<!--
Copyright 2025 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->

<!--
This file is used to generate a comprehensive list of Legion histograms
along with a detailed description for each histogram.

For best practices on writing histogram descriptions, see
https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histograms/README.md

Please follow the instructions in the OWNERS file in this directory to find a
reviewer.
-->

<histogram-configuration>

<histograms>

<histogram name="Legion.Client.FeatureName" enum="LegionFeatureName"
    expires_after="2026-12-01">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the Legion feature name for each request sent. Recorded for every
    request.
  </summary>
</histogram>

<histogram name="Legion.Client.RequestErrorCode" enum="LegionErrorCode"
    expires_after="2026-11-25">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the client-side errors that occur during the request lifecycle.
    Recorded for every failed request.
  </summary>
</histogram>

<histogram name="Legion.Client.RequestLatency.{Status}" units="ms"
    expires_after="2026-11-25">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the latency of a request sent from the Legion Client. This is the
    time from when the request is sent to when the response is received or the
    request times out. Recorded for every request. The suffix on the histogram
    name indicates the outcome: {Status}
  </summary>
  <token key="Status">
    <variant name="Error" summary="The request failed with an error."/>
    <variant name="Success" summary="The request was successful."/>
    <variant name="Timeout" summary="The request timed out."/>
  </token>
</histogram>

<histogram name="Legion.Client.RequestSize" units="bytes"
    expires_after="2026-11-25">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the size of the request payload sent from the Legion Client.
    Recorded for every request.
  </summary>
</histogram>

<histogram name="Legion.Client.ResponseSize.Success" units="bytes"
    expires_after="2026-11-25">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the size of the response payload received by the Legion Client for
    successful requests. Recorded for every successful request.
  </summary>
</histogram>

<histogram name="Legion.SecureChannel.GetAttestationRequestLatency.{Status}"
    units="ms" expires_after="2026-11-25">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the latency of getting the attestation request. This may involve
    server requests to get a blinded token. The suffix indicates the outcome:
    {Status}.
  </summary>
  <token key="Status">
    <variant name="Error" summary="Getting the attestation request failed."/>
    <variant name="Success"
        summary="Getting the attestation request was successful."/>
  </token>
</histogram>

<histogram name="Legion.SecureChannel.GetHandshakeMessageLatency.{Status}"
    units="ms" expires_after="2026-11-25">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the latency of getting the handshake message. The suffix indicates
    the outcome: {Status}.
  </summary>
  <token key="Status">
    <variant name="Error" summary="Getting the handshake message failed."/>
    <variant name="Success"
        summary="Getting the handshake message was successful."/>
  </token>
</histogram>

<histogram name="Legion.SecureChannel.RequestsPerSession" units="requests"
    expires_after="2026-11-28">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the number of requests sent in a single secure channel session.
    Recorded when a session is closed.
  </summary>
</histogram>

<histogram name="Legion.SecureChannel.SendAttestationRequestLatency.{Status}"
    units="ms" expires_after="2026-11-25">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the latency of sending the attestation request and receiving a
    response. This is the time from when the attestation request is sent to when
    the response is received and verified. The suffix indicates the outcome:
    {Status}.
  </summary>
  <token key="Status">
    <variant name="Error"
        summary="The attestation request failed with an error."/>
    <variant name="Success" summary="The attestation was successful."/>
  </token>
</histogram>

<histogram name="Legion.SecureChannel.SendHandshakeRequestLatency.{Status}"
    units="ms" expires_after="2026-11-25">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the latency of sending the handshake request and receiving a
    response. This is the time from when the handshake request is sent to when
    the response is received and verified. The suffix indicates the outcome:
    {Status}.
  </summary>
  <token key="Status">
    <variant name="Error"
        summary="The handshake request failed with an error."/>
    <variant name="Success" summary="The handshake was successful."/>
  </token>
</histogram>

<histogram name="Legion.SecureChannel.SessionDuration" units="ms"
    expires_after="2026-11-28">
  <owner>nikhiljakhar@google.com</owner>
  <owner>arabm@google.com</owner>
  <owner>dullweber@chromium.org</owner>
  <owner>lamzin@google.com</owner>
  <owner>saeideid@google.com</owner>
  <summary>
    Records the duration of a secure channel session. This is the time from when
    the session is established to when it is closed. Recorded when a session is
    closed.
  </summary>
</histogram>

</histograms>

</histogram-configuration>