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      1 // Protocol Buffers - Google's data interchange format
      2 // Copyright 2008 Google Inc.  All rights reserved.
      3 // http://code.google.com/p/protobuf/
      4 //
      5 // Redistribution and use in source and binary forms, with or without
      6 // modification, are permitted provided that the following conditions are
      7 // met:
      8 //
      9 //     * Redistributions of source code must retain the above copyright
     10 // notice, this list of conditions and the following disclaimer.
     11 //     * Redistributions in binary form must reproduce the above
     12 // copyright notice, this list of conditions and the following disclaimer
     13 // in the documentation and/or other materials provided with the
     14 // distribution.
     15 //     * Neither the name of Google Inc. nor the names of its
     16 // contributors may be used to endorse or promote products derived from
     17 // this software without specific prior written permission.
     18 //
     19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30 
     31 // Author: kenton (at) google.com (Kenton Varda)
     32 //         atenasio (at) google.com (Chris Atenasio) (ZigZag transform)
     33 //  Based on original Protocol Buffers design by
     34 //  Sanjay Ghemawat, Jeff Dean, and others.
     35 //
     36 // This header is logically internal, but is made public because it is used
     37 // from protocol-compiler-generated code, which may reside in other components.
     38 
     39 #ifndef GOOGLE_PROTOBUF_WIRE_FORMAT_H__
     40 #define GOOGLE_PROTOBUF_WIRE_FORMAT_H__
     41 
     42 #include <string>
     43 #include <google/protobuf/descriptor.pb.h>
     44 #include <google/protobuf/descriptor.h>
     45 #include <google/protobuf/message.h>
     46 #include <google/protobuf/wire_format_lite.h>
     47 
     48 // Do UTF-8 validation on string type in Debug build only
     49 #ifndef NDEBUG
     50 #define GOOGLE_PROTOBUF_UTF8_VALIDATION_ENABLED
     51 #endif
     52 
     53 namespace google {
     54 namespace protobuf {
     55   namespace io {
     56     class CodedInputStream;      // coded_stream.h
     57     class CodedOutputStream;     // coded_stream.h
     58   }
     59   class UnknownFieldSet;         // unknown_field_set.h
     60 }
     61 
     62 namespace protobuf {
     63 namespace internal {
     64 
     65 // This class is for internal use by the protocol buffer library and by
     66 // protocol-complier-generated message classes.  It must not be called
     67 // directly by clients.
     68 //
     69 // This class contains code for implementing the binary protocol buffer
     70 // wire format via reflection.  The WireFormatLite class implements the
     71 // non-reflection based routines.
     72 //
     73 // This class is really a namespace that contains only static methods
     74 class LIBPROTOBUF_EXPORT WireFormat {
     75  public:
     76 
     77   // Given a field return its WireType
     78   static inline WireFormatLite::WireType WireTypeForField(
     79       const FieldDescriptor* field);
     80 
     81   // Given a FieldSescriptor::Type return its WireType
     82   static inline WireFormatLite::WireType WireTypeForFieldType(
     83       FieldDescriptor::Type type);
     84 
     85   // Compute the byte size of a tag.  For groups, this includes both the start
     86   // and end tags.
     87   static inline int TagSize(int field_number, FieldDescriptor::Type type);
     88 
     89   // These procedures can be used to implement the methods of Message which
     90   // handle parsing and serialization of the protocol buffer wire format
     91   // using only the Reflection interface.  When you ask the protocol
     92   // compiler to optimize for code size rather than speed, it will implement
     93   // those methods in terms of these procedures.  Of course, these are much
     94   // slower than the specialized implementations which the protocol compiler
     95   // generates when told to optimize for speed.
     96 
     97   // Read a message in protocol buffer wire format.
     98   //
     99   // This procedure reads either to the end of the input stream or through
    100   // a WIRETYPE_END_GROUP tag ending the message, whichever comes first.
    101   // It returns false if the input is invalid.
    102   //
    103   // Required fields are NOT checked by this method.  You must call
    104   // IsInitialized() on the resulting message yourself.
    105   static bool ParseAndMergePartial(io::CodedInputStream* input,
    106                                    Message* message);
    107 
    108   // Serialize a message in protocol buffer wire format.
    109   //
    110   // Any embedded messages within the message must have their correct sizes
    111   // cached.  However, the top-level message need not; its size is passed as
    112   // a parameter to this procedure.
    113   //
    114   // These return false iff the underlying stream returns a write error.
    115   static void SerializeWithCachedSizes(
    116       const Message& message,
    117       int size, io::CodedOutputStream* output);
    118 
    119   // Implements Message::ByteSize() via reflection.  WARNING:  The result
    120   // of this method is *not* cached anywhere.  However, all embedded messages
    121   // will have their ByteSize() methods called, so their sizes will be cached.
    122   // Therefore, calling this method is sufficient to allow you to call
    123   // WireFormat::SerializeWithCachedSizes() on the same object.
    124   static int ByteSize(const Message& message);
    125 
    126   // -----------------------------------------------------------------
    127   // Helpers for dealing with unknown fields
    128 
    129   // Skips a field value of the given WireType.  The input should start
    130   // positioned immediately after the tag.  If unknown_fields is non-NULL,
    131   // the contents of the field will be added to it.
    132   static bool SkipField(io::CodedInputStream* input, uint32 tag,
    133                         UnknownFieldSet* unknown_fields);
    134 
    135   // Reads and ignores a message from the input.  If unknown_fields is non-NULL,
    136   // the contents will be added to it.
    137   static bool SkipMessage(io::CodedInputStream* input,
    138                           UnknownFieldSet* unknown_fields);
    139 
    140   // Write the contents of an UnknownFieldSet to the output.
    141   static void SerializeUnknownFields(const UnknownFieldSet& unknown_fields,
    142                                      io::CodedOutputStream* output);
    143   // Same as above, except writing directly to the provided buffer.
    144   // Requires that the buffer have sufficient capacity for
    145   // ComputeUnknownFieldsSize(unknown_fields).
    146   //
    147   // Returns a pointer past the last written byte.
    148   static uint8* SerializeUnknownFieldsToArray(
    149       const UnknownFieldSet& unknown_fields,
    150       uint8* target);
    151 
    152   // Same thing except for messages that have the message_set_wire_format
    153   // option.
    154   static void SerializeUnknownMessageSetItems(
    155       const UnknownFieldSet& unknown_fields,
    156       io::CodedOutputStream* output);
    157   // Same as above, except writing directly to the provided buffer.
    158   // Requires that the buffer have sufficient capacity for
    159   // ComputeUnknownMessageSetItemsSize(unknown_fields).
    160   //
    161   // Returns a pointer past the last written byte.
    162   static uint8* SerializeUnknownMessageSetItemsToArray(
    163       const UnknownFieldSet& unknown_fields,
    164       uint8* target);
    165 
    166   // Compute the size of the UnknownFieldSet on the wire.
    167   static int ComputeUnknownFieldsSize(const UnknownFieldSet& unknown_fields);
    168 
    169   // Same thing except for messages that have the message_set_wire_format
    170   // option.
    171   static int ComputeUnknownMessageSetItemsSize(
    172       const UnknownFieldSet& unknown_fields);
    173 
    174 
    175   // Helper functions for encoding and decoding tags.  (Inlined below and in
    176   // _inl.h)
    177   //
    178   // This is different from MakeTag(field->number(), field->type()) in the case
    179   // of packed repeated fields.
    180   static uint32 MakeTag(const FieldDescriptor* field);
    181 
    182   // Parse a single field.  The input should start out positioned immidately
    183   // after the tag.
    184   static bool ParseAndMergeField(
    185       uint32 tag,
    186       const FieldDescriptor* field,        // May be NULL for unknown
    187       Message* message,
    188       io::CodedInputStream* input);
    189 
    190   // Serialize a single field.
    191   static void SerializeFieldWithCachedSizes(
    192       const FieldDescriptor* field,        // Cannot be NULL
    193       const Message& message,
    194       io::CodedOutputStream* output);
    195 
    196   // Compute size of a single field.  If the field is a message type, this
    197   // will call ByteSize() for the embedded message, insuring that it caches
    198   // its size.
    199   static int FieldByteSize(
    200       const FieldDescriptor* field,        // Cannot be NULL
    201       const Message& message);
    202 
    203   // Parse/serialize a MessageSet::Item group.  Used with messages that use
    204   // opion message_set_wire_format = true.
    205   static bool ParseAndMergeMessageSetItem(
    206       io::CodedInputStream* input,
    207       Message* message);
    208   static void SerializeMessageSetItemWithCachedSizes(
    209       const FieldDescriptor* field,
    210       const Message& message,
    211       io::CodedOutputStream* output);
    212   static int MessageSetItemByteSize(
    213       const FieldDescriptor* field,
    214       const Message& message);
    215 
    216   // Computes the byte size of a field, excluding tags. For packed fields, it
    217   // only includes the size of the raw data, and not the size of the total
    218   // length, but for other length-delimited types, the size of the length is
    219   // included.
    220   static int FieldDataOnlyByteSize(
    221       const FieldDescriptor* field,        // Cannot be NULL
    222       const Message& message);
    223 
    224   enum Operation {
    225     PARSE,
    226     SERIALIZE,
    227   };
    228 
    229   // Verifies that a string field is valid UTF8, logging an error if not.
    230   static void VerifyUTF8String(const char* data, int size, Operation op);
    231 
    232  private:
    233   // Verifies that a string field is valid UTF8, logging an error if not.
    234   static void VerifyUTF8StringFallback(
    235       const char* data,
    236       int size,
    237       Operation op);
    238 
    239 
    240 
    241   GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(WireFormat);
    242 };
    243 
    244 // Subclass of FieldSkipper which saves skipped fields to an UnknownFieldSet.
    245 class LIBPROTOBUF_EXPORT UnknownFieldSetFieldSkipper : public FieldSkipper {
    246  public:
    247   UnknownFieldSetFieldSkipper(UnknownFieldSet* unknown_fields)
    248       : unknown_fields_(unknown_fields) {}
    249   virtual ~UnknownFieldSetFieldSkipper() {}
    250 
    251   // implements FieldSkipper -----------------------------------------
    252   virtual bool SkipField(io::CodedInputStream* input, uint32 tag);
    253   virtual bool SkipMessage(io::CodedInputStream* input);
    254   virtual void SkipUnknownEnum(int field_number, int value);
    255 
    256  private:
    257   UnknownFieldSet* unknown_fields_;
    258 };
    259 
    260 // inline methods ====================================================
    261 
    262 inline WireFormatLite::WireType WireFormat::WireTypeForField(
    263     const FieldDescriptor* field) {
    264   if (field->options().packed()) {
    265     return WireFormatLite::WIRETYPE_LENGTH_DELIMITED;
    266   } else {
    267     return WireTypeForFieldType(field->type());
    268   }
    269 }
    270 
    271 inline WireFormatLite::WireType WireFormat::WireTypeForFieldType(
    272     FieldDescriptor::Type type) {
    273   // Some compilers don't like enum -> enum casts, so we implicit_cast to
    274   // int first.
    275   return WireFormatLite::WireTypeForFieldType(
    276       static_cast<WireFormatLite::FieldType>(
    277         implicit_cast<int>(type)));
    278 }
    279 
    280 inline uint32 WireFormat::MakeTag(const FieldDescriptor* field) {
    281   return WireFormatLite::MakeTag(field->number(), WireTypeForField(field));
    282 }
    283 
    284 inline int WireFormat::TagSize(int field_number, FieldDescriptor::Type type) {
    285   // Some compilers don't like enum -> enum casts, so we implicit_cast to
    286   // int first.
    287   return WireFormatLite::TagSize(field_number,
    288       static_cast<WireFormatLite::FieldType>(
    289         implicit_cast<int>(type)));
    290 }
    291 
    292 inline void WireFormat::VerifyUTF8String(const char* data, int size,
    293     WireFormat::Operation op) {
    294 #ifdef GOOGLE_PROTOBUF_UTF8_VALIDATION_ENABLED
    295   WireFormat::VerifyUTF8StringFallback(data, size, op);
    296 #endif
    297 }
    298 
    299 
    300 }  // namespace internal
    301 }  // namespace protobuf
    302 
    303 }  // namespace google
    304 #endif  // GOOGLE_PROTOBUF_WIRE_FORMAT_H__
    305