Stream Event Log File Format

The CAM Stream Event Log (CSEL) file contains the events and other metadata generated by a critical application whilst running in calibration mode. The generated data is in binary format with the intent to improve throughput and reduce the overhead in the critical applications.

The file is composed of multiple sections as described below. The sections must be in the order as they appear in this specification.

Files should use the extension .csel.

All multi-byte types are little-endian.

About the timestamp fields:
  • The file format does not assume or enforce an epoch.

  • The format depends on the clock used by the application.

About the Universally Unique Identifier (UUID) fields:
  • UUIDs are 16-byte long fields representing the 128-bit UUID in binary format

  • The file format does not enforce any UUID variant. UUIDs are used as an
    opaque data value and does not process the sub-fields of the UUID.

Header Section

Field

Size (in bytes)

Description

Signature

4

0x4d, 0x46, 0x4d, 0x4e

Format version

2

0x01, 0x00 for the 1.0 version

Reserved

2

Metadata Section

Field

Size (in bytes)

Description

UUID

16

Stream UUID

Stream name

64

64-byte string (including null-character)

Timestamp

8

Unsigned integer, stream init timestamp

State Control Section

Field

Size (in bytes)

Description

Target timeout between init and start messages

4

Unsigned integer, 0 indicates no timeout

Target timeout between start and the first event

4

Unsigned integer, cannot be zero

Log Entries Section

The remaining of the data is composed by zero or more entries as described below.

From a file format perspective, entries are allowed to be in any order ensuring that the files are deemed valid and allowing tools to process such files to detect and report on any invalid event sequence.

Start

Field

Size (in bytes)

Description

Entry identifier

1

0x01 - Stream start

Timestamp

8

Unsigned integer, stream start timestamp

Stop

Field

Size (in bytes)

Description

Entry identifier

1

0x02 - Stream stop

Timestamp

8

Unsigned integer, stream stop timestamp

End

Field

Size (in bytes)

Description

Entry identifier

1

0x03 - Stream end

Timestamp

8

Unsigned integer, stream end timestamp

Event

Field

Size (in bytes)

Description

Entry identifier

1

0x04 - Stream event

Timestamp

8

Unsigned integer, stream event timestamp

Sequence identifier

4

Unsigned integer

Event identifier

2

Unsigned integer

Reserved

2