/*
** Close a cache.
*/
static void sqlite3PcacheClose(PCache pCache)
{
if (pCache.pCache != null)
{
sqlite3GlobalConfig.pcache.xDestroy(ref pCache.pCache);
}
}
/*
** Drop every cache entry whose page number is greater than "pgno". The
** caller must ensure that there are no outstanding references to any pages
** other than page 1 with a page number greater than pgno.
**
** If there is a reference to page 1 and the pgno parameter passed to this
** function is 0, then the data area associated with page 1 is zeroed, but
** the page object is not dropped.
*/
private static void sqlite3PcacheTruncate(PCache pCache, uint pgno)
{
if (pCache.pCache != null)
{
PgHdr p;
PgHdr pNext;
for (p = pCache.pDirty; p != null; p = pNext)
{
pNext = p.pDirtyNext;
if (p.pgno > pgno)
{
Debug.Assert((p.flags & PGHDR_DIRTY) != 0);
sqlite3PcacheMakeClean(p);
}
}
if (pgno == 0 && pCache.pPage1 != null)
{
// memset( pCache.pPage1.pData, 0, pCache.szPage );
pCache.pPage1.pData = sqlite3Malloc(pCache.szPage);
pgno = 1;
}
sqlite3GlobalConfig.pcache.xTruncate(pCache.pCache, pgno + 1);
}
}
//# define expensive_assert(X)
#endif
/********************************** Linked List Management ********************/
#if !NDEBUG && SQLITE_ENABLE_EXPENSIVE_ASSERT
/*
** Check that the pCache.pSynced variable is set correctly. If it
** is not, either fail an Debug.Assert or return zero. Otherwise, return
** non-zero. This is only used in debugging builds, as follows:
**
** expensive_assert( pcacheCheckSynced(pCache) );
*/
static int pcacheCheckSynced(PCache pCache){
PgHdr p ;
for(p=pCache.pDirtyTail; p!=pCache.pSynced; p=p.pDirtyPrev){
Debug.Assert( p.nRef !=0|| (p.flags&PGHDR_NEED_SYNC) !=0);
}
return (p==null || p.nRef!=0 || (p.flags&PGHDR_NEED_SYNC)==0)?1:0;
}
/*
** Add page pPage to the head of the dirty list (PCache1.pDirty is set to
** pPage).
*/
static void pcacheAddToDirtyList(PgHdr pPage)
{
PCache p = pPage.pCache;
Debug.Assert(pPage.pDirtyNext == null && pPage.pDirtyPrev == null && p.pDirty != pPage);
pPage.pDirtyNext = p.pDirty;
if (pPage.pDirtyNext != null)
{
Debug.Assert(pPage.pDirtyNext.pDirtyPrev == null);
pPage.pDirtyNext.pDirtyPrev = pPage;
}
p.pDirty = pPage;
if (null == p.pDirtyTail)
{
p.pDirtyTail = pPage;
}
if (null == p.pSynced && 0 == (pPage.flags & PGHDR_NEED_SYNC))
{
p.pSynced = pPage;
}
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(p));
#endif
}
/*
** Drop every cache entry whose page number is greater than "pgno". The
** caller must ensure that there are no outstanding references to any pages
** other than page 1 with a page number greater than pgno.
**
** If there is a reference to page 1 and the pgno parameter passed to this
** function is 0, then the data area associated with page 1 is zeroed, but
** the page object is not dropped.
*/
static void sqlite3PcacheTruncate(PCache pCache, u32 pgno)
{
if (pCache.pCache != null)
{
PgHdr p;
PgHdr pNext;
for (p = pCache.pDirty; p != null; p = pNext)
{
pNext = p.pDirtyNext;
/* This routine never gets call with a positive pgno except right
** after sqlite3PcacheCleanAll(). So if there are dirty pages,
** it must be that pgno==0.
*/
Debug.Assert(p.pgno > 0);
if (ALWAYS(p.pgno > pgno))
{
Debug.Assert((p.flags & PGHDR_DIRTY) != 0);
sqlite3PcacheMakeClean(p);
}
}
if (pgno == 0 && pCache.pPage1 != null)
{
// memset( pCache.pPage1.pData, 0, pCache.szPage );
pCache.pPage1.pData = sqlite3Malloc(pCache.szPage);
pgno = 1;
}
sqlite3GlobalConfig.pcache.xTruncate(pCache.pCache, pgno + 1);
}
}
//# define expensive_assert(X)
#endif
/********************************** Linked List Management ********************/
#if !NDEBUG && SQLITE_ENABLE_EXPENSIVE_ASSERT
/*
** Check that the pCache.pSynced variable is set correctly. If it
** is not, either fail an Debug.Assert or return zero. Otherwise, return
** non-zero. This is only used in debugging builds, as follows:
**
** expensive_assert( pcacheCheckSynced(pCache) );
*/
static int pcacheCheckSynced(PCache pCache){
PgHdr p ;
for(p=pCache.pDirtyTail; p!=pCache.pSynced; p=p.pDirtyPrev){
Debug.Assert( p.nRef !=0|| (p.flags&PGHDR_NEED_SYNC) !=0);
}
return (p==null || p.nRef!=0 || (p.flags&PGHDR_NEED_SYNC)==0)?1:0;
}
/*
** For all dirty pages currently in the cache, invoke the specified
** callback. This is only used if the SQLITE_CHECK_PAGES macro is
** defined.
*/
static void sqlite3PcacheIterateDirty( PCache pCache, dxIter xIter )
{
PgHdr pDirty;
for ( pDirty = pCache.pDirty; pDirty != null; pDirty = pDirty.pDirtyNext )
{
xIter( pDirty );
}
}
/*
** Make every page in the cache clean.
*/
static void sqlite3PcacheCleanAll( PCache pCache )
{
PgHdr p;
while ( ( p = pCache.pDirty ) != null )
{
sqlite3PcacheMakeClean( p );
}
}
/*
** Set the suggested cache-size value.
*/
static void sqlite3PcacheSetCachesize(PCache pCache, int mxPage)
{
pCache.nMax = mxPage;
if (pCache.pCache != null)
{
sqlite3GlobalConfig.pcache.xCachesize(pCache.pCache, mxPage);
}
}
/*
** Return the total number of pages in the cache.
*/
static int sqlite3PcachePagecount( PCache pCache )
{
int nPage = 0;
if ( pCache.pCache != null )
{
nPage = sqlite3GlobalConfig.pcache.xPagecount( pCache.pCache );
}
return nPage;
}
/*
** Return a list of all dirty pages in the cache, sorted by page number.
*/
static PgHdr sqlite3PcacheDirtyList( PCache pCache )
{
PgHdr p;
for ( p = pCache.pDirty; p != null; p = p.pDirtyNext )
{
p.pDirty = p.pDirtyNext;
}
return pcacheSortDirtyList( pCache.pDirty );
}
/*
** Clear the PGHDR_NEED_SYNC flag from all dirty pages.
*/
static void sqlite3PcacheClearSyncFlags( PCache pCache )
{
PgHdr p;
for ( p = pCache.pDirty; p != null; p = p.pDirtyNext )
{
p.flags &= ~PGHDR_NEED_SYNC;
}
pCache.pSynced = pCache.pDirtyTail;
}
/*
** Return the total number of pages in the cache.
*/
private static int sqlite3PcachePagecount(PCache pCache)
{
var nPage = 0;
if (pCache.pCache != null)
{
nPage = sqlite3GlobalConfig.pcache.xPagecount(pCache.pCache);
}
return(nPage);
}
/*
** Change the page size for PCache object. The caller must ensure that there
** are no outstanding page references when this function is called.
*/
static void sqlite3PcacheSetPageSize(PCache pCache, int szPage)
{
Debug.Assert(pCache.nRef == 0 && pCache.pDirty == null);
if (pCache.pCache != null)
{
sqlite3GlobalConfig.pcache.xDestroy(ref pCache.pCache);
pCache.pCache = null;
}
pCache.szPage = szPage;
}
/*
** Wrapper around the pluggable caches xUnpin method. If the cache is
** being used for an in-memory database, this function is a no-op.
*/
static void pcacheUnpin( PgHdr p )
{
PCache pCache = p.pCache;
if ( pCache.bPurgeable )
{
if ( p.pgno == 1 )
{
pCache.pPage1 = null;
}
sqlite3GlobalConfig.pcache.xUnpin( pCache.pCache, p, false );
}
}
/*
** Change the page number of page p to newPgno.
*/
static void sqlite3PcacheMove( PgHdr p, Pgno newPgno )
{
PCache pCache = p.pCache;
Debug.Assert( p.nRef > 0 );
Debug.Assert( newPgno > 0 );
sqlite3GlobalConfig.pcache.xRekey( pCache.pCache, p, p.pgno, newPgno );
p.pgno = newPgno;
if ( ( p.flags & PGHDR_DIRTY ) != 0 && ( p.flags & PGHDR_NEED_SYNC ) != 0 )
{
pcacheRemoveFromDirtyList( p );
pcacheAddToDirtyList( p );
}
}
public void Clear()
{
this.pData = null;
this.pExtra = null;
this.pDirty = null;
this.pgno = 0;
this.pPager = null;
#if SQLITE_CHECK_PAGES
this.pageHash = 0;
#endif
this.flags = 0;
this.nRef = 0;
this.pCache = null;
this.pDirtyNext = null;
this.pDirtyPrev = null;
this.pPgHdr1 = null;
}
}// sizeof( PCache ); }
/*
** Create a new PCache object. Storage space to hold the object
** has already been allocated and is passed in as the p pointer.
** The caller discovers how much space needs to be allocated by
** calling sqlite3PcacheSize().
*/
static void sqlite3PcacheOpen(
int szPage, /* Size of every page */
int szExtra, /* Extra space associated with each page */
bool bPurgeable, /* True if pages are on backing store */
dxStress xStress, //int (*xStress)(void*,PgHdr*),/* Call to try to make pages clean */
object pStress, /* Argument to xStress */
PCache p /* Preallocated space for the PCache */
)
{
p.Clear();//memset(p, 0, sizeof(PCache));
p.szPage = szPage;
p.szExtra = szExtra;
p.bPurgeable = bPurgeable;
p.xStress = xStress;
p.pStress = pStress;
p.nMax = 100;
}
public void Clear()
{
sqlite3_free(ref pData);
pData = null;
pExtra = null;
pDirty = null;
pgno = 0;
pPager = null;
#if SQLITE_CHECK_PAGES
this.pageHash = 0;
#endif
flags = 0;
nRef = 0;
pCache = null;
pDirtyNext = null;
pDirtyPrev = null;
pPgHdr1 = null;
}
public void Clear()
{
sqlite3_free(ref this.pData);
this.pData = null;
this.pExtra = null;
this.pDirty = null;
this.pgno = 0;
this.pPager = null;
#if SQLITE_CHECK_PAGES
this.pageHash=0;
#endif
this.flags = 0;
this.nRef = 0;
this.CacheAllocated = false;
this.pCache = null;
this.pDirtyNext = null;
this.pDirtyPrev = null;
this.pPgHdr1 = null;
}
/*
** Remove page pPage from the list of dirty pages.
*/
static void pcacheRemoveFromDirtyList(PgHdr pPage)
{
PCache p = pPage.pCache;
Debug.Assert(pPage.pDirtyNext != null || pPage == p.pDirtyTail);
Debug.Assert(pPage.pDirtyPrev != null || pPage == p.pDirty);
/* Update the PCache1.pSynced variable if necessary. */
if (p.pSynced == pPage)
{
PgHdr pSynced = pPage.pDirtyPrev;
while (pSynced != null && (pSynced.flags & PGHDR_NEED_SYNC) != 0)
{
pSynced = pSynced.pDirtyPrev;
}
p.pSynced = pSynced;
}
if (pPage.pDirtyNext != null)
{
pPage.pDirtyNext.pDirtyPrev = pPage.pDirtyPrev;
}
else
{
Debug.Assert(pPage == p.pDirtyTail);
p.pDirtyTail = pPage.pDirtyPrev;
}
if (pPage.pDirtyPrev != null)
{
pPage.pDirtyPrev.pDirtyNext = pPage.pDirtyNext;
}
else
{
Debug.Assert(pPage == p.pDirty);
p.pDirty = pPage.pDirtyNext;
}
pPage.pDirtyNext = null;
pPage.pDirtyPrev = null;
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(p));
#endif
}
public void Clear()
{
sqlite3_free(ref this.pData);
this.pData = null;
this.pExtra = null;
this.pDirty = null;
this.pgno = 0;
this.pPager = null;
#if SQLITE_CHECK_PAGES
this.pageHash = 0;
#endif
this.flags = 0;
this.nRef = 0;
this.CacheAllocated = false;
this.pCache = null;
this.pDirtyNext = null;
this.pDirtyPrev = null;
this.pPgHdr1 = null;
}
/*
** Decrement the reference count on a page. If the page is clean and the
** reference count drops to 0, then it is made elible for recycling.
*/
static void sqlite3PcacheRelease(PgHdr p)
{
Debug.Assert(p.nRef > 0);
p.nRef--;
if (p.nRef == 0)
{
PCache pCache = p.pCache;
pCache.nRef--;
if ((p.flags & PGHDR_DIRTY) == 0)
{
pcacheUnpin(p);
}
else
{
/* Move the page to the head of the dirty list. */
pcacheRemoveFromDirtyList(p);
pcacheAddToDirtyList(p);
}
}
}
//RESTORE
public Form1()
{
cacheFile = Application.StartupPath + "\\MyObj.bin";
InitializeComponent();
_cache = new PCache();
if (File.Exists(cacheFile))
{
FileStream fs = new FileStream(cacheFile, FileMode.Open, FileAccess.Read, FileShare.None);
byte[] array = new byte[fs.Length];
fs.Read(array, 0, (Int32)fs.Length);
fs.Close();
//below simple method converts saved byte data into cache object
if(array.Length>0)
_cache.RestoreCache(array, true);
}
CleanView(true);
}
//RESTORE
public Form1()
{
cacheFile = Application.StartupPath + "\\MyObj.bin";
InitializeComponent();
_cache = new PCache();
if (File.Exists(cacheFile))
{
FileStream fs = new FileStream(cacheFile, FileMode.Open, FileAccess.Read, FileShare.None);
byte[] array = new byte[fs.Length];
fs.Read(array, 0, (Int32)fs.Length);
fs.Close();
//below simple method converts saved byte data into cache object
if (array.Length > 0)
{
_cache.RestoreCache(array, true);
}
}
CleanView(true);
}
/*
** Close a cache.
*/
static void sqlite3PcacheClose( PCache pCache )
{
if ( pCache.pCache != null )
{
sqlite3GlobalConfig.pcache.xDestroy( ref pCache.pCache );
}
}
/*
** Discard the contents of the cache.
*/
static void sqlite3PcacheClear( PCache pCache )
{
sqlite3PcacheTruncate( pCache, 0 );
}
/*
** Clear the PGHDR_NEED_SYNC flag from all dirty pages.
*/
static void sqlite3PcacheClearSyncFlags( PCache pCache )
{
PgHdr p;
for ( p = pCache.pDirty; p != null; p = p.pDirtyNext )
{
p.flags &= ~PGHDR_NEED_SYNC;
}
pCache.pSynced = pCache.pDirtyTail;
}
/*
** Drop every cache entry whose page number is greater than "pgno". The
** caller must ensure that there are no outstanding references to any pages
** other than page 1 with a page number greater than pgno.
**
** If there is a reference to page 1 and the pgno parameter passed to this
** function is 0, then the data area associated with page 1 is zeroed, but
** the page object is not dropped.
*/
static void sqlite3PcacheTruncate( PCache pCache, u32 pgno )
{
if ( pCache.pCache != null )
{
PgHdr p;
PgHdr pNext;
for ( p = pCache.pDirty; p != null; p = pNext )
{
pNext = p.pDirtyNext;
/* This routine never gets call with a positive pgno except right
** after sqlite3PcacheCleanAll(). So if there are dirty pages,
** it must be that pgno==0.
*/
Debug.Assert( p.pgno > 0 );
if ( ALWAYS( p.pgno > pgno ) )
{
Debug.Assert( ( p.flags & PGHDR_DIRTY ) != 0 );
sqlite3PcacheMakeClean( p );
}
}
if ( pgno == 0 && pCache.pPage1 != null )
{
// memset( pCache.pPage1.pData, 0, pCache.szPage );
pCache.pPage1.pData = sqlite3Malloc( pCache.szPage );
pgno = 1;
}
sqlite3GlobalConfig.pcache.xTruncate( pCache.pCache, pgno + 1 );
}
}
/*
** Get the suggested cache-size value.
*/
static int sqlite3PcacheGetCachesize(PCache pCache)
{
return(pCache.nMax);
}
/*
** Make every page in the cache clean.
*/
static void sqlite3PcacheCleanAll( PCache pCache )
{
PgHdr p;
while ( ( p = pCache.pDirty ) != null )
{
sqlite3PcacheMakeClean( p );
}
}
}// sizeof( PCache ); }
/*
** Create a new PCache object. Storage space to hold the object
** has already been allocated and is passed in as the p pointer.
** The caller discovers how much space needs to be allocated by
** calling sqlite3PcacheSize().
*/
static void sqlite3PcacheOpen(
int szPage, /* Size of every page */
int szExtra, /* Extra space associated with each page */
bool bPurgeable, /* True if pages are on backing store */
dxStress xStress,//int (*xStress)(void*,PgHdr*),/* Call to try to make pages clean */
object pStress, /* Argument to xStress */
PCache p /* Preallocated space for the PCache */
)
{
p.Clear();//memset(p, 0, sizeof(PCache));
p.szPage = szPage;
p.szExtra = szExtra;
p.bPurgeable = bPurgeable;
p.xStress = xStress;
p.pStress = pStress;
p.nMax = 100;
}
/*
** Return the total number of pages in the cache.
*/
static int sqlite3PcachePagecount( PCache pCache )
{
int nPage = 0;
if ( pCache.pCache != null )
{
nPage = sqlite3GlobalConfig.pcache.xPagecount( pCache.pCache );
}
return nPage;
}
public void Clear()
{
this.pData = null;
this.pExtra = null;
this.pDirty = null;
this.pgno = 0;
this.pPager = null;
#if SQLITE_CHECK_PAGES
this.pageHash=0;
#endif
this.flags = 0;
this.nRef = 0;
this.pCache = null;
this.pDirtyNext = null;
this.pDirtyPrev = null;
this.pPgHdr1 = null;
}
public static PCache ComputePCacheFromMesh(Mesh mesh, int mapSize = 512, int pointCount = 4096, int seed = 0, Distribution distribution = Distribution.RandomUniformArea, MeshBakeMode meshBakeMode = MeshBakeMode.Triangle)
{
if (mapSize % 8 != 0)
{
Debug.LogError("Position map dimensions should be a multiple of 8.");
return(null);
}
if (computeShader == null)
{
computeShader = computeShader = Resources.Load <ComputeShader>("Shaders/ComputeMeshToMap");
}
PCache pCache = new PCache();
// From PointCacheBakeTool
MeshData meshCache = ComputeDataCache(mesh);
Picker picker = null;
if (distribution == Distribution.Sequential)
{
if (meshBakeMode == MeshBakeMode.Vertex)
{
picker = new SequentialPickerVertex(meshCache);
}
else if (meshBakeMode == MeshBakeMode.Triangle)
{
picker = new SequentialPickerTriangle(meshCache);
}
}
else if (distribution == Distribution.Random)
{
if (meshBakeMode == MeshBakeMode.Vertex)
{
picker = new RandomPickerVertex(meshCache, seed);
}
else if (meshBakeMode == MeshBakeMode.Triangle)
{
picker = new RandomPickerTriangle(meshCache, seed);
}
}
else if (distribution == Distribution.RandomUniformArea)
{
picker = new RandomPickerUniformArea(meshCache, seed);
}
if (picker == null)
{
throw new InvalidOperationException("Unable to find picker");
}
pCache.mesh = mesh;
pCache.mapSize = mapSize;
pCache.positions = new List <Vector3>();
pCache.normals = new List <Vector3>();
for (int i = 0; i < pointCount; ++i)
{
var vertex = picker.GetNext();
pCache.positions.Add(vertex.position);
pCache.normals.Add(vertex.normal);
}
// From SMRVFX
pCache.positionMap = new RenderTexture(mapSize, mapSize, 0, RenderTextureFormat.ARGBFloat);
pCache.positionMap.enableRandomWrite = true;
pCache.positionMap.Create();
pCache.normalMap = new RenderTexture(mapSize, mapSize, 0, RenderTextureFormat.ARGBFloat);
pCache.normalMap.enableRandomWrite = true;
pCache.normalMap.Create();
// Transfer data
var vcount = pCache.positions.Count;
var vcount_x3 = vcount * 3;
pCache.positionBuffer = new ComputeBuffer(vcount_x3, sizeof(float));
pCache.normalBuffer = new ComputeBuffer(vcount_x3, sizeof(float));
computeShader.SetInt("VertexCount", vcount);
pCache.positionBuffer.SetData(pCache.positions);
pCache.normalBuffer.SetData(pCache.normals);
computeShader.SetBuffer(0, "PositionBuffer", pCache.positionBuffer);
computeShader.SetBuffer(0, "NormalBuffer", pCache.normalBuffer);
computeShader.SetTexture(0, "PositionMap", pCache.positionMap);
computeShader.SetTexture(0, "NormalMap", pCache.normalMap);
computeShader.Dispatch(0, pCache.mapSize / 8, pCache.mapSize / 8, 1);
return(pCache);
}
/*
** Try to obtain a page from the cache.
*/
static int sqlite3PcacheFetch(
PCache pCache, /* Obtain the page from this cache */
u32 pgno, /* Page number to obtain */
int createFlag, /* If true, create page if it does not exist already */
ref PgHdr ppPage /* Write the page here */
)
{
PgHdr pPage = null;
int eCreate;
Debug.Assert(pCache != null);
Debug.Assert(createFlag == 1 || createFlag == 0);
Debug.Assert(pgno > 0);
/* If the pluggable cache (sqlite3_pcache*) has not been allocated,
** allocate it now.
*/
if (null == pCache.pCache && createFlag != 0)
{
sqlite3_pcache p;
int nByte;
nByte = pCache.szPage + pCache.szExtra + 0;// sizeof( PgHdr );
p = sqlite3GlobalConfig.pcache.xCreate(nByte, pCache.bPurgeable);
if (null == p)
{
return(SQLITE_NOMEM);
}
sqlite3GlobalConfig.pcache.xCachesize(p, pCache.nMax);
pCache.pCache = p;
}
eCreate = createFlag * (1 + ((!pCache.bPurgeable || null == pCache.pDirty) ? 1 : 0));
if (pCache.pCache != null)
{
pPage = sqlite3GlobalConfig.pcache.xFetch(pCache.pCache, pgno, eCreate);
}
if (null == pPage && eCreate == 1)
{
PgHdr pPg;
/* Find a dirty page to write-out and recycle. First try to find a
** page that does not require a journal-sync (one with PGHDR_NEED_SYNC
** cleared), but if that is not possible settle for any other
** unreferenced dirty page.
*/
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert(pcacheCheckSynced(pCache));
#endif
for (pPg = pCache.pSynced;
pPg != null && (pPg.nRef != 0 || (pPg.flags & PGHDR_NEED_SYNC) != 0);
pPg = pPg.pDirtyPrev
)
{
;
}
pCache.pSynced = pPg;
if (null == pPg)
{
for (pPg = pCache.pDirtyTail; pPg != null && pPg.nRef != 0; pPg = pPg.pDirtyPrev)
{
;
}
}
if (pPg != null)
{
int rc;
rc = pCache.xStress(pCache.pStress, pPg);
if (rc != SQLITE_OK && rc != SQLITE_BUSY)
{
return(rc);
}
}
pPage = sqlite3GlobalConfig.pcache.xFetch(pCache.pCache, pgno, 2);
}
if (pPage != null)
{
if (null == pPage.pData)
{
// memset(pPage, 0, sizeof(PgHdr));
pPage.pData = sqlite3Malloc(pCache.szPage);// pPage->pData = (void*)&pPage[1];
//pPage->pExtra = (void*)&((char*)pPage->pData)[pCache->szPage];
//memset(pPage->pExtra, 0, pCache->szExtra);
pPage.pCache = pCache;
pPage.pgno = pgno;
}
Debug.Assert(pPage.pCache == pCache);
Debug.Assert(pPage.pgno == pgno);
//assert(pPage->pData == (void*)&pPage[1]);
//assert(pPage->pExtra == (void*)&((char*)&pPage[1])[pCache->szPage]);
if (0 == pPage.nRef)
{
pCache.nRef++;
}
pPage.nRef++;
if (pgno == 1)
{
pCache.pPage1 = pPage;
}
}
ppPage = pPage;
return((pPage == null && eCreate != 0) ? SQLITE_NOMEM : SQLITE_OK);
}
/*
** Drop every cache entry whose page number is greater than "pgno". The
** caller must ensure that there are no outstanding references to any pages
** other than page 1 with a page number greater than pgno.
**
** If there is a reference to page 1 and the pgno parameter passed to this
** function is 0, then the data area associated with page 1 is zeroed, but
** the page object is not dropped.
*/
static void sqlite3PcacheTruncate( PCache pCache, u32 pgno )
{
if ( pCache.pCache != null )
{
PgHdr p;
PgHdr pNext;
for ( p = pCache.pDirty ; p != null ; p = pNext )
{
pNext = p.pDirtyNext;
if ( p.pgno > pgno )
{
Debug.Assert( ( p.flags & PGHDR_DIRTY ) != 0 );
sqlite3PcacheMakeClean( p );
}
}
if ( pgno == 0 && pCache.pPage1 != null )
{
pCache.pPage1.pData = new byte[pCache.szPage];// memset( pCache.pPage1.pData, 0, pCache.szPage );
pgno = 1;
}
sqlite3GlobalConfig.pcache.xTruncate( pCache.pCache, pgno + 1 );
}
}
/*
** Set the suggested cache-size value.
*/
static void sqlite3PcacheSetCachesize( PCache pCache, int mxPage )
{
pCache.nMax = mxPage;
if ( pCache.pCache != null )
{
sqlite3GlobalConfig.pcache.xCachesize( pCache.pCache, mxPage );
}
}
/*
** Return a list of all dirty pages in the cache, sorted by page number.
*/
static PgHdr sqlite3PcacheDirtyList( PCache pCache )
{
PgHdr p;
for ( p = pCache.pDirty; p != null; p = p.pDirtyNext )
{
p.pDirty = p.pDirtyNext;
}
return pcacheSortDirtyList( pCache.pDirty );
}
/*
** Change the page size for PCache object. The caller must ensure that there
** are no outstanding page references when this function is called.
*/
static void sqlite3PcacheSetPageSize( PCache pCache, int szPage )
{
Debug.Assert( pCache.nRef == 0 && pCache.pDirty == null );
if ( pCache.pCache != null )
{
sqlite3GlobalConfig.pcache.xDestroy( ref pCache.pCache );
pCache.pCache = null;
}
pCache.szPage = szPage;
}
/*
** Return the total number of referenced pages held by the cache.
*/
static int sqlite3PcacheRefCount( PCache pCache )
{
return pCache.nRef;
}
/*
** Try to obtain a page from the cache.
*/
static int sqlite3PcacheFetch(
PCache pCache, /* Obtain the page from this cache */
u32 pgno, /* Page number to obtain */
int createFlag, /* If true, create page if it does not exist already */
ref PgHdr ppPage /* Write the page here */
)
{
PgHdr pPage = null;
int eCreate;
Debug.Assert( pCache != null );
Debug.Assert( createFlag == 1 || createFlag == 0 );
Debug.Assert( pgno > 0 );
/* If the pluggable cache (sqlite3_pcache*) has not been allocated,
** allocate it now.
*/
if ( null == pCache.pCache && createFlag != 0 )
{
sqlite3_pcache p;
int nByte;
nByte = pCache.szPage + pCache.szExtra + 0;// sizeof( PgHdr );
p = sqlite3GlobalConfig.pcache.xCreate( nByte, pCache.bPurgeable );
//if ( null == p )
//{
// return SQLITE_NOMEM;
//}
sqlite3GlobalConfig.pcache.xCachesize( p, pCache.nMax );
pCache.pCache = p;
}
eCreate = createFlag * ( 1 + ( ( !pCache.bPurgeable || null == pCache.pDirty ) ? 1 : 0 ) );
if ( pCache.pCache != null )
{
pPage = sqlite3GlobalConfig.pcache.xFetch( pCache.pCache, pgno, eCreate );
}
if ( null == pPage && eCreate == 1 )
{
PgHdr pPg;
/* Find a dirty page to write-out and recycle. First try to find a
** page that does not require a journal-sync (one with PGHDR_NEED_SYNC
** cleared), but if that is not possible settle for any other
** unreferenced dirty page.
*/
#if SQLITE_ENABLE_EXPENSIVE_ASSERT
expensive_assert( pcacheCheckSynced(pCache) );
#endif
for ( pPg = pCache.pSynced;
pPg != null && ( pPg.nRef != 0 || ( pPg.flags & PGHDR_NEED_SYNC ) != 0 );
pPg = pPg.pDirtyPrev
)
;
pCache.pSynced = pPg;
if ( null == pPg )
{
for ( pPg = pCache.pDirtyTail; pPg != null && pPg.nRef != 0; pPg = pPg.pDirtyPrev )
;
}
if ( pPg != null )
{
int rc;
#if SQLITE_LOG_CACHE_SPILL
sqlite3_log(SQLITE_FULL,
"spill page %d making room for %d - cache used: %d/%d",
pPg->pgno, pgno,
sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache),
pCache->nMax);
#endif
rc = pCache.xStress( pCache.pStress, pPg );
if ( rc != SQLITE_OK && rc != SQLITE_BUSY )
{
return rc;
}
}
pPage = sqlite3GlobalConfig.pcache.xFetch( pCache.pCache, pgno, 2 );
}
if ( pPage != null )
{
if ( null == pPage.pData )
{
// memset(pPage, 0, sizeof(PgHdr));
pPage.pData = sqlite3Malloc( pCache.szPage );// pPage->pData = (void*)&pPage[1];
//pPage->pExtra = (void*)&((char*)pPage->pData)[pCache->szPage];
//memset(pPage->pExtra, 0, pCache->szExtra);
pPage.pCache = pCache;
pPage.pgno = pgno;
}
Debug.Assert( pPage.pCache == pCache );
Debug.Assert( pPage.pgno == pgno );
//assert(pPage->pData == (void*)&pPage[1]);
//assert(pPage->pExtra == (void*)&((char*)&pPage[1])[pCache->szPage]);
if ( 0 == pPage.nRef )
{
pCache.nRef++;
}
pPage.nRef++;
if ( pgno == 1 )
{
pCache.pPage1 = pPage;
}
}
ppPage = pPage;
return ( pPage == null && eCreate != 0 ) ? SQLITE_NOMEM : SQLITE_OK;
}
/*
** Get the suggested cache-size value.
*/
static int sqlite3PcacheGetCachesize( PCache pCache )
{
return pCache.nMax;
}
/*
** Return the total number of referenced pages held by the cache.
*/
static int sqlite3PcacheRefCount(PCache pCache)
{
return(pCache.nRef);
}
/*
** For all dirty pages currently in the cache, invoke the specified
** callback. This is only used if the SQLITE_CHECK_PAGES macro is
** defined.
*/
static void sqlite3PcacheIterateDirty( PCache pCache, dxIter xIter )
{
PgHdr pDirty;
for ( pDirty = pCache.pDirty; pDirty != null; pDirty = pDirty.pDirtyNext )
{
xIter( pDirty );
}
}
/*
** Discard the contents of the cache.
*/
static void sqlite3PcacheClear(PCache pCache)
{
sqlite3PcacheTruncate(pCache, 0);
}
