C++ NamespaceDetails::firstExtent方法代码示例

    Database::Database(TransactionExperiment* txn, const char *nm, bool& newDb, const string& path )
        : _name(nm), _path(path),
          _namespaceIndex( _path, _name ),
          _extentManager(new MmapV1ExtentManager(_name, _path, storageGlobalParams.directoryperdb)),
          _profileName(_name + ".system.profile"),
          _namespacesName(_name + ".system.namespaces"),
          _indexesName(_name + ".system.indexes"),
          _collectionLock( "Database::_collectionLock" )
    {
        Status status = validateDBName( _name );
        if ( !status.isOK() ) {
            warning() << "tried to open invalid db: " << _name << endl;
            uasserted( 10028, status.toString() );
        }

        try {
            newDb = _namespaceIndex.exists();
            _profile = serverGlobalParams.defaultProfile;
            checkDuplicateUncasedNames(true);

            // If already exists, open.  Otherwise behave as if empty until
            // there's a write, then open.
            if (!newDb) {
                _namespaceIndex.init( txn );
                openAllFiles(txn);

                // upgrade freelist
                string oldFreeList = _name + ".$freelist";
                NamespaceDetails* details = _namespaceIndex.details( oldFreeList );
                if ( details ) {
                    if ( !details->firstExtent().isNull() ) {
                        _extentManager->freeExtents(txn,
                                                    details->firstExtent(),
                                                    details->lastExtent());
                    }
                    _namespaceIndex.kill_ns( txn, oldFreeList );
                }
            }
            _magic = 781231;
        }
        catch(std::exception& e) {
            log() << "warning database " << path << " " << nm << " could not be opened" << endl;
            DBException* dbe = dynamic_cast<DBException*>(&e);
            if ( dbe != 0 ) {
                log() << "DBException " << dbe->getCode() << ": " << e.what() << endl;
            }
            else {
                log() << e.what() << endl;
            }
            _extentManager.reset();
            throw;
        }
    }

    shared_ptr<Cursor> DataFileMgr::findAll(const StringData& ns, const DiskLoc &startLoc) {
        NamespaceDetails * d = nsdetails( ns );
        if ( ! d )
            return shared_ptr<Cursor>(new BasicCursor(DiskLoc()));

        DiskLoc loc = d->firstExtent();
        if ( loc.isNull() )
            return shared_ptr<Cursor>(new BasicCursor(DiskLoc()));
        Extent *e = getExtent(loc);

        DEBUGGING {
            out() << "listing extents for " << ns << endl;
            DiskLoc tmp = loc;
            set<DiskLoc> extents;

            while ( 1 ) {
                Extent *f = getExtent(tmp);
                out() << "extent: " << tmp.toString() << endl;
                extents.insert(tmp);
                tmp = f->xnext;
                if ( tmp.isNull() )
                    break;
                f = f->getNextExtent();
            }

            out() << endl;
            d->dumpDeleted(&extents);
        }

        if ( d->isCapped() )
            return shared_ptr<Cursor>( ForwardCappedCursor::make( d , startLoc ) );

        if ( !startLoc.isNull() )
            return shared_ptr<Cursor>(new BasicCursor( startLoc ));

        while ( e->firstRecord.isNull() && !e->xnext.isNull() ) {
            /* todo: if extent is empty, free it for reuse elsewhere.
               that is a bit complicated have to clean up the freelists.
            */
            RARELY out() << "info DFM::findAll(): extent " << loc.toString() << " was empty, skipping ahead. ns:" << ns << endl;
            // find a nonempty extent
            // it might be nice to free the whole extent here!  but have to clean up free recs then.
            e = e->getNextExtent();
        }
        return shared_ptr<Cursor>(new BasicCursor( e->firstRecord ));
    }

        virtual bool run(const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
            string source = cmdObj.getStringField( name.c_str() );
            string target = cmdObj.getStringField( "to" );
            uassert(15967,
                    "invalid collection name: " + target,
                    NamespaceString::validCollectionComponent(target.c_str()));
            if ( source.empty() || target.empty() ) {
                errmsg = "invalid command syntax";
                return false;
            }

            string sourceDB = nsToDatabase(source);
            string targetDB = nsToDatabase(target);
            string databaseName = sourceDB;
            databaseName += ".system.indexes";

            int longestIndexNameLength = 0;
            vector<BSONObj> oldIndSpec = Helpers::findAll(databaseName, BSON("ns" << source));
            for (size_t i = 0; i < oldIndSpec.size(); ++i) {
                int thisLength = oldIndSpec[i].getField("name").valuesize();
                if (thisLength > longestIndexNameLength) {
                     longestIndexNameLength = thisLength;
                }
            }
            unsigned int longestAllowed = maxNamespaceLen - longestIndexNameLength - 1;
            if (target.size() > longestAllowed) {
                StringBuilder sb;
                sb << "collection name length of " << target.size()
                << " exceeds maximum length of " << longestAllowed
                << ", allowing for index names";
                uasserted(16451, sb.str());
            }

            bool capped = false;
            long long size = 0;
            std::vector<BSONObj> indexesInProg;
            {
                Client::Context ctx( source );
                NamespaceDetails *nsd = nsdetails( source );
                uassert( 10026 ,  "source namespace does not exist", nsd );
                indexesInProg = stopIndexBuilds(dbname, cmdObj);
                capped = nsd->isCapped();
                if ( capped )
                    for( DiskLoc i = nsd->firstExtent(); !i.isNull(); i = i.ext()->xnext )
                        size += i.ext()->length;
            }

            Client::Context ctx( target );

            if ( nsdetails( target ) ) {
                uassert( 10027 ,  "target namespace exists", cmdObj["dropTarget"].trueValue() );

                Status s = cc().database()->dropCollection( target );
                if ( !s.isOK() ) {
                    errmsg = s.toString();
                    return false;
                }

            }


            // if we are renaming in the same database, just
            // rename the namespace and we're done.
            {
                if ( sourceDB == targetDB ) {
                    Status s = ctx.db()->renameCollection( source, target, cmdObj["stayTemp"].trueValue() );
                    if ( !s.isOK() ) {
                        errmsg = s.toString();
                        return false;
                    }
                    return true;
                }
            }

            // renaming across databases, so we must copy all
            // the data and then remove the source collection.
            BSONObjBuilder spec;
            if ( capped ) {
                spec.appendBool( "capped", true );
                spec.append( "size", double( size ) );
            }
            if ( !userCreateNS( target.c_str(), spec.done(), errmsg, false ) )
                return false;

            auto_ptr< DBClientCursor > c;
            DBDirectClient bridge;

            {
                c = bridge.query( source, BSONObj(), 0, 0, 0, fromRepl ? QueryOption_SlaveOk : 0 );
            }
            while( 1 ) {
                {
                    if ( !c->more() )
                        break;
                }
                BSONObj o = c->next();
                theDataFileMgr.insertWithObjMod( target.c_str(), o );
            }

            string sourceIndexes = nsToDatabase( source ) + ".system.indexes";
//.........这里部分代码省略.........

    StatusWith<CompactStats> Collection::compact( const CompactOptions* compactOptions ) {

        if ( isCapped() )
            return StatusWith<CompactStats>( ErrorCodes::BadValue,
                                             "cannot compact capped collection" );

        if ( _indexCatalog.numIndexesInProgress() )
            return StatusWith<CompactStats>( ErrorCodes::BadValue,
                                             "cannot compact when indexes in progress" );

        NamespaceDetails* d = details();

        // this is a big job, so might as well make things tidy before we start just to be nice.
        getDur().commitIfNeeded();

        list<DiskLoc> extents;
        for( DiskLoc L = d->firstExtent(); !L.isNull(); L = L.ext()->xnext )
            extents.push_back(L);
        log() << "compact " << extents.size() << " extents" << endl;

        // same data, but might perform a little different after compact?
        _infoCache.reset();

        vector<BSONObj> indexSpecs;
        {
            IndexCatalog::IndexIterator ii( _indexCatalog.getIndexIterator( false ) );
            while ( ii.more() ) {
                IndexDescriptor* descriptor = ii.next();

                const BSONObj spec = _compactAdjustIndexSpec(descriptor->infoObj());
                const BSONObj key = spec.getObjectField("key");
                const Status keyStatus = validateKeyPattern(key);
                if (!keyStatus.isOK()) {
                    return StatusWith<CompactStats>(
                        ErrorCodes::CannotCreateIndex,
                        str::stream() << "Cannot rebuild index " << spec << ": "
                                      << keyStatus.reason()
                                      << " For more info see"
                                      << " http://dochub.mongodb.org/core/index-validation");
                }
                indexSpecs.push_back(spec);
            }
        }

        log() << "compact orphan deleted lists" << endl;
        d->orphanDeletedList();

        // Start over from scratch with our extent sizing and growth
        d->setLastExtentSize( 0 );

        // before dropping indexes, at least make sure we can allocate one extent!
        // this will allocate an extent and add to free list
        // if it cannot, it will throw an exception
        increaseStorageSize( _details->lastExtentSize(), true );

        // note that the drop indexes call also invalidates all clientcursors for the namespace,
        // which is important and wanted here
        log() << "compact dropping indexes" << endl;
        Status status = _indexCatalog.dropAllIndexes( true );
        if ( !status.isOK() ) {
            return StatusWith<CompactStats>( status );
        }

        getDur().commitIfNeeded();
        killCurrentOp.checkForInterrupt();

        CompactStats stats;

        MultiIndexBlock multiIndexBlock( this );
        status = multiIndexBlock.init( indexSpecs );
        if ( !status.isOK() )
            return StatusWith<CompactStats>( status );

        // reset data size and record counts to 0 for this namespace
        // as we're about to tally them up again for each new extent
        d->setStats( 0, 0 );

        ProgressMeterHolder pm(cc().curop()->setMessage("compact extent",
                                                        "Extent Compacting Progress",
                                                        extents.size()));

        int extentNumber = 0;
        for( list<DiskLoc>::iterator i = extents.begin(); i != extents.end(); i++ ) {
            _compactExtent(*i, extentNumber++, multiIndexBlock, compactOptions, &stats );
            pm.hit();
        }

        verify( d->firstExtent().ext()->xprev.isNull() );

        // indexes will do their own progress meter?
        pm.finished();

        log() << "starting index commits";

        status = multiIndexBlock.commit();
        if ( !status.isOK() )
            return StatusWith<CompactStats>( status );

        return StatusWith<CompactStats>( stats );
    }

        void validateNS(const string& ns,
                        Collection* collection,
                        const BSONObj& cmdObj,
                        BSONObjBuilder& result) {

            const bool full = cmdObj["full"].trueValue();
            const bool scanData = full || cmdObj["scandata"].trueValue();

            NamespaceDetails* nsd = collection->details();

            bool valid = true;
            BSONArrayBuilder errors; // explanation(s) for why valid = false
            if ( collection->isCapped() ){
                result.append("capped", nsd->isCapped());
                result.appendNumber("max", nsd->maxCappedDocs());
            }

            if ( nsd->firstExtent().isNull() )
                result.append( "firstExtent", "null" );
            else
                result.append( "firstExtent", str::stream() << nsd->firstExtent().toString()
                               << " ns:" << nsd->firstExtent().ext()->nsDiagnostic.toString());
            if ( nsd->lastExtent().isNull() )
                result.append( "lastExtent", "null" );
            else
                result.append( "lastExtent", str::stream() <<  nsd->lastExtent().toString()
                               << " ns:" <<  nsd->lastExtent().ext()->nsDiagnostic.toString());

            BSONArrayBuilder extentData;
            int extentCount = 0;
            try {

                if ( !nsd->firstExtent().isNull() ) {
                    nsd->firstExtent().ext()->assertOk();
                    nsd->lastExtent().ext()->assertOk();
                }

                DiskLoc extentDiskLoc = nsd->firstExtent();
                while (!extentDiskLoc.isNull()) {
                    Extent* thisExtent = extentDiskLoc.ext();
                    if (full) {
                        extentData << thisExtent->dump();
                    }
                    if (!thisExtent->validates(extentDiskLoc, &errors)) {
                        valid = false;
                    }
                    DiskLoc nextDiskLoc = thisExtent->xnext;
                    if (extentCount > 0 && !nextDiskLoc.isNull()
                                        &&  nextDiskLoc.ext()->xprev != extentDiskLoc) {
                        StringBuilder sb;
                        sb << "'xprev' pointer " << nextDiskLoc.ext()->xprev.toString()
                           << " in extent " << nextDiskLoc.toString()
                           << " does not point to extent " << extentDiskLoc.toString();
                        errors << sb.str();
                        valid = false;
                    }
                    if (nextDiskLoc.isNull() && extentDiskLoc != nsd->lastExtent()) {
                        StringBuilder sb;
                        sb << "'lastExtent' pointer " << nsd->lastExtent().toString()
                           << " does not point to last extent in list " << extentDiskLoc.toString();
                        errors << sb.str();
                        valid = false;
                    }
                    extentDiskLoc = nextDiskLoc;
                    extentCount++;
                    killCurrentOp.checkForInterrupt();
                }
            }
            catch (const DBException& e) {
                StringBuilder sb;
                sb << "exception validating extent " << extentCount
                   << ": " << e.what();
                errors << sb.str();
                valid = false;
            }
            result.append("extentCount", extentCount);

            if ( full )
                result.appendArray( "extents" , extentData.arr() );

            result.appendNumber("datasize", nsd->dataSize());
            result.appendNumber("nrecords", nsd->numRecords());
            result.appendNumber("lastExtentSize", nsd->lastExtentSize());
            result.appendNumber("padding", nsd->paddingFactor());

            try {

                bool testingLastExtent = false;
                try {
                    if (nsd->firstExtent().isNull()) {
                        // this is ok
                    }
                    else {
                        result.append("firstExtentDetails", nsd->firstExtent().ext()->dump());
                        if (!nsd->firstExtent().ext()->xprev.isNull()) {
                            StringBuilder sb;
                            sb << "'xprev' pointer in 'firstExtent' " << nsd->firstExtent().toString()
                               << " is " << nsd->firstExtent().ext()->xprev.toString()
                               << ", should be null";
                            errors << sb.str();
//.........这里部分代码省略.........

    StatusWith<CompactStats> Collection::compact( const CompactOptions* compactOptions ) {

        if ( isCapped() )
            return StatusWith<CompactStats>( ErrorCodes::BadValue,
                                             "cannot compact capped collection" );

        if ( _indexCatalog.numIndexesInProgress() )
            return StatusWith<CompactStats>( ErrorCodes::BadValue,
                                             "cannot compact when indexes in progress" );

        NamespaceDetails* d = details();

        // this is a big job, so might as well make things tidy before we start just to be nice.
        getDur().commitIfNeeded();

        list<DiskLoc> extents;
        for( DiskLoc L = d->firstExtent(); !L.isNull(); L = L.ext()->xnext )
            extents.push_back(L);
        log() << "compact " << extents.size() << " extents" << endl;

        // same data, but might perform a little different after compact?
        _infoCache.reset();

        vector<BSONObj> indexSpecs;
        {
            IndexCatalog::IndexIterator ii( _indexCatalog.getIndexIterator( false ) );
            while ( ii.more() ) {
                IndexDescriptor* descriptor = ii.next();
                indexSpecs.push_back( _compactAdjustIndexSpec( descriptor->infoObj() ) );
            }
        }

        log() << "compact orphan deleted lists" << endl;
        d->orphanDeletedList();

        // Start over from scratch with our extent sizing and growth
        d->setLastExtentSize( 0 );

        // before dropping indexes, at least make sure we can allocate one extent!
        if ( allocateSpaceForANewRecord( _ns.ns().c_str(),
                                         d,
                                         Record::HeaderSize+1,
                                         false).isNull() ) {
            return StatusWith<CompactStats>( ErrorCodes::InternalError,
                                             "compact error no space available to allocate" );
        }

        // note that the drop indexes call also invalidates all clientcursors for the namespace,
        // which is important and wanted here
        log() << "compact dropping indexes" << endl;
        Status status = _indexCatalog.dropAllIndexes( true );
        if ( !status.isOK() ) {
            return StatusWith<CompactStats>( status );
        }

        getDur().commitIfNeeded();

        CompactStats stats;

        OwnedPointerVector<IndexCatalog::IndexBuildBlock> indexBuildBlocks;
        vector<IndexAccessMethod*> indexesToInsertTo;
        vector< std::pair<IndexAccessMethod*,IndexAccessMethod*> > bulkToCommit;
        for ( size_t i = 0; i < indexSpecs.size(); i++ ) {
            killCurrentOp.checkForInterrupt(false);
            BSONObj info = indexSpecs[i];
            info = _compactAdjustIndexSpec( info );
            info = _indexCatalog.fixIndexSpec( info );
            auto_ptr<IndexCatalog::IndexBuildBlock> block( new IndexCatalog::IndexBuildBlock( this,info ) );
            Status status = block->init();
            if ( !status.isOK() )
                return StatusWith<CompactStats>(status);

            IndexAccessMethod* accessMethod = block->getEntry()->accessMethod();
            status = accessMethod->initializeAsEmpty();
            if ( !status.isOK() )
                return StatusWith<CompactStats>(status);

            IndexAccessMethod* bulk = accessMethod->initiateBulk();
            if ( bulk ) {
                indexesToInsertTo.push_back( bulk );
                bulkToCommit.push_back( std::pair<IndexAccessMethod*,IndexAccessMethod*>( accessMethod, bulk ) );
            }
            else {
                indexesToInsertTo.push_back( accessMethod );
            }

            indexBuildBlocks.mutableVector().push_back( block.release() );
        }

        // reset data size and record counts to 0 for this namespace
        // as we're about to tally them up again for each new extent
        d->setStats( 0, 0 );

        ProgressMeterHolder pm(cc().curop()->setMessage("compact extent",
                                                        "Extent Compacting Progress",
                                                        extents.size()));

        int extentNumber = 0;
        for( list<DiskLoc>::iterator i = extents.begin(); i != extents.end(); i++ ) {
            _compactExtent(*i, extentNumber++, indexesToInsertTo, compactOptions, &stats );
//.........这里部分代码省略.........