**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement test interfaces to the
** memory allocation subsystem.
**
** $Id: test_malloc.c,v 1.51 2008/11/19 01:20:26 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

................................................................................
static int test_alt_pcache(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  int installFlag;
  int discardChance;
  int prngSeed;

  extern void installTestPCache(int,unsigned,unsigned);
  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "INSTALLFLAG DISCARDCHANCE PRNGSEEED");

    return TCL_ERROR;
  }
  if( Tcl_GetIntFromObj(interp, objv[1], &installFlag) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[2], &discardChance) ) return TCL_ERROR;


  if( Tcl_GetIntFromObj(interp, objv[3], &prngSeed) ) return TCL_ERROR;





  if( discardChance<0 || discardChance>100 ){
    Tcl_AppendResult(interp, "discard-chance should be between 0 and 100",
                     (char*)0);
    return TCL_ERROR;
  }
  installTestPCache(installFlag, (unsigned)discardChance, (unsigned)prngSeed);

  return TCL_OK;
}

/*
** Usage:    sqlite3_config_memstatus BOOLEAN
**
** Enable or disable memory status reporting using SQLITE_CONFIG_MEMSTATUS.

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code used to implement test interfaces to the
** memory allocation subsystem.
**
** $Id: test_malloc.c,v 1.52 2009/01/07 03:59:47 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>

................................................................................
static int test_alt_pcache(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  int installFlag;
  int discardChance = 0;
  int prngSeed = 0;
  int highStress = 0;
  extern void installTestPCache(int,unsigned,unsigned,unsigned);
  if( objc<2 || objc>5 ){
    Tcl_WrongNumArgs(interp, 1, objv, 
        "INSTALLFLAG DISCARDCHANCE PRNGSEEED HIGHSTRESS");
    return TCL_ERROR;
  }
  if( Tcl_GetIntFromObj(interp, objv[1], &installFlag) ) return TCL_ERROR;
  if( objc>=3 && Tcl_GetIntFromObj(interp, objv[2], &discardChance) ){
     return TCL_ERROR;
  }
  if( objc>=4 && Tcl_GetIntFromObj(interp, objv[3], &prngSeed) ){
     return TCL_ERROR;
  }
  if( objc>=5 && Tcl_GetIntFromObj(interp, objv[4], &highStress) ){
    return TCL_ERROR;
  }
  if( discardChance<0 || discardChance>100 ){
    Tcl_AppendResult(interp, "discard-chance should be between 0 and 100",
                     (char*)0);
    return TCL_ERROR;
  }
  installTestPCache(installFlag, (unsigned)discardChance, (unsigned)prngSeed,
                    (unsigned)highStress);
  return TCL_OK;
}

/*
** Usage:    sqlite3_config_memstatus BOOLEAN
**
** Enable or disable memory status reporting using SQLITE_CONFIG_MEMSTATUS.

** implementation that can be plugged in in place of the
** default pcache.  This alternative pager cache will throw
** some errors that the default cache does not.
**
** This pagecache implementation is designed for simplicity
** not speed.  
**
** $Id: test_pcache.c,v 1.1 2008/11/19 01:20:26 drh Exp $
*/
#include "sqlite3.h"
#include <string.h>
#include <assert.h>

/*
** Global data used by this test implementation.  There is no
................................................................................
** mutexing, which means this page cache will not work in a
** multi-threaded test.
*/
typedef struct testpcacheGlobalType testpcacheGlobalType;
struct testpcacheGlobalType {
  void *pDummy;             /* Dummy allocation to simulate failures */
  int nInstance;            /* Number of current instances */
  unsigned discardChance;   /* Chance of discarding on an unpin */
  unsigned prngSeed;        /* Seed for the PRNG */

};
static testpcacheGlobalType testpcacheGlobal;

/*
** Initializer.
**
** Verify that the initializer is only called when the system is
................................................................................
    return 0;
  }

  /* Do not allocate the last TESTPCACHE_RESERVE pages unless createFlag is 2 */
  if( p->nPinned>=TESTPCACHE_NPAGE-TESTPCACHE_RESERVE && createFlag<2 ){
    return 0;
  }










  /* Find a free page to allocate if there are any free pages.
  ** Withhold TESTPCACHE_RESERVE free pages until createFlag is 2.
  */
  if( p->nFree>TESTPCACHE_RESERVE || (createFlag==2 && p->nFree>0) ){
    j = testpcacheRandom(p) % TESTPCACHE_NPAGE;
    for(i=0; i<TESTPCACHE_NPAGE; i++, j = (j+1)%TESTPCACHE_NPAGE){
................................................................................
** indicates the probability of discarding a page when unpinning the
** page.  0 means never discard (unless the discard flag is set).
** 100 means always discard.
*/
void installTestPCache(
  int installFlag,            /* True to install.  False to uninstall. */
  unsigned discardChance,     /* 0-100.  Chance to discard on unpin */
  unsigned prngSeed           /* Seed for the PRNG */

){
  static const sqlite3_pcache_methods testPcache = {
    (void*)&testpcacheGlobal,
    testpcacheInit,
    testpcacheShutdown,
    testpcacheCreate,
    testpcacheCachesize,
................................................................................
  static int isInstalled = 0;

  assert( testpcacheGlobal.nInstance==0 );
  assert( testpcacheGlobal.pDummy==0 );
  assert( discardChance<=100 );
  testpcacheGlobal.discardChance = discardChance;
  testpcacheGlobal.prngSeed = prngSeed ^ (prngSeed<<16);

  if( installFlag!=isInstalled ){
    if( installFlag ){
      sqlite3_config(SQLITE_CONFIG_GETPCACHE, &defaultPcache);
      assert( defaultPcache.xCreate!=testpcacheCreate );
      sqlite3_config(SQLITE_CONFIG_PCACHE, &testPcache);
    }else{
      assert( defaultPcache.xCreate!=0 );
      sqlite3_config(SQLITE_CONFIG_PCACHE, &defaultPcache);
    }
    isInstalled = installFlag;
  }
}

** implementation that can be plugged in in place of the
** default pcache.  This alternative pager cache will throw
** some errors that the default cache does not.
**
** This pagecache implementation is designed for simplicity
** not speed.  
**
** $Id: test_pcache.c,v 1.2 2009/01/07 03:59:47 drh Exp $
*/
#include "sqlite3.h"
#include <string.h>
#include <assert.h>

/*
** Global data used by this test implementation.  There is no
................................................................................
** mutexing, which means this page cache will not work in a
** multi-threaded test.
*/
typedef struct testpcacheGlobalType testpcacheGlobalType;
struct testpcacheGlobalType {
  void *pDummy;             /* Dummy allocation to simulate failures */
  int nInstance;            /* Number of current instances */
  unsigned discardChance;   /* Chance of discarding on an unpin (0-100) */
  unsigned prngSeed;        /* Seed for the PRNG */
  unsigned highStress;      /* Call xStress agressively */
};
static testpcacheGlobalType testpcacheGlobal;

/*
** Initializer.
**
** Verify that the initializer is only called when the system is
................................................................................
    return 0;
  }

  /* Do not allocate the last TESTPCACHE_RESERVE pages unless createFlag is 2 */
  if( p->nPinned>=TESTPCACHE_NPAGE-TESTPCACHE_RESERVE && createFlag<2 ){
    return 0;
  }

  /* Do not allocate if highStress is enabled and createFlag is not 2.  
  **
  ** The highStress setting causes pagerStress() to be called much more
  ** often, which exercises the pager logic more intensely.
  */
  if( testpcacheGlobal.highStress && createFlag<2 ){
    return 0;
  }

  /* Find a free page to allocate if there are any free pages.
  ** Withhold TESTPCACHE_RESERVE free pages until createFlag is 2.
  */
  if( p->nFree>TESTPCACHE_RESERVE || (createFlag==2 && p->nFree>0) ){
    j = testpcacheRandom(p) % TESTPCACHE_NPAGE;
    for(i=0; i<TESTPCACHE_NPAGE; i++, j = (j+1)%TESTPCACHE_NPAGE){
................................................................................
** indicates the probability of discarding a page when unpinning the
** page.  0 means never discard (unless the discard flag is set).
** 100 means always discard.
*/
void installTestPCache(
  int installFlag,            /* True to install.  False to uninstall. */
  unsigned discardChance,     /* 0-100.  Chance to discard on unpin */
  unsigned prngSeed,          /* Seed for the PRNG */
  unsigned highStress         /* Call xStress agressively */
){
  static const sqlite3_pcache_methods testPcache = {
    (void*)&testpcacheGlobal,
    testpcacheInit,
    testpcacheShutdown,
    testpcacheCreate,
    testpcacheCachesize,
................................................................................
  static int isInstalled = 0;

  assert( testpcacheGlobal.nInstance==0 );
  assert( testpcacheGlobal.pDummy==0 );
  assert( discardChance<=100 );
  testpcacheGlobal.discardChance = discardChance;
  testpcacheGlobal.prngSeed = prngSeed ^ (prngSeed<<16);
  testpcacheGlobal.highStress = highStress;
  if( installFlag!=isInstalled ){
    if( installFlag ){
      sqlite3_config(SQLITE_CONFIG_GETPCACHE, &defaultPcache);
      assert( defaultPcache.xCreate!=testpcacheCreate );
      sqlite3_config(SQLITE_CONFIG_PCACHE, &testPcache);
    }else{
      assert( defaultPcache.xCreate!=0 );
      sqlite3_config(SQLITE_CONFIG_PCACHE, &defaultPcache);
    }
    isInstalled = installFlag;
  }
}