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Diffstat (limited to 'src/google/protobuf/wire_format_lite.h')
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diff --git a/src/google/protobuf/wire_format_lite.h b/src/google/protobuf/wire_format_lite.h new file mode 100644 index 00000000..580d4db0 --- /dev/null +++ b/src/google/protobuf/wire_format_lite.h @@ -0,0 +1,724 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. All rights reserved. +// https://developers.google.com/protocol-buffers/ +// +// Redistribution and use in source and binary forms, with or without +// 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. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// Author: kenton@google.com (Kenton Varda) +// atenasio@google.com (Chris Atenasio) (ZigZag transform) +// wink@google.com (Wink Saville) (refactored from wire_format.h) +// Based on original Protocol Buffers design by +// Sanjay Ghemawat, Jeff Dean, and others. +// +// This header is logically internal, but is made public because it is used +// from protocol-compiler-generated code, which may reside in other components. + +#ifndef GOOGLE_PROTOBUF_WIRE_FORMAT_LITE_H__ +#define GOOGLE_PROTOBUF_WIRE_FORMAT_LITE_H__ + +#include <string> +#include <google/protobuf/stubs/common.h> +#include <google/protobuf/message_lite.h> +#include <google/protobuf/io/coded_stream.h> // for CodedOutputStream::Varint32Size + +namespace google { + +namespace protobuf { + template <typename T> class RepeatedField; // repeated_field.h +} + +namespace protobuf { +namespace internal { + +class StringPieceField; + +// This class is for internal use by the protocol buffer library and by +// protocol-complier-generated message classes. It must not be called +// directly by clients. +// +// This class contains helpers for implementing the binary protocol buffer +// wire format without the need for reflection. Use WireFormat when using +// reflection. +// +// This class is really a namespace that contains only static methods. +class LIBPROTOBUF_EXPORT WireFormatLite { + public: + + // ----------------------------------------------------------------- + // Helper constants and functions related to the format. These are + // mostly meant for internal and generated code to use. + + // The wire format is composed of a sequence of tag/value pairs, each + // of which contains the value of one field (or one element of a repeated + // field). Each tag is encoded as a varint. The lower bits of the tag + // identify its wire type, which specifies the format of the data to follow. + // The rest of the bits contain the field number. Each type of field (as + // declared by FieldDescriptor::Type, in descriptor.h) maps to one of + // these wire types. Immediately following each tag is the field's value, + // encoded in the format specified by the wire type. Because the tag + // identifies the encoding of this data, it is possible to skip + // unrecognized fields for forwards compatibility. + + enum WireType { + WIRETYPE_VARINT = 0, + WIRETYPE_FIXED64 = 1, + WIRETYPE_LENGTH_DELIMITED = 2, + WIRETYPE_START_GROUP = 3, + WIRETYPE_END_GROUP = 4, + WIRETYPE_FIXED32 = 5, + }; + + // Lite alternative to FieldDescriptor::Type. Must be kept in sync. + enum FieldType { + TYPE_DOUBLE = 1, + TYPE_FLOAT = 2, + TYPE_INT64 = 3, + TYPE_UINT64 = 4, + TYPE_INT32 = 5, + TYPE_FIXED64 = 6, + TYPE_FIXED32 = 7, + TYPE_BOOL = 8, + TYPE_STRING = 9, + TYPE_GROUP = 10, + TYPE_MESSAGE = 11, + TYPE_BYTES = 12, + TYPE_UINT32 = 13, + TYPE_ENUM = 14, + TYPE_SFIXED32 = 15, + TYPE_SFIXED64 = 16, + TYPE_SINT32 = 17, + TYPE_SINT64 = 18, + MAX_FIELD_TYPE = 18, + }; + + // Lite alternative to FieldDescriptor::CppType. Must be kept in sync. + enum CppType { + CPPTYPE_INT32 = 1, + CPPTYPE_INT64 = 2, + CPPTYPE_UINT32 = 3, + CPPTYPE_UINT64 = 4, + CPPTYPE_DOUBLE = 5, + CPPTYPE_FLOAT = 6, + CPPTYPE_BOOL = 7, + CPPTYPE_ENUM = 8, + CPPTYPE_STRING = 9, + CPPTYPE_MESSAGE = 10, + MAX_CPPTYPE = 10, + }; + + // Helper method to get the CppType for a particular Type. + static CppType FieldTypeToCppType(FieldType type); + + // Given a FieldSescriptor::Type return its WireType + static inline WireFormatLite::WireType WireTypeForFieldType( + WireFormatLite::FieldType type) { + return kWireTypeForFieldType[type]; + } + + // Number of bits in a tag which identify the wire type. + static const int kTagTypeBits = 3; + // Mask for those bits. + static const uint32 kTagTypeMask = (1 << kTagTypeBits) - 1; + + // Helper functions for encoding and decoding tags. (Inlined below and in + // _inl.h) + // + // This is different from MakeTag(field->number(), field->type()) in the case + // of packed repeated fields. + static uint32 MakeTag(int field_number, WireType type); + static WireType GetTagWireType(uint32 tag); + static int GetTagFieldNumber(uint32 tag); + + // Compute the byte size of a tag. For groups, this includes both the start + // and end tags. + static inline int TagSize(int field_number, WireFormatLite::FieldType type); + + // Skips a field value with the given tag. The input should start + // positioned immediately after the tag. Skipped values are simply discarded, + // not recorded anywhere. See WireFormat::SkipField() for a version that + // records to an UnknownFieldSet. + static bool SkipField(io::CodedInputStream* input, uint32 tag); + + // Skips a field value with the given tag. The input should start + // positioned immediately after the tag. Skipped values are recorded to a + // CodedOutputStream. + static bool SkipField(io::CodedInputStream* input, uint32 tag, + io::CodedOutputStream* output); + + // Reads and ignores a message from the input. Skipped values are simply + // discarded, not recorded anywhere. See WireFormat::SkipMessage() for a + // version that records to an UnknownFieldSet. + static bool SkipMessage(io::CodedInputStream* input); + + // Reads and ignores a message from the input. Skipped values are recorded + // to a CodedOutputStream. + static bool SkipMessage(io::CodedInputStream* input, + io::CodedOutputStream* output); + +// This macro does the same thing as WireFormatLite::MakeTag(), but the +// result is usable as a compile-time constant, which makes it usable +// as a switch case or a template input. WireFormatLite::MakeTag() is more +// type-safe, though, so prefer it if possible. +#define GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(FIELD_NUMBER, TYPE) \ + static_cast<uint32>( \ + ((FIELD_NUMBER) << ::google::protobuf::internal::WireFormatLite::kTagTypeBits) \ + | (TYPE)) + + // These are the tags for the old MessageSet format, which was defined as: + // message MessageSet { + // repeated group Item = 1 { + // required int32 type_id = 2; + // required string message = 3; + // } + // } + static const int kMessageSetItemNumber = 1; + static const int kMessageSetTypeIdNumber = 2; + static const int kMessageSetMessageNumber = 3; + static const int kMessageSetItemStartTag = + GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kMessageSetItemNumber, + WireFormatLite::WIRETYPE_START_GROUP); + static const int kMessageSetItemEndTag = + GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kMessageSetItemNumber, + WireFormatLite::WIRETYPE_END_GROUP); + static const int kMessageSetTypeIdTag = + GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kMessageSetTypeIdNumber, + WireFormatLite::WIRETYPE_VARINT); + static const int kMessageSetMessageTag = + GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(kMessageSetMessageNumber, + WireFormatLite::WIRETYPE_LENGTH_DELIMITED); + + // Byte size of all tags of a MessageSet::Item combined. + static const int kMessageSetItemTagsSize; + + // Helper functions for converting between floats/doubles and IEEE-754 + // uint32s/uint64s so that they can be written. (Assumes your platform + // uses IEEE-754 floats.) + static uint32 EncodeFloat(float value); + static float DecodeFloat(uint32 value); + static uint64 EncodeDouble(double value); + static double DecodeDouble(uint64 value); + + // Helper functions for mapping signed integers to unsigned integers in + // such a way that numbers with small magnitudes will encode to smaller + // varints. If you simply static_cast a negative number to an unsigned + // number and varint-encode it, it will always take 10 bytes, defeating + // the purpose of varint. So, for the "sint32" and "sint64" field types, + // we ZigZag-encode the values. + static uint32 ZigZagEncode32(int32 n); + static int32 ZigZagDecode32(uint32 n); + static uint64 ZigZagEncode64(int64 n); + static int64 ZigZagDecode64(uint64 n); + + // ================================================================= + // Methods for reading/writing individual field. The implementations + // of these methods are defined in wire_format_lite_inl.h; you must #include + // that file to use these. + +// Avoid ugly line wrapping +#define input io::CodedInputStream* input_arg +#define output io::CodedOutputStream* output_arg +#define field_number int field_number_arg +#define INL GOOGLE_ATTRIBUTE_ALWAYS_INLINE + + // Read fields, not including tags. The assumption is that you already + // read the tag to determine what field to read. + + // For primitive fields, we just use a templatized routine parameterized by + // the represented type and the FieldType. These are specialized with the + // appropriate definition for each declared type. + template <typename CType, enum FieldType DeclaredType> INL + static bool ReadPrimitive(input, CType* value); + + // Reads repeated primitive values, with optimizations for repeats. + // tag_size and tag should both be compile-time constants provided by the + // protocol compiler. + template <typename CType, enum FieldType DeclaredType> INL + static bool ReadRepeatedPrimitive(int tag_size, + uint32 tag, + input, + RepeatedField<CType>* value); + + // Identical to ReadRepeatedPrimitive, except will not inline the + // implementation. + template <typename CType, enum FieldType DeclaredType> + static bool ReadRepeatedPrimitiveNoInline(int tag_size, + uint32 tag, + input, + RepeatedField<CType>* value); + + // Reads a primitive value directly from the provided buffer. It returns a + // pointer past the segment of data that was read. + // + // This is only implemented for the types with fixed wire size, e.g. + // float, double, and the (s)fixed* types. + template <typename CType, enum FieldType DeclaredType> INL + static const uint8* ReadPrimitiveFromArray(const uint8* buffer, CType* value); + + // Reads a primitive packed field. + // + // This is only implemented for packable types. + template <typename CType, enum FieldType DeclaredType> INL + static bool ReadPackedPrimitive(input, RepeatedField<CType>* value); + + // Identical to ReadPackedPrimitive, except will not inline the + // implementation. + template <typename CType, enum FieldType DeclaredType> + static bool ReadPackedPrimitiveNoInline(input, RepeatedField<CType>* value); + + // Read a packed enum field. If the is_valid function is not NULL, values for + // which is_valid(value) returns false are silently dropped. + static bool ReadPackedEnumNoInline(input, + bool (*is_valid)(int), + RepeatedField<int>* values); + + // Read a packed enum field. If the is_valid function is not NULL, values for + // which is_valid(value) returns false are appended to unknown_fields_stream. + static bool ReadPackedEnumPreserveUnknowns( + input, + field_number, + bool (*is_valid)(int), + io::CodedOutputStream* unknown_fields_stream, + RepeatedField<int>* values); + + // Read a string. ReadString(..., string* value) requires an existing string. + static inline bool ReadString(input, string* value); + // ReadString(..., string** p) is internal-only, and should only be called + // from generated code. It starts by setting *p to "new string" + // if *p == &GetEmptyStringAlreadyInited(). It then invokes + // ReadString(input, *p). This is useful for reducing code size. + static inline bool ReadString(input, string** p); + // Analogous to ReadString(). + static bool ReadBytes(input, string* value); + static bool ReadBytes(input, string** p); + + + enum Operation { + PARSE = 0, + SERIALIZE = 1, + }; + + // Returns true if the data is valid UTF-8. + static bool VerifyUtf8String(const char* data, int size, + Operation op, + const char* field_name); + + static inline bool ReadGroup (field_number, input, MessageLite* value); + static inline bool ReadMessage(input, MessageLite* value); + + // Like above, but de-virtualize the call to MergePartialFromCodedStream(). + // The pointer must point at an instance of MessageType, *not* a subclass (or + // the subclass must not override MergePartialFromCodedStream()). + template<typename MessageType> + static inline bool ReadGroupNoVirtual(field_number, input, + MessageType* value); + template<typename MessageType> + static inline bool ReadMessageNoVirtual(input, MessageType* value); + + // The same, but do not modify input's recursion depth. This is useful + // when reading a bunch of groups or messages in a loop, because then the + // recursion depth can be incremented before the loop and decremented after. + template<typename MessageType> + static inline bool ReadGroupNoVirtualNoRecursionDepth(field_number, input, + MessageType* value); + + template<typename MessageType> + static inline bool ReadMessageNoVirtualNoRecursionDepth(input, + MessageType* value); + + // Write a tag. The Write*() functions typically include the tag, so + // normally there's no need to call this unless using the Write*NoTag() + // variants. + INL static void WriteTag(field_number, WireType type, output); + + // Write fields, without tags. + INL static void WriteInt32NoTag (int32 value, output); + INL static void WriteInt64NoTag (int64 value, output); + INL static void WriteUInt32NoTag (uint32 value, output); + INL static void WriteUInt64NoTag (uint64 value, output); + INL static void WriteSInt32NoTag (int32 value, output); + INL static void WriteSInt64NoTag (int64 value, output); + INL static void WriteFixed32NoTag (uint32 value, output); + INL static void WriteFixed64NoTag (uint64 value, output); + INL static void WriteSFixed32NoTag(int32 value, output); + INL static void WriteSFixed64NoTag(int64 value, output); + INL static void WriteFloatNoTag (float value, output); + INL static void WriteDoubleNoTag (double value, output); + INL static void WriteBoolNoTag (bool value, output); + INL static void WriteEnumNoTag (int value, output); + + // Write fields, including tags. + static void WriteInt32 (field_number, int32 value, output); + static void WriteInt64 (field_number, int64 value, output); + static void WriteUInt32 (field_number, uint32 value, output); + static void WriteUInt64 (field_number, uint64 value, output); + static void WriteSInt32 (field_number, int32 value, output); + static void WriteSInt64 (field_number, int64 value, output); + static void WriteFixed32 (field_number, uint32 value, output); + static void WriteFixed64 (field_number, uint64 value, output); + static void WriteSFixed32(field_number, int32 value, output); + static void WriteSFixed64(field_number, int64 value, output); + static void WriteFloat (field_number, float value, output); + static void WriteDouble (field_number, double value, output); + static void WriteBool (field_number, bool value, output); + static void WriteEnum (field_number, int value, output); + + static void WriteString(field_number, const string& value, output); + static void WriteBytes (field_number, const string& value, output); + static void WriteStringMaybeAliased( + field_number, const string& value, output); + static void WriteBytesMaybeAliased( + field_number, const string& value, output); + + static void WriteGroup( + field_number, const MessageLite& value, output); + static void WriteMessage( + field_number, const MessageLite& value, output); + // Like above, but these will check if the output stream has enough + // space to write directly to a flat array. + static void WriteGroupMaybeToArray( + field_number, const MessageLite& value, output); + static void WriteMessageMaybeToArray( + field_number, const MessageLite& value, output); + + // Like above, but de-virtualize the call to SerializeWithCachedSizes(). The + // pointer must point at an instance of MessageType, *not* a subclass (or + // the subclass must not override SerializeWithCachedSizes()). + template<typename MessageType> + static inline void WriteGroupNoVirtual( + field_number, const MessageType& value, output); + template<typename MessageType> + static inline void WriteMessageNoVirtual( + field_number, const MessageType& value, output); + +#undef output +#define output uint8* target + + // Like above, but use only *ToArray methods of CodedOutputStream. + INL static uint8* WriteTagToArray(field_number, WireType type, output); + + // Write fields, without tags. + INL static uint8* WriteInt32NoTagToArray (int32 value, output); + INL static uint8* WriteInt64NoTagToArray (int64 value, output); + INL static uint8* WriteUInt32NoTagToArray (uint32 value, output); + INL static uint8* WriteUInt64NoTagToArray (uint64 value, output); + INL static uint8* WriteSInt32NoTagToArray (int32 value, output); + INL static uint8* WriteSInt64NoTagToArray (int64 value, output); + INL static uint8* WriteFixed32NoTagToArray (uint32 value, output); + INL static uint8* WriteFixed64NoTagToArray (uint64 value, output); + INL static uint8* WriteSFixed32NoTagToArray(int32 value, output); + INL static uint8* WriteSFixed64NoTagToArray(int64 value, output); + INL static uint8* WriteFloatNoTagToArray (float value, output); + INL static uint8* WriteDoubleNoTagToArray (double value, output); + INL static uint8* WriteBoolNoTagToArray (bool value, output); + INL static uint8* WriteEnumNoTagToArray (int value, output); + + // Write fields, including tags. + INL static uint8* WriteInt32ToArray(field_number, int32 value, output); + INL static uint8* WriteInt64ToArray(field_number, int64 value, output); + INL static uint8* WriteUInt32ToArray(field_number, uint32 value, output); + INL static uint8* WriteUInt64ToArray(field_number, uint64 value, output); + INL static uint8* WriteSInt32ToArray(field_number, int32 value, output); + INL static uint8* WriteSInt64ToArray(field_number, int64 value, output); + INL static uint8* WriteFixed32ToArray(field_number, uint32 value, output); + INL static uint8* WriteFixed64ToArray(field_number, uint64 value, output); + INL static uint8* WriteSFixed32ToArray(field_number, int32 value, output); + INL static uint8* WriteSFixed64ToArray(field_number, int64 value, output); + INL static uint8* WriteFloatToArray(field_number, float value, output); + INL static uint8* WriteDoubleToArray(field_number, double value, output); + INL static uint8* WriteBoolToArray(field_number, bool value, output); + INL static uint8* WriteEnumToArray(field_number, int value, output); + + INL static uint8* WriteStringToArray( + field_number, const string& value, output); + INL static uint8* WriteBytesToArray( + field_number, const string& value, output); + + // Whether to serialize deterministically (e.g., map keys are + // sorted) is a property of a CodedOutputStream, and in the process + // of serialization, the "ToArray" variants may be invoked. But they don't + // have a CodedOutputStream available, so they get an additional parameter + // telling them whether to serialize deterministically. + INL static uint8* InternalWriteGroupToArray( + field_number, const MessageLite& value, bool deterministic, output); + INL static uint8* InternalWriteMessageToArray( + field_number, const MessageLite& value, bool deterministic, output); + + // Like above, but de-virtualize the call to SerializeWithCachedSizes(). The + // pointer must point at an instance of MessageType, *not* a subclass (or + // the subclass must not override SerializeWithCachedSizes()). + template<typename MessageType> + INL static uint8* InternalWriteGroupNoVirtualToArray( + field_number, const MessageType& value, bool deterministic, output); + template<typename MessageType> + INL static uint8* InternalWriteMessageNoVirtualToArray( + field_number, const MessageType& value, bool deterministic, output); + + // For backward-compatibility, the last four methods also have versions + // that are non-deterministic always. + INL static uint8* WriteGroupToArray( + field_number, const MessageLite& value, output) { + return InternalWriteGroupToArray(field_number_arg, value, false, target); + } + INL static uint8* WriteMessageToArray( + field_number, const MessageLite& value, output) { + return InternalWriteMessageToArray(field_number_arg, value, false, target); + } + template<typename MessageType> + INL static uint8* WriteGroupNoVirtualToArray( + field_number, const MessageType& value, output) { + return InternalWriteGroupNoVirtualToArray(field_number_arg, value, false, + target); + } + template<typename MessageType> + INL static uint8* WriteMessageNoVirtualToArray( + field_number, const MessageType& value, output) { + return InternalWriteMessageNoVirtualToArray(field_number_arg, value, false, + target); + } + +#undef output +#undef input +#undef INL + +#undef field_number + + // Compute the byte size of a field. The XxSize() functions do NOT include + // the tag, so you must also call TagSize(). (This is because, for repeated + // fields, you should only call TagSize() once and multiply it by the element + // count, but you may have to call XxSize() for each individual element.) + static inline int Int32Size ( int32 value); + static inline int Int64Size ( int64 value); + static inline int UInt32Size (uint32 value); + static inline int UInt64Size (uint64 value); + static inline int SInt32Size ( int32 value); + static inline int SInt64Size ( int64 value); + static inline int EnumSize ( int value); + + // These types always have the same size. + static const int kFixed32Size = 4; + static const int kFixed64Size = 8; + static const int kSFixed32Size = 4; + static const int kSFixed64Size = 8; + static const int kFloatSize = 4; + static const int kDoubleSize = 8; + static const int kBoolSize = 1; + + static inline int StringSize(const string& value); + static inline int BytesSize (const string& value); + + static inline int GroupSize (const MessageLite& value); + static inline int MessageSize(const MessageLite& value); + + // Like above, but de-virtualize the call to ByteSize(). The + // pointer must point at an instance of MessageType, *not* a subclass (or + // the subclass must not override ByteSize()). + template<typename MessageType> + static inline int GroupSizeNoVirtual (const MessageType& value); + template<typename MessageType> + static inline int MessageSizeNoVirtual(const MessageType& value); + + // Given the length of data, calculate the byte size of the data on the + // wire if we encode the data as a length delimited field. + static inline int LengthDelimitedSize(int length); + + private: + // A helper method for the repeated primitive reader. This method has + // optimizations for primitive types that have fixed size on the wire, and + // can be read using potentially faster paths. + template <typename CType, enum FieldType DeclaredType> GOOGLE_ATTRIBUTE_ALWAYS_INLINE + static bool ReadRepeatedFixedSizePrimitive( + int tag_size, + uint32 tag, + google::protobuf::io::CodedInputStream* input, + RepeatedField<CType>* value); + + // Like ReadRepeatedFixedSizePrimitive but for packed primitive fields. + template <typename CType, enum FieldType DeclaredType> GOOGLE_ATTRIBUTE_ALWAYS_INLINE + static bool ReadPackedFixedSizePrimitive(google::protobuf::io::CodedInputStream* input, + RepeatedField<CType>* value); + + static const CppType kFieldTypeToCppTypeMap[]; + static const WireFormatLite::WireType kWireTypeForFieldType[]; + + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(WireFormatLite); +}; + +// A class which deals with unknown values. The default implementation just +// discards them. WireFormat defines a subclass which writes to an +// UnknownFieldSet. This class is used by ExtensionSet::ParseField(), since +// ExtensionSet is part of the lite library but UnknownFieldSet is not. +class LIBPROTOBUF_EXPORT FieldSkipper { + public: + FieldSkipper() {} + virtual ~FieldSkipper() {} + + // Skip a field whose tag has already been consumed. + virtual bool SkipField(io::CodedInputStream* input, uint32 tag); + + // Skip an entire message or group, up to an end-group tag (which is consumed) + // or end-of-stream. + virtual bool SkipMessage(io::CodedInputStream* input); + + // Deal with an already-parsed unrecognized enum value. The default + // implementation does nothing, but the UnknownFieldSet-based implementation + // saves it as an unknown varint. + virtual void SkipUnknownEnum(int field_number, int value); +}; + +// Subclass of FieldSkipper which saves skipped fields to a CodedOutputStream. + +class LIBPROTOBUF_EXPORT CodedOutputStreamFieldSkipper : public FieldSkipper { + public: + explicit CodedOutputStreamFieldSkipper(io::CodedOutputStream* unknown_fields) + : unknown_fields_(unknown_fields) {} + virtual ~CodedOutputStreamFieldSkipper() {} + + // implements FieldSkipper ----------------------------------------- + virtual bool SkipField(io::CodedInputStream* input, uint32 tag); + virtual bool SkipMessage(io::CodedInputStream* input); + virtual void SkipUnknownEnum(int field_number, int value); + + protected: + io::CodedOutputStream* unknown_fields_; +}; + + +// inline methods ==================================================== + +inline WireFormatLite::CppType +WireFormatLite::FieldTypeToCppType(FieldType type) { + return kFieldTypeToCppTypeMap[type]; +} + +inline uint32 WireFormatLite::MakeTag(int field_number, WireType type) { + return GOOGLE_PROTOBUF_WIRE_FORMAT_MAKE_TAG(field_number, type); +} + +inline WireFormatLite::WireType WireFormatLite::GetTagWireType(uint32 tag) { + return static_cast<WireType>(tag & kTagTypeMask); +} + +inline int WireFormatLite::GetTagFieldNumber(uint32 tag) { + return static_cast<int>(tag >> kTagTypeBits); +} + +inline int WireFormatLite::TagSize(int field_number, + WireFormatLite::FieldType type) { + int result = io::CodedOutputStream::VarintSize32( + field_number << kTagTypeBits); + if (type == TYPE_GROUP) { + // Groups have both a start and an end tag. + return result * 2; + } else { + return result; + } +} + +inline uint32 WireFormatLite::EncodeFloat(float value) { + union {float f; uint32 i;}; + f = value; + return i; +} + +inline float WireFormatLite::DecodeFloat(uint32 value) { + union {float f; uint32 i;}; + i = value; + return f; +} + +inline uint64 WireFormatLite::EncodeDouble(double value) { + union {double f; uint64 i;}; + f = value; + return i; +} + +inline double WireFormatLite::DecodeDouble(uint64 value) { + union {double f; uint64 i;}; + i = value; + return f; +} + +// ZigZag Transform: Encodes signed integers so that they can be +// effectively used with varint encoding. +// +// varint operates on unsigned integers, encoding smaller numbers into +// fewer bytes. If you try to use it on a signed integer, it will treat +// this number as a very large unsigned integer, which means that even +// small signed numbers like -1 will take the maximum number of bytes +// (10) to encode. ZigZagEncode() maps signed integers to unsigned +// in such a way that those with a small absolute value will have smaller +// encoded values, making them appropriate for encoding using varint. +// +// int32 -> uint32 +// ------------------------- +// 0 -> 0 +// -1 -> 1 +// 1 -> 2 +// -2 -> 3 +// ... -> ... +// 2147483647 -> 4294967294 +// -2147483648 -> 4294967295 +// +// >> encode >> +// << decode << + +inline uint32 WireFormatLite::ZigZagEncode32(int32 n) { + // Note: the right-shift must be arithmetic + return (static_cast<uint32>(n) << 1) ^ (n >> 31); +} + +inline int32 WireFormatLite::ZigZagDecode32(uint32 n) { + return (n >> 1) ^ -static_cast<int32>(n & 1); +} + +inline uint64 WireFormatLite::ZigZagEncode64(int64 n) { + // Note: the right-shift must be arithmetic + return (static_cast<uint64>(n) << 1) ^ (n >> 63); +} + +inline int64 WireFormatLite::ZigZagDecode64(uint64 n) { + return (n >> 1) ^ -static_cast<int64>(n & 1); +} + +// String is for UTF-8 text only, but, even so, ReadString() can simply +// call ReadBytes(). + +inline bool WireFormatLite::ReadString(io::CodedInputStream* input, + string* value) { + return ReadBytes(input, value); +} + +inline bool WireFormatLite::ReadString(io::CodedInputStream* input, + string** p) { + return ReadBytes(input, p); +} + +} // namespace internal +} // namespace protobuf + +} // namespace google +#endif // GOOGLE_PROTOBUF_WIRE_FORMAT_LITE_H__ |