Stream object

A CTF stream.

Stream objects are used in the streams property of the metadata object.

Properties

Property	Type	Description	Required?	Default value
$default	Boolean	True if this stream is the default stream	Optional	false
packet-context-type	Type object or string (alias name)	Type of packet context (must be a Structure type object)	Required	N/A
event-header-type	Type object or string (alias name)	Type of event header (must be a Structure type object)	Optional	No event header
event-context-type	Type object or string (alias name)	Type of stream event context (must be a Structure type object)	Optional	No stream event context
events	Associative array of event names (string) to Event objects	Stream events	Required	N/A
$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.

The $default property, if true, must not be set to false in other streams. Note that you can also set the default stream by name with the $default-stream property of the metadata object.

Each field of the packet context structure type (packet-context-type property) corresponds to one parameter of the generated packet opening function (prefixed with pc_), except for the following special fields, which are automatically written if present:

• timestamp_begin and timestamp_end (unsigned integer type objects, with a clock value property mapping): resp. open and close timestamps
• packet_size (unsigned integer type object, mandatory): packet size
• content_size (unsigned integer type object, mandatory): content size
• events_discarded (unsigned integer type object): number of discarded events so far

The timestamp_end field must exist if the timestamp_begin field exists, and vice versa.

Each field of the event header structure type (event-header-type property) corresponds to one parameter of the generated tracing function (prefixed with ecc_) (for a given event), except for the following special fields, which are automatically written if present:

• id (unsigned integer type object): event ID
• timestamp (unsigned integer type object, with a clock value property mapping): event timestamp

The id field must exist if there's more than one defined event in the stream.

Each field of the stream event context structure type (event-context-type property) corresponds to one parameter of the generated tracing function (prefixed with eh_) (for a given event).

Each field name of the packet-context-type, event-header-type, and event-context-type properties must be a valid C identifier.

The events property must contain at least one entry.

Example

$default: true
packet-context-type:
  class: struct
  fields:
    timestamp_begin: clock-int
    timestamp_end: clock-int
    packet_size: uint32
    content_size: uint32
    events_discarded: uint16
    my_custom_field: int12
event-header-type:
  class: struct
  fields:
    id: uint16
    timestamp: clock-int
event-context-type:
  class: struct
  fields:
    obj_id: uint8
events:
  msg_in:
    payload-type: msg-type