io.trino.metadata.SignatureBinder Maven / Gradle / Ivy
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.trino.metadata;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.VerifyException;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import io.trino.spi.TrinoException;
import io.trino.spi.function.BoundSignature;
import io.trino.spi.function.FunctionId;
import io.trino.spi.function.LongVariableConstraint;
import io.trino.spi.function.Signature;
import io.trino.spi.function.TypeVariableConstraint;
import io.trino.spi.type.NamedTypeSignature;
import io.trino.spi.type.ParameterKind;
import io.trino.spi.type.RowType;
import io.trino.spi.type.Type;
import io.trino.spi.type.TypeManager;
import io.trino.spi.type.TypeSignature;
import io.trino.spi.type.TypeSignatureParameter;
import io.trino.sql.analyzer.TypeSignatureProvider;
import io.trino.type.FunctionType;
import io.trino.type.JsonType;
import io.trino.type.TypeCoercion;
import io.trino.type.UnknownType;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.base.Verify.verify;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static com.google.common.collect.ImmutableSortedMap.toImmutableSortedMap;
import static io.trino.metadata.SignatureBinder.RelationshipType.EXACT;
import static io.trino.metadata.SignatureBinder.RelationshipType.EXPLICIT_COERCION_FROM;
import static io.trino.metadata.SignatureBinder.RelationshipType.EXPLICIT_COERCION_TO;
import static io.trino.metadata.SignatureBinder.RelationshipType.IMPLICIT_COERCION;
import static io.trino.sql.analyzer.TypeSignatureProvider.fromTypes;
import static io.trino.type.TypeCalculation.calculateLiteralValue;
import static io.trino.type.TypeCoercion.isCovariantTypeBase;
import static io.trino.type.UnknownType.UNKNOWN;
import static java.lang.String.CASE_INSENSITIVE_ORDER;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
import static java.util.function.Function.identity;
import static java.util.stream.Collectors.toList;
/**
* Determines whether, and how, a callsite matches a generic function signature.
* Which is equivalent to finding assignments for the variables in the generic signature,
* such that all of the function's declared parameters are super types of the corresponding
* arguments, and also satisfy the declared constraints (such as a given type parameter must
* bind to an orderable type)
*
* This implementation has made assumptions. When any of the assumptions is not satisfied, it will fail loudly.
*
* - A type cannot have both type parameter and literal parameter.
*
- A literal parameter cannot be used across types. see {@link #checkNoLiteralVariableUsageAcrossTypes(TypeSignature, Map)}.
*
*
* Here are some known implementation limitations:
*
* - Binding signature {@code (decimal(x,2))boolean} with arguments {@code decimal(1,0)} fails.
* It should produce {@code decimal(3,1)}.
*
*/
public class SignatureBinder
{
// 4 is chosen arbitrarily here. This limit is set to avoid having infinite loops in iterative solving.
private static final int SOLVE_ITERATION_LIMIT = 4;
private final Metadata metadata;
private final TypeManager typeManager;
private final TypeCoercion typeCoercion;
private final Signature declaredSignature;
private final boolean allowCoercion;
private final Map typeVariableConstraints;
// this could use the function resolver instead of Metadata, but Metadata caches coercion resolution
SignatureBinder(Metadata metadata, TypeManager typeManager, Signature declaredSignature, boolean allowCoercion)
{
checkNoLiteralVariableUsageAcrossTypes(declaredSignature);
this.metadata = requireNonNull(metadata, "metadata is null");
this.typeManager = requireNonNull(typeManager, "typeManager is null");
this.typeCoercion = new TypeCoercion(typeManager::getType);
this.declaredSignature = requireNonNull(declaredSignature, "declaredSignature is null");
this.allowCoercion = allowCoercion;
this.typeVariableConstraints = declaredSignature.getTypeVariableConstraints().stream()
.collect(toImmutableSortedMap(CASE_INSENSITIVE_ORDER, TypeVariableConstraint::getName, identity()));
}
public Optional bind(List actualArgumentTypes)
{
Optional boundVariables = bindVariables(actualArgumentTypes);
if (boundVariables.isEmpty()) {
return Optional.empty();
}
return Optional.of(applyBoundVariables(declaredSignature, boundVariables.get(), actualArgumentTypes.size()));
}
public Optional bind(List actualArgumentTypes, Type actualReturnType)
{
Optional boundVariables = bindVariables(actualArgumentTypes, actualReturnType.getTypeSignature());
if (boundVariables.isEmpty()) {
return Optional.empty();
}
return Optional.of(applyBoundVariables(declaredSignature, boundVariables.get(), actualArgumentTypes.size()));
}
public boolean canBind(List actualArgumentTypes)
{
return bindVariables(actualArgumentTypes).isPresent();
}
@VisibleForTesting
Optional bindVariables(List actualArgumentTypes)
{
ImmutableList.Builder constraintSolvers = ImmutableList.builder();
if (!appendConstraintSolversForArguments(constraintSolvers, actualArgumentTypes)) {
return Optional.empty();
}
return iterativeSolve(constraintSolvers.build());
}
public boolean canBind(List actualArgumentTypes, TypeSignature actualReturnType)
{
return bindVariables(actualArgumentTypes, actualReturnType).isPresent();
}
@VisibleForTesting
Optional bindVariables(List actualArgumentTypes, TypeSignature actualReturnType)
{
ImmutableList.Builder constraintSolvers = ImmutableList.builder();
if (!appendConstraintSolversForReturnValue(constraintSolvers, new TypeSignatureProvider(actualReturnType))) {
return Optional.empty();
}
if (!appendConstraintSolversForArguments(constraintSolvers, actualArgumentTypes)) {
return Optional.empty();
}
return iterativeSolve(constraintSolvers.build());
}
public static Signature applyBoundVariables(Signature signature, FunctionBinding functionBinding, int arity)
{
return applyBoundVariables(signature, new FunctionTypeVariables(functionBinding), arity);
}
private static Signature applyBoundVariables(Signature signature, TypeVariables typeVariables, int arity)
{
List argumentSignatures;
if (signature.isVariableArity()) {
argumentSignatures = expandVarargFormalTypeSignature(signature.getArgumentTypes(), arity);
}
else {
checkArgument(signature.getArgumentTypes().size() == arity);
argumentSignatures = signature.getArgumentTypes();
}
List boundArgumentSignatures = applyBoundVariables(argumentSignatures, typeVariables);
TypeSignature boundReturnTypeSignature = applyBoundVariables(signature.getReturnType(), typeVariables);
return Signature.builder()
.returnType(boundReturnTypeSignature)
.argumentTypes(boundArgumentSignatures)
.build();
}
public static List applyBoundVariables(List typeSignatures, FunctionBinding functionBinding)
{
return applyBoundVariables(typeSignatures, new FunctionTypeVariables(functionBinding));
}
private static List applyBoundVariables(List typeSignatures, TypeVariables typeVariables)
{
ImmutableList.Builder builder = ImmutableList.builder();
for (TypeSignature typeSignature : typeSignatures) {
builder.add(applyBoundVariables(typeSignature, typeVariables));
}
return builder.build();
}
public static TypeSignature applyBoundVariables(TypeSignature typeSignature, FunctionBinding functionBinding)
{
return applyBoundVariables(typeSignature, new FunctionTypeVariables(functionBinding));
}
static TypeSignature applyBoundVariables(TypeSignature typeSignature, TypeVariables typeVariables)
{
String baseType = typeSignature.getBase();
if (typeVariables.containsTypeVariable(baseType)) {
checkState(typeSignature.getParameters().isEmpty(), "Type parameters cannot have parameters");
return typeVariables.getTypeVariable(baseType).getTypeSignature();
}
List parameters = typeSignature.getParameters().stream()
.map(typeSignatureParameter -> applyBoundVariables(typeSignatureParameter, typeVariables))
.collect(toList());
return new TypeSignature(baseType, parameters);
}
public static FunctionBinding bindFunction(FunctionId functionId, Signature declaredSignature, BoundSignature boundSignature)
{
requireNonNull(declaredSignature, "declaredSignature is null");
requireNonNull(boundSignature, "boundSignature is null");
checkNoLiteralVariableUsageAcrossTypes(declaredSignature);
Map typeVariableConstraints = declaredSignature.getTypeVariableConstraints().stream()
.collect(toImmutableSortedMap(CASE_INSENSITIVE_ORDER, TypeVariableConstraint::getName, identity()));
boolean variableArity = declaredSignature.isVariableArity();
List formalTypeSignatures = declaredSignature.getArgumentTypes();
if (variableArity) {
verifyBoundSignature(boundSignature.getArgumentTypes().size() >= formalTypeSignatures.size() - 1, boundSignature, declaredSignature);
formalTypeSignatures = expandVarargFormalTypeSignature(formalTypeSignatures, boundSignature.getArgumentTypes().size());
}
verifyBoundSignature(formalTypeSignatures.size() == boundSignature.getArgumentTypes().size(), boundSignature, declaredSignature);
BoundVariables bindings = new BoundVariables();
for (int i = 0; i < formalTypeSignatures.size(); i++) {
extractBoundVariables(boundSignature, declaredSignature, typeVariableConstraints, bindings, boundSignature.getArgumentTypes().get(i), formalTypeSignatures.get(i));
}
extractBoundVariables(boundSignature, declaredSignature, typeVariableConstraints, bindings, boundSignature.getReturnType(), declaredSignature.getReturnType());
verifyBoundSignature(bindings.getTypeVariables().keySet().equals(typeVariableConstraints.keySet()), boundSignature, declaredSignature);
return new FunctionBinding(
functionId,
boundSignature,
bindings.getTypeVariables(),
bindings.getLongVariables());
}
private static void extractBoundVariables(
BoundSignature boundSignature,
Signature declaredSignature,
Map typeVariableConstraints,
BoundVariables bindings,
Type actualType,
TypeSignature declaredTypeSignature)
{
// type without nested type parameters
if (declaredTypeSignature.getParameters().isEmpty()) {
String typeVariable = declaredTypeSignature.getBase();
TypeVariableConstraint typeVariableConstraint = typeVariableConstraints.get(typeVariable);
if (typeVariableConstraint == null) {
return;
}
if (bindings.containsTypeVariable(typeVariable)) {
Type existingTypeBinding = bindings.getTypeVariable(typeVariable);
verifyBoundSignature(actualType.equals(existingTypeBinding), boundSignature, declaredSignature);
}
else {
bindings.setTypeVariable(typeVariable, actualType);
}
return;
}
verifyBoundSignature(declaredTypeSignature.getBase().equalsIgnoreCase(actualType.getTypeSignature().getBase()), boundSignature, declaredSignature);
// type with nested literal parameters
if (isTypeWithLiteralParameters(declaredTypeSignature)) {
for (int i = 0; i < declaredTypeSignature.getParameters().size(); i++) {
TypeSignatureParameter typeSignatureParameter = declaredTypeSignature.getParameters().get(i);
Long actualLongBinding = actualType.getTypeSignature().getParameters().get(i).getLongLiteral();
if (typeSignatureParameter.getKind() == ParameterKind.VARIABLE) {
if (bindings.containsLongVariable(typeSignatureParameter.getVariable())) {
Long existingLongBinding = bindings.getLongVariable(typeSignatureParameter.getVariable());
verifyBoundSignature(actualLongBinding.equals(existingLongBinding), boundSignature, declaredSignature);
}
else {
bindings.setLongVariable(typeSignatureParameter.getVariable(), actualLongBinding);
}
}
else {
verify(typeSignatureParameter.getKind() == ParameterKind.LONG);
verifyBoundSignature(actualLongBinding.equals(typeSignatureParameter.getLongLiteral()), boundSignature, declaredSignature);
}
}
return;
}
// type with nested type parameters
List actualTypeParameters = actualType.getTypeParameters();
// unknown types are assumed to have unknown nested types
if (UNKNOWN.equals(actualType)) {
actualTypeParameters = Collections.nCopies(declaredTypeSignature.getParameters().size(), UNKNOWN);
}
verifyBoundSignature(declaredTypeSignature.getParameters().size() == actualTypeParameters.size(), boundSignature, declaredSignature);
for (int i = 0; i < declaredTypeSignature.getParameters().size(); i++) {
TypeSignatureParameter typeSignatureParameter = declaredTypeSignature.getParameters().get(i);
TypeSignature typeSignature = typeSignatureParameter.getTypeSignatureOrNamedTypeSignature()
.orElseThrow(() -> new UnsupportedOperationException("Types with both type parameters and literal parameters at the same time are not supported"));
Type actualTypeParameter = actualTypeParameters.get(i);
extractBoundVariables(boundSignature, declaredSignature, typeVariableConstraints, bindings, actualTypeParameter, typeSignature);
}
}
private static void verifyBoundSignature(boolean expression, BoundSignature boundSignature, Signature declaredSignature)
{
checkArgument(expression, "Bound signature %s does not match declared signature %s", boundSignature, declaredSignature);
}
/**
* Example of not allowed literal variable usages across typeSignatures:
*
* - x used in different base types: char(x) and varchar(x)
*
- x used in different positions of the same base type: decimal(x,y) and decimal(z,x)
*
- p used in combination with different literals, types, or literal variables: decimal(p,s1) and decimal(p,s2)
*
*/
private static void checkNoLiteralVariableUsageAcrossTypes(Signature declaredSignature)
{
Map existingUsages = new HashMap<>();
for (TypeSignature parameter : declaredSignature.getArgumentTypes()) {
checkNoLiteralVariableUsageAcrossTypes(parameter, existingUsages);
}
}
private static void checkNoLiteralVariableUsageAcrossTypes(TypeSignature typeSignature, Map existingUsages)
{
List variables = typeSignature.getParameters().stream()
.filter(TypeSignatureParameter::isVariable)
.collect(toList());
for (TypeSignatureParameter variable : variables) {
TypeSignature existing = existingUsages.get(variable.getVariable());
if (existing != null && !existing.equals(typeSignature)) {
throw new UnsupportedOperationException("Literal parameters may not be shared across different types");
}
existingUsages.put(variable.getVariable(), typeSignature);
}
for (TypeSignatureParameter parameter : typeSignature.getParameters()) {
if (parameter.isLongLiteral() || parameter.isVariable()) {
continue;
}
checkNoLiteralVariableUsageAcrossTypes(parameter.getTypeSignatureOrNamedTypeSignature().get(), existingUsages);
}
}
private boolean appendConstraintSolversForReturnValue(ImmutableList.Builder resultBuilder, TypeSignatureProvider actualReturnType)
{
TypeSignature formalReturnTypeSignature = declaredSignature.getReturnType();
return appendTypeRelationshipConstraintSolver(resultBuilder, formalReturnTypeSignature, actualReturnType, EXACT)
&& appendConstraintSolvers(resultBuilder, formalReturnTypeSignature, actualReturnType, false);
}
private boolean appendConstraintSolversForArguments(ImmutableList.Builder resultBuilder, List actualTypes)
{
boolean variableArity = declaredSignature.isVariableArity();
List formalTypeSignatures = declaredSignature.getArgumentTypes();
if (variableArity) {
if (actualTypes.size() < formalTypeSignatures.size() - 1) {
return false;
}
formalTypeSignatures = expandVarargFormalTypeSignature(formalTypeSignatures, actualTypes.size());
}
if (formalTypeSignatures.size() != actualTypes.size()) {
return false;
}
for (int i = 0; i < formalTypeSignatures.size(); i++) {
if (!appendTypeRelationshipConstraintSolver(resultBuilder, formalTypeSignatures.get(i), actualTypes.get(i), allowCoercion ? IMPLICIT_COERCION : EXACT)) {
return false;
}
}
return appendConstraintSolvers(resultBuilder, formalTypeSignatures, actualTypes, allowCoercion);
}
private boolean appendConstraintSolvers(
ImmutableList.Builder resultBuilder,
List formalTypeSignatures,
List actualTypes,
boolean allowCoercion)
{
if (formalTypeSignatures.size() != actualTypes.size()) {
return false;
}
for (int i = 0; i < formalTypeSignatures.size(); i++) {
if (!appendConstraintSolvers(resultBuilder, formalTypeSignatures.get(i), actualTypes.get(i), allowCoercion)) {
return false;
}
}
return true;
}
private boolean appendConstraintSolvers(
ImmutableList.Builder resultBuilder,
TypeSignature formalTypeSignature,
TypeSignatureProvider actualTypeSignatureProvider,
boolean allowCoercion)
{
// formalTypeSignature can be categorized into one of the 5 cases below:
// * function type
// * type without type parameter
// * type parameter of type/named_type kind
// * type with type parameter of literal/variable kind
// * type with type parameter of type/named_type kind (except function type)
if (FunctionType.NAME.equalsIgnoreCase(formalTypeSignature.getBase())) {
List formalTypeParameterTypeSignatures = formalTypeSignature.getTypeParametersAsTypeSignatures();
resultBuilder.add(new FunctionSolver(
getLambdaArgumentTypeSignatures(formalTypeSignature),
formalTypeParameterTypeSignatures.getLast(),
actualTypeSignatureProvider));
return true;
}
if (actualTypeSignatureProvider.hasDependency()) {
return false;
}
if (formalTypeSignature.getParameters().isEmpty()) {
TypeVariableConstraint typeVariableConstraint = typeVariableConstraints.get(formalTypeSignature.getBase());
if (typeVariableConstraint == null) {
return true;
}
Type actualType = typeManager.getType(actualTypeSignatureProvider.getTypeSignature());
for (TypeSignature castToSignature : typeVariableConstraint.getCastableTo()) {
appendTypeRelationshipConstraintSolver(resultBuilder, castToSignature, actualTypeSignatureProvider, EXPLICIT_COERCION_TO);
}
for (TypeSignature castFromSignature : typeVariableConstraint.getCastableFrom()) {
appendTypeRelationshipConstraintSolver(resultBuilder, castFromSignature, actualTypeSignatureProvider, EXPLICIT_COERCION_FROM);
}
if (typeVariableConstraint.getVariadicBound().isPresent() && !typeVariableConstraint.getVariadicBound().get().equalsIgnoreCase(actualType.getTypeSignature().getBase())) {
return actualType == UNKNOWN;
}
resultBuilder.add(new TypeParameterSolver(
formalTypeSignature.getBase(),
actualType,
typeVariableConstraint.isComparableRequired(),
typeVariableConstraint.isOrderableRequired(),
typeVariableConstraint.getVariadicBound()));
return true;
}
Type actualType = typeManager.getType(actualTypeSignatureProvider.getTypeSignature());
if (isTypeWithLiteralParameters(formalTypeSignature)) {
resultBuilder.add(new TypeWithLiteralParametersSolver(formalTypeSignature, actualType));
return true;
}
List actualTypeParametersTypeSignatureProvider;
if (UNKNOWN.equals(actualType)) {
actualTypeParametersTypeSignatureProvider = Collections.nCopies(formalTypeSignature.getParameters().size(), new TypeSignatureProvider(UNKNOWN.getTypeSignature()));
}
else {
actualTypeParametersTypeSignatureProvider = fromTypes(actualType.getTypeParameters());
}
ImmutableList.Builder formalTypeParameterTypeSignatures = ImmutableList.builder();
for (TypeSignatureParameter formalTypeParameter : formalTypeSignature.getParameters()) {
TypeSignature typeSignature = formalTypeParameter.getTypeSignatureOrNamedTypeSignature()
.orElseThrow(() -> new UnsupportedOperationException("Types with both type parameters and literal parameters at the same time are not supported"));
formalTypeParameterTypeSignatures.add(typeSignature);
}
return appendConstraintSolvers(
resultBuilder,
formalTypeParameterTypeSignatures.build(),
actualTypeParametersTypeSignatureProvider,
allowCoercion && isCovariantTypeBase(formalTypeSignature.getBase()));
}
private Set typeVariablesOf(TypeSignature typeSignature)
{
if (typeVariableConstraints.containsKey(typeSignature.getBase())) {
return ImmutableSet.of(typeSignature.getBase());
}
ImmutableSet.Builder variables = ImmutableSet.builder();
for (TypeSignatureParameter parameter : typeSignature.getParameters()) {
switch (parameter.getKind()) {
case TYPE:
variables.addAll(typeVariablesOf(parameter.getTypeSignature()));
break;
case NAMED_TYPE:
variables.addAll(typeVariablesOf(parameter.getNamedTypeSignature().getTypeSignature()));
break;
case LONG:
break;
case VARIABLE:
break;
default:
throw new UnsupportedOperationException("Unknown parameter kind: " + parameter.getKind());
}
}
return variables.build();
}
private static Set longVariablesOf(TypeSignature typeSignature)
{
ImmutableSet.Builder variables = ImmutableSet.builder();
for (TypeSignatureParameter parameter : typeSignature.getParameters()) {
switch (parameter.getKind()) {
case TYPE:
variables.addAll(longVariablesOf(parameter.getTypeSignature()));
break;
case NAMED_TYPE:
variables.addAll(longVariablesOf(parameter.getNamedTypeSignature().getTypeSignature()));
break;
case LONG:
break;
case VARIABLE:
variables.add(parameter.getVariable());
break;
default:
throw new UnsupportedOperationException("Unknown parameter kind: " + parameter.getKind());
}
}
return variables.build();
}
private static boolean isTypeWithLiteralParameters(TypeSignature typeSignature)
{
return typeSignature.getParameters().stream()
.map(TypeSignatureParameter::getKind)
.allMatch(kind -> kind == ParameterKind.LONG || kind == ParameterKind.VARIABLE);
}
private Optional iterativeSolve(List constraints)
{
BoundVariables boundVariables = new BoundVariables();
for (int i = 0; true; i++) {
if (i == SOLVE_ITERATION_LIMIT) {
throw new VerifyException(format("SignatureBinder.iterativeSolve does not converge after %d iterations.", SOLVE_ITERATION_LIMIT));
}
SolverReturnStatusMerger statusMerger = new SolverReturnStatusMerger();
for (TypeConstraintSolver constraint : constraints) {
statusMerger.add(constraint.update(boundVariables));
if (statusMerger.getCurrent() == SolverReturnStatus.UNSOLVABLE) {
return Optional.empty();
}
}
switch (statusMerger.getCurrent()) {
case UNCHANGED_SATISFIED:
break;
case UNCHANGED_NOT_SATISFIED:
return Optional.empty();
case CHANGED:
continue;
case UNSOLVABLE:
throw new VerifyException();
default:
throw new UnsupportedOperationException("unknown status");
}
break;
}
calculateVariableValuesForLongConstraints(boundVariables);
if (!allTypeVariablesBound(boundVariables)) {
return Optional.empty();
}
return Optional.of(boundVariables);
}
private void calculateVariableValuesForLongConstraints(BoundVariables variableBinder)
{
for (LongVariableConstraint longVariableConstraint : declaredSignature.getLongVariableConstraints()) {
String calculation = longVariableConstraint.getExpression();
String variableName = longVariableConstraint.getName();
Long calculatedValue = calculateLiteralValue(calculation, variableBinder.getLongVariables());
if (variableBinder.containsLongVariable(variableName)) {
Long currentValue = variableBinder.getLongVariable(variableName);
checkState(Objects.equals(currentValue, calculatedValue),
"variable '%s' is already set to %s when trying to set %s", variableName, currentValue, calculatedValue);
}
variableBinder.setLongVariable(variableName, calculatedValue);
}
}
private boolean allTypeVariablesBound(TypeVariables typeVariables)
{
return typeVariableConstraints.keySet().stream()
.allMatch(typeVariables::containsTypeVariable);
}
private static TypeSignatureParameter applyBoundVariables(TypeSignatureParameter parameter, TypeVariables typeVariables)
{
ParameterKind parameterKind = parameter.getKind();
switch (parameterKind) {
case TYPE: {
TypeSignature typeSignature = parameter.getTypeSignature();
return TypeSignatureParameter.typeParameter(applyBoundVariables(typeSignature, typeVariables));
}
case NAMED_TYPE: {
NamedTypeSignature namedTypeSignature = parameter.getNamedTypeSignature();
TypeSignature typeSignature = namedTypeSignature.getTypeSignature();
return TypeSignatureParameter.namedTypeParameter(new NamedTypeSignature(
namedTypeSignature.getFieldName(),
applyBoundVariables(typeSignature, typeVariables)));
}
case VARIABLE: {
String variableName = parameter.getVariable();
checkState(
typeVariables.containsLongVariable(variableName),
"Variable is not bound: %s", variableName);
Long variableValue = typeVariables.getLongVariable(variableName);
return TypeSignatureParameter.numericParameter(variableValue);
}
case LONG: {
return parameter;
}
}
throw new IllegalStateException("Unknown parameter kind: " + parameter.getKind());
}
private static List expandVarargFormalTypeSignature(List formalTypeSignatures, int actualArity)
{
int variableArityArgumentsCount = actualArity - formalTypeSignatures.size() + 1;
if (variableArityArgumentsCount == 0) {
return formalTypeSignatures.subList(0, formalTypeSignatures.size() - 1);
}
if (variableArityArgumentsCount == 1) {
return formalTypeSignatures;
}
checkArgument(variableArityArgumentsCount > 1 && !formalTypeSignatures.isEmpty());
ImmutableList.Builder builder = ImmutableList.builder();
builder.addAll(formalTypeSignatures);
TypeSignature lastTypeSignature = formalTypeSignatures.getLast();
for (int i = 1; i < variableArityArgumentsCount; i++) {
builder.add(lastTypeSignature);
}
return builder.build();
}
private boolean satisfiesCoercion(RelationshipType relationshipType, Type actualType, TypeSignature constraintTypeSignature)
{
return switch (relationshipType) {
case EXACT -> actualType.getTypeSignature().equals(constraintTypeSignature);
case IMPLICIT_COERCION -> typeCoercion.canCoerce(actualType, typeManager.getType(constraintTypeSignature));
case EXPLICIT_COERCION_TO -> canCast(actualType, typeManager.getType(constraintTypeSignature));
case EXPLICIT_COERCION_FROM -> canCast(typeManager.getType(constraintTypeSignature), actualType);
};
}
private boolean canCast(Type fromType, Type toType)
{
if (toType instanceof UnknownType) {
return true;
}
if (fromType instanceof RowType) {
if (toType instanceof RowType) {
List fromTypeParameters = fromType.getTypeParameters();
List toTypeParameters = toType.getTypeParameters();
if (fromTypeParameters.size() != toTypeParameters.size()) {
return false;
}
for (int fieldIndex = 0; fieldIndex < fromTypeParameters.size(); fieldIndex++) {
if (!canCast(fromTypeParameters.get(fieldIndex), toTypeParameters.get(fieldIndex))) {
return false;
}
}
return true;
}
if (toType instanceof JsonType) {
return fromType.getTypeParameters().stream()
.allMatch(fromTypeParameter -> canCast(fromTypeParameter, toType));
}
return false;
}
if (fromType instanceof JsonType) {
if (toType instanceof RowType) {
return toType.getTypeParameters().stream()
.allMatch(toTypeParameter -> canCast(fromType, toTypeParameter));
}
}
try {
metadata.getCoercion(fromType, toType);
return true;
}
catch (TrinoException e) {
return false;
}
}
private static List getLambdaArgumentTypeSignatures(TypeSignature lambdaTypeSignature)
{
List typeParameters = lambdaTypeSignature.getTypeParametersAsTypeSignatures();
return typeParameters.subList(0, typeParameters.size() - 1);
}
private interface TypeConstraintSolver
{
SolverReturnStatus update(BoundVariables bindings);
}
private enum SolverReturnStatus
{
UNCHANGED_SATISFIED,
UNCHANGED_NOT_SATISFIED,
CHANGED,
UNSOLVABLE,
}
private static class SolverReturnStatusMerger
{
// This class gives the overall status when multiple status are seen from different parts.
// The logic is simple and can be summarized as finding the right most item (based on the list below) seen so far:
// UNCHANGED_SATISFIED, UNCHANGED_NOT_SATISFIED, CHANGED, UNSOLVABLE
// If no item was seen ever, it provides UNCHANGED_SATISFIED.
private SolverReturnStatus current = SolverReturnStatus.UNCHANGED_SATISFIED;
public void add(SolverReturnStatus newStatus)
{
switch (newStatus) {
case UNCHANGED_SATISFIED:
break;
case UNCHANGED_NOT_SATISFIED:
if (current == SolverReturnStatus.UNCHANGED_SATISFIED) {
current = SolverReturnStatus.UNCHANGED_NOT_SATISFIED;
}
break;
case CHANGED:
if (current == SolverReturnStatus.UNCHANGED_SATISFIED || current == SolverReturnStatus.UNCHANGED_NOT_SATISFIED) {
current = SolverReturnStatus.CHANGED;
}
break;
case UNSOLVABLE:
current = SolverReturnStatus.UNSOLVABLE;
break;
}
}
public SolverReturnStatus getCurrent()
{
return current;
}
}
private class TypeParameterSolver
implements TypeConstraintSolver
{
private final String typeParameter;
private final Type actualType;
private final boolean comparableRequired;
private final boolean orderableRequired;
private final Optional requiredBaseName;
public TypeParameterSolver(String typeParameter, Type actualType, boolean comparableRequired, boolean orderableRequired, Optional requiredBaseName)
{
this.typeParameter = typeParameter;
this.actualType = actualType;
this.comparableRequired = comparableRequired;
this.orderableRequired = orderableRequired;
this.requiredBaseName = requiredBaseName;
}
@Override
public SolverReturnStatus update(BoundVariables bindings)
{
if (!bindings.containsTypeVariable(typeParameter)) {
if (!satisfiesConstraints(actualType)) {
return SolverReturnStatus.UNSOLVABLE;
}
bindings.setTypeVariable(typeParameter, actualType);
return SolverReturnStatus.CHANGED;
}
Type originalType = bindings.getTypeVariable(typeParameter);
Optional commonSuperType = typeCoercion.getCommonSuperType(originalType, actualType);
if (commonSuperType.isEmpty()) {
return SolverReturnStatus.UNSOLVABLE;
}
if (!satisfiesConstraints(commonSuperType.get())) {
// This check must not be skipped even if commonSuperType is equal to originalType
return SolverReturnStatus.UNSOLVABLE;
}
if (commonSuperType.get().equals(originalType)) {
return SolverReturnStatus.UNCHANGED_SATISFIED;
}
bindings.setTypeVariable(typeParameter, commonSuperType.get());
return SolverReturnStatus.CHANGED;
}
private boolean satisfiesConstraints(Type type)
{
if (comparableRequired && !type.isComparable()) {
return false;
}
if (orderableRequired && !type.isOrderable()) {
return false;
}
if (requiredBaseName.isPresent() && !UNKNOWN.equals(type) && !requiredBaseName.get().equalsIgnoreCase(type.getBaseName())) {
// TODO: the case below should be properly handled:
// * `type` does not have the `requiredBaseName` but can be coerced to some type that has the `requiredBaseName`.
return false;
}
return true;
}
}
private class TypeWithLiteralParametersSolver
implements TypeConstraintSolver
{
private final TypeSignature formalTypeSignature;
private final Type actualType;
public TypeWithLiteralParametersSolver(TypeSignature formalTypeSignature, Type actualType)
{
this.formalTypeSignature = formalTypeSignature;
this.actualType = actualType;
}
@Override
public SolverReturnStatus update(BoundVariables bindings)
{
ImmutableList.Builder originalTypeTypeParametersBuilder = ImmutableList.builder();
List parameters = formalTypeSignature.getParameters();
for (int i = 0; i < parameters.size(); i++) {
TypeSignatureParameter typeSignatureParameter = parameters.get(i);
if (typeSignatureParameter.getKind() == ParameterKind.VARIABLE) {
if (bindings.containsLongVariable(typeSignatureParameter.getVariable())) {
originalTypeTypeParametersBuilder.add(TypeSignatureParameter.numericParameter(bindings.getLongVariable(typeSignatureParameter.getVariable())));
}
else {
// if an existing value doesn't exist for the given variable name, use the value that comes from the actual type.
Optional type = typeCoercion.coerceTypeBase(actualType, formalTypeSignature.getBase());
if (type.isEmpty()) {
return SolverReturnStatus.UNSOLVABLE;
}
verify(
type.get().getBaseName().equals(formalTypeSignature.getBase()),
"Unexpected coerce result for %s and %s: %s",
actualType,
formalTypeSignature.getBase(),
type.get());
TypeSignature typeSignature = type.get().getTypeSignature();
originalTypeTypeParametersBuilder.add(TypeSignatureParameter.numericParameter(typeSignature.getParameters().get(i).getLongLiteral()));
}
}
else {
verify(typeSignatureParameter.getKind() == ParameterKind.LONG);
originalTypeTypeParametersBuilder.add(typeSignatureParameter);
}
}
Type originalType = typeManager.getType(new TypeSignature(formalTypeSignature.getBase(), originalTypeTypeParametersBuilder.build()));
Optional commonSuperType = typeCoercion.getCommonSuperType(originalType, actualType);
if (commonSuperType.isEmpty()) {
return SolverReturnStatus.UNSOLVABLE;
}
TypeSignature commonSuperTypeSignature = commonSuperType.get().getTypeSignature();
if (!commonSuperTypeSignature.getBase().equals(formalTypeSignature.getBase())) {
return SolverReturnStatus.UNSOLVABLE;
}
SolverReturnStatus result = SolverReturnStatus.UNCHANGED_SATISFIED;
for (int i = 0; i < parameters.size(); i++) {
TypeSignatureParameter typeSignatureParameter = parameters.get(i);
long commonSuperLongLiteral = commonSuperTypeSignature.getParameters().get(i).getLongLiteral();
if (typeSignatureParameter.getKind() == ParameterKind.VARIABLE) {
String variableName = typeSignatureParameter.getVariable();
if (!bindings.containsLongVariable(variableName) || !bindings.getLongVariable(variableName).equals(commonSuperLongLiteral)) {
bindings.setLongVariable(variableName, commonSuperLongLiteral);
result = SolverReturnStatus.CHANGED;
}
}
else {
verify(typeSignatureParameter.getKind() == ParameterKind.LONG);
if (commonSuperLongLiteral != typeSignatureParameter.getLongLiteral()) {
return SolverReturnStatus.UNSOLVABLE;
}
}
}
return result;
}
}
private class FunctionSolver
implements TypeConstraintSolver
{
private final List formalLambdaArgumentsTypeSignature;
private final TypeSignature formalLambdaReturnTypeSignature;
private final TypeSignatureProvider typeSignatureProvider;
public FunctionSolver(
List formalLambdaArgumentsTypeSignature,
TypeSignature formalLambdaReturnTypeSignature,
TypeSignatureProvider typeSignatureProvider)
{
this.formalLambdaArgumentsTypeSignature = formalLambdaArgumentsTypeSignature;
this.formalLambdaReturnTypeSignature = formalLambdaReturnTypeSignature;
this.typeSignatureProvider = typeSignatureProvider;
}
@Override
public SolverReturnStatus update(BoundVariables bindings)
{
Optional> lambdaArgumentTypes = synthesizeLambdaArgumentTypes(bindings, formalLambdaArgumentsTypeSignature);
if (lambdaArgumentTypes.isEmpty()) {
return SolverReturnStatus.UNCHANGED_NOT_SATISFIED;
}
TypeSignature actualLambdaTypeSignature;
if (!typeSignatureProvider.hasDependency()) {
actualLambdaTypeSignature = typeSignatureProvider.getTypeSignature();
if (!FunctionType.NAME.equals(actualLambdaTypeSignature.getBase()) || !getLambdaArgumentTypeSignatures(actualLambdaTypeSignature).equals(toTypeSignatures(lambdaArgumentTypes.get()))) {
return SolverReturnStatus.UNSOLVABLE;
}
}
else {
actualLambdaTypeSignature = typeSignatureProvider.getTypeSignature(lambdaArgumentTypes.get());
if (!FunctionType.NAME.equals(actualLambdaTypeSignature.getBase())) {
return SolverReturnStatus.UNSOLVABLE;
}
verify(getLambdaArgumentTypeSignatures(actualLambdaTypeSignature).equals(toTypeSignatures(lambdaArgumentTypes.get())));
}
Type actualLambdaType = typeManager.getType(actualLambdaTypeSignature);
Type actualReturnType = ((FunctionType) actualLambdaType).getReturnType();
ImmutableList.Builder constraintsBuilder = ImmutableList.builder();
// Coercion on function type is not supported yet.
if (!appendTypeRelationshipConstraintSolver(constraintsBuilder, formalLambdaReturnTypeSignature, new TypeSignatureProvider(actualReturnType.getTypeSignature()), EXACT)) {
return SolverReturnStatus.UNSOLVABLE;
}
if (!appendConstraintSolvers(constraintsBuilder, formalLambdaReturnTypeSignature, new TypeSignatureProvider(actualReturnType.getTypeSignature()), allowCoercion)) {
return SolverReturnStatus.UNSOLVABLE;
}
SolverReturnStatusMerger statusMerger = new SolverReturnStatusMerger();
for (TypeConstraintSolver constraint : constraintsBuilder.build()) {
statusMerger.add(constraint.update(bindings));
if (statusMerger.getCurrent() == SolverReturnStatus.UNSOLVABLE) {
return SolverReturnStatus.UNSOLVABLE;
}
}
return statusMerger.getCurrent();
}
private Optional> synthesizeLambdaArgumentTypes(
BoundVariables bindings,
List formalLambdaArgumentTypeSignatures)
{
ImmutableList.Builder lambdaArgumentTypesBuilder = ImmutableList.builder();
for (TypeSignature lambdaArgument : formalLambdaArgumentTypeSignatures) {
if (typeVariableConstraints.containsKey(lambdaArgument.getBase())) {
if (!bindings.containsTypeVariable(lambdaArgument.getBase())) {
return Optional.empty();
}
Type typeVariable = bindings.getTypeVariable(lambdaArgument.getBase());
lambdaArgumentTypesBuilder.add(typeVariable);
}
else {
lambdaArgumentTypesBuilder.add(typeManager.getType(lambdaArgument));
}
}
return Optional.of(lambdaArgumentTypesBuilder.build());
}
private List toTypeSignatures(List types)
{
return types.stream()
.map(Type::getTypeSignature)
.collect(toImmutableList());
}
}
private boolean appendTypeRelationshipConstraintSolver(
ImmutableList.Builder resultBuilder,
TypeSignature formalTypeSignature,
TypeSignatureProvider actualTypeSignatureProvider,
RelationshipType relationshipType)
{
if (actualTypeSignatureProvider.hasDependency()) {
// Fail if the formal type is not function.
// Otherwise do nothing because FunctionConstraintSolver will handle type relationship constraint directly
return FunctionType.NAME.equals(formalTypeSignature.getBase());
}
Set typeVariables = typeVariablesOf(formalTypeSignature);
Set longVariables = longVariablesOf(formalTypeSignature);
resultBuilder.add(new TypeRelationshipConstraintSolver(
formalTypeSignature,
typeVariables,
longVariables,
typeManager.getType(actualTypeSignatureProvider.getTypeSignature()),
relationshipType));
return true;
}
private final class TypeRelationshipConstraintSolver
implements TypeConstraintSolver
{
private final TypeSignature formalTypeSignature;
private final Set typeVariables;
private final Set longVariables;
private final Type actualType;
private final RelationshipType relationshipType;
public TypeRelationshipConstraintSolver(TypeSignature formalTypeSignature, Set typeVariables, Set longVariables, Type actualType, RelationshipType relationshipType)
{
this.formalTypeSignature = requireNonNull(formalTypeSignature, "formalTypeSignature is null");
this.typeVariables = ImmutableSet.copyOf(typeVariables);
this.longVariables = ImmutableSet.copyOf(longVariables);
this.actualType = requireNonNull(actualType, "actualType is null");
this.relationshipType = requireNonNull(relationshipType, "relationshipType is null");
}
@Override
public SolverReturnStatus update(BoundVariables bindings)
{
for (String variable : typeVariables) {
if (!bindings.containsTypeVariable(variable)) {
return SolverReturnStatus.UNCHANGED_NOT_SATISFIED;
}
}
for (String variable : longVariables) {
if (!bindings.containsLongVariable(variable)) {
return SolverReturnStatus.UNCHANGED_NOT_SATISFIED;
}
}
TypeSignature constraintTypeSignature = applyBoundVariables(formalTypeSignature, bindings);
return satisfiesCoercion(relationshipType, actualType, constraintTypeSignature) ? SolverReturnStatus.UNCHANGED_SATISFIED : SolverReturnStatus.UNCHANGED_NOT_SATISFIED;
}
}
public enum RelationshipType
{
EXACT, IMPLICIT_COERCION, EXPLICIT_COERCION_TO, EXPLICIT_COERCION_FROM
}
private record FunctionTypeVariables(FunctionBinding functionBinding)
implements TypeVariables
{
private FunctionTypeVariables
{
requireNonNull(functionBinding, "functionBinding is null");
}
@Override
public Type getTypeVariable(String variableName)
{
return functionBinding.getTypeVariable(variableName);
}
@Override
public boolean containsTypeVariable(String variableName)
{
return functionBinding.containsTypeVariable(variableName);
}
@Override
public Long getLongVariable(String variableName)
{
return functionBinding.getLongVariable(variableName);
}
@Override
public boolean containsLongVariable(String variableName)
{
return functionBinding.containsLongVariable(variableName);
}
}
}