C++ MongoDataFile::getFd方法代码示例

    void touchNs( const std::string& ns ) { 
        std::vector< touch_location > ranges;
        Client::ReadContext ctx(ns);
        {

            NamespaceDetails *nsd = nsdetails(ns.c_str());
            uassert( 16154, "namespace does not exist", nsd );
            
            for( DiskLoc L = nsd->firstExtent; !L.isNull(); L = L.ext()->xnext )  {
                MongoDataFile* mdf = cc().database()->getFile( L.a() );
                massert( 16238, "can't fetch extent file structure", mdf );
                touch_location tl;
                tl.fd = mdf->getFd();
                tl.offset = L.getOfs();
                tl.ext = L.ext();
                tl.length = tl.ext->length;
                
                ranges.push_back(tl);                
            }

        }
        LockMongoFilesShared lk;
        Lock::TempRelease tr;
        std::string progress_msg = "touch " + ns + " extents";
        ProgressMeterHolder pm( cc().curop()->setMessage( progress_msg.c_str() , ranges.size() ) );
        for ( std::vector< touch_location >::iterator it = ranges.begin(); it != ranges.end(); ++it ) {
            touch_pages( it->fd, it->offset, it->length, it->ext );
            pm.hit();
            killCurrentOp.checkForInterrupt(false);
        }
        pm.finished();
    }

    /** @return number of skipped (invalid) documents */
    unsigned compactExtent(const char *ns, NamespaceDetails *d, const DiskLoc diskloc, int n,
                const scoped_array<IndexSpec> &indexSpecs,
                scoped_array<SortPhaseOne>& phase1, int nidx, bool validate, 
                double pf, int pb)
    {
        log() << "compact begin extent #" << n << " for namespace " << ns << endl;
        unsigned oldObjSize = 0; // we'll report what the old padding was
        unsigned oldObjSizeWithPadding = 0;

        Extent *e = diskloc.ext();
        e->assertOk();
        verify( e->validates() );
        unsigned skipped = 0;

        {
            // the next/prev pointers within the extent might not be in order so we first page the whole thing in 
            // sequentially
            log() << "compact paging in len=" << e->length/1000000.0 << "MB" << endl;
            Timer t;
            MongoDataFile* mdf = cc().database()->getFile( diskloc.a() );
            HANDLE fd = mdf->getFd();
            int offset = diskloc.getOfs();
            Extent* ext = diskloc.ext();
            size_t length = ext->length;
                
            touch_pages(fd, offset, length, ext);
            int ms = t.millis();
            if( ms > 1000 ) 
                log() << "compact end paging in " << ms << "ms " << e->length/1000000.0/ms << "MB/sec" << endl;
        }

        {
            log() << "compact copying records" << endl;
            long long datasize = 0;
            long long nrecords = 0;
            DiskLoc L = e->firstRecord;
            if( !L.isNull() ) {
                while( 1 ) {
                    Record *recOld = L.rec();
                    L = recOld->nextInExtent(L);
                    BSONObj objOld = BSONObj::make(recOld);

                    if( !validate || objOld.valid() ) {
                        nrecords++;
                        unsigned sz = objOld.objsize();

                        oldObjSize += sz;
                        oldObjSizeWithPadding += recOld->netLength();

                        unsigned lenWHdr = sz + Record::HeaderSize;
                        unsigned lenWPadding = lenWHdr;
                        {
                            lenWPadding = static_cast<unsigned>(pf*lenWPadding);
                            lenWPadding += pb;
                            lenWPadding = lenWPadding & quantizeMask(lenWPadding);
                            if( lenWPadding < lenWHdr || lenWPadding > BSONObjMaxUserSize / 2 ) { 
                                lenWPadding = lenWHdr;
                            }
                        }
                        DiskLoc loc = allocateSpaceForANewRecord(ns, d, lenWPadding, false);
                        uassert(14024, "compact error out of space during compaction", !loc.isNull());
                        Record *recNew = loc.rec();
                        datasize += recNew->netLength();
                        recNew = (Record *) getDur().writingPtr(recNew, lenWHdr);
                        addRecordToRecListInExtent(recNew, loc);
                        memcpy(recNew->data(), objOld.objdata(), sz);

                        {
                            // extract keys for all indexes we will be rebuilding
                            for( int x = 0; x < nidx; x++ ) { 
                                phase1[x].addKeys(indexSpecs[x], objOld, loc);
                            }
                        }
                    }
                    else { 
                        if( ++skipped <= 10 )
                            log() << "compact skipping invalid object" << endl;
                    }

                    if( L.isNull() ) { 
                        // we just did the very last record from the old extent.  it's still pointed to 
                        // by the old extent ext, but that will be fixed below after this loop
                        break;
                    }

                    // remove the old records (orphan them) periodically so our commit block doesn't get too large
                    bool stopping = false;
                    RARELY stopping = *killCurrentOp.checkForInterruptNoAssert() != 0;
                    if( stopping || getDur().aCommitIsNeeded() ) {
                        e->firstRecord.writing() = L;
                        Record *r = L.rec();
                        getDur().writingInt(r->prevOfs()) = DiskLoc::NullOfs;
                        getDur().commitIfNeeded();
                        killCurrentOp.checkForInterrupt(false);
                    }
                }
            } // if !L.isNull()

            verify( d->firstExtent == diskloc );
//.........这里部分代码省略.........