public static SqlObject Concat(SqlObject[] args)
{
StringBuilder sb = new StringBuilder();
for (int i = 0; i < args.Length; ++i) {
sb.Append(args[i].Value.ToString());
}
return new SqlObject(sb.ToString());
}
public FunctionResultTable(SqlObject[] values)
{
this.values = values;
columns = new ColumnCollection(this);
for (int i = 0; i < values.Length; i++) {
columns.Add(new TableColumn(this, "column" + i, values[i].Type));
}
columns.MakeReadOnly();
}
public static SqlObject And(SqlObject[] args)
{
if (IsBooleanType(args[0]) && IsBooleanType(args[1])) {
bool? b1 = args[0].Value.ToBoolean();
bool? b2 = args[1].Value.ToBoolean();
return b1 == null || b2 == null ? SqlObject.MakeNull(SqlType.Boolean) : AsBooleanValue(b1.Value && b2.Value);
}
// Return null boolean,
return SqlObject.MakeNull(SqlType.Boolean);
}
public ITable Evaluate(QueryProcessor processor, Expression[] args)
{
// 'CAST' is a special case,
if (function.Name.Equals("@cast")) {
// Get the value to cast, and the type to cast it to,
SqlObject val = QueryProcessor.Result(processor.Execute(args[0]))[0];
SqlObject castType = QueryProcessor.Result(processor.Execute(args[1]))[0];
string castTypeString = castType.Value.ToString();
SqlType type = SqlType.Parse(castTypeString);
// Do the cast,
SqlObject result = val.CastTo(type);
// And return the result,
return QueryProcessor.ResultTable(result);
}
if (function.IsAggregate)
throw new InvalidOperationException("The function is aggregate.");
try {
// Execute it
if (invokeType == 6) {
object[] funArgs = { function.Name, processor, args };
return (ITable)method.Invoke(null, funArgs);
}
// The QueryProcessor, Expression[] construct
if (invokeType == 1) {
object[] funArgs = { processor, args };
return (ITable)method.Invoke(null, funArgs);
}
// The SqlObject construct
if (invokeType == 2) {
int sz = args.Length;
// Resolve the arguments into TypedValues
SqlObject[] obs = new SqlObject[sz];
for (int i = 0; i < sz; ++i) {
obs[i] = QueryProcessor.Result(processor.Execute(args[i]))[0];
}
// Set up the arguments and invoke the method
object[] funArgs = { obs };
SqlObject result = (SqlObject)method.Invoke(null, funArgs);
// Wrap on a FunctionTable and return
return QueryProcessor.ResultTable(result);
}
throw new ApplicationException("Unknown invoke type");
} catch (MethodAccessException e) {
throw new ApplicationException(e.Message, e);
} catch (TargetInvocationException e) {
throw new ApplicationException(e.InnerException.Message, e.InnerException);
}
}
public static SqlObject[] Result(ITable table)
{
if (!(table is FunctionResultTable))
throw new ArgumentException("The table must be the result of a function execution.", "table");
int cols = table.Columns.Count;
SqlObject[] result = new SqlObject[cols];
for (int i = 0; i < cols; ++i) {
result[i] = table.GetValue(i, new RowId(0));
}
return result;
}
public override SqlObject[] GetValue(RowId rowid)
{
SqlObject[] values;
if (columns.Length == 1) {
// Single value
values = new SqlObject[] { table.GetValue(columns[0], rowid) };
} else {
// Composite value so create a composite object as the key.
int sz = columns.Length;
values = new SqlObject[sz];
for (int i = 0; i < sz; ++i) {
values[i] = table.GetValue(columns[i], rowid);
}
}
return values;
}
private ITable FetchStatic(SqlObject[] ob)
{
return ResultTable(ob);
}
public SqlObject Concat(SqlObject[] others)
{
SqlObject[] args = new SqlObject[others.Length + 1];
args[0] = this;
Array.Copy(others, 0, args, 1, others.Length);
return SystemFunctions.Concat(args);
}
public FetchStaticExpression(SqlObject[] values)
: base(ExpressionType.FetchStatic)
{
SetArgument("static", values);
}
public override SqlObject[] GetValue(RowId rowid)
{
// Set the top of stack table row_id
processor.UpdateTableRow(rowid);
if (columnExps.Length == 1)
// If a single part,
return Result(processor.DoExecute(columnExps[0]));
// TODO: We can clean this up a great deal! We should make
// 'DoExecute' produce a table with multiple columns when a
// composite function is given.
int compParts = columnExps.Length;
// If composite,
SqlObject[] arr = new SqlObject[compParts];
for (int i = 0; i < compParts; ++i)
arr[i] = Result(processor.DoExecute(columnExps[i]))[0];
return arr;
}
internal void RemoveIndex(long index_id)
{
IIndexSetDataSource index = GetIndex(SystemTableNames.Index, "id_idx");
SqlObject val = new SqlObject(index_id);
// Query the index
IRowCursor cursor = index.Select(SelectableRange.Is(val));
// We assert this (we have already checked the index exists and this
// iterator is valid).
if (cursor.Count != 1)
throw new ApplicationException();
// The index table,
IMutableTable indexTable = GetTable(SystemTableNames.Index);
if (!cursor.MoveNext())
throw new ApplicationException();
RowId rowId = cursor.Current;
indexTable.Delete(rowId);
// Update indexes on index table
IIndexSetDataSource[] idxs = GetTableIndexes(SystemTableNames.Index);
foreach (IIndexSetDataSource idx in idxs) {
idx.Remove(rowId);
}
}
public void PerformSample(SystemTransaction transaction)
{
// Translate into tables and column names
ITable tableSource = transaction.GetTable(var.TableName);
// DOn't bother unless the table has 64 or more values
if (tableSource.RowCount < (DivisionPointCount * 2)) {
sampleCount = 0;
totalSize = 0;
return;
}
// The number of elements in total
totalSize = tableSource.RowCount;
// The actual number of samples,
sampleCount = (int)System.Math.Min(tableSource.RowCount / 2, MaxSampleCount);
String col_name = var.Name;
int colId = tableSource.Columns.IndexOf(var.Name);
// Work out the size
long size = tableSource.RowCount;
// The sample point difference
double sampleDiff = (double)size / sampleCount;
// The index of the tables used in sampling
IIndex<RowId> sampleIndex = transaction.CreateTemporaryIndex<RowId>(sampleCount);
// Create a RowIndexCollation for this
SqlType type;
type = tableSource.Columns[colId].Type;
IndexCollation collation = new IndexCollation(type, col_name);
// Create the collation object,
CollationIndexResolver resolver = new CollationIndexResolver(tableSource, collation);
// The row cursor
IRowCursor rowCursor = tableSource.GetRowCursor();
RowId[] sampleRowset = new RowId[sampleCount];
// First read in the row_ids we are sampling,
{
// The current sample point
double p = 0;
// The number read,
int samplesRead = 0;
// Make a sorted sample index of the dataset
while (samplesRead < sampleCount) {
long pos = ((long)p) - 1;
pos = System.Math.Min(pos, tableSource.RowCount - 2);
rowCursor.MoveTo(pos);
if (!rowCursor.MoveNext())
throw new SystemException();
RowId rowId = rowCursor.Current;
sampleRowset[samplesRead] = rowId;
// Should this be Math.random(sample_diff * 2) for random distribution
// of the samples?
p += sampleDiff;
++samplesRead;
}
}
// Now read the samples,
{
int samplePoint = 0;
foreach (RowId rowId in sampleRowset) {
// Hint ahead the samples we are picking,
if ((samplePoint % 24) == 0) {
for (int i = samplePoint;
i < samplePoint + 24 && i < sampleRowset.Length;
++i) {
tableSource.PrefetchValue(-1, sampleRowset[i]);
}
}
// Pick the sample and sort it,
SqlObject[] sample = new SqlObject[] { tableSource.GetValue(colId, rowId) };
sampleIndex.Insert(sample, rowId, resolver);
++samplePoint;
}
}
// Now extract the interesting sample points from the sorted set
IIndexCursor<RowId> samplesCursor = sampleIndex.GetCursor();
long sampleIndexSize = sampleIndex.Count;
double divisionDiff = sampleIndexSize / (DivisionPointCount - 1);
for (int i = 0; i < DivisionPointCount; ++i) {
long samplePoint = (long)(divisionDiff * i);
if (samplePoint >= sampleIndexSize) {
samplePoint = sampleIndexSize - 1;
}
samplesCursor.Position = samplePoint - 1;
if (!samplesCursor.MoveNext())
throw new SystemException();
RowId rowId = samplesCursor.Current;
divisionPoints[i] = tableSource.GetValue(colId, rowId);
}
// Clear the temporary index
sampleIndex.Clear();
}
private static void AutoCastSystemOperator(FunctionExpression exp, IList<Expression> parameters, List<SqlType> paramTypes)
{
SqlType t1 = paramTypes[0];
SqlType t2 = paramTypes[1];
// If both the types are identical, we good to go,
if (!t1.IsComparableTo(t2))
throw InvalidTypes(t1, t2, exp);
// Types are compatible,
// If they are numeric,
if (t1.IsNumeric) {
// The encoding is different, so now we do a static check
if (!t1.Equals(t2)) {
// TODO: We should do a check on each parameter by walking the tree
// to determine if it's static or not.
Expression exp1 = parameters[0];
Expression exp2 = parameters[1];
int staticop;
int varop;
// If the left or right is FETCHSTATIC,
if (exp1 is FetchStaticExpression) {
staticop = 0;
varop = 1;
} else if (exp2 is FetchStaticExpression) {
staticop = 1;
varop = 0;
} else {
// Neither static, so report error,
throw InvalidTypes(t1, t2, exp);
}
// The type of the variable and static sides,
SqlType varType = paramTypes[varop];
SqlObject castType = new SqlObject(varType.ToString());
FetchStaticExpression castExp = new FetchStaticExpression(castType);
castExp.ReturnType = SqlType.GetSqlType(typeof(string));
// Cast the static type to the variable type,
FunctionExpression newStaticExp = new FunctionExpression("@cast", new Expression[] {parameters[staticop], castExp});
newStaticExp.ReturnType = varType;
exp.Parameters[staticop] = newStaticExp;
}
}
}
public SqlObject Or(SqlObject other)
{
return SystemFunctions.Or(new SqlObject[]{this, other});
}
public override void SetValue(int columnOffset, SqlObject value)
{
if (query == null)
throw new InvalidOperationException("The backed query is null.");
if (columnOffset >= query.Parameters.Count) {
for (int i = query.Parameters.Count - 1; i < columnOffset; i++) {
query.Parameters.Add(SqlObject.Null);
}
}
query.Parameters[columnOffset].Value = value;
}
public SqlObject LesserThan(SqlObject other)
{
return SystemFunctions.LesserThan(new SqlObject[] {this, other});
}
public SqlObject IsNot(SqlObject other)
{
return SystemFunctions.IsNot(new SqlObject[] {this, other});
}
public SqlObject GreaterOrEqualThan(SqlObject other)
{
return SystemFunctions.GreaterOrEqualThan(new SqlObject[] { this, other });
}
public static FunctionResultTable ResultTable(SqlObject[] val)
{
return new FunctionResultTable(val);
}
public virtual void SetValue(int columnOffset, SqlObject value)
{
CheckMutable();
if (columnOffset < 0 || columnOffset >= table.Columns.Count)
throw new ArgumentOutOfRangeException("columnOffset");
TableColumn column = table.Columns[columnOffset];
if (value == null) {
value = SqlObject.MakeNull(column.Type);
} else if (!column.Type.Equals(value.Type)) {
value = value.CastTo(column.Type);
}
cachedValues[columnOffset] = value;
dirty = true;
}
public override int Compare(RowId rowid, SqlObject[] value)
{
SqlObject[] val1 = GetValue(rowid);
SqlObject[] val2 = value;
// Compare until we reach the end of the array.
int min_compare = System.Math.Min(val1.Length, val2.Length);
for (int i = 0; i < min_compare; ++i) {
int c = SqlObject.Compare(val1[i], val2[i]);
if (c != 0) {
bool rev = ascending[i];
return rev ? c : -c;
}
}
// If the sizes are equal, compare equally,
if (val1.Length == val2.Length)
return 0;
// If val1.length is greater, return +1, else return -1 (val1.length is
// less)
if (val1.Length > val2.Length) {
return 1;
} else {
return -1;
}
}
private ITable FilterByIndex(ITable table, IIndexSetDataSource index, Expression order, string compareFunction, SqlObject[] values)
{
// Make a selectable range set
SelectableRange range = SelectableRange.Full;
range = range.Intersect(SelectableRange.GetOperatorFromFunction(compareFunction), values);
// And return the subset
return FilterByIndex(table, index, order, range);
}
public static FunctionResultTable ResultTable(SqlObject val)
{
return new FunctionResultTable(new SqlObject[] { val });
}
public FetchStaticExpression(SqlObject value)
: this(new SqlObject[] { value })
{
}
public override void SetValue(int columnOffset, SqlObject value)
{
if (columnOffset == 0) {
queryString = value;
} else {
if (columnOffset >= table.Columns.Count) {
int toAdd = columnOffset - table.Columns.Count - 1;
for (int i = 0; i < toAdd; i++)
table.Columns.Add("#PARAM" + (table.Columns.Count - 1), SqlType.Null, false);
table.Columns.Add("#PARAM" + (table.Columns.Count - 1), value.Type, false);
}
columnOffset = columnOffset - 1;
if (columnOffset >= values.Count) {
int toAdd = columnOffset - values.Count;
for (int i = 0; i < toAdd; i++)
values.Add(SqlObject.Null);
values.Add(SqlObject.Null);
}
values[columnOffset] = value;
}
}
public SqlObject Concat(SqlObject other)
{
return Concat(new SqlObject[] { other});
}
public void SetValue(string columnName, SqlObject value)
{
if (String.IsNullOrEmpty(columnName))
throw new ArgumentNullException("columnName");
SetValue(GetColumnOffset(columnName), value);
}
private static SqlObject CreateValue(ITable table, RowId rowid, IList<string> columns)
{
int sz = columns.Count;
if (sz == 0)
throw new ArgumentException();
// If there's just 1 column reference, we fetch the TObject and return
// it.
if (sz == 1) {
string columnName = columns[0];
int columnOffset = table.Columns.IndexOf(columnName);
return table.GetValue(columnOffset, rowid);
}
// Otherwise we make a composite object
// Make the composite type
SqlObject[] val = new SqlObject[sz];
for (int i = 0; i < sz; ++i) {
int columnOffset = table.Columns.IndexOf(columns[i]);
val[i] = table.GetValue(columnOffset, rowid);
}
// Create the composite type and return the object
return SqlObject.MakeComposite(val);
}
private ITable FilterByIndex(ITable table, IIndexSetDataSource index, Expression order, string compareFunction, SqlObject value)
{
return FilterByIndex(table, index, order, compareFunction, new SqlObject[] { value });
}
private static IRowCursor QueryAllMatches(SystemTransaction transaction, TableName tableName, SystemTable table,
IList<string> columns, SqlObject val)
{
// Try and find an index on these columns
SystemIndexSetDataSource indexSet = transaction.FindIndexOn(tableName, columns);
// If index found
if (indexSet != null)
// Query the index and find all matches
return indexSet.Select(SelectableRange.Is(val));
// Otherwise no index, so scan the table for matches
// Make an Expression for the operation;
// (column1, column2, ...columnn) = val
Expression compExp;
int sz = columns.Count;
if (sz > 1) {
FunctionExpression cfunExp = new FunctionExpression("composite_fetch");
for (int i = 0; i < sz; ++i) {
Expression varRef = new FetchVariableExpression(new Variable(tableName, columns[i]));
cfunExp.Parameters.Add(varRef);
}
compExp = cfunExp;
} else if (sz == 1) {
compExp = new FetchVariableExpression(new Variable(tableName, columns[0]));
} else {
throw new ApplicationException("Invalid columns list size");
}
// Equality test
FunctionExpression funExp = new FunctionExpression("@is_sql");
funExp.Parameters.Add(compExp);
funExp.Parameters.Add(new FetchStaticExpression(val));
// Create a query processor and perform the scan operation
QueryProcessor processor = new QueryProcessor(transaction);
ITable result = processor.FilterByScan(table, funExp);
// Return the row cursor
return result.GetRowCursor();
}