Simple Log Service:Data encoding

Protobuf is a language-neutral, platform-independent format for exchanging structured data. Before writing logs to the server through an API, serialize the raw log data into a protobuf data stream. The following schema defines the required format:

message Log
{
    required uint32 Time = 1; // UNIX time format
    message Content
    {
        required string Key = 1;
        required string Value = 2;
    }  
    repeated Content Contents = 2;
    optional fixed32 Time_ns = 4; // The nanosecond part of the time
}

message LogTag
{
    required string Key = 1;
    required string Value = 2;
}

message LogGroup
{
    repeated Log Logs= 1;
    optional string Topic = 3;
    optional string Source = 4;
    repeated LogTag LogTags = 6;
}

message LogGroupList
{
    repeated LogGroup logGroupList = 1;
}

The schema defines four message types. The following table describes each field: