dur.h

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// @file dur.h durability support

#pragma once

#include "diskloc.h"
#include "mongommf.h"

namespace mongo {

    class NamespaceDetails;

    namespace dur {

        // a smaller limit is likely better on 32 bit
#if defined(__i386__) || defined(_M_IX86)
        const unsigned UncommittedBytesLimit = 50 * 1024 * 1024;
#else
        const unsigned UncommittedBytesLimit = 100 * 1024 * 1024;
#endif

        void startup();

        class DurableInterface : boost::noncopyable {
        public:
            virtual ~DurableInterface() { log() << "ERROR warning ~DurableInterface not intended to be called" << endl; }

            virtual void createdFile(string filename, unsigned long long len) = 0;

            virtual void* writingPtr(void *x, unsigned len) = 0;

            virtual void declareWriteIntent(void *x, unsigned len) = 0;

            virtual void* writingAtOffset(void *buf, unsigned ofs, unsigned len) = 0;

            virtual void* writingRangesAtOffsets(void *buf, const vector< pair< long long, unsigned > > &ranges ) = 0;

            virtual bool awaitCommit() = 0;

            virtual bool commitNow() = 0;

            virtual bool commitIfNeeded() = 0;

            inline DiskLoc& writingDiskLoc(DiskLoc& d) { return *((DiskLoc*) writingPtr(&d, sizeof(d))); }

            inline int& writingInt(const int& d) { return *((int*) writingPtr((int*) &d, sizeof(d))); }

            template <typename T>
            inline
            T* alreadyDeclared(T *x) {
#if defined(_TESTINTENT)
                return (T*) MongoMMF::switchToPrivateView(x);
#else
                return x;
#endif
            }

            template <typename T>
            inline
            T* writing(T *x) {
                return (T*) writingPtr(x, sizeof(T));
            }

            virtual void setNoJournal(void *dst, void *src, unsigned len) = 0;

            virtual void syncDataAndTruncateJournal() = 0;

            static DurableInterface& getDur() { return *_impl; }

        private:
            Record* writing(Record* r);
            BtreeBucket* writing( BtreeBucket* );
            NamespaceDetails* writing( NamespaceDetails* );

            static DurableInterface* _impl; // NonDurableImpl at startup()
            static void enableDurability(); // makes _impl a DurableImpl
            static void disableDurability(); // makes _impl a NonDurableImpl

            // these need to be able to enable/disable Durability
            friend void startup();
            friend class TempDisableDurability;
        }; // class DurableInterface

        class NonDurableImpl : public DurableInterface {
            void* writingPtr(void *x, unsigned len) { return x; }
            void* writingAtOffset(void *buf, unsigned ofs, unsigned len) { return buf; }
            void* writingRangesAtOffsets(void *buf, const vector< pair< long long, unsigned > > &ranges) { return buf; }
            void declareWriteIntent(void *, unsigned) { }
            void createdFile(string filename, unsigned long long len) { }
            bool awaitCommit() { return false; }
            bool commitNow() { return false; }
            bool commitIfNeeded() { return false; }
            void setNoJournal(void *dst, void *src, unsigned len);
            void syncDataAndTruncateJournal() {}
        };

        class DurableImpl : public DurableInterface {
            void* writingPtr(void *x, unsigned len);
            void* writingAtOffset(void *buf, unsigned ofs, unsigned len);
            void* writingRangesAtOffsets(void *buf, const vector< pair< long long, unsigned > > &ranges);
            void declareWriteIntent(void *, unsigned);
            void createdFile(string filename, unsigned long long len);
            bool awaitCommit();
            bool commitNow();
            bool commitIfNeeded();
            void setNoJournal(void *dst, void *src, unsigned len);
            void syncDataAndTruncateJournal();
        };

    } // namespace dur

    inline dur::DurableInterface& getDur() { return dur::DurableInterface::getDur(); }

    inline DiskLoc& DiskLoc::writing() const { return getDur().writingDiskLoc(*const_cast< DiskLoc * >( this )); }

}

---

mongodb
Author(s): Nate Koenig
autogenerated on Fri Jan 11 12:15:18 2013