Synnefo » snf-ganeti

``/2/jobs/[job_id]/wait``

+++++++++++++++++++++++++

``GET``

~~~~~~~

Waits for changes on a job. Takes the following body parameters in a

dict:

``fields``

  The job fields on which to watch for changes.

``previous_job_info``

  Previously received field values or None if not yet available.

``previous_log_serial``

  Highest log serial number received so far or None if not yet

  available.

Returns None if no changes have been detected and a dict with two keys,

``job_info`` and ``log_entries`` otherwise.

# WaitForJobChange timeout

WFJC_TIMEOUT = (DEF_RWTO - 1) / 2

                           prev_job_info, prev_log_serial,

                           timeout=WFJC_TIMEOUT):

    """Waits for changes on a job.

    @param job_id: Job ID

    @type fields: list

    @param fields: List of field names to be observed

    @type prev_job_info: None or list

    @param prev_job_info: Previously received job information

    @type prev_log_serial: None or int/long

    @param prev_log_serial: Highest log serial number previously received

    @type timeout: int/float

    @param timeout: Timeout in seconds (values larger than L{WFJC_TIMEOUT} will

                    be capped to that value)

    """

    assert timeout >= 0, "Timeout can not be negative"

                            prev_log_serial,

                            min(WFJC_TIMEOUT, timeout)))

    re.compile(r'/2/jobs/(%s)/wait$' % job_id_pattern):

      rlib2.R_2_jobs_id_wait,

# Timeout for /2/jobs/[job_id]/wait. Gives job up to 10 seconds to change.

_WFJC_TIMEOUT = 10

class R_2_jobs_id_wait(baserlib.R_Generic):

  """/2/jobs/[job_id]/wait resource.

  """

  # WaitForJobChange provides access to sensitive information and blocks

  # machine resources (it's a blocking RAPI call), hence restricting access.

  GET_ACCESS = [rapi.RAPI_ACCESS_WRITE]

  def GET(self):

    """Waits for job changes.

    """

    job_id = self.items[0]

    fields = self.getBodyParameter("fields")

    prev_job_info = self.getBodyParameter("previous_job_info", None)

    prev_log_serial = self.getBodyParameter("previous_log_serial", None)

    if not isinstance(fields, list):

      raise http.HttpBadRequest("The 'fields' parameter should be a list")

    if not (prev_job_info is None or isinstance(prev_job_info, list)):

      raise http.HttpBadRequest("The 'previous_job_info' parameter should"

                                " be a list")

    if not (prev_log_serial is None or

            isinstance(prev_log_serial, (int, long))):

      raise http.HttpBadRequest("The 'previous_log_serial' parameter should"

                                " be a number")

    client = baserlib.GetClient()

    result = client.WaitForJobChangeOnce(job_id, fields,

                                         prev_job_info, prev_log_serial,

                                         timeout=_WFJC_TIMEOUT)

    if not result:

      raise http.HttpNotFound()

    if result == constants.JOB_NOTCHANGED:

      # No changes

      return None

    (job_info, log_entries) = result

    return {

      "job_info": job_info,

      "log_entries": log_entries,

      }