stasis-aries-wal/lladd/operations/alloc.h

/**
   @file 

   Allocates and deallocates records.

   @todo Talloc() should reuse space freed by Tdealloc(), but
   currently just leaks it.

   @ingroup OPERATIONS

   $Id$
*/


#ifndef __ALLOC_H
#define __ALLOC_H 1

Operation getAlloc();
Operation getDealloc();
Operation getRealloc();
Operation getInitializePage();

void allocTransactionAbort(int xid);
void allocTransactionCommit(int xid);

void TallocInit();

/** 
    Allocate a record.  

    @param xid The transaction responsible for the allocation 
    @param size The size of the new record to be allocated.  Talloc will allocate a
    blob if the record will not easily fit on a page.

    @todo need to obtain (transaction-level) write locks _before_ writing log entries.  Otherwise, we can deadlock at recovery.

    @return the recordid of the new record.
*/
compensated_function recordid Talloc(int xid, unsigned long size);

compensated_function recordid TallocFromPage(int xid, long page, unsigned long size);

/** 
   Free a record.  
    @todo Currently, we just leak store space on dealloc. 
*/
compensated_function void Tdealloc(int xid, recordid rid);

/**
   Obtain the type of a record, as returned by getRecordType.  

   @param xid the transaction id.  

   @param rid the record of interest.  The size field will be ignored,
   allowing this function to be used to probe for records in pages.
    
   @return UNINITIALIZED_RECORD, BLOB_RECORD, SLOTTED_RECORD, or FIXED_RECORD.

   @see getRecordType

*/
compensated_function int TrecordType(int xid, recordid rid);

/**
   Obtain the length of the data stored in a record.

   @param xid the transaction id.  

   @param rid the record of interest.  The size field will be ignored,
   allowing this function to be used to probe for records in pages.

   @return -1 if the record does not exist, the size of the record otherwise.
*/
compensated_function int TrecordSize(int xid, recordid rid);

/** Return the number of records stored in page pageid */
compensated_function int TrecordsInPage(int xid, int pageid);

compensated_function void TinitializeSlottedPage(int xid, int pageid);
compensated_function void TinitializeFixedPage(int xid, int pageid, int slotLength);

#endif