package virtdb.interface.pb;
import "common.proto";

// symbols are used to minimize the transfer of
// repeated information, such as hostname, filename and company
// we do not require the symbol value to be unique across SeqNo's
// however implementation should do its best to minimize duplicates
// otherwise this magic makes little sense.
// SeqNo is a sequnce number expected to be unique within the
// running application.

message Symbol {
  required   uint32       SeqNo                = 1;
  required   string       Value                = 2;
}

// start-date and time are represented as YYYYMMDD and HHMMSS
// format decimal numers. their purpose is to give a rough idea
// about the start time and distinguish betweeen processes together
// with Pid, Random, and the Symbols. these times are by no means
// precise timing information

message ProcessInfo {
  required   uint32       StartDate            = 1;
  required   uint32       StartTime            = 2;
  required   uint32       Pid                  = 3;
  required   uint32       Random               = 4;
  optional   uint32       NameSymbol           = 5;
  optional   uint32       HostSymbol           = 6;
}

// INFO and ERROR are expected to go unfiltered to the log sink.
// TRACEs can be buffered and discarded and may be sent only when
// there is a need for diagnosing the application. SIMPLE and SCOPED
// traces differ in that SCOPED traces go in pairs and show the
// entry and exit of a given scope, while SIMPLE traces are one-off
// trace events.

enum LogLevel {
  VIRTDB_INFO            = 1;
  VIRTDB_ERROR           = 2;
  VIRTDB_SIMPLE_TRACE    = 3;
  VIRTDB_SCOPED_TRACE    = 4;
  VIRTDB_STATUS          = 5;
}

// Log entries are sliced into a sequence of strings, variables or (string=variable)
// entries. i.e: 'Bad thing happened at' 'time=2000.01.01'
// This results a few Symbols:
//   Symbol := (SeqNo=#x, Value='Bad thing happened at')
//   Symbol := (SeqNo=#y, Value='time')
// And also a few LogParts:
//   LogPart := (IsVariable=false, Type=STRING, PartSymbol=#x)
//   LogPart := (IsVariable=true,  Type=DATE,   PartSymbol=#y)
// Plus one LogData record to store '2000.01.01' value.

// 1, if( part.isvariable() && part.hasdata() )
// 2, else if( part.hasdata() )
// 3, else if( part.has_partsymbol() )

message LogPart {
  required   bool         IsVariable         = 1;
  required   bool         HasData            = 2;
  optional   uint32       PartSymbol         = 3;
}

// LogHeader's purpose is to identify the log location. a static
// information that is identified by a sequence number. sequence
// number must be unique in the given process (running application).

message LogHeader {
  required   uint32       SeqNo                = 1;
  required   uint32       FileNameSymbol       = 2;
  required   uint32       LineNumber           = 3;
  required   uint32       FunctionNameSymbol   = 4;
  required   LogLevel     Level                = 5;
  required   uint32       LogStringSymbol      = 6;
  repeated   LogPart      Parts                = 7;
}

// LogData has the dynamic part of the actual log entry.
// The static non-changing parts are stored in the LogHeader
// to minimize the data transfers.

message LogData {
  required   uint32       HeaderSeqNo          = 1;
  required   uint64       ElapsedMicroSec      = 2;
  required   uint64       ThreadId             = 3;
  repeated   ValueType    Values               = 4;
  optional   bool         EndScope             = 5;
  optional   uint64       ReceivedAtMicroSec   = 6;
}

// LogRecord binds the Symbols, Headers and Data to the
// actual process. Symbols and Headers are sent at least
// once, but may be re-sent from time to time (or when
// asked). Data is the dynamic part of the log message.

// level# is the max importance of the message based on this
// priority list:
//  VIRTDB_ERROR           = 2;
//  VIRTDB_INFO            = 1;
//  VIRTDB_STATUS          = 5;
//  VIRTDB_SIMPLE_TRACE    = 3;
//  VIRTDB_SCOPED_TRACE    = 4;
//

message LogRecord { // PUSH, PUB-SUB: channel: "level# procname hostname"
  required   ProcessInfo  Process              = 1;
  repeated   Symbol       Symbols              = 2;
  repeated   LogHeader    Headers              = 3;
  repeated   LogData      Data                 = 4;
}