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