| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 |
| * |
| * https://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 org.apache.avro.compiler.schema; |
| |
| import java.util.ArrayDeque; |
| import java.util.Collections; |
| import java.util.Deque; |
| import java.util.IdentityHashMap; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.function.Supplier; |
| import java.util.stream.Collectors; |
| |
| import org.apache.avro.JsonProperties; |
| import org.apache.avro.LogicalType; |
| import org.apache.avro.Schema; |
| import org.apache.avro.Schema.Field; |
| import org.apache.avro.compiler.specific.SpecificCompiler; |
| |
| /** |
| * Avro Schema utilities, to traverse... |
| */ |
| public final class Schemas { |
| |
| private Schemas() { |
| } |
| |
| public static void copyAliases(final Schema from, final Schema to) { |
| switch (from.getType()) { // only named types. |
| case RECORD: |
| case ENUM: |
| case FIXED: |
| Set<String> aliases = from.getAliases(); |
| for (String alias : aliases) { |
| to.addAlias(alias); |
| } |
| } |
| } |
| |
| public static void copyAliases(final Schema.Field from, final Schema.Field to) { |
| Set<String> aliases = from.aliases(); |
| for (String alias : aliases) { |
| to.addAlias(alias); |
| } |
| } |
| |
| public static void copyLogicalTypes(final Schema from, final Schema to) { |
| LogicalType logicalType = from.getLogicalType(); |
| if (logicalType != null) { |
| logicalType.addToSchema(to); |
| } |
| } |
| |
| public static void copyProperties(final JsonProperties from, final JsonProperties to) { |
| Map<String, Object> objectProps = from.getObjectProps(); |
| for (Map.Entry<String, Object> entry : objectProps.entrySet()) { |
| to.addProp(entry.getKey(), entry.getValue()); |
| } |
| } |
| |
| public static boolean hasGeneratedJavaClass(final Schema schema) { |
| Schema.Type type = schema.getType(); |
| switch (type) { |
| case ENUM: |
| case RECORD: |
| case FIXED: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| public static String getJavaClassName(final Schema schema) { |
| String namespace = schema.getNamespace(); |
| if (namespace == null) { |
| return SpecificCompiler.mangle(schema.getName()); |
| } else { |
| return namespace + '.' + SpecificCompiler.mangle(schema.getName()); |
| } |
| } |
| |
| /** |
| * depth first visit. |
| * |
| * @param start |
| * @param visitor |
| */ |
| public static <T> T visit(final Schema start, final SchemaVisitor<T> visitor) { |
| // Set of Visited Schemas |
| IdentityHashMap<Schema, Schema> visited = new IdentityHashMap<>(); |
| // Stack that contains the Schams to process and afterVisitNonTerminal |
| // functions. |
| // Deque<Either<Schema, Supplier<SchemaVisitorAction>>> |
| // Using either has a cost which we want to avoid... |
| Deque<Object> dq = new ArrayDeque<>(); |
| dq.addLast(start); |
| Object current; |
| while ((current = dq.pollLast()) != null) { |
| if (current instanceof Supplier) { |
| // we are executing a non terminal post visit. |
| SchemaVisitorAction action = ((Supplier<SchemaVisitorAction>) current).get(); |
| switch (action) { |
| case CONTINUE: |
| break; |
| case SKIP_SUBTREE: |
| throw new UnsupportedOperationException(); |
| case SKIP_SIBLINGS: |
| while (dq.getLast() instanceof Schema) { |
| dq.removeLast(); |
| } |
| break; |
| case TERMINATE: |
| return visitor.get(); |
| default: |
| throw new UnsupportedOperationException("Invalid action " + action); |
| } |
| } else { |
| Schema schema = (Schema) current; |
| boolean terminate; |
| if (!visited.containsKey(schema)) { |
| Schema.Type type = schema.getType(); |
| switch (type) { |
| case ARRAY: |
| terminate = visitNonTerminal(visitor, schema, dq, Collections.singleton(schema.getElementType())); |
| visited.put(schema, schema); |
| break; |
| case RECORD: |
| terminate = visitNonTerminal(visitor, schema, dq, () -> schema.getFields().stream().map(Field::schema) |
| .collect(Collectors.toCollection(ArrayDeque::new)).descendingIterator()); |
| visited.put(schema, schema); |
| break; |
| case UNION: |
| terminate = visitNonTerminal(visitor, schema, dq, schema.getTypes()); |
| visited.put(schema, schema); |
| break; |
| case MAP: |
| terminate = visitNonTerminal(visitor, schema, dq, Collections.singleton(schema.getValueType())); |
| visited.put(schema, schema); |
| break; |
| case NULL: |
| case BOOLEAN: |
| case BYTES: |
| case DOUBLE: |
| case ENUM: |
| case FIXED: |
| case FLOAT: |
| case INT: |
| case LONG: |
| case STRING: |
| terminate = visitTerminal(visitor, schema, dq); |
| break; |
| default: |
| throw new UnsupportedOperationException("Invalid type " + type); |
| } |
| |
| } else { |
| terminate = visitTerminal(visitor, schema, dq); |
| } |
| if (terminate) { |
| return visitor.get(); |
| } |
| } |
| } |
| return visitor.get(); |
| } |
| |
| private static boolean visitNonTerminal(final SchemaVisitor visitor, final Schema schema, final Deque<Object> dq, |
| final Iterable<Schema> itSupp) { |
| SchemaVisitorAction action = visitor.visitNonTerminal(schema); |
| switch (action) { |
| case CONTINUE: |
| dq.addLast((Supplier<SchemaVisitorAction>) () -> visitor.afterVisitNonTerminal(schema)); |
| for (Schema child : itSupp) { |
| dq.addLast(child); |
| } |
| break; |
| case SKIP_SUBTREE: |
| dq.addLast((Supplier<SchemaVisitorAction>) () -> visitor.afterVisitNonTerminal(schema)); |
| break; |
| case SKIP_SIBLINGS: |
| while (!dq.isEmpty() && dq.getLast() instanceof Schema) { |
| dq.removeLast(); |
| } |
| break; |
| case TERMINATE: |
| return true; |
| default: |
| throw new UnsupportedOperationException("Invalid action " + action + " for " + schema); |
| } |
| return false; |
| } |
| |
| private static boolean visitTerminal(final SchemaVisitor visitor, final Schema schema, final Deque<Object> dq) { |
| SchemaVisitorAction action = visitor.visitTerminal(schema); |
| switch (action) { |
| case CONTINUE: |
| break; |
| case SKIP_SUBTREE: |
| throw new UnsupportedOperationException("Invalid action " + action + " for " + schema); |
| case SKIP_SIBLINGS: |
| while (!dq.isEmpty() && dq.getLast() instanceof Schema) { |
| dq.removeLast(); |
| } |
| break; |
| case TERMINATE: |
| return true; |
| default: |
| throw new UnsupportedOperationException("Invalid action " + action + " for " + schema); |
| } |
| return false; |
| } |
| |
| } |