stasis-aries-wal/src/lladd/operations/prepare.c

/*---
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---*/

/**********************************************
 * $Id$
 * 
 * sets the given reference to dat
 **********************************************/

#include <lladd/operations/prepare.h>
#include "../logger/logWriter.h"
#include <malloc.h>
#include <assert.h>
recordid prepare_bogus_rec  = { 0, 0, 0};

static int operate(int xid, Page * p, lsn_t lsn, recordid rid, const void *dat) {
  syncLog();
  return 0;
}

Operation getPrepare() { 
	Operation o = {
		OPERATION_PREPARE, /* id */
		0, /* No extra data. */
		OPERATION_NOOP, 
		&operate /* Function */
	};
	return o;
}

/** PrepareGuardState is 1 if the iterator should continue on the next
    (previous) log entry, 0 otherwise. */
typedef struct{
  int continueIterating;
  int prevLSN;
  int xid;
} PrepareGuardState;

void * getPrepareGuardState() { 
  PrepareGuardState * s = malloc (sizeof(PrepareGuardState));
  s->continueIterating = 1;
  s->prevLSN = -1;
  s->xid = -1;
  return s;
}


int prepareGuard(LogEntry * e, void * state) {
  PrepareGuardState * pgs = state; 
  int ret = pgs->continueIterating;
  if(e->type == UPDATELOG) {
    if(e->contents.update.funcID == OPERATION_PREPARE) { 
      pgs->continueIterating = 0;
      pgs->prevLSN           = e->prevLSN;
    }
  }
  if(pgs->xid == -1) {
    pgs->xid = e->xid;
  } else {
    assert(pgs->xid == e->xid);
  }

  return ret;
}

/** @todo When fleshing out the logHandle's prepareAction interface, figure out what the return value should mean... */
int prepareAction(
void * state) {
  PrepareGuardState * pgs = state; 
  if(!pgs->continueIterating) {
    assert(pgs->prevLSN != -1);
    Trevive(pgs->xid, pgs->prevLSN);
  }
  return 0;
}