C++ DiskLoc::drec方法代码示例

 void NamespaceDetails::cappedTruncateLastDelUpdate() {
     if ( capExtent == firstExtent ) {
         // Only one extent of the collection is in use, so there
         // is no deleted record in a previous extent, so nullify
         // cappedLastDelRecLastExtent().
         cappedLastDelRecLastExtent().writing() = DiskLoc();
     }
     else {
         // Scan through all deleted records in the collection
         // until the last deleted record for the extent prior
         // to the new capExtent is found.  Then set
         // cappedLastDelRecLastExtent() to that deleted record.
         DiskLoc i = cappedListOfAllDeletedRecords();
         for( ;
              !i.drec()->nextDeleted().isNull() &&
                  !inCapExtent( i.drec()->nextDeleted() );
              i = i.drec()->nextDeleted() );
         // In our capped storage model, every extent must have at least one
         // deleted record.  Here we check that 'i' is not the last deleted
         // record.  (We expect that there will be deleted records in the new
         // capExtent as well.)
         verify( !i.drec()->nextDeleted().isNull() );
         cappedLastDelRecLastExtent().writing() = i;
     }
 }

 void NamespaceDetails::cappedDumpDelInfo() {
     cout << "dl[0]: " << _deletedList[0].toString() << endl;
     for( DiskLoc z = _deletedList[0]; !z.isNull(); z = z.drec()->nextDeleted() ) {
         cout << "  drec:" << z.toString() << " dreclen:" << hex << z.drec()->lengthWithHeaders() <<
              " ext:" << z.drec()->myExtent(z)->myLoc.toString() << endl;
     }
     cout << "dl[1]: " << _deletedList[1].toString() << endl;
 }

 bool NamespaceDetails::inCapExtent( const DiskLoc &dl ) const {
     verify( !dl.isNull() );
     // We could have a rec or drec, doesn't matter.
     bool res = dl.drec()->myExtentLoc(dl) == _capExtent;
     DEV {
         // old implementation. this check is temp to test works the same.  new impl should be a little faster.
         verify( res == (dl.drec()->myExtent( dl ) == _capExtent.ext()) );
     }
     return res;
 }

 bool NamespaceDetails::nextIsInCapExtent( const DiskLoc &dl ) const {
     verify( !dl.isNull() );
     DiskLoc next = dl.drec()->nextDeleted();
     if ( next.isNull() )
         return false;
     return inCapExtent( next );
 }

    DiskLoc NamespaceDetails::__capAlloc( int len ) {
        DiskLoc prev = cappedLastDelRecLastExtent();
        DiskLoc i = cappedFirstDeletedInCurExtent();
        DiskLoc ret;
        for (; !i.isNull() && inCapExtent( i ); prev = i, i = i.drec()->nextDeleted() ) {
            // We need to keep at least one DR per extent in cappedListOfAllDeletedRecords(),
            // so make sure there's space to create a DR at the end.
            if ( i.drec()->lengthWithHeaders() >= len + 24 ) {
                ret = i;
                break;
            }
        }

        /* unlink ourself from the deleted list */
        if ( !ret.isNull() ) {
            if ( prev.isNull() )
                cappedListOfAllDeletedRecords().writing() = ret.drec()->nextDeleted();
            else
                prev.drec()->nextDeleted().writing() = ret.drec()->nextDeleted();
            ret.drec()->nextDeleted().writing().setInvalid(); // defensive.
            verify( ret.drec()->extentOfs() < ret.getOfs() );
        }

        return ret;
    }

    void NamespaceDetails::cappedCheckMigrate() {
        // migrate old NamespaceDetails format
        verify( isCapped() );
        if ( _capExtent.a() == 0 && _capExtent.getOfs() == 0 ) {
            //capFirstNewRecord = DiskLoc();
            _capFirstNewRecord.writing().setInvalid();
            // put all the DeletedRecords in cappedListOfAllDeletedRecords()
            for ( int i = 1; i < Buckets; ++i ) {
                DiskLoc first = _deletedList[ i ];
                if ( first.isNull() )
                    continue;
                DiskLoc last = first;
                for (; !last.drec()->nextDeleted().isNull(); last = last.drec()->nextDeleted() );
                last.drec()->nextDeleted().writing() = cappedListOfAllDeletedRecords();
                cappedListOfAllDeletedRecords().writing() = first;
                _deletedList[i].writing() = DiskLoc();
            }
            // NOTE cappedLastDelRecLastExtent() set to DiskLoc() in above

            // Last, in case we're killed before getting here
            _capExtent.writing() = _firstExtent;
        }
    }

    void NamespaceDetails::emptyCappedCollection( const char *ns ) {
        DEV verify( this == nsdetails(ns) );
        massert( 13424, "collection must be capped", capped );
        massert( 13425, "background index build in progress", !indexBuildInProgress );
        massert( 13426, "indexes present", nIndexes == 0 );

        // Clear all references to this namespace.
        ClientCursor::invalidate( ns );
        NamespaceDetailsTransient::clearForPrefix( ns );

        // Get a writeable reference to 'this' and reset all pertinent
        // attributes.
        NamespaceDetails *t = writingWithoutExtra();

        t->cappedLastDelRecLastExtent() = DiskLoc();
        t->cappedListOfAllDeletedRecords() = DiskLoc();

        // preserve firstExtent/lastExtent
        t->capExtent = firstExtent;
        t->stats.datasize = stats.nrecords = 0;
        // lastExtentSize preserve
        // nIndexes preserve 0
        // capped preserve true
        // max preserve
        t->paddingFactor = 1.0;
        t->flags = 0;
        t->capFirstNewRecord = DiskLoc();
        t->capFirstNewRecord.setInvalid();
        t->cappedLastDelRecLastExtent().setInvalid();
        // dataFileVersion preserve
        // indexFileVersion preserve
        t->multiKeyIndexBits = 0;
        t->reservedA = 0;
        t->extraOffset = 0;
        // indexBuildInProgress preserve 0
        memset(t->reserved, 0, sizeof(t->reserved));

        // Reset all existing extents and recreate the deleted list.
        for( DiskLoc ext = firstExtent; !ext.isNull(); ext = ext.ext()->xnext ) {
            DiskLoc prev = ext.ext()->xprev;
            DiskLoc next = ext.ext()->xnext;
            DiskLoc empty = ext.ext()->reuse( ns, true );
            ext.ext()->xprev.writing() = prev;
            ext.ext()->xnext.writing() = next;
            addDeletedRec( empty.drec(), empty );
        }
    }

    /* combine adjacent deleted records *for the current extent* of the capped collection

       this is O(n^2) but we call it for capped tables where typically n==1 or 2!
       (or 3...there will be a little unused sliver at the end of the extent.)
    */
    void NamespaceDetails::compact() {
        DDD( "NamespaceDetails::compact enter" );
        verify( isCapped() );
        
        vector<DiskLoc> drecs;
        
        // Pull out capExtent's DRs from deletedList
        DiskLoc i = cappedFirstDeletedInCurExtent();
        for (; !i.isNull() && inCapExtent( i ); i = i.drec()->nextDeleted() ) {
            DDD( "\t" << i );
            drecs.push_back( i );
        }

        getDur().writingDiskLoc( cappedFirstDeletedInCurExtent() ) = i;
        
        std::sort( drecs.begin(), drecs.end() );
        DDD( "\t drecs.size(): " << drecs.size() );

        vector<DiskLoc>::const_iterator j = drecs.begin();
        verify( j != drecs.end() );
        DiskLoc a = *j;
        while ( 1 ) {
            j++;
            if ( j == drecs.end() ) {
                DDD( "\t compact adddelrec" );
                addDeletedRec(a.drec(), a);
                break;
            }
            DiskLoc b = *j;
            while ( a.a() == b.a() && a.getOfs() + a.drec()->lengthWithHeaders() == b.getOfs() ) {
                // a & b are adjacent.  merge.
                getDur().writingInt( a.drec()->lengthWithHeaders() ) += b.drec()->lengthWithHeaders();
                j++;
                if ( j == drecs.end() ) {
                    DDD( "\t compact adddelrec2" );
                    addDeletedRec(a.drec(), a);
                    return;
                }
                b = *j;
            }
            DDD( "\t compact adddelrec3" );
            addDeletedRec(a.drec(), a);
            a = b;
        }

    }

            void run() {
                create();
                nsd()->deletedList[ 2 ] = nsd()->deletedList[ 0 ].drec()->nextDeleted.drec()->nextDeleted;
                nsd()->deletedList[ 0 ].drec()->nextDeleted.drec()->nextDeleted = DiskLoc();
                nsd()->deletedList[ 1 ].Null();
                NamespaceDetails *d = nsd();
                zero( &d->capExtent );
                zero( &d->capFirstNewRecord );

                nsd();

                ASSERT( nsd()->firstExtent == nsd()->capExtent );
                ASSERT( nsd()->capExtent.getOfs() != 0 );
                ASSERT( !nsd()->capFirstNewRecord.isValid() );
                int nDeleted = 0;
                for ( DiskLoc i = nsd()->deletedList[ 0 ]; !i.isNull(); i = i.drec()->nextDeleted, ++nDeleted );
                ASSERT_EQUALS( 10, nDeleted );
                ASSERT( nsd()->deletedList[ 1 ].isNull() );
            }

    void NamespaceDetails::advanceCapExtent( const char *ns ) {
        // We want cappedLastDelRecLastExtent() to be the last DeletedRecord of the prev cap extent
        // (or DiskLoc() if new capExtent == firstExtent)
        if ( capExtent == lastExtent )
            getDur().writingDiskLoc( cappedLastDelRecLastExtent() ) = DiskLoc();
        else {
            DiskLoc i = cappedFirstDeletedInCurExtent();
            for (; !i.isNull() && nextIsInCapExtent( i ); i = i.drec()->nextDeleted );
            getDur().writingDiskLoc( cappedLastDelRecLastExtent() ) = i;
        }

        getDur().writingDiskLoc( capExtent ) = theCapExtent()->xnext.isNull() ? firstExtent : theCapExtent()->xnext;

        /* this isn't true if a collection has been renamed...that is ok just used for diagnostics */
        //dassert( theCapExtent()->ns == ns );

        theCapExtent()->assertOk();
        getDur().writingDiskLoc( capFirstNewRecord ) = DiskLoc();
    }

    void NamespaceDetails::emptyCappedCollection( const char *ns ) {
        DEV assert( this == nsdetails(ns) );
        massert( 13424, "collection must be capped", capped );
        massert( 13425, "background index build in progress", !backgroundIndexBuildInProgress );
        massert( 13426, "indexes present", nIndexes == 0 );

        ClientCursor::invalidate( ns );
		NamespaceDetailsTransient::clearForPrefix( ns );

        cappedLastDelRecLastExtent() = DiskLoc();
        cappedListOfAllDeletedRecords() = DiskLoc();
        
        // preserve firstExtent/lastExtent
        capExtent = firstExtent;
        stats.datasize = stats.nrecords = 0;
        // lastExtentSize preserve
        // nIndexes preserve 0
        // capped preserve true
        // max preserve
        paddingFactor = 1.0;
        flags = 0;
        capFirstNewRecord = DiskLoc();
        capFirstNewRecord.setInvalid();
        cappedLastDelRecLastExtent().setInvalid();
        // dataFileVersion preserve
        // indexFileVersion preserve
        multiKeyIndexBits = 0;
        reservedA = 0;
        extraOffset = 0;
        // backgroundIndexBuildInProgress preserve 0
        memset(reserved, 0, sizeof(reserved));

        for( DiskLoc ext = firstExtent; !ext.isNull(); ext = ext.ext()->xnext ) {
            DiskLoc prev = ext.ext()->xprev;
            DiskLoc next = ext.ext()->xnext;
            DiskLoc empty = ext.ext()->reuse( ns );
            ext.ext()->xprev = prev;
            ext.ext()->xnext = next;
            addDeletedRec( empty.drec(), empty );
        }
    }

    /* combine adjacent deleted records *for the current extent* of the capped collection
     
       this is O(n^2) but we call it for capped tables where typically n==1 or 2!
       (or 3...there will be a little unused sliver at the end of the extent.)
    */
    void NamespaceDetails::compact() {
        assert(capped);

        list<DiskLoc> drecs;

        // Pull out capExtent's DRs from deletedList
        DiskLoc i = cappedFirstDeletedInCurExtent();
        for (; !i.isNull() && inCapExtent( i ); i = i.drec()->nextDeleted )
            drecs.push_back( i );

        getDur().writingDiskLoc( cappedFirstDeletedInCurExtent() ) = i;

        // This is the O(n^2) part.
        drecs.sort();

        list<DiskLoc>::iterator j = drecs.begin();
        assert( j != drecs.end() );
        DiskLoc a = *j;
        while ( 1 ) {
            j++;
            if ( j == drecs.end() ) {
                DEBUGGING out() << "TEMP: compact adddelrec\n";
                addDeletedRec(a.drec(), a);
                break;
            }
            DiskLoc b = *j;
            while ( a.a() == b.a() && a.getOfs() + a.drec()->lengthWithHeaders == b.getOfs() ) {
                // a & b are adjacent.  merge.
                getDur().writingInt( a.drec()->lengthWithHeaders ) += b.drec()->lengthWithHeaders;
                j++;
                if ( j == drecs.end() ) {
                    DEBUGGING out() << "temp: compact adddelrec2\n";
                    addDeletedRec(a.drec(), a);
                    return;
                }
                b = *j;
            }
            DEBUGGING out() << "temp: compact adddelrec3\n";
            addDeletedRec(a.drec(), a);
            a = b;
        }
    }

//.........这里部分代码省略.........
                            if ( cl < cl_last )
                                outOfOrder++;
                            cl_last = cl;
                        }

                        Record *r = c->_current();
                        len += r->lengthWithHeaders;
                        nlen += r->netLength();
                        c->advance();
                    }
                    if ( d->capped && !d->capLooped() ) {
                        ss << "  capped outOfOrder:" << outOfOrder;
                        if ( outOfOrder > 1 ) {
                            valid = false;
                            ss << " ???";
                        }
                        else ss << " (OK)";
                        ss << '\n';
                    }
                    ss << "  " << n << " objects found, nobj:" << d->stats.nrecords << '\n';
                    ss << "  " << len << " bytes data w/headers\n";
                    ss << "  " << nlen << " bytes data wout/headers\n";
                }

                ss << "  deletedList: ";
                for ( int i = 0; i < Buckets; i++ ) {
                    ss << (d->deletedList[i].isNull() ? '0' : '1');
                }
                ss << endl;
                int ndel = 0;
                long long delSize = 0;
                int incorrect = 0;
                for ( int i = 0; i < Buckets; i++ ) {
                    DiskLoc loc = d->deletedList[i];
                    try {
                        int k = 0;
                        while ( !loc.isNull() ) {
                            if ( recs.count(loc) )
                                incorrect++;
                            ndel++;

                            if ( loc.questionable() ) {
                                if( d->capped && !loc.isValid() && i == 1 ) {
                                    /* the constructor for NamespaceDetails intentionally sets deletedList[1] to invalid
                                       see comments in namespace.h
                                    */
                                    break;
                                }

                                if ( loc.a() <= 0 || strstr(ns, "hudsonSmall") == 0 ) {
                                    ss << "    ?bad deleted loc: " << loc.toString() << " bucket:" << i << " k:" << k << endl;
                                    valid = false;
                                    break;
                                }
                            }

                            DeletedRecord *d = loc.drec();
                            delSize += d->lengthWithHeaders;
                            loc = d->nextDeleted;
                            k++;
                            killCurrentOp.checkForInterrupt();
                        }
                    }
                    catch (...) {
                        ss <<"    ?exception in deleted chain for bucket " << i << endl;
                        valid = false;
                    }
                }
                ss << "  deleted: n: " << ndel << " size: " << delSize << endl;
                if ( incorrect ) {
                    ss << "    ?corrupt: " << incorrect << " records from datafile are in deleted list\n";
                    valid = false;
                }

                int idxn = 0;
                try  {
                    ss << "  nIndexes:" << d->nIndexes << endl;
                    NamespaceDetails::IndexIterator i = d->ii();
                    while( i.more() ) {
                        IndexDetails& id = i.next();
                        ss << "    " << id.indexNamespace() << " keys:" <<
                           id.head.btree()->fullValidate(id.head, id.keyPattern()) << endl;
                    }
                }
                catch (...) {
                    ss << "\n    exception during index validate idxn:" << idxn << endl;
                    valid=false;
                }

            }
            catch (AssertionException) {
                ss << "\n    exception during validate\n" << endl;
                valid = false;
            }

            if ( !valid )
                ss << " ns corrupt, requires dbchk\n";

            return ss.str();
        }

    void NamespaceDetails::emptyCappedCollection( const char *ns ) {
        DEV verify( this == nsdetails(ns) );
        massert( 13424, "collection must be capped", isCapped() );
        massert( 13425, "background index build in progress", !_indexBuildsInProgress );

        vector<BSONObj> indexes = Helpers::findAll( Namespace( ns ).getSisterNS( "system.indexes" ) , BSON( "ns" << ns ) );
        for ( unsigned i=0; i<indexes.size(); i++ ) {
            indexes[i] = indexes[i].copy();
        }

        if ( _nIndexes ) {
            string errmsg;
            BSONObjBuilder note;
            bool res = dropIndexes( this , ns , "*" , errmsg , note , true );
            massert( 13426 , str::stream() << "failed during index drop: " << errmsg , res );
        }

        // Clear all references to this namespace.
        ClientCursor::invalidate( ns );
        NamespaceDetailsTransient::resetCollection( ns );

        // Get a writeable reference to 'this' and reset all pertinent
        // attributes.
        NamespaceDetails *t = writingWithoutExtra();

        t->cappedLastDelRecLastExtent() = DiskLoc();
        t->cappedListOfAllDeletedRecords() = DiskLoc();

        // preserve firstExtent/lastExtent
        t->_capExtent = _firstExtent;
        t->_stats.datasize = _stats.nrecords = 0;
        // lastExtentSize preserve
        // nIndexes preserve 0
        // capped preserve true
        // max preserve
        t->_paddingFactor = 1.0;
        t->_systemFlags = 0;
        t->_capFirstNewRecord = DiskLoc();
        t->_capFirstNewRecord.setInvalid();
        t->cappedLastDelRecLastExtent().setInvalid();
        // dataFileVersion preserve
        // indexFileVersion preserve
        t->_multiKeyIndexBits = 0;
        t->_reservedA = 0;
        t->_extraOffset = 0;
        // indexBuildInProgress preserve 0
        memset(t->_reserved, 0, sizeof(t->_reserved));

        // Reset all existing extents and recreate the deleted list.
        for( DiskLoc ext = _firstExtent; !ext.isNull(); ext = ext.ext()->xnext ) {
            DiskLoc prev = ext.ext()->xprev;
            DiskLoc next = ext.ext()->xnext;
            DiskLoc empty = ext.ext()->reuse( ns, true );
            ext.ext()->xprev.writing() = prev;
            ext.ext()->xnext.writing() = next;
            addDeletedRec( empty.drec(), empty );
        }

        for ( unsigned i=0; i<indexes.size(); i++ ) {
            theDataFileMgr.insertWithObjMod(Namespace( ns ).getSisterNS( "system.indexes" ).c_str(),
                                            indexes[i],
                                            false,
                                            true);
        }
        
    }

//.........这里部分代码省略.........

                    if (full) {
                        result.append("invalidObjects", nInvalid);
                    }

                    result.appendNumber("bytesWithHeaders", len);
                    result.appendNumber("bytesWithoutHeaders", nlen);
                }

                BSONArrayBuilder deletedListArray;
                for ( int i = 0; i < Buckets; i++ ) {
                    deletedListArray << d->deletedList[i].isNull();
                }

                int ndel = 0;
                long long delSize = 0;
                int incorrect = 0;
                for ( int i = 0; i < Buckets; i++ ) {
                    DiskLoc loc = d->deletedList[i];
                    try {
                        int k = 0;
                        while ( !loc.isNull() ) {
                            if ( recs.count(loc) )
                                incorrect++;
                            ndel++;

                            if ( loc.questionable() ) {
                                if( d->isCapped() && !loc.isValid() && i == 1 ) {
                                    /* the constructor for NamespaceDetails intentionally sets deletedList[1] to invalid
                                       see comments in namespace.h
                                    */
                                    break;
                                }

                                if ( loc.a() <= 0 || strstr(ns, "hudsonSmall") == 0 ) {
                                    string err (str::stream() << "bad deleted loc: " << loc.toString() << " bucket:" << i << " k:" << k);
                                    errors << err;

                                    valid = false;
                                    break;
                                }
                            }

                            DeletedRecord *d = loc.drec();
                            delSize += d->lengthWithHeaders();
                            loc = d->nextDeleted();
                            k++;
                            killCurrentOp.checkForInterrupt();
                        }
                    }
                    catch (...) {
                        errors << ("exception in deleted chain for bucket " + BSONObjBuilder::numStr(i));
                        valid = false;
                    }
                }
                result.appendNumber("deletedCount", ndel);
                result.appendNumber("deletedSize", delSize);

                if ( incorrect ) {
                    errors << (BSONObjBuilder::numStr(incorrect) + " records from datafile are in deleted list");
                    valid = false;
                }

                int idxn = 0;
                try  {
                    result.append("nIndexes", d->nIndexes);
                    BSONObjBuilder indexes; // not using subObjStart to be exception safe
                    NamespaceDetails::IndexIterator i = d->ii();
                    while( i.more() ) {
                        IndexDetails& id = i.next();
                        log() << "validating index " << idxn << ": " << id.indexNamespace() << endl;
                        long long keys = id.idxInterface().fullValidate(id.head, id.keyPattern());
                        indexes.appendNumber(id.indexNamespace(), keys);
                        idxn++;
                    }
                    result.append("keysPerIndex", indexes.done());
                }
                catch (...) {
                    errors << ("exception during index validate idxn " + BSONObjBuilder::numStr(idxn));
                    valid=false;
                }

            }
            catch (AssertionException) {
                errors << "exception during validate";
                valid = false;
            }

            result.appendBool("valid", valid);
            result.append("errors", errors.arr());

            if ( !full ){
                result.append("warning", "Some checks omitted for speed. use {full:true} option to do more thorough scan.");
            }
            
            if ( !valid ) {
                result.append("advice", "ns corrupt, requires repair");
            }

        }