static IEnumerable <Key> Equal <Key>(BTreeBase <Key, Key> sourceCollection, BinaryExpression binExp)
#if WINDOWS_PHONE
where Key : new()
#endif
{
SessionBase session = sourceCollection.Session;
CompareByField <Key> comparer = sourceCollection.Comparer as CompareByField <Key>;
Expression leftSide = binExp.Left;
Expression rightSide = binExp.Right;
object rightValue = GetRightValue(leftSide, rightSide);
if (leftSide.NodeType == ExpressionType.Parameter)
{
Key key = (Key)rightValue;
if (key != null)
{
BTreeSetIterator <Key> itr = sourceCollection.Iterator();
itr.GoTo(key);
while (sourceCollection.Comparer.Compare(itr.Current(), key) == 0)
{
yield return(itr.Next());
}
}
}
else
{
if (comparer != null)
{
MemberExpression returnedEx = null;
#if WINDOWS_PHONE || WINDOWS_UWP
Key key = (Key)Activator.CreateInstance(typeof(Key));
#else
Key key = (Key)FormatterServices.GetUninitializedObject(typeof(Key));
#endif
if (comparer.FieldsToCompare == null)
{
comparer.SetupFieldsToCompare();
}
DataMember dataMember = comparer.FieldsToCompare[0];
if (rightValue != null && HasIndexablePropertyOnLeft <Key>(leftSide, sourceCollection, dataMember, out returnedEx))
{
MemberExpression propExp = (MemberExpression)returnedEx;
MemberInfo property = propExp.Member;
dataMember.SetMemberValueWithPossibleConvert(key, rightValue);
BTreeSetIterator <Key> itr = sourceCollection.Iterator();
itr.GoTo(key);
Key current = itr.Current();
while (current != null && comparer.CompareField(dataMember, key, current, 0) == 0)
{
yield return(current);
current = itr.Next();
}
}
}
}
}
static bool GreaterThanOrEqualUseIndex <Key>(BTreeBase <Key, Key> sourceCollection, BinaryExpression binExp)
#if WINDOWS_PHONE
where Key : new()
#endif
{
SessionBase session = sourceCollection.Session;
CompareByField <Key> comparer = sourceCollection.Comparer as CompareByField <Key>;
Expression leftSide = binExp.Left;
Expression rightSide = binExp.Right;
object rightValue = GetRightValue(leftSide, rightSide);
if (leftSide.NodeType == ExpressionType.Parameter)
{
Key key = (Key)rightValue;
if (key != null)
{
if (session.TraceIndexUsage)
{
Trace.WriteLine(DateTime.Now.ToString("HH:mm:ss:fff") + " Index used with " + sourceCollection.ToString());
}
return(true);
}
}
else
{
if (comparer != null)
{
//if we were able to create a hash from the right side (likely)
MemberExpression returnedEx = null;
if (comparer.FieldsToCompare == null)
{
comparer.SetupFieldsToCompare();
}
DataMember dataMember = comparer.FieldsToCompare[0];
if (rightValue != null && HasIndexablePropertyOnLeft <Key>(leftSide, sourceCollection, dataMember, out returnedEx))
{
if (session.TraceIndexUsage)
{
Trace.WriteLine(DateTime.Now.ToString("HH:mm:ss:fff") + " Index used with " + sourceCollection.ToString());
}
return(true);
}
else if (leftSide.NodeType == ExpressionType.Call)
{
// don't know yet how to handle TODO
/*MethodCallExpression expression = leftSide as MethodCallExpression;
* Trace.Out.WriteLine("Method: " + expression.Method.Name);
* Trace.Out.WriteLine("Args: ");
* foreach (var exp in expression.Arguments)
* sourceCollection where */
}
}
}
return(false);
}
static bool GreaterThanUseIndex <Key>(BTreeBase <Key, Key> sourceCollection, BinaryExpression binExp)
#if WINDOWS_PHONE
where Key : new()
#endif
{
SessionBase session = sourceCollection.GetSession();
CompareByField <Key> comparer = sourceCollection.Comparer as CompareByField <Key>;
Expression leftSide = binExp.Left;
Expression rightSide = binExp.Right;
object rightValue = GetRightValue(leftSide, rightSide);
if (leftSide.NodeType == ExpressionType.Parameter)
{
Key key = (Key)rightValue;
if (key != null)
{
if (session.TraceIndexUsage)
{
Trace.WriteLine(DateTime.Now.ToString("HH:mm:ss:fff") + " Index used with " + sourceCollection.ToString());
}
return(true);
}
}
else
{
if (comparer != null)
{
//if we were able to create a hash from the right side (likely)
MemberExpression returnedEx = null;
if (comparer.FieldsToCompare == null)
{
comparer.SetupFieldsToCompare();
}
DataMember dataMember = comparer.FieldsToCompare[0];
if (rightValue != null && HasIndexablePropertyOnLeft <Key>(leftSide, sourceCollection, dataMember, out returnedEx))
{
if (session.TraceIndexUsage)
{
Trace.WriteLine(DateTime.Now.ToString("HH:mm:ss:fff") + " Index used with " + sourceCollection.ToString());
}
return(true);
}
}
}
return(false);
}
static bool canUseIndex <Key>(BTreeBase <Key, Key> sourceCollection, BinaryExpression binExp, CompareByField <Key> comparer)
#if WINDOWS_PHONE
where Key : new()
#endif
{
if (comparer.FieldsToCompare == null)
{
comparer.SetupFieldsToCompare();
}
int indexNumberOfFields = comparer.FieldsToCompare.Length;
while (binExp.NodeType == ExpressionType.AndAlso)
{
BinaryExpression leftExpr = (BinaryExpression)binExp.Left;
BinaryExpression rightExpr = (BinaryExpression)binExp.Right;
MemberExpression returnedEx = null;
if (indexNumberOfFields == 0 || !HasIndexablePropertyOnLeft(rightExpr.Left, sourceCollection, comparer.FieldsToCompare[--indexNumberOfFields], out returnedEx))
{
return(false);
}
binExp = leftExpr;
}
return(true);
}
static IEnumerable <Key> LessThan <Key>(BTreeBase <Key, Key> sourceCollection, BinaryExpression binExp)
#if WINDOWS_PHONE
where Key : new()
#endif
{
SessionBase session = sourceCollection.Session;
Expression leftSide = binExp.Left;
Expression rightSide = binExp.Right;
object rightValue = GetRightValue(leftSide, rightSide);
CompareByField <Key> comparer = sourceCollection.Comparer as CompareByField <Key>;
if (leftSide.NodeType == ExpressionType.Parameter)
{
Key key = (Key)rightValue;
if (key != null)
{
BTreeSetIterator <Key> itr = sourceCollection.Iterator();
if (itr.GoTo(key))
{
while (itr.Previous() != null)
{
yield return(itr.Current());
}
}
}
}
else
{
if (comparer != null)
{
//if we were able to create a hash from the right side (likely)
MemberExpression returnedEx = null;
#if WINDOWS_PHONE || WINDOWS_UWP
Key key = (Key)Activator.CreateInstance(typeof(Key));
#else
Key key = (Key)FormatterServices.GetUninitializedObject(typeof(Key));
#endif
if (comparer.FieldsToCompare == null)
{
comparer.SetupFieldsToCompare();
}
DataMember dataMember = comparer.FieldsToCompare[0];
if (rightValue != null && HasIndexablePropertyOnLeft <Key>(leftSide, sourceCollection, dataMember, out returnedEx))
{
//cast to MemberExpression - it allows us to get the property
MemberExpression propExp = (MemberExpression)returnedEx;
MemberInfo property = propExp.Member;
foreach (DataMember member in comparer.FieldsToCompare.Skip(1))
{
if (member.GetTypeCode == TypeCode.String)
{
member.SetMemberValue(key, "");
}
}
dataMember.SetMemberValueWithPossibleConvert(key, rightValue);
BTreeSetIterator <Key> itr = sourceCollection.Iterator();
itr.GoTo(key);
var v = itr.Current();
if (v == null)
{
v = itr.Previous();
}
while (v != null && comparer.CompareField(dataMember, key, v, 0) == 0)
{
v = itr.Previous();
}
while (v != null)
{
yield return(v);
v = itr.Previous();
}
}
else if (leftSide.NodeType == ExpressionType.Call)
{
// don't know yet how to handle TODO
/*MethodCallExpression expression = leftSide as MethodCallExpression;
* Trace.Out.WriteLine("Method: " + expression.Method.Name);
* Trace.Out.WriteLine("Args: ");
* foreach (var exp in expression.Arguments)
* sourceCollection where */
}
}
}
}