public override object VisitScientific([NotNull] MiniSQLParser.ScientificContext context)
{
AtomValue value = new AtomValue();
if (context.INT_NUMBER() != null)
{
value.Type = AttributeTypes.Int;
value.IntegerValue = int.Parse(context.INT_NUMBER().GetText());
}
else if (context.DECIMAL_NUMBER() != null)
{
value.Type = AttributeTypes.Float;
value.FloatValue = float.Parse(context.DECIMAL_NUMBER().GetText());
}
else if (context.SINGLE_QUOTED_TEXT() != null)
{
value.Type = AttributeTypes.Char;
string withQuotes = context.SINGLE_QUOTED_TEXT().GetText();
value.StringValue = withQuotes.Substring(1, withQuotes.Length - 2);
value.CharLimit = Encoding.UTF8.GetByteCount(value.StringValue);
}
else if (context.DOUBLE_QUOTED_TEXT() != null)
{
value.Type = AttributeTypes.Char;
string withQuotes = context.DOUBLE_QUOTED_TEXT().GetText();
value.StringValue = withQuotes.Substring(1, withQuotes.Length - 2);
value.CharLimit = Encoding.UTF8.GetByteCount(value.StringValue);
}
else
{
throw new System.NotImplementedException();
}
return(value);
}
private static void TestFullCalculate()
{
Expression exp = GetAndsExpression();
List <AttributeValue> nameValuePairs = new List <AttributeValue>();
nameValuePairs.Add(new AttributeValue("a", new AtomValue {
Type = AttributeTypes.Int, IntegerValue = 33
}));
nameValuePairs.Add(new AttributeValue("b", new AtomValue {
Type = AttributeTypes.Char, CharLimit = 5, StringValue = "stc"
}));
nameValuePairs.Add(new AttributeValue("c", new AtomValue {
Type = AttributeTypes.Float, FloatValue = 6.0
}));
AtomValue result = exp.Calculate(nameValuePairs);
Assert.True(result.BooleanValue);
nameValuePairs[1].Value.StringValue = "stz";
result = exp.Calculate(nameValuePairs);
Assert.False(result.BooleanValue);
}
private SelectResult HandleSelectStatement(ShowStatement statement)
{
List <SchemaRecord> tableSchemas = _catalogManager.GetTablesSchemaRecord();
SelectResult result = new SelectResult();
result.ColumnDeclarations = new List <AttributeDeclaration>()
{
new AttributeDeclaration()
{
AttributeName = "Table", Type = AttributeTypes.Char, CharLimit = 80
}
};
result.Rows = new List <List <AtomValue> >();
foreach (SchemaRecord tableSchema in tableSchemas)
{
List <AtomValue> row = new List <AtomValue>();
AtomValue col = new AtomValue();
col.Type = AttributeTypes.Char;
col.CharLimit = 80;
col.StringValue = tableSchema.Name;
row.Add(col);
result.Rows.Add(row);
}
return(result);
}
static void TestInternalIndexCell()
{
// init record
DBRecord record = GetTestBRecord();
// init key
List <AtomValue> keyValues = new List <AtomValue>();
AtomValue key = new AtomValue()
{
Type = AttributeTypes.Char, CharLimit = 8, StringValue = "114514"
};
keyValues.Add(key);
DBRecord keyRecord = new DBRecord(keyValues);
// make raw bytes
List <byte> rawNode = new List <byte>();
rawNode.AddRange(new byte[30]);
// build cell
InternalIndexCell internalIndexCell = new InternalIndexCell(record, 114514, keyRecord);
byte[] raw = internalIndexCell.Pack();
rawNode.AddRange(raw);
// clone
InternalIndexCell clone = new InternalIndexCell(rawNode.ToArray(), 30);
// assert
AssertCell(internalIndexCell, clone);
Assert.Equal(internalIndexCell.ChildPage, clone.ChildPage);
AssertDBRecords(internalIndexCell.PrimaryKey, clone.PrimaryKey);
}
public int CreateIndex(int tableRootPage, string indexedColumnName, List <AttributeDeclaration> attributeDeclarations)
{
BTreeNode indexRoot = _bTree.OccupyNewTableNode();
BTreeNode tableRoot = BTreeNodeHelper.GetBTreeNode(_pager, tableRootPage);
int indexedColumnIndex = attributeDeclarations.FindIndex(x => x.AttributeName == indexedColumnName);
foreach (BTreeCell tableCell in _bTree.LinearSearch(tableRoot))
{
AtomValue indexedValue = ((LeafTableCell)tableCell).DBRecord.GetValues()[indexedColumnIndex];
AtomValue primaryKey = ((LeafTableCell)tableCell).Key.GetValues()[0];
// List<AtomValue> indexPrimaryKeyPair = new List<AtomValue>() { indexedValue, primaryKey };
List <AtomValue> wrappedPrimaryKey = new List <AtomValue>()
{
primaryKey
};
DBRecord wrappedKey = new DBRecord(new List <AtomValue>()
{
indexedValue
});
// DBRecord wrappedValues = new DBRecord(indexPrimaryKeyPair);
DBRecord wrappedValues = new DBRecord(wrappedPrimaryKey);
indexRoot = _bTree.InsertCell(indexRoot, wrappedKey, wrappedValues);
}
return(indexRoot.RawPage.PageNumber);
}
static void TestLeafTableCell()
{
// init record
DBRecord record = GetTestBRecord();
// init key
List <AtomValue> keyValues = new List <AtomValue>();
AtomValue key = new AtomValue()
{
Type = AttributeTypes.Char, CharLimit = 8, StringValue = "114514"
};
keyValues.Add(key);
DBRecord keyRecord = new DBRecord(keyValues);
// make raw bytes
List <byte> rawNode = new List <byte>();
rawNode.AddRange(new byte[30]);
// build cell
LeafTableCell leafTableCell = new LeafTableCell(keyRecord, record);
byte[] raw = leafTableCell.Pack();
rawNode.AddRange(raw);
// clone
LeafTableCell leafTableCellClone = new LeafTableCell(rawNode.ToArray(), 30);
// assert
AssertDBRecords(leafTableCell.DBRecord, leafTableCellClone.DBRecord);
AssertCell(leafTableCell, leafTableCellClone);
}
public static AtomValue operator +(AtomValue leftValue, AtomValue rightValue)
{
ThrowErrorIfNotSameType(leftValue, rightValue);
AtomValue result = new AtomValue();
result.Type = leftValue.Type;
switch (leftValue.Type)
{
case AttributeTypes.Char:
result.StringValue = leftValue.StringValue + rightValue.StringValue;
break;
case AttributeTypes.Float:
result.FloatValue = leftValue.FloatValue + rightValue.FloatValue;
break;
case AttributeTypes.Int:
result.IntegerValue = leftValue.IntegerValue + rightValue.IntegerValue;
break;
case AttributeTypes.Null:
throw new System.NullReferenceException();
}
return(result);
}
static DBRecord GetTestBRecord(int key = 222)
{
// init record
List <AtomValue> values = new List <AtomValue>();
AtomValue value1 = new AtomValue()
{
Type = AttributeTypes.Int, IntegerValue = key
};
AtomValue value2 = new AtomValue()
{
Type = AttributeTypes.Null
};
AtomValue value3 = new AtomValue()
{
Type = AttributeTypes.Char, CharLimit = 5, StringValue = "222"
};
values.Add(value1);
values.Add(value2);
values.Add(value3);
DBRecord record = new DBRecord(values);
DBRecord cloneRecord = new DBRecord(record.Pack(), 0);
AssertDBRecords(record, cloneRecord);
return(record);
}
static void AssertAtomValue(AtomValue v1, AtomValue v2)
{
Assert.Equal(v1.Type, v2.Type);
Assert.Equal(v1.CharLimit, v2.CharLimit);
Assert.Equal(v1.FloatValue, v2.FloatValue);
Assert.Equal(v1.IntegerValue, v2.IntegerValue);
Assert.Equal(v1.StringValue, v2.StringValue);
}
private static void ThrowErrorIfNotSameType(AtomValue leftValue, AtomValue rightValue)
{
// make sure the types of children are the same
if (leftValue?.Type != rightValue?.Type)
{
throw new System.Exception("Operands type not matched!");
}
}
static void AssertAtomValue(AtomValue v1, AtomValue v2)
{
Debug.Assert(v1.Type == v2.Type);
Debug.Assert(v1.CharLimit == v2.CharLimit);
Debug.Assert(v1.FloatValue == v2.FloatValue);
Debug.Assert(v1.IntegerValue == v2.IntegerValue);
Debug.Assert(v1.StringValue == v2.StringValue);
}
public override bool Equals(AtomValue other)
{
IntValue o = (IntValue)other;
if (o != null)
{
return(this.value == o.value);
}
return(false);
}
private static void TestCalculateSingleValue()
{
Expression andsExpression = GetAndsExpression();
string attributeName = "b";
AtomValue attributeValue = new AtomValue();
attributeValue.Type = AttributeTypes.Char;
attributeValue.CharLimit = 10;
attributeValue.StringValue = "aaa";
Assert.True(andsExpression.CheckKey(attributeName, attributeValue));
}
// return new root page number
public int InsertRecord(List <AtomValue> values, AtomValue key, int rootPage)
{
BTreeNode node = BTreeNodeHelper.GetBTreeNode(_pager, rootPage);
DBRecord wrappedKey = new DBRecord(new List <AtomValue>()
{
key
});
DBRecord wrappedValues = new DBRecord(values);
BTreeNode newRoot = _bTree.InsertCell(node, wrappedKey, wrappedValues);
return(newRoot.RawPage.PageNumber);
}
public static AtomValue operator <(AtomValue leftValue, AtomValue rightValue)
{
AtomValue result = new AtomValue();
result.Type = AttributeTypes.Int;
switch (leftValue.Type)
{
case AttributeTypes.Char:
ThrowErrorIfNotSameType(leftValue, rightValue);
result.IntegerValue = string.Compare(leftValue.StringValue, rightValue.StringValue) < 0 ? 1 : 0;
break;
case AttributeTypes.Float:
switch (rightValue.Type)
{
case AttributeTypes.Int:
result.IntegerValue = leftValue.FloatValue < rightValue.IntegerValue ? 1 : 0;
break;
case AttributeTypes.Float:
result.IntegerValue = leftValue.FloatValue < rightValue.FloatValue ? 1 : 0;
break;
default:
ThrowErrorIfNotSameType(leftValue, rightValue);
break;
}
break;
case AttributeTypes.Int:
switch (rightValue.Type)
{
case AttributeTypes.Int:
result.IntegerValue = leftValue.IntegerValue < rightValue.IntegerValue ? 1 : 0;
break;
case AttributeTypes.Float:
result.IntegerValue = leftValue.IntegerValue < rightValue.FloatValue ? 1 : 0;
break;
default:
ThrowErrorIfNotSameType(leftValue, rightValue);
break;
}
result.IntegerValue = leftValue.IntegerValue < rightValue.IntegerValue ? 1 : 0;
break;
case AttributeTypes.Null:
throw new System.NullReferenceException();
}
return(result);
}
private static DBRecord GetTestKey_expression(int value_1)
{
List <AtomValue> values = new List <AtomValue>();
AtomValue value1 = new AtomValue()
{
Type = AttributeTypes.Int, IntegerValue = value_1
};
values.Add(value1);
DBRecord record = new DBRecord(values);
return(record);
}
// return null if not found
public List <AtomValue> SelectRecord(AtomValue key, int rootPage)
{
List <AtomValue> wrapper = new List <AtomValue> {
key
};
DBRecord keyDBRecord = new DBRecord(wrapper);
BTreeNode node = BTreeNodeHelper.GetBTreeNode(_pager, rootPage);
BTreeCell cell = _bTree.FindCell(keyDBRecord, node);
List <AtomValue> result = null;
result = ((LeafTableCell)cell)?.DBRecord.GetValues();
return(result);
}
private static void TestAtomValueOperators()
{
AtomValue left = new AtomValue();
AtomValue right = new AtomValue();
left.StringValue = "abedeb";
left.IntegerValue = 114;
left.FloatValue = 14.14;
right.StringValue = "abeceb";
right.IntegerValue = 514;
right.FloatValue = 14.14;
left.Type = AttributeTypes.Char;
right.Type = AttributeTypes.Char;
Debug.Assert((left < right).BooleanValue == false);
Debug.Assert((left > right).BooleanValue == true);
Debug.Assert((left == right).BooleanValue == false);
Debug.Assert((left != right).BooleanValue == true);
Debug.Assert((left <= right).BooleanValue == false);
Debug.Assert((left >= right).BooleanValue == true);
Debug.Assert((left + right).StringValue == "abedebabeceb");
left.Type = AttributeTypes.Int;
right.Type = AttributeTypes.Int;
Debug.Assert((left < right).BooleanValue == true);
Debug.Assert((left > right).BooleanValue == false);
Debug.Assert((left == right).BooleanValue == false);
Debug.Assert((left != right).BooleanValue == true);
Debug.Assert((left <= right).BooleanValue == true);
Debug.Assert((left >= right).BooleanValue == false);
Debug.Assert((left + right).IntegerValue == 628);
Debug.Assert((left - right).IntegerValue == -400);
Debug.Assert((left * right).IntegerValue == 114 * 514);
Debug.Assert((left / right).IntegerValue == 114 / 514);
left.Type = AttributeTypes.Float;
right.Type = AttributeTypes.Float;
Debug.Assert((left < right).BooleanValue == false);
Debug.Assert((left > right).BooleanValue == false);
Debug.Assert((left == right).BooleanValue == true);
Debug.Assert((left != right).BooleanValue == false);
Debug.Assert((left <= right).BooleanValue == true);
Debug.Assert((left >= right).BooleanValue == true);
Debug.Assert((left + right).FloatValue == 28.28);
Debug.Assert((left - right).FloatValue == 0.0);
Debug.Assert((left * right).FloatValue == 14.14 * 14.14);
Debug.Assert((left / right).FloatValue == 1);
}
private static void TestAtomValueOperators()
{
AtomValue left = new AtomValue();
AtomValue right = new AtomValue();
left.StringValue = "abedeb";
left.IntegerValue = 114;
left.FloatValue = 14.14;
right.StringValue = "abeceb";
right.IntegerValue = 514;
right.FloatValue = 14.14;
left.Type = AttributeTypes.Char;
right.Type = AttributeTypes.Char;
Assert.False((left < right).BooleanValue);
Assert.True((left > right).BooleanValue);
Assert.False((left == right).BooleanValue);
Assert.True((left != right).BooleanValue);
Assert.False((left <= right).BooleanValue);
Assert.True((left >= right).BooleanValue);
Assert.Equal("abedebabeceb", (left + right).StringValue);
left.Type = AttributeTypes.Int;
right.Type = AttributeTypes.Int;
Assert.True((left < right).BooleanValue);
Assert.False((left > right).BooleanValue);
Assert.False((left == right).BooleanValue);
Assert.True((left != right).BooleanValue);
Assert.True((left <= right).BooleanValue);
Assert.False((left >= right).BooleanValue);
Assert.Equal(628, (left + right).IntegerValue);
Assert.Equal(-400, (left - right).IntegerValue);
Assert.Equal(114 * 514, (left * right).IntegerValue);
Assert.Equal(114 / 514, (left / right).IntegerValue);
left.Type = AttributeTypes.Float;
right.Type = AttributeTypes.Float;
Assert.False((left < right).BooleanValue);
Assert.False((left > right).BooleanValue);
Assert.True((left == right).BooleanValue);
Assert.False((left != right).BooleanValue);
Assert.True((left <= right).BooleanValue);
Assert.True((left >= right).BooleanValue);
Assert.Equal(28.28, (left + right).FloatValue);
Assert.Equal(0.0, (left - right).FloatValue);
Assert.Equal(14.14 * 14.14, (left * right).FloatValue);
Assert.Equal(1, (left / right).FloatValue);
}
private static void TestInsertRandomRecord(int maxCell)
{
string dbPath = "./testdbfile.minidb";
File.Delete(dbPath);
Pager pager = new Pager(dbPath);
FreeList freeList = new FreeList(pager);
BTreeController controller = new BTreeController(pager, freeList);
RecordContext recordManager = new RecordContext(pager, controller);
// create new table
CreateStatement createStatement = GetCreateStatement();
int newRoot = recordManager.CreateTable();
// insert
BTreeNode node;
InsertStatement insertStatement;
int key;
int newRootAfterInsert = newRoot;
int i;
for (i = 0; i < maxCell; i++)
{
(insertStatement, key) = GetInsertStatement(1);
AtomValue atomValue = GetAtomValue(key);
newRootAfterInsert = recordManager.InsertRecord(insertStatement.Values, atomValue, newRootAfterInsert);
Console.WriteLine(key);
Debug.Assert(newRoot == newRootAfterInsert);
}
node = BTreeNodeHelper.GetBTreeNode(pager, newRootAfterInsert);
BTreeNodeHelper.VisualizeIntegerTree(pager, node);
Console.WriteLine();
for (i = 0; i < maxCell; i++)
{
(insertStatement, key) = GetInsertStatement(1);
AtomValue atomValue = GetAtomValue(key);
newRootAfterInsert = recordManager.InsertRecord(insertStatement.Values, atomValue, newRootAfterInsert);
Console.WriteLine(key);
}
node = BTreeNodeHelper.GetBTreeNode(pager, newRootAfterInsert);
BTreeNodeHelper.VisualizeIntegerTree(pager, node);
pager.Close();
}
static void TestDBRecord()
{
// init record
List <AtomValue> values = new List <AtomValue>();
AtomValue value1 = new AtomValue()
{
Type = AttributeTypes.Int, IntegerValue = 222
};
AtomValue value2 = new AtomValue()
{
Type = AttributeTypes.Null
};
AtomValue value3 = new AtomValue()
{
Type = AttributeTypes.Char, CharLimit = 5, StringValue = "222"
};
values.Add(value1);
values.Add(value2);
values.Add(value3);
DBRecord record = new DBRecord(values);
// make raw bytes
List <byte> rawNode = new List <byte>();
rawNode.AddRange(new byte[30]);
// clone
List <AtomValue> valuesOut1 = record.GetValues();
// clone
byte[] raw = record.Pack();
rawNode.AddRange(raw);
record.Unpack(rawNode.ToArray(), 30);
List <AtomValue> valuesOut2 = record.GetValues();
int i;
for (i = 0; i < valuesOut2.Count; i++)
{
AssertAtomValue(values[i], valuesOut2[i]);
AssertAtomValue(valuesOut1[i], valuesOut2[i]);
}
}
private void HandleStatement(InsertStatement statement)
{
_catalogManager.CheckValidation(statement);
// get table schema
SchemaRecord schema = _catalogManager.GetTableSchemaRecord(statement.TableName);
// adjust inlined type in insert statement
if (schema.SQL.AttributeDeclarations.Count != statement.Values.Count)
{
throw new Exception("number of columns between \"create table\" and \"insert statement\' do not match");
}
int i;
for (i = 0; i < statement.Values.Count; i++)
{
statement.Values[i].CharLimit = schema.SQL.AttributeDeclarations[i].CharLimit;
}
// find out primary key from insert values
AtomValue primaryKey =
statement.Values[schema.SQL.AttributeDeclarations.FindIndex(x =>
x.AttributeName == schema.SQL.PrimaryKey)];
// insert into index trees
List <SchemaRecord> indexSchemas = _catalogManager.GetIndicesSchemaRecord(statement.TableName);
foreach (SchemaRecord indexSchema in indexSchemas)
{
// find indexed value from insert values
AtomValue indexedValue =
statement.Values[schema.SQL.AttributeDeclarations.FindIndex(x =>
x.AttributeName == indexSchema.SQL.AttributeName)];
// wrap up indexed value and primary key
List <AtomValue> indexPrimaryKeyPair = new List <AtomValue>()
{
indexedValue, primaryKey
};
// insert into index trees
int newIndexRoot = _recordManager.InsertRecord(indexPrimaryKeyPair, indexedValue, indexSchema.RootPage);
_catalogManager.TryUpdateSchemaRecord(indexSchema.Name, newIndexRoot);
}
// insert into table tree
int newRoot = _recordManager.InsertRecord(statement.Values, primaryKey, schema.RootPage);
_catalogManager.TryUpdateSchemaRecord(statement.TableName, newRoot);
}
public static AtomValue operator !(AtomValue leftValue)
{
AtomValue result = new AtomValue();
result.Type = AttributeTypes.Int;
switch (leftValue.Type)
{
case AttributeTypes.Char:
throw new System.InvalidOperationException("String could not Not");
case AttributeTypes.Float:
case AttributeTypes.Int:
result.IntegerValue = leftValue.BooleanValue ? 0 : 1;
break;
case AttributeTypes.Null:
throw new System.NullReferenceException();
}
return(result);
}
// get stored values in models (objects)
public List <AtomValue> GetValues()
{
List <AtomValue> values = new List <AtomValue>();
int i;
for (i = 0; i < this.HeaderList.Count; i++)
{
AtomValue value = new AtomValue();
uint headerValue = this.HeaderList[i];
if (headerValue == (int)HeaderValue.INTEGER)
{
value.Type = AttributeTypes.Int;
value.IntegerValue = BitConverter.ToInt32(this.FieldData, this.FieldOffsets[i]);
}
else if (headerValue == (int)HeaderValue.FloatingPoint)
{
value.Type = AttributeTypes.Float;
value.FloatValue = BitConverter.ToDouble(this.FieldData, this.FieldOffsets[i]);
}
else if (headerValue == (int)HeaderValue.NULL)
{
value.Type = AttributeTypes.Null;
}
else if ((headerValue - (int)HeaderValue.TEXT) % 2 == 0)
{
value.Type = AttributeTypes.Char;
int stringLength = (int)(headerValue - (uint)HeaderValue.TEXT) / 2;
value.CharLimit = stringLength;
value.StringValue = Encoding.UTF8.GetString(this.FieldData, this.FieldOffsets[i], stringLength).TrimEnd('\0');
}
else
{
throw new Exception($"Header value {headerValue} does not exists");
}
values.Add(value);
}
return(values);
}
private static DBRecord GetTestRecord_expression(int value_1, string value_2, float value_3)
{
List <AtomValue> values = new List <AtomValue>();
AtomValue value1 = new AtomValue()
{
Type = AttributeTypes.Int, IntegerValue = value_1
};
AtomValue value2 = new AtomValue()
{
Type = AttributeTypes.Char, CharLimit = 5, StringValue = value_2
};
AtomValue value3 = new AtomValue()
{
Type = AttributeTypes.Float, FloatValue = value_3
};
values.Add(value1);
values.Add(value2);
values.Add(value3);
DBRecord record = new DBRecord(values);
return(record);
}
public static AtomValue operator -(AtomValue leftValue)
{
AtomValue result = new AtomValue();
result.Type = leftValue.Type;
switch (leftValue.Type)
{
case AttributeTypes.Char:
throw new System.InvalidOperationException("String could not Subtract");
case AttributeTypes.Float:
result.FloatValue = -leftValue.FloatValue;
break;
case AttributeTypes.Int:
result.IntegerValue = -leftValue.IntegerValue;
break;
case AttributeTypes.Null:
throw new System.NullReferenceException();
}
return(result);
}
public override object VisitAtom([NotNull] MiniSQLParser.AtomContext context)
{
Expression obj = new Expression();
// TODO: review
if (context.scientific() != null)
{
AtomValue atomValue = (AtomValue)Visit(context.scientific());
obj.Operator = Operator.AtomConcreteValue;
obj.ConcreteValue = atomValue;
}
else if (context.variable() != null)
{
string variableName = context.variable().GetText();
obj.Operator = Operator.AtomVariable;
obj.AttributeName = variableName;
}
else
{
throw new System.NotImplementedException();
}
return(obj);
}
static DBRecord GetTestBRecord(double height, int pid, string name, string identity, int age)
{
// init record
List <AtomValue> values = new List <AtomValue>();
AtomValue value1 = new AtomValue()
{
Type = AttributeTypes.Float, FloatValue = height
};
AtomValue value2 = new AtomValue()
{
Type = AttributeTypes.Int, IntegerValue = pid
};
AtomValue value3 = new AtomValue()
{
Type = AttributeTypes.Char, CharLimit = 32, StringValue = name
};
AtomValue value4 = new AtomValue()
{
Type = AttributeTypes.Char, CharLimit = 128, StringValue = identity
};
AtomValue value5 = new AtomValue()
{
Type = AttributeTypes.Int, IntegerValue = age
};
values.Add(value1);
values.Add(value2);
values.Add(value3);
values.Add(value4);
values.Add(value5);
DBRecord record = new DBRecord(values);
DBRecord cloneRecord = new DBRecord(record.Pack(), 0);
BTreeNodeHelper.AssertDBRecords(record, cloneRecord);
return(record);
}
public AttributeValue(string attributeName, AtomValue value)
{
this.Value = value;
this.AttributeName = attributeName;
}
// `keyName` := primary key in table tree; indexed value in index tree
public List <BTreeCell> FindCells(BTreeNode root, Expression condition, string keyName, List <AttributeDeclaration> attributeDeclarations)
{
if (condition == null)
{
return(LinearSearch(root, condition, attributeDeclarations));
}
else if (condition.SimpleMinterms.ContainsKey(keyName))
{
List <BTreeCell> result = new List <BTreeCell>();
List <AtomValue> values = new List <AtomValue>();
BTreeNode startNode;
BTreeCell cell;
int startIndexOfCellInStartNode;
AtomValue bound = condition.SimpleMinterms[keyName].RightOperand.ConcreteValue;
values.Add(bound);
DBRecord keyFind = new DBRecord(values);
switch (condition.SimpleMinterms[keyName].Operator)
{
case Operator.NotEqual:
return(LinearSearch(root, condition, attributeDeclarations));
case Operator.Equal:
LeafTableCell tmpCell = (LeafTableCell)FindCell(keyFind, root);
if (tmpCell == null)
{
break;
}
else if (condition.Calculate(attributeDeclarations, tmpCell.DBRecord.GetValues()).BooleanValue == true)
{
result.Add(tmpCell);
}
break;
case Operator.LessThan:
startNode = FindMin(root);
return(FindCells(startNode, condition, attributeDeclarations, bound, false));
case Operator.LessThanOrEqualTo:
startNode = FindMin(root);
return(FindCells(startNode, condition, attributeDeclarations, bound, true));
case Operator.MoreThan:
startNode = FindNode(keyFind, root, true);
// nothing is equal or more than the value of `keyFind` in the tree
if (startNode == null)
{
return(result);
}
(cell, _, startIndexOfCellInStartNode) = startNode.FindBTreeCell(keyFind);
// 2 possible situations for `cell == null`:
// 1: The `keyFind` is bigger than all the key in `startNode`
// 2: The `keyFind` is just between the bigest one in `startNode` and the smallest one in next node
if (cell == null)
{
if (startNode.RightPage == 0)
{
return(result);
}
else
{
startIndexOfCellInStartNode = 0;
MemoryPage nextpage = _pager.ReadPage((int)startNode.RightPage);
startNode = new BTreeNode(nextpage);
}
}
return(FindCells(startNode, startIndexOfCellInStartNode, condition, attributeDeclarations, false));
case Operator.MoreThanOrEqualTo:
startNode = FindNode(keyFind, root, true);
// nothing is equal or more than the value of `keyFind` in the tree
if (startNode == null)
{
return(result);
}
(cell, _, startIndexOfCellInStartNode) = startNode.FindBTreeCell(keyFind);
if (cell == null)
{
if (startNode.RightPage == 0)
{
return(result);
}
else
{
startIndexOfCellInStartNode = 0;
MemoryPage nextpage = _pager.ReadPage((int)startNode.RightPage);
startNode = new BTreeNode(nextpage);
}
}
return(FindCells(startNode, startIndexOfCellInStartNode, condition, attributeDeclarations, true));
default:
throw new Exception("The Operand is not supported!");
}
//This step may not need?
return(result);
}
else
{
return(LinearSearch(root, condition, attributeDeclarations));
}
}
