieldRef& field) {
     StringData firstPart = field.getPart(0);
     if (firstPart.compare("_id") == 0) {
         return Status(ErrorCodes::BadValue, "updated cannot affect the _id");
     }
     return Status::OK();
 }

    /* must call this on a delete so we clean up the cursors. */
    void ClientCursor::aboutToDelete(const StringData& ns,
                                     const NamespaceDetails* nsd,
                                     const DiskLoc& dl) {
        // Begin cursor-only
        NoPageFaultsAllowed npfa;
        // End cursor-only

        recursive_scoped_lock lock(ccmutex);

        Database *db = cc().database();
        verify(db);

        aboutToDeleteForSharding( ns, db, nsd, dl );

        // Check our non-cached active runner list.
        for (set<Runner*>::iterator it = nonCachedRunners.begin(); it != nonCachedRunners.end();
             ++it) {

            Runner* runner = *it;
            if (0 == ns.compare(runner->ns())) {
                runner->invalidate(dl);
            }
        }

        // TODO: This requires optimization.  We walk through *all* CCs and send the delete to every
        // CC open on the db we're deleting from.  We could:
        // 1. Map from ns to open runners,
        // 2. Map from ns -> (a map of DiskLoc -> runners who care about that DL)
        //
        // We could also queue invalidations somehow and have them processed later in the runner's
        // read locks.
        for (CCById::const_iterator it = clientCursorsById.begin(); it != clientCursorsById.end();
             ++it) {

            ClientCursor* cc = it->second;
            // We're only interested in cursors over one db.
            if (cc->_db != db) { continue; }
            if (NULL == cc->_runner.get()) { continue; }
            cc->_runner->invalidate(dl);
        }
    }

int SimpleStringDataComparator::compare(StringData left, StringData right) const {
    return left.compare(right);
}

    /* must call this on a delete so we clean up the cursors. */
    void ClientCursor::aboutToDelete(const StringData& ns,
                                     const NamespaceDetails* nsd,
                                     const DiskLoc& dl) {
        // Begin cursor-only
        NoPageFaultsAllowed npfa;
        // End cursor-only

        recursive_scoped_lock lock(ccmutex);

        Database *db = cc().database();
        verify(db);

        aboutToDeleteForSharding( ns, db, nsd, dl );

        // Check our non-cached active runner list.
        for (set<Runner*>::iterator it = nonCachedRunners.begin(); it != nonCachedRunners.end();
             ++it) {

            Runner* runner = *it;
            if (0 == ns.compare(runner->ns())) {
                runner->invalidate(dl);
            }
        }

        // TODO: This requires optimization.  We walk through *all* CCs and send the delete to every
        // CC open on the db we're deleting from.  We could:
        // 1. Map from ns to open runners,
        // 2. Map from ns -> (a map of DiskLoc -> runners who care about that DL)
        //
        // We could also queue invalidations somehow and have them processed later in the runner's
        // read locks.
        for (CCById::const_iterator it = clientCursorsById.begin(); it != clientCursorsById.end();
             ++it) {

            ClientCursor* cc = it->second;
            // We're only interested in cursors over one db.
            if (cc->_db != db) { continue; }
            if (NULL == cc->_runner.get()) { continue; }
            cc->_runner->invalidate(dl);
        }

        // Begin cursor-only.  Only cursors that are in ccByLoc are processed here.
        CCByLoc& bl = db->ccByLoc();
        CCByLoc::iterator j = bl.lower_bound(ByLocKey::min(dl));
        CCByLoc::iterator stop = bl.upper_bound(ByLocKey::max(dl));
        if ( j == stop )
            return;

        vector<ClientCursor*> toAdvance;

        while ( 1 ) {
            toAdvance.push_back(j->second);
            DEV verify( j->first.loc == dl );
            ++j;
            if ( j == stop )
                break;
        }

        if( toAdvance.size() >= 3000 ) {
            log() << "perf warning MPW101: " << toAdvance.size() << " cursors for one diskloc "
                  << dl.toString()
                  << ' ' << toAdvance[1000]->_ns
                  << ' ' << toAdvance[2000]->_ns
                  << ' ' << toAdvance[1000]->_pinValue
                  << ' ' << toAdvance[2000]->_pinValue
                  << ' ' << toAdvance[1000]->_pos
                  << ' ' << toAdvance[2000]->_pos
                  << ' ' << toAdvance[1000]->_idleAgeMillis
                  << ' ' << toAdvance[2000]->_idleAgeMillis
                  << ' ' << toAdvance[1000]->_doingDeletes
                  << ' ' << toAdvance[2000]->_doingDeletes
                  << endl;
            //wassert( toAdvance.size() < 5000 );
        }

        for ( vector<ClientCursor*>::iterator i = toAdvance.begin(); i != toAdvance.end(); ++i ) {
            ClientCursor* cc = *i;
            wassert(cc->_db == db);

            if ( cc->_doingDeletes ) continue;

            Cursor *c = cc->_c.get();
            if ( c->capped() ) {
                /* note we cannot advance here. if this condition occurs, writes to the oplog
                   have "caught" the reader.  skipping ahead, the reader would miss postentially
                   important data.
                   */
                delete cc;
                continue;
            }

            c->recoverFromYield();
            DiskLoc tmp1 = c->refLoc();
            if ( tmp1 != dl ) {
                // This might indicate a failure to call ClientCursor::prepareToYield() but it can
                // also happen during correct operation, see SERVER-2009.
                problem() << "warning: cursor loc " << tmp1 << " does not match byLoc position " << dl << " !" << endl;
            }
            else {
//.........这里部分代码省略.........

bool IdWrapper::equals(StringData sd) const {
    return sd.compare(toString()) == 0;
}