/*---
This software is copyrighted by the Regents of the University of
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associated with the software unless explicitly disclaimed in
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The authors hereby grant permission to use, copy, modify, distribute,
and license this software and its documentation for any purpose,
provided that existing copyright notices are retained in all copies
and that this notice is included verbatim in any distributions. No
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FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY
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POSSIBILITY OF SUCH DAMAGE.

THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, AND
THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

GOVERNMENT USE: If you are acquiring this software on behalf of the
U.S. government, the Government shall have only "Restricted Rights" in
the software and related documentation as defined in the Federal
Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2). If you are
acquiring the software on behalf of the Department of Defense, the
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Government shall have only "Restricted Rights" as defined in Clause
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---*/

#ifndef __LLADD_LOGGING_LOGENTRY_H
#define __LLADD_LOGGING_LOGENTRY_H

#include <lladd/common.h>
#include <lladd/page.h>

BEGIN_C_DECLS

/**
   @file 

   Next generation logger api.  

   @todo Was getting some memory over-runs from the fact that I didn't
   know the exact length of a raw log entry.  This seems to be fixed
   now.  (Need to run through electric fence / determine the 'right
   way' to do this...)
*/

typedef struct {
  lsn_t    thisUpdateLSN;
  recordid rid; 
  lsn_t    undoNextLSN;
} CLRLogEntry;

typedef struct {
  unsigned int funcID : 8;
  recordid rid;
  unsigned int argSize;
  /*  int invertible; */ /* no longer needed */
  /* Implicit members:
     args;     @ ((byte*)ule) + sizeof(UpdateLogEntry)
     preImage; @ ((byte*)ule) + sizeof(UpdateLogEntry) + ule.argSize */
} UpdateLogEntry;

struct __raw_log_entry {
  lsn_t LSN;
  lsn_t prevLSN;
  int   xid;
  unsigned int type;
};

/*#define sizeofRawLogEntry (sizeof(lsn_t)*2+sizeof(int)+4)*/

typedef struct {
  lsn_t LSN;
  lsn_t prevLSN;
  int   xid;
  unsigned int type;
  union {
    UpdateLogEntry update;
    CLRLogEntry    clr;
  } contents;
} LogEntry;

/**
   All of these return a pointer to a single malloced region that should be freed. 
*/

/**
   Allocate a log entry that does not contain any extra payload information.  (Eg:  Tbegin, Tcommit, etc.)
 */
LogEntry * allocCommonLogEntry(lsn_t prevLSN, int xid, unsigned int type);
/** 
   Allocate a log entry with extra payload info.(eg:  Tupdate, Talloc, etc)
*/
LogEntry * allocUpdateLogEntry(lsn_t prevLSN, int xid, 
			       unsigned int operation, recordid rid, 
			       const byte * args, unsigned int argSize, const byte * preImage);
/**
   Allocate a CLR entry.  These are written during recovery to
   indicate that the stable copy of the store file reflects the state
   of the database after an operation has successfuly been
   redone/undone.
 */
LogEntry * allocCLRLogEntry   (lsn_t prevLSN, int xid, 
			       lsn_t thisUpdateLSN, recordid rid, lsn_t undoNextLSN);



size_t sizeofLogEntry(const LogEntry * log);
const byte * getUpdateArgs(const LogEntry * log);
const byte * getUpdatePreImage(const LogEntry * log);

END_C_DECLS

#endif /* __LOGENTRY_H */