Reader.java
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
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// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
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package com.google.protobuf;
import java.io.IOException;
import java.util.List;
import java.util.Map;
/** A reader of fields from a serialized protobuf message. */
// TODO(nathanmittler): Refactor to allow the reader to allocate properly sized lists.
@ExperimentalApi
interface Reader {
/** Value used to indicate that the end of input has been reached. */
int READ_DONE = Integer.MAX_VALUE;
/** Value used to indicate that the reader does not know the tag about the field. */
int TAG_UNKNOWN = 0;
boolean shouldDiscardUnknownFields();
/**
* Gets the field number for the current field being read.
*
* <p>TODO(liujisi): Rename it to make it more explicit about the side effect on the underlying
* buffer.
*
* @return the current field number or {@link #READ_DONE} if the end of input has been reached.
*/
int getFieldNumber() throws IOException;
/**
* Gets the wire tag of the current field.
*
* @return the current wire tag or {@link #TAG_UNKNOWN} if the reader does not know the tag of the
* current field.
*/
int getTag();
/**
* Skips the current field and advances the reader to the next field.
*
* @return {@code true} if there are more fields or {@code false} if the end of input has been
* reached.
*/
boolean skipField() throws IOException;
/**
* Reads and returns the next field of type {@code DOUBLE} and advances the reader to the next
* field.
*/
double readDouble() throws IOException;
/**
* Reads and returns the next field of type {@code FLOAT} and advances the reader to the next
* field.
*/
float readFloat() throws IOException;
/**
* Reads and returns the next field of type {@code UINT64} and advances the reader to the next
* field.
*/
long readUInt64() throws IOException;
/**
* Reads and returns the next field of type {@code INT64} and advances the reader to the next
* field.
*/
long readInt64() throws IOException;
/**
* Reads and returns the next field of type {@code INT32} and advances the reader to the next
* field.
*/
int readInt32() throws IOException;
/**
* Reads and returns the next field of type {@code FIXED64} and advances the reader to the next
* field.
*/
long readFixed64() throws IOException;
/**
* Reads and returns the next field of type {@code FIXED32} and advances the reader to the next
* field.
*/
int readFixed32() throws IOException;
/**
* Reads and returns the next field of type {@code BOOL} and advances the reader to the next
* field.
*/
boolean readBool() throws IOException;
/**
* Reads and returns the next field of type {@code STRING} and advances the reader to the next
* field. If the stream contains malformed UTF-8, replace the offending bytes with the standard
* UTF-8 replacement character.
*/
String readString() throws IOException;
/**
* Reads and returns the next field of type {@code STRING} and advances the reader to the next
* field. If the stream contains malformed UTF-8, throw exception {@link
* InvalidProtocolBufferException}.
*/
String readStringRequireUtf8() throws IOException;
// TODO(yilunchong): the lack of other opinions for whether to expose this on the interface
<T> T readMessageBySchemaWithCheck(Schema<T> schema, ExtensionRegistryLite extensionRegistry)
throws IOException;
/**
* Reads and returns the next field of type {@code MESSAGE} and advances the reader to the next
* field.
*/
<T> T readMessage(Class<T> clazz, ExtensionRegistryLite extensionRegistry) throws IOException;
/**
* Reads and returns the next field of type {@code GROUP} and advances the reader to the next
* field.
*
* @deprecated groups fields are deprecated.
*/
@Deprecated
<T> T readGroup(Class<T> clazz, ExtensionRegistryLite extensionRegistry) throws IOException;
// TODO(yilunchong): the lack of other opinions for whether to expose this on the interface
@Deprecated
<T> T readGroupBySchemaWithCheck(Schema<T> schema, ExtensionRegistryLite extensionRegistry)
throws IOException;
/**
* Reads and returns the next field of type {@code BYTES} and advances the reader to the next
* field.
*/
ByteString readBytes() throws IOException;
/**
* Reads and returns the next field of type {@code UINT32} and advances the reader to the next
* field.
*/
int readUInt32() throws IOException;
/**
* Reads and returns the next field of type {@code ENUM} and advances the reader to the next
* field.
*/
int readEnum() throws IOException;
/**
* Reads and returns the next field of type {@code SFIXED32} and advances the reader to the next
* field.
*/
int readSFixed32() throws IOException;
/**
* Reads and returns the next field of type {@code SFIXED64} and advances the reader to the next
* field.
*/
long readSFixed64() throws IOException;
/**
* Reads and returns the next field of type {@code SINT32} and advances the reader to the next
* field.
*/
int readSInt32() throws IOException;
/**
* Reads and returns the next field of type {@code SINT64} and advances the reader to the next
* field.
*/
long readSInt64() throws IOException;
/**
* Reads the next field of type {@code DOUBLE_LIST} or {@code DOUBLE_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readDoubleList(List<Double> target) throws IOException;
/**
* Reads the next field of type {@code FLOAT_LIST} or {@code FLOAT_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readFloatList(List<Float> target) throws IOException;
/**
* Reads the next field of type {@code UINT64_LIST} or {@code UINT64_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readUInt64List(List<Long> target) throws IOException;
/**
* Reads the next field of type {@code INT64_LIST} or {@code INT64_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readInt64List(List<Long> target) throws IOException;
/**
* Reads the next field of type {@code INT32_LIST} or {@code INT32_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readInt32List(List<Integer> target) throws IOException;
/**
* Reads the next field of type {@code FIXED64_LIST} or {@code FIXED64_LIST_PACKED} and advances
* the reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readFixed64List(List<Long> target) throws IOException;
/**
* Reads the next field of type {@code FIXED32_LIST} or {@code FIXED32_LIST_PACKED} and advances
* the reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readFixed32List(List<Integer> target) throws IOException;
/**
* Reads the next field of type {@code BOOL_LIST} or {@code BOOL_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readBoolList(List<Boolean> target) throws IOException;
/**
* Reads the next field of type {@code STRING_LIST} and advances the reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readStringList(List<String> target) throws IOException;
/**
* Reads the next field of type {@code STRING_LIST} and advances the reader to the next field. If
* the stream contains malformed UTF-8, throw exception {@link InvalidProtocolBufferException}.
*
* @param target the list that will receive the read values.
*/
void readStringListRequireUtf8(List<String> target) throws IOException;
/**
* Reads the next field of type {@code MESSAGE_LIST} and advances the reader to the next field.
*
* @param target the list that will receive the read values.
* @param targetType the type of the elements stored in the {@code target} list.
*/
<T> void readMessageList(
List<T> target, Schema<T> schema, ExtensionRegistryLite extensionRegistry) throws IOException;
<T> void readMessageList(
List<T> target, Class<T> targetType, ExtensionRegistryLite extensionRegistry)
throws IOException;
/**
* Reads the next field of type {@code GROUP_LIST} and advances the reader to the next field.
*
* @param target the list that will receive the read values.
* @param targetType the type of the elements stored in the {@code target} list.
* @deprecated groups fields are deprecated.
*/
@Deprecated
<T> void readGroupList(
List<T> target, Class<T> targetType, ExtensionRegistryLite extensionRegistry)
throws IOException;
@Deprecated
<T> void readGroupList(
List<T> target, Schema<T> targetType, ExtensionRegistryLite extensionRegistry)
throws IOException;
/**
* Reads the next field of type {@code BYTES_LIST} and advances the reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readBytesList(List<ByteString> target) throws IOException;
/**
* Reads the next field of type {@code UINT32_LIST} or {@code UINT32_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readUInt32List(List<Integer> target) throws IOException;
/**
* Reads the next field of type {@code ENUM_LIST} or {@code ENUM_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readEnumList(List<Integer> target) throws IOException;
/**
* Reads the next field of type {@code SFIXED32_LIST} or {@code SFIXED32_LIST_PACKED} and advances
* the reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readSFixed32List(List<Integer> target) throws IOException;
/**
* Reads the next field of type {@code SFIXED64_LIST} or {@code SFIXED64_LIST_PACKED} and advances
* the reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readSFixed64List(List<Long> target) throws IOException;
/**
* Reads the next field of type {@code SINT32_LIST} or {@code SINT32_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readSInt32List(List<Integer> target) throws IOException;
/**
* Reads the next field of type {@code SINT64_LIST} or {@code SINT64_LIST_PACKED} and advances the
* reader to the next field.
*
* @param target the list that will receive the read values.
*/
void readSInt64List(List<Long> target) throws IOException;
/**
* Reads the next field of type {@code MAP} and advances the reader to the next field.
*
* @param target the mutable map that will receive the read values.
* @param mapDefaultEntry the default entry of the map field.
* @param extensionRegistry the extension registry for parsing message value fields.
*/
<K, V> void readMap(
Map<K, V> target,
MapEntryLite.Metadata<K, V> mapDefaultEntry,
ExtensionRegistryLite extensionRegistry)
throws IOException;
}