1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // 4 // Use of this source code is governed by a BSD-style 5 // license that can be found in the LICENSE file or at 6 // https://developers.google.com/open-source/licenses/bsd 7 8 // Adapted from the patch of kenton@google.com (Kenton Varda) 9 // See https://github.com/protocolbuffers/protobuf/pull/710 for details. 10 11 #ifndef GOOGLE_PROTOBUF_UTIL_DELIMITED_MESSAGE_UTIL_H__ 12 #define GOOGLE_PROTOBUF_UTIL_DELIMITED_MESSAGE_UTIL_H__ 13 14 #include <ostream> 15 16 #include "google/protobuf/io/coded_stream.h" 17 #include "google/protobuf/io/zero_copy_stream_impl.h" 18 #include "google/protobuf/message_lite.h" 19 20 // Must be included last. 21 #include "google/protobuf/port_def.inc" 22 23 namespace google { 24 namespace protobuf { 25 namespace util { 26 27 // Write a single size-delimited message to the given stream. Delimited 28 // format allows a single file or stream to contain multiple messages, 29 // whereas normally writing multiple non-delimited messages to the same 30 // stream would cause them to be merged. A delimited message is a varint 31 // encoding the message size followed by a message of exactly that size. 32 // 33 // Note that if you want to *read* a delimited message from a file descriptor 34 // or istream, you will need to construct an io::FileInputStream or 35 // io::OstreamInputStream (implementations of io::ZeroCopyStream) and use the 36 // utility function ParseDelimitedFromZeroCopyStream(). You must then 37 // continue to use the same ZeroCopyInputStream to read all further data from 38 // the stream until EOF. This is because these ZeroCopyInputStream 39 // implementations are buffered: they read a big chunk of data at a time, 40 // then parse it. As a result, they may read past the end of the delimited 41 // message. There is no way for them to push the extra data back into the 42 // underlying source, so instead you must keep using the same stream object. 43 bool PROTOBUF_EXPORT SerializeDelimitedToFileDescriptor( 44 const MessageLite& message, int file_descriptor); 45 46 bool PROTOBUF_EXPORT SerializeDelimitedToOstream(const MessageLite& message, 47 std::ostream* output); 48 49 // Read a single size-delimited message from the given stream. Delimited 50 // format allows a single file or stream to contain multiple messages, 51 // whereas normally parsing consumes the entire input. A delimited message 52 // is a varint encoding the message size followed by a message of exactly 53 // that size. 54 // 55 // If |clean_eof| is not NULL, then it will be set to indicate whether the 56 // stream ended cleanly. That is, if the stream ends without this method 57 // having read any data at all from it, then *clean_eof will be set true, 58 // otherwise it will be set false. Note that these methods return false 59 // on EOF, but they also return false on other errors, so |clean_eof| is 60 // needed to distinguish a clean end from errors. 61 bool PROTOBUF_EXPORT ParseDelimitedFromZeroCopyStream( 62 MessageLite* message, io::ZeroCopyInputStream* input, bool* clean_eof); 63 64 bool PROTOBUF_EXPORT ParseDelimitedFromCodedStream(MessageLite* message, 65 io::CodedInputStream* input, 66 bool* clean_eof); 67 68 // Write a single size-delimited message from the given stream. Delimited 69 // format allows a single file or stream to contain multiple messages, 70 // whereas normally writing multiple non-delimited messages to the same 71 // stream would cause them to be merged. A delimited message is a varint 72 // encoding the message size followed by a message of exactly that size. 73 bool PROTOBUF_EXPORT SerializeDelimitedToZeroCopyStream( 74 const MessageLite& message, io::ZeroCopyOutputStream* output); 75 76 bool PROTOBUF_EXPORT SerializeDelimitedToCodedStream( 77 const MessageLite& message, io::CodedOutputStream* output); 78 79 } // namespace util 80 } // namespace protobuf 81 } // namespace google 82 83 #include "google/protobuf/port_undef.inc" 84 85 #endif // GOOGLE_PROTOBUF_UTIL_DELIMITED_MESSAGE_UTIL_H__ 86