dur.h

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#pragma once

#include <string>
#include <vector>

#include "mongo/base/disallow_copying.h"
#include "mongo/db/storage/journal_listener.h"

namespace mongo {

class ClockSource;
class OperationContext;

namespace dur {

// a smaller limit is likely better on 32 bit
const unsigned UncommittedBytesLimit = (sizeof(void*) == 4) ? 50 * 1024 * 1024 : 512 * 1024 * 1024;

class DurableInterface {
    MONGO_DISALLOW_COPYING(DurableInterface);

public:
    virtual ~DurableInterface();

    virtual void createdFile(const std::string& filename, unsigned long long len) = 0;

    // Declare write intents. Use these methods to declare "i'm about to write to x and it
    // should be logged for redo."
    //
    // Failure to call declare write intents is checked in MONGO_CONFIG_DEBUG_BUILD mode by
    // using a read only mapped view (i.e., you'll segfault if the code is covered in that
    // situation).  The debug check doesn't verify that your length is correct though.
    virtual void declareWriteIntents(const std::vector<std::pair<void*, unsigned>>& intents) = 0;

    virtual bool waitUntilDurable() = 0;

    virtual bool commitNow(OperationContext* opCtx) = 0;

    virtual bool commitIfNeeded() = 0;


    virtual void closingFileNotification() = 0;

    virtual void commitAndStopDurThread(OperationContext* opCtx) = 0;

    virtual void syncDataAndTruncateJournal(OperationContext* opCtx) = 0;

    virtual bool isDurable() const = 0;

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

protected:
    DurableInterface();

private:
    friend void startup(ClockSource* cs, int64_t serverStartMs);

    static DurableInterface* _impl;
};


void startup(ClockSource* cs, int64_t serverStartMs);

// Sets a new JournalListener, which is used to alert the rest of the system about
// journaled write progress.
void setJournalListener(JournalListener* jl);

// Expose the JournalListener, needed for the journal writer thread.
JournalListener* getJournalListener();

}  // namespace dur


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

}  // namespace mongo