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RESTCONF Northbound application
/*
* Copyright (c) 2016 Cisco Systems, Inc. and others. All rights reserved.
* Copyright (c) 2023 PANTHEON.tech, s.r.o.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.restconf.server.api;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Verify.verify;
import static java.util.Objects.requireNonNull;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableList.Builder;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.atomic.AtomicReference;
import org.eclipse.jdt.annotation.NonNull;
import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
import org.opendaylight.restconf.common.patch.PatchContext;
import org.opendaylight.restconf.common.patch.PatchEntity;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.patch.rev170222.yang.patch.yang.patch.Edit.Operation;
import org.opendaylight.yangtools.yang.common.ErrorTag;
import org.opendaylight.yangtools.yang.common.ErrorType;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
import org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream;
import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
import org.opendaylight.yangtools.yang.data.impl.schema.NormalizationResultHolder;
import org.opendaylight.yangtools.yang.model.api.SchemaNode;
import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack.Inference;
public final class JsonPatchBody extends PatchBody {
public JsonPatchBody(final InputStream inputStream) {
super(inputStream);
}
@Override
PatchContext toPatchContext(final ResourceContext resource, final InputStream inputStream) throws IOException {
try (var jsonReader = new JsonReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8))) {
final var patchId = new AtomicReference();
final var resultList = read(jsonReader, resource, patchId);
// Note: patchId side-effect of above
return new PatchContext(patchId.get(), resultList);
}
}
private static ImmutableList read(final JsonReader in, final @NonNull ResourceContext resource,
final AtomicReference patchId) throws IOException {
final var edits = ImmutableList.builder();
final var edit = new PatchEdit();
while (in.hasNext()) {
switch (in.peek()) {
case STRING:
case NUMBER:
in.nextString();
break;
case BOOLEAN:
Boolean.toString(in.nextBoolean());
break;
case NULL:
in.nextNull();
break;
case BEGIN_ARRAY:
in.beginArray();
break;
case BEGIN_OBJECT:
in.beginObject();
break;
case END_DOCUMENT:
break;
case NAME:
parseByName(in.nextName(), edit, in, resource, edits, patchId);
break;
case END_OBJECT:
in.endObject();
break;
case END_ARRAY:
in.endArray();
break;
default:
break;
}
}
return edits.build();
}
// Switch value of parsed JsonToken.NAME and read edit definition or patch id
private static void parseByName(final @NonNull String name, final @NonNull PatchEdit edit,
final @NonNull JsonReader in, final @NonNull ResourceContext resource,
final @NonNull Builder resultCollection, final @NonNull AtomicReference patchId)
throws IOException {
switch (name) {
case "edit":
if (in.peek() == JsonToken.BEGIN_ARRAY) {
in.beginArray();
while (in.hasNext()) {
readEditDefinition(edit, in, resource);
resultCollection.add(prepareEditOperation(edit));
edit.clear();
}
in.endArray();
} else {
readEditDefinition(edit, in, resource);
resultCollection.add(prepareEditOperation(edit));
edit.clear();
}
break;
case "patch-id":
patchId.set(in.nextString());
break;
default:
break;
}
}
// Read one patch edit object from JSON input
private static void readEditDefinition(final @NonNull PatchEdit edit, final @NonNull JsonReader in,
final @NonNull ResourceContext resource) throws IOException {
String deferredValue = null;
in.beginObject();
final var codecs = resource.path.databind().jsonCodecs();
while (in.hasNext()) {
final String editDefinition = in.nextName();
switch (editDefinition) {
case "edit-id":
edit.setId(in.nextString());
break;
case "operation":
edit.setOperation(Operation.ofName(in.nextString()));
break;
case "target":
// target can be specified completely in request URI
final var target = parsePatchTarget(resource, in.nextString());
edit.setTarget(target.instance());
final var stack = target.inference().toSchemaInferenceStack();
if (!stack.isEmpty()) {
stack.exit();
}
if (!stack.isEmpty()) {
final var parentStmt = stack.currentStatement();
verify(parentStmt instanceof SchemaNode, "Unexpected parent %s", parentStmt);
}
edit.setTargetSchemaNode(stack.toInference());
break;
case "value":
checkArgument(edit.getData() == null && deferredValue == null, "Multiple value entries found");
if (edit.getTargetSchemaNode() == null) {
// save data defined in value node for next (later) processing, because target needs to be read
// always first and there is no ordering in Json input
deferredValue = readValueNode(in);
} else {
// We have a target schema node, reuse this reader without buffering the value.
edit.setData(readEditData(in, edit.getTargetSchemaNode(), codecs));
}
break;
default:
// FIXME: this does not look right, as it can wreck our logic
break;
}
}
in.endObject();
if (deferredValue != null) {
// read saved data to normalized node when target schema is already known
edit.setData(readEditData(new JsonReader(new StringReader(deferredValue)), edit.getTargetSchemaNode(),
codecs));
}
}
/**
* Parse data defined in value node and saves it to buffer.
* @param sb Buffer to read value node
* @param in JsonReader reader
* @throws IOException if operation fails
*/
private static String readValueNode(final @NonNull JsonReader in) throws IOException {
in.beginObject();
final StringBuilder sb = new StringBuilder().append("{\"").append(in.nextName()).append("\":");
switch (in.peek()) {
case BEGIN_ARRAY:
in.beginArray();
sb.append('[');
while (in.hasNext()) {
if (in.peek() == JsonToken.STRING) {
sb.append('"').append(in.nextString()).append('"');
} else {
readValueObject(sb, in);
}
if (in.peek() != JsonToken.END_ARRAY) {
sb.append(',');
}
}
in.endArray();
sb.append(']');
break;
default:
readValueObject(sb, in);
break;
}
in.endObject();
return sb.append('}').toString();
}
/**
* Parse one value object of data and saves it to buffer.
* @param sb Buffer to read value object
* @param in JsonReader reader
* @throws IOException if operation fails
*/
private static void readValueObject(final @NonNull StringBuilder sb, final @NonNull JsonReader in)
throws IOException {
// read simple leaf value
if (in.peek() == JsonToken.STRING) {
sb.append('"').append(in.nextString()).append('"');
return;
}
in.beginObject();
sb.append('{');
while (in.hasNext()) {
sb.append('"').append(in.nextName()).append("\":");
switch (in.peek()) {
case STRING:
sb.append('"').append(in.nextString()).append('"');
break;
case BEGIN_ARRAY:
in.beginArray();
sb.append('[');
while (in.hasNext()) {
if (in.peek() == JsonToken.STRING) {
sb.append('"').append(in.nextString()).append('"');
} else {
readValueObject(sb, in);
}
if (in.peek() != JsonToken.END_ARRAY) {
sb.append(',');
}
}
in.endArray();
sb.append(']');
break;
default:
readValueObject(sb, in);
}
if (in.peek() != JsonToken.END_OBJECT) {
sb.append(',');
}
}
in.endObject();
sb.append('}');
}
/**
* Read patch edit data defined in value node to NormalizedNode.
* @param in reader JsonReader reader
* @return NormalizedNode representing data
*/
private static NormalizedNode readEditData(final @NonNull JsonReader in, final @NonNull Inference targetSchemaNode,
final @NonNull JSONCodecFactory codecs) {
final var resultHolder = new NormalizationResultHolder();
final var writer = ImmutableNormalizedNodeStreamWriter.from(resultHolder);
JsonParserStream.create(writer, codecs, targetSchemaNode).parse(in);
return resultHolder.getResult().data();
}
/**
* Prepare PatchEntity from PatchEdit instance when it satisfies conditions, otherwise throws exception.
* @param edit Instance of PatchEdit
* @return PatchEntity Patch entity
*/
private static PatchEntity prepareEditOperation(final @NonNull PatchEdit edit) {
if (edit.getOperation() != null && edit.getTargetSchemaNode() != null
&& checkDataPresence(edit.getOperation(), edit.getData() != null)) {
if (!requiresValue(edit.getOperation())) {
return new PatchEntity(edit.getId(), edit.getOperation(), edit.getTarget());
}
// for lists allow to manipulate with list items through their parent
final YangInstanceIdentifier targetNode;
if (edit.getTarget().getLastPathArgument() instanceof NodeIdentifierWithPredicates) {
targetNode = edit.getTarget().getParent();
} else {
targetNode = edit.getTarget();
}
return new PatchEntity(edit.getId(), edit.getOperation(), targetNode, edit.getData());
}
throw new RestconfDocumentedException("Error parsing input", ErrorType.PROTOCOL, ErrorTag.MALFORMED_MESSAGE);
}
/**
* Check if data is present when operation requires it and not present when operation data is not allowed.
* @param operation Name of operation
* @param hasData Data in edit are present/not present
* @return true if data is present when operation requires it or if there are no data when operation does not
* allow it, false otherwise
*/
private static boolean checkDataPresence(final @NonNull Operation operation, final boolean hasData) {
return requiresValue(operation) == hasData;
}
/**
* Helper class representing one patch edit.
*/
private static final class PatchEdit {
private String id;
private Operation operation;
private YangInstanceIdentifier target;
private Inference targetSchemaNode;
private NormalizedNode data;
String getId() {
return id;
}
void setId(final String id) {
this.id = requireNonNull(id);
}
Operation getOperation() {
return operation;
}
void setOperation(final Operation operation) {
this.operation = requireNonNull(operation);
}
YangInstanceIdentifier getTarget() {
return target;
}
void setTarget(final YangInstanceIdentifier target) {
this.target = requireNonNull(target);
}
Inference getTargetSchemaNode() {
return targetSchemaNode;
}
void setTargetSchemaNode(final Inference targetSchemaNode) {
this.targetSchemaNode = requireNonNull(targetSchemaNode);
}
NormalizedNode getData() {
return data;
}
void setData(final NormalizedNode data) {
this.data = requireNonNull(data);
}
void clear() {
id = null;
operation = null;
target = null;
targetSchemaNode = null;
data = null;
}
}
}