When fetching try jobs for a CL, include only the latest for each builder.

third_party/WebKit/Tools/Scripts/webkitpy/common/net/rietveld.py

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Utility functions to communicate with Rietveld."""
 
 import collections
 import json
 import logging
 import urllib2
 
 
 _log = logging.getLogger(__name__)
 
 BASE_CODEREVIEW_URL = 'https://codereview.chromium.org/api'
 
 TryJob = collections.namedtuple('TryJob', ('builder_name', 'build_number'))
 
 def latest_try_jobs(issue_number, builder_names, web, patchset_number=None):
     """Returns a list of TryJob objects for jobs on the latest patchset.
 
     Args:
         issue_number: A Rietveld issue number.
         builder_names: Builders that we're interested in; try jobs for only
             these builders will be listed.
         web: webkitpy.common.net.web.Web object (which can be mocked out).
         patchset_number: Use a specific patchset instead of the latest one.
 
     Returns:
-        A list of TryJob objects; empty list if none were found.
+        A list of TryJob objects for the latest job for each builder, on the
+        latest patchset. If none were found, an empty list is returned.
     """
     try:
         if patchset_number:
             url = _patchset_url(issue_number, patchset_number)
         else:
             url = _latest_patchset_url(issue_number, web)
         patchset_data = _get_json(url, web)
     except (urllib2.URLError, ValueError):
         return []
     jobs = []
     for job in patchset_data['try_job_results']:
         if job['builder'] not in builder_names:
             continue
         jobs.append(TryJob(
             builder_name=job['builder'],
             build_number=job['buildnumber']))
-    return jobs
+    return filter_latest_jobs(jobs)
 
 
 def _latest_patchset_url(issue_number, web):
     issue_data = _get_json(_issue_url(issue_number), web)
     latest_patchset_number = issue_data["patchsets"][-1]
     return _patchset_url(issue_number, latest_patchset_number)
 
 
 def _get_json(url, web):
     """Fetches JSON from a URL, and logs errors if the request was unsuccessful.
@@ skipping 15 matching lines @@
 
 
 def _issue_url(issue_number):
     return '%s/%s' % (BASE_CODEREVIEW_URL, issue_number)
 
 
 def _patchset_url(issue_number, patchset_number):
     return '%s/%s' % (_issue_url(issue_number), patchset_number)
 
 
+def filter_latest_jobs(jobs):
+    """Filters out the list of jobs to include only the latest for each builder.
+
+    Args:
+        jobs: A list of TryJob objects.
+
+    Returns:
+        A list of TryJob objects such that only the latest job for each builder
+        is kept.
+    """
+    builder_to_highest_number = {}
+    for j in jobs:
+        if j.build_number > builder_to_highest_number.get(j.builder_name, 0):
+            builder_to_highest_number[j.builder_name] = j.build_number
+    return [j for j in jobs if builder_to_highest_number[j.builder_name] == j.build_number]
+
+
 def get_latest_try_job_results(issue_number, web):
     url = _latest_patchset_url(issue_number, web)
     patchset_data = _get_json(url, web)
     results = {}
     for job in patchset_data['try_job_results']:
         results[job['builder']] = job['result']
     return results