Add Map to XContentParser Wrapper (#44036)

In some cases we need to parse some XContent that is already parsed into
a map. This is currently happening in handling source in SQL and ingest
processors as well as parsing null_value values in geo mappings. To avoid
re-serializing and parsing the value again or writing another map-based
parser this commit adds an iterator that iterates over a map as if it was
XContent. This makes reusing existing XContent parser on maps possible.

Relates to #43554

libs/x-content/src/main/java/org/elasticsearch/common/xcontent/support/MapXContentParser.java

@@ -0,0 +1,440 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch 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
+ *
+ *    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 org.elasticsearch.common.xcontent.support;
+
+import org.elasticsearch.common.xcontent.DeprecationHandler;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
+import org.elasticsearch.common.xcontent.XContentLocation;
+import org.elasticsearch.common.xcontent.XContentType;
+
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.nio.CharBuffer;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Wraps a map generated by XContentParser's map() method into XContent Parser
+ */
+public class MapXContentParser extends AbstractXContentParser {
+
+    private XContentType xContentType;
+    private TokenIterator iterator;
+    private boolean closed;
+
+    public MapXContentParser(NamedXContentRegistry xContentRegistry, DeprecationHandler deprecationHandler, Map<String, Object> map,
+                             XContentType xContentType) {
+        super(xContentRegistry, deprecationHandler);
+        this.xContentType = xContentType;
+        this.iterator = new MapIterator(null, null, map);
+    }
+
+
+    @Override
+    protected boolean doBooleanValue() throws IOException {
+        if (iterator != null && iterator.currentValue() instanceof Boolean) {
+            return (Boolean) iterator.currentValue();
+        } else {
+            throw new IllegalStateException("Cannot get boolean value for the current token " + currentToken());
+        }
+    }
+
+    @Override
+    protected short doShortValue() throws IOException {
+        return numberValue().shortValue();
+    }
+
+    @Override
+    protected int doIntValue() throws IOException {
+        return numberValue().intValue();
+    }
+
+    @Override
+    protected long doLongValue() throws IOException {
+        return numberValue().longValue();
+    }
+
+    @Override
+    protected float doFloatValue() throws IOException {
+        return numberValue().floatValue();
+    }
+
+    @Override
+    protected double doDoubleValue() throws IOException {
+        return numberValue().doubleValue();
+    }
+
+    @Override
+    public XContentType contentType() {
+        return xContentType;
+    }
+
+    @Override
+    public Token nextToken() throws IOException {
+        if (iterator == null) {
+            return null;
+        } else {
+            iterator = iterator.next();
+        }
+        return currentToken();
+    }
+
+    @Override
+    public void skipChildren() throws IOException {
+        Token token = currentToken();
+        if (token == Token.START_OBJECT || token == Token.START_ARRAY) {
+            iterator = iterator.skipChildren();
+        }
+    }
+
+    @Override
+    public Token currentToken() {
+        if (iterator == null) {
+            return null;
+        } else {
+            return iterator.currentToken();
+        }
+    }
+
+    @Override
+    public String currentName() throws IOException {
+        if (iterator == null) {
+            return null;
+        } else {
+            return iterator.currentName();
+        }
+    }
+
+    @Override
+    public String text() throws IOException {
+        if (iterator != null) {
+            if (currentToken() == Token.VALUE_STRING || currentToken() == Token.VALUE_NUMBER || currentToken() == Token.VALUE_BOOLEAN) {
+                return iterator.currentValue().toString();
+            } else if (currentToken() == Token.FIELD_NAME) {
+                return iterator.currentName();
+            } else {
+                return null;
+            }
+        } else {
+            throw new IllegalStateException("Cannot get text for the current token " + currentToken());
+        }
+    }
+
+    @Override
+    public CharBuffer charBuffer() throws IOException {
+        throw new UnsupportedOperationException("use text() instead");
+    }
+
+    @Override
+    public Object objectText() throws IOException {
+        throw new UnsupportedOperationException("use text() instead");
+    }
+
+    @Override
+    public Object objectBytes() throws IOException {
+        throw new UnsupportedOperationException("use text() instead");
+    }
+
+    @Override
+    public boolean hasTextCharacters() {
+        throw new UnsupportedOperationException("use text() instead");
+    }
+
+    @Override
+    public char[] textCharacters() throws IOException {
+        throw new UnsupportedOperationException("use text() instead");
+    }
+
+    @Override
+    public int textLength() throws IOException {
+        throw new UnsupportedOperationException("use text() instead");
+    }
+
+    @Override
+    public int textOffset() throws IOException {
+        throw new UnsupportedOperationException("use text() instead");
+    }
+
+    @Override
+    public Number numberValue() throws IOException {
+        if (iterator != null && currentToken() == Token.VALUE_NUMBER) {
+            return (Number) iterator.currentValue();
+        } else {
+            throw new IllegalStateException("Cannot get numeric value for the current token " + currentToken());
+        }
+    }
+
+    @Override
+    public NumberType numberType() throws IOException {
+        Number number = numberValue();
+        if (number instanceof Integer) {
+            return NumberType.INT;
+        } else if (number instanceof BigInteger) {
+            return NumberType.BIG_INTEGER;
+        } else if (number instanceof Long) {
+            return NumberType.LONG;
+        } else if (number instanceof Float) {
+            return NumberType.FLOAT;
+        } else if (number instanceof Double) {
+            return NumberType.DOUBLE;
+        } else if (number instanceof BigDecimal) {
+            return NumberType.BIG_DECIMAL;
+        }
+        throw new IllegalStateException("No matching token for number_type [" + number.getClass() + "]");
+    }
+
+    @Override
+    public byte[] binaryValue() throws IOException {
+        if (iterator != null && iterator.currentValue() instanceof byte[]) {
+            return (byte[]) iterator.currentValue();
+        } else {
+            throw new IllegalStateException("Cannot get binary value for the current token " + currentToken());
+        }
+    }
+
+    @Override
+    public XContentLocation getTokenLocation() {
+        return new XContentLocation(0, 0);
+    }
+
+    @Override
+    public boolean isClosed() {
+        return closed;
+    }
+
+    @Override
+    public void close() throws IOException {
+        closed = true;
+    }
+
+    /**
+     * Iterator over the elements of the map
+     */
+    private abstract static class TokenIterator {
+        protected final TokenIterator parent;
+        protected final String name;
+        protected Token currentToken;
+        protected State state = State.BEFORE;
+
+        TokenIterator(TokenIterator parent, String name) {
+            this.parent = parent;
+            this.name = name;
+        }
+
+        public abstract TokenIterator next();
+
+        public abstract TokenIterator skipChildren();
+
+        public Token currentToken() {
+            return currentToken;
+        }
+
+        public abstract Object currentValue();
+
+        /**
+         * name of the field name of the current element
+         */
+        public abstract String currentName();
+
+        /**
+         * field name that the child element needs to inherit.
+         *
+         * In most cases this is the same as currentName() except with embedded arrays. In "foo": [[42]] the first START_ARRAY
+         * token will have the name "foo", but the second START_ARRAY will have no name.
+         */
+        public abstract String childName();
+
+        @SuppressWarnings("unchecked")
+        TokenIterator processValue(Object value) {
+            if (value instanceof Map) {
+                return new MapIterator(this, childName(), (Map<String, Object>) value).next();
+            } else if (value instanceof List) {
+                return new ArrayIterator(this, childName(), (List<Object>) value).next();
+            } else if (value instanceof Number) {
+                currentToken = Token.VALUE_NUMBER;
+            } else if (value instanceof String) {
+                currentToken = Token.VALUE_STRING;
+            } else if (value instanceof Boolean) {
+                currentToken = Token.VALUE_BOOLEAN;
+            } else if (value instanceof byte[]) {
+                currentToken = Token.VALUE_EMBEDDED_OBJECT;
+            } else if (value == null) {
+                currentToken = Token.VALUE_NULL;
+            }
+            return this;
+        }
+
+    }
+
+    private enum State {
+        BEFORE,
+        NAME,
+        VALUE,
+        AFTER
+    }
+
+    /**
+     * Iterator over the map
+     */
+    private static class MapIterator extends TokenIterator {
+
+        private final Iterator<Map.Entry<String, Object>> iterator;
+
+        private Map.Entry<String, Object> entry;
+
+        MapIterator(TokenIterator parent, String name, Map<String, Object> map) {
+            super(parent, name);
+            iterator = map.entrySet().iterator();
+        }
+
+        @Override
+        public TokenIterator next() {
+            switch (state) {
+                case BEFORE:
+                    state = State.NAME;
+                    currentToken = Token.START_OBJECT;
+                    return this;
+                case NAME:
+                    if (iterator.hasNext()) {
+                        state = State.VALUE;
+                        entry = iterator.next();
+                        currentToken = Token.FIELD_NAME;
+                        return this;
+                    } else {
+                        state = State.AFTER;
+                        entry = null;
+                        currentToken = Token.END_OBJECT;
+                        return this;
+                    }
+                case VALUE:
+                    state = State.NAME;
+                    return processValue(entry.getValue());
+                case AFTER:
+                    currentToken = null;
+                    if (parent == null) {
+                        return null;
+                    } else {
+                        return parent.next();
+                    }
+                default:
+                    throw new IllegalArgumentException("Unknown state " + state);
+
+            }
+        }
+
+        @Override
+        public TokenIterator skipChildren() {
+            state = State.AFTER;
+            entry = null;
+            currentToken = Token.END_OBJECT;
+            return this;
+        }
+
+        @Override
+        public Object currentValue() {
+            if (entry == null) {
+                throw new IllegalStateException("Cannot get value for non-value token " + currentToken);
+            }
+            return entry.getValue();
+        }
+
+        @Override
+        public String currentName() {
+            if (entry == null) {
+                return name;
+            }
+            return entry.getKey();
+        }
+
+        @Override
+        public String childName() {
+            return currentName();
+        }
+    }
+
+    private static class ArrayIterator extends TokenIterator {
+        private final Iterator<Object> iterator;
+
+        private Object value;
+
+        private ArrayIterator(TokenIterator parent, String name, List<Object> list) {
+            super(parent, name);
+            iterator = list.iterator();
+        }
+
+        @Override
+        public TokenIterator next() {
+            switch (state) {
+                case BEFORE:
+                    state = State.VALUE;
+                    currentToken = Token.START_ARRAY;
+                    return this;
+                case VALUE:
+                    if (iterator.hasNext()) {
+                        value = iterator.next();
+                        return processValue(value);
+                    } else {
+                        state = State.AFTER;
+                        value = null;
+                        currentToken = Token.END_ARRAY;
+                        return this;
+                    }
+                case AFTER:
+                    currentToken = null;
+                    if (parent == null) {
+                        return null;
+                    } else {
+                        return parent.next();
+                    }
+                default:
+                    throw new IllegalArgumentException("Unknown state " + state);
+            }
+        }
+
+        @Override
+        public TokenIterator skipChildren() {
+            state = State.AFTER;
+            value = null;
+            currentToken = Token.END_ARRAY;
+            return this;
+        }
+
+        @Override
+        public Object currentValue() {
+            return value;
+        }
+
+        @Override
+        public String currentName() {
+            if (parent == null || (currentToken != Token.START_ARRAY && currentToken != Token.END_ARRAY)) {
+                return null;
+            } else {
+                return name;
+            }
+        }
+
+        @Override
+        public String childName() {
+            return null;
+        }
+    }
+}

libs/x-content/src/test/java/org/elasticsearch/common/xcontent/MapXContentParserTests.java

@@ -0,0 +1,147 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch 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
+ *
+ *    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 org.elasticsearch.common.xcontent;
+
+import org.elasticsearch.common.CheckedConsumer;
+import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.xcontent.support.MapXContentParser;
+import org.elasticsearch.test.ESTestCase;
+
+import java.io.IOException;
+import java.util.Map;
+
+import static org.elasticsearch.common.xcontent.XContentParserTests.generateRandomObject;
+
+public class MapXContentParserTests extends ESTestCase {
+
+    public void testSimpleMap() throws IOException {
+        compareTokens(builder -> {
+            builder.startObject();
+            builder.field("string", "foo");
+            builder.field("number", 42);
+            builder.field("double", 42.5);
+            builder.field("bool", false);
+            builder.startArray("arr");
+            {
+                builder.value(10).value(20.0).value("30");
+                builder.startArray();
+                builder.value(30);
+                builder.endArray();
+            }
+            builder.endArray();
+            builder.startArray("nested_arr");
+            {
+                builder.startArray();
+                builder.value(10);
+                builder.endArray();
+            }
+            builder.endArray();
+            builder.startObject("obj");
+            {
+                builder.field("inner_string", "bar");
+                builder.startObject("inner_empty_obj");
+                builder.field("f", "a");
+                builder.endObject();
+            }
+            builder.endObject();
+            builder.field("bytes", new byte[]{1, 2, 3});
+            builder.nullField("nothing");
+            builder.endObject();
+        });
+    }
+
+
+    public void testRandomObject() throws IOException {
+        compareTokens(builder -> generateRandomObject(builder, randomIntBetween(0, 10)));
+    }
+
+    public void compareTokens(CheckedConsumer<XContentBuilder, IOException> consumer) throws IOException {
+        final XContentType xContentType = randomFrom(XContentType.values());
+        try (XContentBuilder builder = XContentBuilder.builder(xContentType.xContent())) {
+            consumer.accept(builder);
+            final Map<String, Object> map;
+            try (XContentParser parser = createParser(xContentType.xContent(), BytesReference.bytes(builder))) {
+                map = parser.mapOrdered();
+            }
+
+            try (XContentParser parser = createParser(xContentType.xContent(), BytesReference.bytes(builder))) {
+                try (XContentParser mapParser = new MapXContentParser(
+                    xContentRegistry(), LoggingDeprecationHandler.INSTANCE, map, xContentType)) {
+                    assertEquals(parser.contentType(), mapParser.contentType());
+                    XContentParser.Token token;
+                    assertEquals(parser.currentToken(), mapParser.currentToken());
+                    assertEquals(parser.currentName(), mapParser.currentName());
+                    do {
+                        token = parser.nextToken();
+                        XContentParser.Token mapToken = mapParser.nextToken();
+                        assertEquals(token, mapToken);
+                        assertEquals(parser.currentName(), mapParser.currentName());
+                        if (token != null && (token.isValue() || token == XContentParser.Token.VALUE_NULL)) {
+                            assertEquals(parser.textOrNull(), mapParser.textOrNull());
+                            switch (token) {
+                                case VALUE_STRING:
+                                    assertEquals(parser.text(), mapParser.text());
+                                    break;
+                                case VALUE_NUMBER:
+                                    assertEquals(parser.numberType(), mapParser.numberType());
+                                    assertEquals(parser.numberValue(), mapParser.numberValue());
+                                    if (parser.numberType() == XContentParser.NumberType.LONG ||
+                                        parser.numberType() == XContentParser.NumberType.INT) {
+                                        assertEquals(parser.longValue(), mapParser.longValue());
+                                        if (parser.longValue() <= Integer.MAX_VALUE && parser.longValue() >= Integer.MIN_VALUE) {
+                                            assertEquals(parser.intValue(), mapParser.intValue());
+                                            if (parser.longValue() <= Short.MAX_VALUE && parser.longValue() >= Short.MIN_VALUE) {
+                                                assertEquals(parser.shortValue(), mapParser.shortValue());
+                                            }
+                                        }
+                                    } else {
+                                        assertEquals(parser.doubleValue(), mapParser.doubleValue(), 0.000001);
+                                    }
+                                    break;
+                                case VALUE_BOOLEAN:
+                                    assertEquals(parser.booleanValue(), mapParser.booleanValue());
+                                    break;
+                                case VALUE_EMBEDDED_OBJECT:
+                                    assertArrayEquals(parser.binaryValue(), mapParser.binaryValue());
+                                    break;
+                                case VALUE_NULL:
+                                    assertNull(mapParser.textOrNull());
+                                    break;
+                            }
+                            assertEquals(parser.currentName(), mapParser.currentName());
+                            assertEquals(parser.isClosed(), mapParser.isClosed());
+                        } else if (token == XContentParser.Token.START_ARRAY || token == XContentParser.Token.START_OBJECT) {
+                            if (randomInt(5) == 0) {
+                                parser.skipChildren();
+                                mapParser.skipChildren();
+                            }
+                        }
+                    } while (token != null);
+                    assertEquals(parser.nextToken(), mapParser.nextToken());
+                    parser.close();
+                    mapParser.close();
+                    assertEquals(parser.isClosed(), mapParser.isClosed());
+                    assertTrue(mapParser.isClosed());
+                }
+            }
+
+        }
+    }
+}

libs/x-content/src/test/java/org/elasticsearch/common/xcontent/XContentParserTests.java

@@ -504,7 +504,7 @@ public class XContentParserTests extends ESTestCase {
      *
      * Returns the number of tokens in the marked field
      */
-    private int generateRandomObjectForMarking(XContentBuilder builder) throws IOException {
+    private static int generateRandomObjectForMarking(XContentBuilder builder) throws IOException {
         builder.startObject()
             .field("first_field", "foo")
             .field("marked_field");
@@ -513,7 +513,7 @@ public class XContentParserTests extends ESTestCase {
         return numberOfTokens;
     }
 
-    private int generateRandomObject(XContentBuilder builder, int level) throws IOException {
+    public static int generateRandomObject(XContentBuilder builder, int level) throws IOException {
         int tokens = 2;
         builder.startObject();
         int numberOfElements = randomInt(5);
@@ -525,7 +525,7 @@ public class XContentParserTests extends ESTestCase {
         return tokens;
     }
 
-    private int generateRandomValue(XContentBuilder builder, int level) throws IOException {
+    private static int generateRandomValue(XContentBuilder builder, int level) throws IOException {
         @SuppressWarnings("unchecked") CheckedSupplier<Integer, IOException> fieldGenerator = randomFrom(
             () -> {
                 builder.value(randomInt());
@@ -560,7 +560,7 @@ public class XContentParserTests extends ESTestCase {
         return fieldGenerator.get();
     }
 
-    private int generateRandomArray(XContentBuilder builder, int level) throws IOException {
+    private static int generateRandomArray(XContentBuilder builder, int level) throws IOException {
         int tokens = 2;
         int arraySize = randomInt(3);
         builder.startArray();

server/src/main/java/org/elasticsearch/common/geo/GeoUtils.java

@@ -23,15 +23,13 @@ import org.apache.lucene.spatial.prefix.tree.GeohashPrefixTree;
 import org.apache.lucene.spatial.prefix.tree.QuadPrefixTree;
 import org.apache.lucene.util.SloppyMath;
 import org.elasticsearch.ElasticsearchParseException;
-import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.unit.DistanceUnit;
 import org.elasticsearch.common.xcontent.LoggingDeprecationHandler;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
-import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 import org.elasticsearch.common.xcontent.XContentSubParser;
-import org.elasticsearch.common.xcontent.json.JsonXContent;
+import org.elasticsearch.common.xcontent.support.MapXContentParser;
 import org.elasticsearch.common.xcontent.support.XContentMapValues;
 import org.elasticsearch.geo.geometry.Rectangle;
 import org.elasticsearch.geo.utils.Geohash;
@@ -43,7 +41,7 @@ import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
 import org.elasticsearch.index.fielddata.SortingNumericDoubleValues;
 
 import java.io.IOException;
-import java.io.InputStream;
+import java.util.Collections;
 
 public class GeoUtils {
 
@@ -376,21 +374,12 @@ public class GeoUtils {
      * Array: two or more elements, the first element is longitude, the second is latitude, the rest is ignored if ignoreZValue is true
      */
     public static GeoPoint parseGeoPoint(Object value, final boolean ignoreZValue) throws ElasticsearchParseException {
-        try {
-            XContentBuilder content = JsonXContent.contentBuilder();
-            content.startObject();
-            content.field("null_value", value);
-            content.endObject();
-
-            try (InputStream stream = BytesReference.bytes(content).streamInput();
-                 XContentParser parser = JsonXContent.jsonXContent.createParser(
-                     NamedXContentRegistry.EMPTY, LoggingDeprecationHandler.INSTANCE, stream)) {
-                parser.nextToken(); // start object
-                parser.nextToken(); // field name
-                parser.nextToken(); // field value
-                return parseGeoPoint(parser, new GeoPoint(), ignoreZValue);
-            }
-
+        try (XContentParser parser = new MapXContentParser(NamedXContentRegistry.EMPTY, LoggingDeprecationHandler.INSTANCE,
+                Collections.singletonMap("null_value", value), null)) {
+            parser.nextToken(); // start object
+            parser.nextToken(); // field name
+            parser.nextToken(); // field value
+            return parseGeoPoint(parser, new GeoPoint(), ignoreZValue);
         } catch (IOException ex) {
             throw new ElasticsearchParseException("error parsing geopoint", ex);
         }

server/src/main/java/org/elasticsearch/common/geo/parsers/ShapeParser.java

@@ -20,18 +20,16 @@ package org.elasticsearch.common.geo.parsers;
 
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.geo.builders.ShapeBuilder;
 import org.elasticsearch.common.xcontent.LoggingDeprecationHandler;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.common.xcontent.XContent;
-import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.common.xcontent.json.JsonXContent;
+import org.elasticsearch.common.xcontent.support.MapXContentParser;
 import org.elasticsearch.index.mapper.BaseGeoShapeFieldMapper;
 
 import java.io.IOException;
-import java.io.InputStream;
+import java.util.Collections;
 
 /**
  * first point of entry for a shape parser
@@ -75,14 +73,8 @@ public interface ShapeParser {
     }
 
     static ShapeBuilder parse(Object value) throws IOException {
-        XContentBuilder content = JsonXContent.contentBuilder();
-        content.startObject();
-        content.field("value", value);
-        content.endObject();
-
-        try (InputStream stream = BytesReference.bytes(content).streamInput();
-             XContentParser parser = JsonXContent.jsonXContent.createParser(
-                 NamedXContentRegistry.EMPTY, LoggingDeprecationHandler.INSTANCE, stream)) {
+        try (XContentParser parser = new MapXContentParser(NamedXContentRegistry.EMPTY, LoggingDeprecationHandler.INSTANCE,
+                Collections.singletonMap("value", value), null)) {
             parser.nextToken(); // start object
             parser.nextToken(); // field name
             parser.nextToken(); // field value