public SqlRexConvertlet get(SqlCall call) {
SqlRexConvertlet convertlet;
final SqlOperator op = call.getOperator();
// Is there a convertlet for this operator
// (e.g. SqlStdOperatorTable.plusOperator)?
convertlet = (SqlRexConvertlet) map.get(op);
if (convertlet != null) {
return convertlet;
}
// Is there a convertlet for this class of operator
// (e.g. SqlBinaryOperator)?
Class<? extends Object> clazz = op.getClass();
while (clazz != null) {
convertlet = (SqlRexConvertlet) map.get(clazz);
if (convertlet != null) {
return convertlet;
}
clazz = clazz.getSuperclass();
}
// Is there a convertlet for this class of expression
// (e.g. SqlCall)?
clazz = call.getClass();
while (clazz != null) {
convertlet = (SqlRexConvertlet) map.get(clazz);
if (convertlet != null) {
return convertlet;
}
clazz = clazz.getSuperclass();
}
return null;
}
/**
* Registers method if it: a. is public, and b. is named "convertXxx", and c. has a return type of
* "RexNode" or a subtype d. has a 2 parameters with types ConvertletContext and SqlNode (or a
* subtype) respectively.
*/
private void registerNodeTypeMethod(final Method method) {
if (!Modifier.isPublic(method.getModifiers())) {
return;
}
if (!method.getName().startsWith("convert")) {
return;
}
if (!RexNode.class.isAssignableFrom(method.getReturnType())) {
return;
}
final Class[] parameterTypes = method.getParameterTypes();
if (parameterTypes.length != 2) {
return;
}
if (parameterTypes[0] != SqlRexContext.class) {
return;
}
final Class parameterType = parameterTypes[1];
if (!SqlNode.class.isAssignableFrom(parameterType)) {
return;
}
map.put(
parameterType,
new SqlRexConvertlet() {
public RexNode convertCall(SqlRexContext cx, SqlCall call) {
try {
return (RexNode) method.invoke(ReflectiveConvertletTable.this, cx, call);
} catch (IllegalAccessException e) {
throw Util.newInternal(e, "while converting " + call);
} catch (InvocationTargetException e) {
throw Util.newInternal(e, "while converting " + call);
}
}
});
}
protected RexNode register(RexNode expr) {
final String key = expr.toString();
final RexNode previous = mapDigestToExpr.put(key, expr);
if (!allowDups && (previous != null)) {
throw new SubExprExistsException(expr);
}
return expr;
}
/** Converts a {@link Map} of integers to a {@link TargetMapping}. */
public static TargetMapping target(Map<Integer, Integer> map, int sourceCount, int targetCount) {
final PartialFunctionImpl mapping =
new PartialFunctionImpl(sourceCount, targetCount, MappingType.FUNCTION);
for (Map.Entry<Integer, Integer> entry : map.entrySet()) {
mapping.set(entry.getKey(), entry.getValue());
}
return mapping;
}
/**
* Registers that one operator is an alias for another.
*
* @param alias Operator which is alias
* @param target Operator to translate calls to
*/
protected void addAlias(final SqlOperator alias, final SqlOperator target) {
map.put(
alias,
new SqlRexConvertlet() {
public RexNode convertCall(SqlRexContext cx, SqlCall call) {
Util.permAssert(call.getOperator() == alias, "call to wrong operator");
final SqlCall newCall = target.createCall(SqlParserPos.ZERO, call.getOperandList());
return cx.convertExpression(newCall);
}
});
}
private List<Object> explainInputs(List<RelNode> inputs) {
final List<Object> list = jsonBuilder.list();
for (RelNode input : inputs) {
String id = relIdMap.get(input);
if (id == null) {
input.explain(this);
id = previousId;
}
list.add(id);
}
return list;
}
@SuppressWarnings("unchecked")
private static <K, V> HashMap<K, V> copy(Map<K, V> map) {
HashMap<K, V> copy = new HashMap<K, V>();
for (Iterator<Map.Entry<K, V>> i = map.entrySet().iterator(); i.hasNext(); ) {
Map.Entry<K, V> e = i.next();
if (e.getValue() instanceof Set) {
copy.put(e.getKey(), (V) copy((Set) e.getValue()));
} else {
copy.put(e.getKey(), e.getValue());
}
}
return copy;
}
protected void explain_(RelNode rel, List<Pair<String, Object>> values) {
final Map<String, Object> map = jsonBuilder.map();
map.put("id", null); // ensure that id is the first attribute
map.put("relOp", relJson.classToTypeName(rel.getClass()));
for (Pair<String, Object> value : values) {
if (value.right instanceof RelNode) {
continue;
}
put(map, value.left, value.right);
}
// omit 'inputs: ["3"]' if "3" is the preceding rel
final List<Object> list = explainInputs(rel.getInputs());
if (list.size() != 1 || !list.get(0).equals(previousId)) {
map.put("inputs", list);
}
final String id = Integer.toString(relIdMap.size());
relIdMap.put(rel, id);
map.put("id", id);
relList.add(map);
previousId = id;
}
protected RexNode lookup(RexNode expr) {
return mapDigestToExpr.get(expr.toString());
}
private void put(Map<String, Object> map, String name, Object value) {
map.put(name, relJson.toJson(value));
}
/** Returns a JSON string describing the relational expressions that were just explained. */
public String asString() {
final Map<String, Object> map = jsonBuilder.map();
map.put("rels", relList);
return jsonBuilder.toJsonString(map);
}
/**
* Registers a convertlet for a given operator instance
*
* @param op Operator instance, say {@link org.eigenbase.sql.fun.SqlStdOperatorTable#MINUS}
* @param convertlet Convertlet
*/
protected void registerOp(SqlOperator op, SqlRexConvertlet convertlet) {
map.put(op, convertlet);
}