Metadata object

A metadata object defines the desired layout of the CTF trace to be produced by the generated C code. It is used by barectf to generate C code, as well as a corresponding CTF metadata file.

A metadata object is used as the metadata property of the configuration object.

Properties

Property	Type	Description	Required?	Default value
type-aliases	Associative array of strings (alias names) to [[type objects	Type object]] or strings (previous alias names)	Type aliases to be used in trace, stream, and event objects	Optional
$log-levels	Associative array of strings (log level names) to log level constant integers	Log levels to be used in event objects	Optional	{}
clocks	Associative array of strings (clock names) to [[clock objects	Clock object]]	Trace clocks	Optional
env	Associative array of strings (names) to strings or integers (values)	Trace environment variables	Optional	{}
trace	Trace object	Metadata common to the whole trace	Required	N/A
streams	Associative array of strings (stream names) to [[stream objects	Stream object]]	Trace streams	Required
[[$include	Including external YAML files]]	String or array of strings	Include base properties from external YAML file(s)	Optional

All the properties which have a default value can also be set to null to force this default value. This is especially useful when including external YAML files.

Each clock name of the clocks property must be a valid C identifier.

The streams property must contain at least one entry. Each stream name must be a valid C identifier.

Each environment variable name in the env property must be a valid C identifier. Those variables will be appended to some environment variables set by barectf itself.

The order of the type-aliases entries is important: a type alias may only inherit from another type alias if the latter is defined before.

Example

type-aliases:
  uint8:
    class: integer
    size: 8
  uint16:
    class: integer
    size: 16
  uint32:
    class: integer
    size: 32
  uint64:
    class: integer
    size: 64
  clock-int:
    $inherit: uint64
    property-mappings:
      - type: clock
        name: my_clock
        property: value
  byte: uint8
  uuid:
    class: array
    length: 16
    element-type: byte
$log-levels:
  emerg: 0
  alert: 1
  critical: 2
  error: 3
  warning: 4
  notice: 5
  info: 6
clocks:
  my_clock:
    freq: 1000000000
    offset:
      seconds: 1434072888
    $return-ctype: uint64_t
env:
  my_system_version: '0.3.2-2015.03'
  bID: 15
trace:
  byte-order: le
  uuid: auto
  packet-header-type:
    class: struct
    min-align: 8
    fields:
      magic: uint32
      uuid: uuid
      stream_id: uint8
streams:
  my_stream:
    packet-context-type:
      class: struct
      fields:
        timestamp_begin: clock-int
        timestamp_end: clock-int
        packet_size: uint32
        something: float
        content_size: uint32
        events_discarded: uint32
    event-header-type:
      class: struct
      fields:
        timestamp: clock-int
        id: uint16
    events:
      simple_uint32:
        log-level: error
        payload-type:
          class: struct
          fields:
            value: uint32
      simple_int16:
        payload-type:
          class: struct
          fields:
            value:
              $inherit: uint16
              signed: true