C++ DurableMappedFile::view_write方法代码示例

            void operator () (MongoFile *mf) {
                if( mf->isDurableMappedFile() ) {
                    DurableMappedFile *mmf = (DurableMappedFile*) mf;
                    const unsigned char *p = (const unsigned char *) mmf->getView();
                    const unsigned char *w = (const unsigned char *) mmf->view_write();

                    if (!p || !w) return; // File not fully opened yet

                    _bytes += mmf->length();

                    verify( mmf->length() == (unsigned) mmf->length() );

                    if (memcmp(p, w, (unsigned) mmf->length()) == 0)
                        return; // next file

                    unsigned low = 0xffffffff;
                    unsigned high = 0;
                    log() << "DurParanoid mismatch in " << mmf->filename() << endl;
                    int logged = 0;
                    unsigned lastMismatch = 0xffffffff;
                    for( unsigned i = 0; i < mmf->length(); i++ ) {
                        if( p[i] != w[i] ) {
                            if( lastMismatch != 0xffffffff && lastMismatch+1 != i )
                                log() << endl; // separate blocks of mismatches
                            lastMismatch= i;
                            if( ++logged < 60 ) {
                                if( logged == 1 )
                                    log() << "ofs % 628 = 0x" << hex << (i%628) << endl; // for .ns files to find offset in record
                                stringstream ss;
                                ss << "mismatch ofs:" << hex << i <<  "\tfilemap:" << setw(2) << (unsigned) w[i] << "\tprivmap:" << setw(2) << (unsigned) p[i];
                                if( p[i] > 32 && p[i] <= 126 )
                                    ss << '\t' << p[i];
                                log() << ss.str() << endl;
                            }
                            if( logged == 60 )
                                log() << "..." << endl;
                            if( i < low ) low = i;
                            if( i > high ) high = i;
                        }
                    }
                    if( low != 0xffffffff ) {
                        std::stringstream ss;
                        ss << "journal error warning views mismatch " << mmf->filename() << ' ' << (hex) << low << ".." << high << " len:" << high-low+1;
                        log() << ss.str() << endl;
                        log() << "priv loc: " << (void*)(p+low) << ' ' << endl;
                        //vector<WriteIntent>& _intents = commitJob.wi()._intents;
                        //(void) _intents; // mark as unused. Useful for inspection in debugger

                        // should we abort() here so this isn't unnoticed in some circumstances?
                        massert(13599, "Written data does not match in-memory view. Missing WriteIntent?", false);
                    }
                }
            }

        void DurableImpl::debugCheckLastDeclaredWrite() {
            static int n;
            ++n;

            verify(debug && storageGlobalParams.dur);
            if (commitJob.writes().empty())
                return;
            const WriteIntent &i = commitJob.lastWrite();
            size_t ofs;
            DurableMappedFile *mmf = privateViews.find(i.start(), ofs);
            if( mmf == 0 )
                return;
            size_t past = ofs + i.length();
            if( mmf->length() < past + 8 )
                return; // too close to end of view
            char *priv = (char *) mmf->getView();
            char *writ = (char *) mmf->view_write();
            unsigned long long *a = (unsigned long long *) (priv+past);
            unsigned long long *b = (unsigned long long *) (writ+past);
            if( *a != *b ) {
                for( set<WriteIntent>::iterator it(commitJob.writes().begin()), end((commitJob.writes().begin())); it != end; ++it ) {
                    const WriteIntent& wi = *it;
                    char *r1 = (char*) wi.start();
                    char *r2 = (char*) wi.end();
                    if( r1 <= (((char*)a)+8) && r2 > (char*)a ) {
                        //log() << "it's ok " << wi.p << ' ' << wi.len << endl;
                        return;
                    }
                }
                log() << "journal data after write area " << i.start() << " does not agree" << endl;
                log() << " was:  " << ((void*)b) << "  " << hexdump((char*)b, 8) << endl;
                log() << " now:  " << ((void*)a) << "  " << hexdump((char*)a, 8) << endl;
                log() << " n:    " << n << endl;
                log() << endl;
            }
        }

        void run() {

            try { boost::filesystem::remove(fn); }
            catch(...) { }

            MMAPV1LockerImpl lockState;
            Lock::GlobalWrite lk(&lockState);

            {
                DurableMappedFile f;
                unsigned long long len = 256 * 1024 * 1024;
                verify( f.create(fn, len, /*sequential*/false) );
                {
                    char *p = (char *) f.getView();
                    verify(p);
                    // write something to the private view as a test
                    if (storageGlobalParams.dur)
                        privateViews.makeWritable(p, 6);
                    strcpy(p, "hello");
                }
                if (storageGlobalParams.dur) {
                    char *w = (char *) f.view_write();
                    strcpy(w + 6, "world");
                }
                MongoFileFinder ff;
                ASSERT( ff.findByPath(fn) );
                ASSERT( ff.findByPath("asdf") == 0 );
            }
            {
                MongoFileFinder ff;
                ASSERT( ff.findByPath(fn) == 0 );
            }

            int N = 10000;
#if !defined(_WIN32) && !defined(__linux__)
            // seems this test is slow on OS X.
            N = 100;
#endif

            // we make a lot here -- if we were leaking, presumably it would fail doing this many.
            Timer t;
            for( int i = 0; i < N; i++ ) {
                DurableMappedFile f;
                verify( f.open(fn, i%4==1) );
                {
                    char *p = (char *) f.getView();
                    verify(p);
                    if (storageGlobalParams.dur)
                        privateViews.makeWritable(p, 4);
                    strcpy(p, "zzz");
                }
                if (storageGlobalParams.dur) {
                    char *w = (char *) f.view_write();
                    if( i % 2 == 0 )
                        ++(*w);
                    verify( w[6] == 'w' );
                }
            }
            if( t.millis() > 10000 ) {
                mongo::unittest::log() << "warning: MMap LeakTest is unusually slow N:" << N <<
                    ' ' << t.millis() << "ms" << endl;
            }

        }