// rec.h

/* TODO for _RECSTORE

   _ support > 2GB data per file
   _ multiple files, not just indexes.dat
   _ lazier writes? (may be done?)
   _ configurable cache size
   _ fix on abnormal terminations to be able to restart some
*/

#pragma once

#include "reci.h"
#include "reccache.h"

namespace mongo { 

/* --------------------------------------------------------------------------
   A RecStoreInterface for the normal mongo mem mapped file (MongoDataFile) 
   storage
*/

class MongoMemMapped_RecStore : public RecStoreInterface { 
public:
    virtual char* get(DiskLoc d, unsigned len) { return d.rec()->data; }

    virtual DiskLoc insert(const char *ns, const void *obuf, int len, bool god) { 
        return theDataFileMgr.insert(ns, obuf, len, god);
    }

    virtual void modified(DiskLoc d) { }

    virtual void drop(const char *ns) { 
        dropNS(ns);
    }

    /* close datafiles associated with the db specified. */
    virtual void closeFiles(string dbname, string path) {
        /* as this is only used for indexes so far, and we are in the same 
           PDFiles as the nonindex data, we just rely on them having been closed 
           at the same time.  one day this may need to change.
        */
    }

};

/* An in memory RecStoreInterface implementation ----------------------------
*/

#if 0
class InMem_RecStore : public RecStoreInterface { 
    enum InmemfileValue { INMEMFILE = 0x70000000 };
public:
    static char* get(DiskLoc d, unsigned len) { 
        assert( d.a() == INMEMFILE );
#ifdef __LP64__
		massert("64 bit not done", false);
		return 0;
#else
		return (char *) d.getOfs();
#endif
    }

    static DiskLoc insert(const char *ns, const void *obuf, int len, bool god) {
#ifdef __LP64__
      assert( 0 );
      throw -1;
#else
        char *p = (char *) malloc(len);
        assert( p );
        memcpy(p, obuf, len);
        int b = (int) p;
        assert( b > 0 );
        return DiskLoc(INMEMFILE, b);
#endif
    }

    static void modified(DiskLoc d) { }

    static void drop(const char *ns) { 
        log() << "warning: drop() not yet implemented for InMem_RecStore" << endl;
    }
};
#endif

/* Glue btree to RecStoreInterface: ---------------------------- */

extern RecStoreInterface *btreeStore;

const int BucketSize = 8192;

inline BtreeBucket* DiskLoc::btree() const {
    assert( fileNo != -1 );
    return (BtreeBucket*) btreeStore->get(*this, BucketSize);
}

inline BtreeBucket* DiskLoc::btreemod() const {
    assert( fileNo != -1 );
    BtreeBucket *b = (BtreeBucket*) btreeStore->get(*this, BucketSize);
    btreeStore->modified(*this);
    return b;
}

}
