/*---
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FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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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
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GOVERNMENT USE: If you are acquiring this software on behalf of the
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the software and related documentation as defined in the Federal
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---*/

#ifndef __LLADD_LOGGING_LOGENTRY_H
#define __LLADD_LOGGING_LOGENTRY_H

/**
   @file

   Structs and memory management routines for log entries

   @todo Other than some typedefs, is there anything in logEntry that belongs in the API?

   @ingroup LLADD_CORE

   $Id$
*/

#include <stasis/common.h>

BEGIN_C_DECLS

typedef struct UpdateLogEntry UpdateLogEntry;
typedef struct LogEntry LogEntry;
typedef struct __raw_log_entry CLRLogEntry;

#include <stasis/logger/logger2.h>
struct UpdateLogEntry {
  unsigned int funcID : 8;
  pageid_t page;
  int64_t  arg_size;
  /* Implicit members:
     args;     @ ((byte*)ule) + sizeof(UpdateLogEntry)
  */
};

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

struct LogEntry {
  lsn_t LSN;
  lsn_t prevLSN;
  int   xid;
  unsigned int type;
  UpdateLogEntry update;
};

/**
   Allocate a log entry that does not contain any extra payload
   information.  (Eg: Tbegin, Tcommit, etc.)

   @return a LogEntry that should be freed with free().
 */
LogEntry * allocCommonLogEntry(stasis_log_t *log, lsn_t prevLSN, int xid, unsigned int type);

LogEntry * allocPrepareLogEntry(stasis_log_t *log, lsn_t prevLSN, int xid, lsn_t recLSN);
/**
   Allocate a log entry associated with an operation implemention.  This
   is usually called inside of Tupdate().

   @return a LogEntry that should be freed with free().

*/
LogEntry * allocUpdateLogEntry(stasis_log_t *log, lsn_t prevLSN, int xid,
			       unsigned int op, pageid_t page, unsigned int arg_size);

/**
   Allocate a CLR entry.  These are written during recovery as log
   entries are undone.  This moves undo operations into the redo
   phase, by recording the inverse of the original operation, and sets
   prevLSN to the prevLSN of old_e.
*/
LogEntry * allocCLRLogEntry(stasis_log_t *log, const LogEntry * e);
/**
   @param e a log entry returned from one of the alloc???LogEntry functions.
 */
void freeLogEntry(stasis_log_t *log, const LogEntry * e);
/**
   @param lh The log handle the entry will be stored in.  (Needed because some log entries are of type INTERNALLOG)  May be NULL if e is not of type INTERNALLOG.
   @param e A log entry of any type.
   @return the length, in bytes, of e.
*/
lsn_t sizeofLogEntry(stasis_log_t * log, const LogEntry * e);
/**
 *    @return the operation's arguments, or NULL if there are no arguments.
*/
void * stasis_log_entry_update_args_ptr(LogEntry * e);
const void * stasis_log_entry_update_args_cptr(const LogEntry * e);

/**
	@return a copy of the log entry that this CLR compensated.
 */
static inline const LogEntry * getCLRCompensated(const CLRLogEntry * e) {
	return (const LogEntry*)(
			((const struct __raw_log_entry*)e)+1
			);
}

lsn_t getPrepareRecLSN(const LogEntry *e);

END_C_DECLS

#endif /* __LOGENTRY_H */