public MyPage GetWritablePage(long pageNumber)
{
var lookup = new Vector <long>(pageNumber);
for (int i = 0; i < _cacheSize; i += Vector <long> .Count)
{
var pageNumbers = new Vector <long>(_pages, i);
var comparison = Vector.Equals(pageNumbers, lookup);
var result = Vector.ConditionalSelect(comparison, Vector <long> .One, Vector <long> .Zero);
long index = Vector.Dot(_indexes, result);
if (index != 0)
{
int j = i + (int)index - 1;
if (!_writeable[j])
{
_cache[j] = LowLevelTransactionStub.ModifyPage(pageNumber);
_writeable[j] = true;
}
return(_cache[j]);
}
}
// If we got here, there was a cache miss
_current = (_current + 1) % _cacheSize;
_cache[_current] = LowLevelTransactionStub.ModifyPage(pageNumber);
_pages[_current] = pageNumber;
_writeable[_current] = true;
return(_cache[_current]);
}
public MyPage GetWritablePage(long pageNumber)
{
ushort fingerprint = GetFingerprint(pageNumber);
int i;
for (i = 0; i < _cacheSize; i++)
{
// This is used to force the JIT to layout the code as if unlikely() compiler directive exists.
if (_fingerprints[i] == fingerprint)
{
goto Found;
}
}
// If we got here, there was a cache miss
_current = (_current + 1) % _cacheSize;
_cache[_current] = new PageHandlePtrV3(pageNumber, LowLevelTransactionStub.ModifyPage(pageNumber), true);
_fingerprints[_current] = fingerprint;
return(_cache[_current].Value);
Found:
if (_cache[i].PageNumber == pageNumber && _cache[i].IsWritable)
{
return(_cache[i].Value);
}
_cache[i] = new PageHandlePtrV3(pageNumber, LowLevelTransactionStub.ModifyPage(pageNumber), true);
return(_cache[i].Value);
}
public MyPage GetWritablePage(long pageNumber)
{
int position = _current;
int itemsLeft = _cache.Length;
while (itemsLeft > 0)
{
int i = position % _cache.Length;
// If the page number is equal to the page number we are looking for (therefore it's valid)
// Will not fail at PageNumber=0 because the accesor will handle that.
if (_cache[i].PageNumber != pageNumber)
{
// we continue.
itemsLeft--;
position++;
continue;
}
if (!_cache[i].IsWritable)
{
_cache[i] = new PageHandlePtrV1(LowLevelTransactionStub.ModifyPage(pageNumber), true);
}
return(_cache[i].Value);
}
_current = (_current + 1) % _cache.Length;
_cache[_current] = new PageHandlePtrV1(LowLevelTransactionStub.ModifyPage(pageNumber), true);
return(_cache[_current].Value);
}
public MyPage GetWritablePage(long pageNumber)
{
ushort sfingerprint = (ushort)pageNumber;
int fingerprint = sfingerprint;
int i = 0;
int size = _cacheSize;
while (i < size)
{
int f1 = _fingerprints[i + 0];
int f2 = _fingerprints[i + 1];
int f3 = _fingerprints[i + 2];
int f4 = _fingerprints[i + 3];
// This is used to force the JIT to layout the code as if unlikely() compiler directive existed.
if (f1 == fingerprint)
{
goto Found;
}
if (f2 == fingerprint)
{
goto Found1;
}
if (f3 == fingerprint)
{
goto Found2;
}
if (f4 == fingerprint)
{
goto Found3;
}
i += 4;
}
// If we got here, there was a cache miss
_current = (_current + 1) % _cacheSize;
_cache[_current] = new PageHandlePtrV3(pageNumber, LowLevelTransactionStub.ModifyPage(pageNumber), true);
_fingerprints[_current] = sfingerprint;
return(_cache[_current].Value);
Found1 : i += 1; goto Found;
Found2 : i += 2; goto Found;
Found3 : i += 3;
Found:
if (_cache[i].PageNumber == pageNumber && _cache[i].IsWritable)
{
return(_cache[i].Value);
}
_cache[i] = new PageHandlePtrV3(pageNumber, LowLevelTransactionStub.ModifyPage(pageNumber), true);
return(_cache[i].Value);
}
public MyPage GetWritablePage(long pageNumber)
{
int fingerprint = (int)pageNumber;
var lookup = new Vector <int>(fingerprint);
int count = Vector <short> .Count;
for (int i = 0; i < _cacheSize; i += count)
{
var pageNumbers = new Vector <int>(_fingerprints, i);
if (Vector.EqualsAny(pageNumbers, lookup))
{
for (int index = 0; index < count; index++)
{
int j = i + index;
if (_fingerprints[j] == fingerprint)
{
if (_cache[j].PageNumber == pageNumber && _cache[j].IsWritable)
{
return(_cache[j].Value);
}
_cache[j] = new PageHandlePtrV3(pageNumber, LowLevelTransactionStub.ModifyPage(pageNumber), true);
return(_cache[j].Value);
}
}
throw new InvalidOperationException("This cant happen");
}
}
// If we got here, there was a cache miss
_current = (_current + 1) % _cacheSize;
_cache[_current] = new PageHandlePtrV3(pageNumber, LowLevelTransactionStub.ModifyPage(pageNumber), true);
_fingerprints[_current] = fingerprint;
return(_cache[_current].Value);
}