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The AWS Java SDK for AWS Lambda module holds the client classes that are used for communicating with
AWS Lambda Service
/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file except in compliance with
* the License. A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.services.lambda.endpoints.internal;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import software.amazon.awssdk.annotations.SdkInternalApi;
@SdkInternalApi
public class GetAttr extends Fn {
public static final String ID = "getAttr";
public GetAttr(FnNode node) {
super(node);
}
@Override
public Value eval(Scope scope) {
Value root = target().eval(scope);
List path;
try {
path = path();
} catch (InnerParseError e) {
throw new RuntimeException(e);
}
for (Part part : path) {
root = part.eval(root);
}
return root;
}
public interface Part {
Value eval(Value container);
final class Key implements Part {
private final Identifier key;
public Key(Identifier key) {
this.key = key;
}
@Override
public String toString() {
return key.asString();
}
public static Key of(String key) {
return new Key(Identifier.of(key));
}
@Override
public Value eval(Value container) {
return container.expectRecord().get(key);
}
public Identifier key() {
return key;
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj == null || obj.getClass() != this.getClass()) {
return false;
}
Key that = (Key) obj;
return Objects.equals(this.key, that.key);
}
@Override
public int hashCode() {
return key != null ? key.hashCode() : 0;
}
}
final class Index implements Part {
private final int index;
public Index(int index) {
this.index = index;
}
@Override
public Value eval(Value container) {
return container.expectArray().get(index);
}
@Override
public String toString() {
return String.format("[%s]", index);
}
public int index() {
return index;
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj == null || obj.getClass() != this.getClass()) {
return false;
}
Index that = (Index) obj;
return this.index == that.index;
}
@Override
public int hashCode() {
return index;
}
}
}
private static GetAttr fromBuilder(Builder builder) {
return new GetAttr(FnNode.builder().fn("getAttr")
.argv(Arrays.asList(builder.target, Literal.fromStr(String.join(".", builder.path)))).build());
}
public static Builder builder() {
return new Builder();
}
public Expr target() {
return expectTwoArgs().left();
}
public List path() throws InnerParseError {
Expr right = expectTwoArgs().right();
if (right instanceof Literal) {
Literal path = (Literal) right;
return parse(path.expectLiteralString());
} else {
throw SourceException.builder().message("second argument must be a string literal").build();
}
}
private static List parse(String path) throws InnerParseError {
String[] components = path.split("\\.");
List result = new ArrayList<>();
for (String component : components) {
if (component.contains("[")) {
int slicePartIndex = component.indexOf("[");
String slicePart = component.substring(slicePartIndex);
if (!slicePart.endsWith("]")) {
throw new InnerParseError("Invalid path component: %s. Must end with `]`");
}
try {
String number = slicePart.substring(1, slicePart.length() - 1);
int slice = Integer.parseInt(number);
if (slice < 0) {
throw new InnerParseError("Invalid path component: slice index must be >= 0");
}
if (slicePartIndex > 0) {
result.add(Part.Key.of(component.substring(0, slicePartIndex)));
}
result.add(new Part.Index(slice));
} catch (NumberFormatException ex) {
throw new InnerParseError(String.format("%s could not be parsed as a number", slicePart));
}
} else {
result.add(Part.Key.of(component));
}
}
if (result.isEmpty()) {
throw new InnerParseError("Invalid argument to GetAttr: path may not be empty");
}
return result;
}
@Override
public T acceptFnVisitor(FnVisitor visitor) {
return visitor.visitGetAttr(this);
}
@Override
public String toString() {
StringBuilder out = new StringBuilder();
out.append(target());
try {
for (Part part : path()) {
out.append(".");
out.append(part);
}
} catch (InnerParseError e) {
throw new RuntimeException(e);
}
return out.toString();
}
@Override
public String template() {
String target = ((Ref) this.target()).getName().asString();
StringBuilder pathPart = new StringBuilder();
List partList;
try {
partList = path();
} catch (InnerParseError e) {
throw new RuntimeException(e);
}
for (int i = 0; i < partList.size(); i++) {
if (i != 0) {
if (partList.get(i) instanceof Part.Key) {
pathPart.append(".");
}
}
pathPart.append(partList.get(i).toString());
}
return "{" + target + "#" + pathPart + "}";
}
public static class Builder {
Expr target;
String path;
public Builder target(Expr target) {
this.target = target;
return this;
}
public Builder path(String path) {
this.path = path;
return this;
}
public GetAttr build() {
return GetAttr.fromBuilder(this);
}
}
}