content: /*
   * 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.generic;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.util.ConcurrentModificationException;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Collection;
  
  import org.apache.avro.AvroRuntimeException;
  import org.apache.avro.AvroTypeException;
  import org.apache.avro.Conversion;
  import org.apache.avro.Conversions;
  import org.apache.avro.LogicalType;
  import org.apache.avro.Schema;
  import org.apache.avro.Schema.Field;
  import org.apache.avro.path.TracingAvroTypeException;
  import org.apache.avro.UnresolvedUnionException;
  import org.apache.avro.io.DatumWriter;
  import org.apache.avro.io.Encoder;
  import org.apache.avro.path.ArrayPositionPredicate;
  import org.apache.avro.path.LocationStep;
  import org.apache.avro.path.MapKeyPredicate;
  import org.apache.avro.path.TracingClassCastException;
  import org.apache.avro.path.TracingNullPointException;
  import org.apache.avro.path.UnionTypePredicate;
  import org.apache.avro.util.SchemaUtil;
  
  /** {@link DatumWriter} for generic Java objects. */
  public class GenericDatumWriter<D> implements DatumWriter<D> {
    private final GenericData data;
    private Schema root;
  
    public GenericDatumWriter() {
      this(GenericData.get());
    }
  
    protected GenericDatumWriter(GenericData data) {
      this.data = data;
    }
  
    public GenericDatumWriter(Schema root) {
      this();
      setSchema(root);
    }
  
    public GenericDatumWriter(Schema root, GenericData data) {
      this(data);
      setSchema(root);
    }
  
    /** Return the {@link GenericData} implementation. */
    public GenericData getData() {
      return data;
    }
  
    public void setSchema(Schema root) {
      this.root = root;
    }
  
    public void write(D datum, Encoder out) throws IOException {
      Objects.requireNonNull(out, "Encoder cannot be null");
      try {
        write(root, datum, out);
      } catch (TracingNullPointException | TracingClassCastException | TracingAvroTypeException e) {
        throw e.summarize(root);
      }
    }
  
    /** Called to write data. */
    protected void write(Schema schema, Object datum, Encoder out) throws IOException {
      LogicalType logicalType = schema.getLogicalType();
      if (datum != null && logicalType != null) {
        Conversion<?> conversion = getData().getConversionByClass(datum.getClass(), logicalType);
        writeWithoutConversion(schema, convert(schema, logicalType, conversion, datum), out);
      } else {
        writeWithoutConversion(schema, datum, out);
      }
    }
  
    /**
     * Convert a high level representation of a logical type (such as a BigDecimal)
     * to its underlying representation object (such as a ByteBuffer).
     *
     * @throws IllegalArgumentException if a null schema or logicalType is passed in
     *                                  while datum and conversion are not null.
     *                                  Please be noticed that the exception type
     *                                  has changed. With version 1.8.0 and earlier,
     *                                  in above circumstance, the exception thrown
     *                                  out depends on the implementation of
     *                                  conversion (most likely a
     *                                  NullPointerException). Now, an
     *                                  IllegalArgumentException will be thrown out
     *                                  instead.
     */
    protected <T> Object convert(Schema schema, LogicalType logicalType, Conversion<T> conversion, Object datum) {
      try {
        if (conversion == null) {
          return datum;
        } else {
          return Conversions.convertToRawType(datum, schema, logicalType, conversion);
        }
      } catch (AvroRuntimeException e) {
        Throwable cause = e.getCause();
        if (cause != null && cause.getClass() == ClassCastException.class) {
          // This is to keep backwards compatibility. The convert function here used to
          // throw CCE. After being moved to Conversions, it throws AvroRuntimeException
          // instead. To keep as much same behaviour as before, this function checks if
          // the cause is a CCE. If yes, rethrow it in case any child class checks it.
          // This
          // behaviour can be changed later in future versions to make it consistent with
          // reading path, which throws AvroRuntimeException
          throw (ClassCastException) cause;
        } else {
          throw e;
        }
      }
    }
  
    /** Called to write data. */
    protected void writeWithoutConversion(Schema schema, Object datum, Encoder out) throws IOException {
      int unionIndex = -1;
      Schema.Type schemaType = schema.getType();
      try {
        switch (schemaType) {
        case RECORD:
          writeRecord(schema, datum, out);
          break;
        case ENUM:
          writeEnum(schema, datum, out);
          break;
        case ARRAY:
          writeArray(schema, datum, out);
          break;
        case MAP:
          writeMap(schema, datum, out);
          break;
        case UNION:
          unionIndex = resolveUnion(schema, datum);
          out.writeIndex(unionIndex);
          write(schema.getTypes().get(unionIndex), datum, out);
          break;
        case FIXED:
          writeFixed(schema, datum, out);
          break;
        case STRING:
          writeString(schema, datum, out);
          break;
        case BYTES:
          writeBytes(datum, out);
          break;
        case INT:
          out.writeInt(((Number) datum).intValue());
          break;
        case LONG:
          out.writeLong(((Number) datum).longValue());
          break;
        case FLOAT:
          out.writeFloat(((Number) datum).floatValue());
          break;
        case DOUBLE:
          out.writeDouble(((Number) datum).doubleValue());
          break;
        case BOOLEAN:
          out.writeBoolean((Boolean) datum);
          break;
        case NULL:
          out.writeNull();
          break;
        default:
          error(schema, datum);
        }
      } catch (TracingNullPointException | TracingClassCastException | TracingAvroTypeException e) {
        if (schemaType == Schema.Type.UNION) {
          e.tracePath(new UnionTypePredicate(schema.getTypes().get(unionIndex).getName()));
        }
        // writeArray() and writeMap() have their own handling
        throw e;
      } catch (NullPointerException e) {
        throw new TracingNullPointException(e, schema, false);
      } catch (ClassCastException e) {
        throw new TracingClassCastException(e, datum, schema, false);
      } catch (AvroTypeException e) {
        throw new TracingAvroTypeException(e);
      }
    }
  
    /** Helper method for adding a message to an NPE . */
    protected NullPointerException npe(NullPointerException e, String s) {
      NullPointerException result = new NullPointerException(e.getMessage() + s);
      result.initCause(e.getCause() == null ? e : e.getCause());
      return result;
    }
  
    /** Helper method for adding a message to an Class Cast Exception . */
    protected ClassCastException addClassCastMsg(ClassCastException e, String s) {
      ClassCastException result = new ClassCastException(e.getMessage() + s);
      result.initCause(e.getCause() == null ? e : e.getCause());
      return result;
    }
  
    /** Helper method for adding a message to an Avro Type Exception . */
    protected AvroTypeException addAvroTypeMsg(AvroTypeException e, String s) {
      return new AvroTypeException(e.getMessage() + s, e.getCause() == null ? e : e.getCause());
    }
  
    /**
     * Called to write a record. May be overridden for alternate record
     * representations.
     */
    protected void writeRecord(Schema schema, Object datum, Encoder out) throws IOException {
      Object state = data.getRecordState(datum, schema);
      for (Field f : schema.getFields()) {
        writeField(datum, f, out, state);
      }
    }
  
    /**
     * Called to write a single field of a record. May be overridden for more
     * efficient or alternate implementations.
     */
    protected void writeField(Object datum, Field f, Encoder out, Object state) throws IOException {
      Object value = data.getField(datum, f.name(), f.pos(), state);
      try {
        write(f.schema(), value, out);
      } catch (final UnresolvedUnionException uue) { // recreate it with the right field info
        final UnresolvedUnionException unresolvedUnionException = new UnresolvedUnionException(f.schema(), f, value);
        unresolvedUnionException.addSuppressed(uue);
        throw unresolvedUnionException;
      } catch (TracingNullPointException | TracingClassCastException | TracingAvroTypeException e) {
        e.tracePath(new LocationStep(".", f.name()));
        throw e;
      } catch (NullPointerException e) {
        throw npe(e, " in field " + f.name());
      } catch (ClassCastException cce) {
        throw addClassCastMsg(cce, " in field " + f.name());
      } catch (AvroTypeException ate) {
        throw addAvroTypeMsg(ate, " in field " + f.name());
      }
    }
  
    /**
     * Called to write an enum value. May be overridden for alternate enum
     * representations.
     */
    protected void writeEnum(Schema schema, Object datum, Encoder out) throws IOException {
      if (!data.isEnum(datum)) {
        AvroTypeException cause = new AvroTypeException(
            "value " + SchemaUtil.describe(datum) + " is not a " + SchemaUtil.describe(schema));
        throw new TracingAvroTypeException(cause);
      }
      out.writeEnum(schema.getEnumOrdinal(datum.toString()));
    }
  
    /**
     * Called to write a array. May be overridden for alternate array
     * representations.
     */
    protected void writeArray(Schema schema, Object datum, Encoder out) throws IOException {
      Schema element = schema.getElementType();
      long size = getArraySize(datum);
      long actualSize = 0;
      out.writeArrayStart();
      out.setItemCount(size);
      for (Iterator<?> it = getArrayElements(datum); it.hasNext();) {
        out.startItem();
        try {
          write(element, it.next(), out);
        } catch (TracingNullPointException | TracingClassCastException | TracingAvroTypeException e) {
          e.tracePath(new ArrayPositionPredicate(actualSize));
          throw e;
        }
        actualSize++;
      }
      out.writeArrayEnd();
      if (actualSize != size) {
        throw new ConcurrentModificationException(
            "Size of array written was " + size + ", but number of elements written was " + actualSize + ". ");
      }
    }
  
    /**
     * Called to find the index for a datum within a union. By default calls
     * {@link GenericData#resolveUnion(Schema,Object)}.
     */
    protected int resolveUnion(Schema union, Object datum) {
      return data.resolveUnion(union, datum);
    }
  
    /**
     * Called by the default implementation of {@link #writeArray} to get the size
     * of an array. The default implementation is for {@link Collection}.
     */
    protected long getArraySize(Object array) {
      return ((Collection<?>) array).size();
    }
  
    /**
     * Called by the default implementation of {@link #writeArray} to enumerate
     * array elements. The default implementation is for {@link Collection}.
     */
    protected Iterator<?> getArrayElements(Object array) {
      return ((Collection<?>) array).iterator();
    }
  
    /**
     * Called to write a map. May be overridden for alternate map representations.
     */
    protected void writeMap(Schema schema, Object datum, Encoder out) throws IOException {
      Schema value = schema.getValueType();
      int size = getMapSize(datum);
      int actualSize = 0;
      out.writeMapStart();
      out.setItemCount(size);
      for (Map.Entry<Object, Object> entry : getMapEntries(datum)) {
        out.startItem();
        String key;
        try {
          key = entry.getKey().toString();
        } catch (NullPointerException npe) {
          TracingNullPointException tnpe = new TracingNullPointException(npe, Schema.create(Schema.Type.STRING), false);
          tnpe.tracePath(new MapKeyPredicate(null));
          throw tnpe;
        }
        writeString(key, out);
        try {
          write(value, entry.getValue(), out);
        } catch (TracingNullPointException | TracingClassCastException | TracingAvroTypeException e) {
          e.tracePath(new MapKeyPredicate(key));
          throw e;
        }
        actualSize++;
      }
      out.writeMapEnd();
      if (actualSize != size) {
        throw new ConcurrentModificationException(
            "Size of map written was " + size + ", but number of entries written was " + actualSize + ". ");
      }
    }
  
    /**
     * Called by the default implementation of {@link #writeMap} to get the size of
     * a map. The default implementation is for {@link Map}.
     */
    @SuppressWarnings("unchecked")
    protected int getMapSize(Object map) {
      return ((Map) map).size();
    }
  
    /**
     * Called by the default implementation of {@link #writeMap} to enumerate map
     * elements. The default implementation is for {@link Map}.
     */
    @SuppressWarnings("unchecked")
    protected Iterable<Map.Entry<Object, Object>> getMapEntries(Object map) {
      return ((Map) map).entrySet();
    }
  
    /**
     * Called to write a string. May be overridden for alternate string
     * representations.
     */
    protected void writeString(Schema schema, Object datum, Encoder out) throws IOException {
      writeString(datum, out);
    }
  
    /**
     * Called to write a string. May be overridden for alternate string
     * representations.
     */
    protected void writeString(Object datum, Encoder out) throws IOException {
      out.writeString((CharSequence) datum);
    }
  
    /**
     * Called to write a bytes. May be overridden for alternate bytes
     * representations.
     */
    protected void writeBytes(Object datum, Encoder out) throws IOException {
      out.writeBytes((ByteBuffer) datum);
    }
  
    /**
     * Called to write a fixed value. May be overridden for alternate fixed
     * representations.
     */
    protected void writeFixed(Schema schema, Object datum, Encoder out) throws IOException {
      out.writeFixed(((GenericFixed) datum).bytes(), 0, schema.getFixedSize());
    }
  
    private void error(Schema schema, Object datum) {
      throw new AvroTypeException("value " + SchemaUtil.describe(datum) + " is not a " + SchemaUtil.describe(schema));
    }
  
  }
  