Only calculate slave->build mapping once in json output.

third_party/buildbot_8_4p1/README.chromium

Index: third_party/buildbot_8_4p1/README.chromium
diff --git a/third_party/buildbot_8_4p1/README.chromium b/third_party/buildbot_8_4p1/README.chromium
index 6747f5a366d277182c08a5094d2fe4b1c5646201..516c8b3f262dbf6f1288c201ded789aa11b119ce 100644
--- a/third_party/buildbot_8_4p1/README.chromium
+++ b/third_party/buildbot_8_4p1/README.chromium
@@ -2916,3 +2916,65 @@ index df80ca6..5304401 100644
  
  from zope.interface import implements
  from twisted.python import log, components
+
+
+Speed up slave JSON construction.
+
+diff --git a/third_party/buildbot_8_4p1/buildbot/status/web/status_json.py b/third_party/buildbot_8_4p1/buildbot/status/web/status_json.py
+index 87a7f2d..09fa54f 100644
+--- a/third_party/buildbot_8_4p1/buildbot/status/web/status_json.py
++++ b/third_party/buildbot_8_4p1/buildbot/status/web/status_json.py
+@@ -623,7 +623,7 @@ class SlaveJsonResource(JsonResource):
+ """
+     pageTitle = 'Slave'
+ 
+-    def __init__(self, status, slave_status, buildcache=None):
++    def __init__(self, status, slave_status, buildcache):
+         JsonResource.__init__(self, status)
+         self.slave_status = slave_status
+         self.name = self.slave_status.getName()
+@@ -631,9 +631,8 @@ class SlaveJsonResource(JsonResource):
+ 
+         # buildcache is used to cache build information across multiple
+         # invocations of SlaveJsonResource. It should be set to an empty
+-        # collections.defaultdict(dict). Without it, each invocation will
+-        # do a full build scan.
+-        self.buildcache = buildcache or collections.defaultdict(dict)
++        # collections.defaultdict(dict).
++        self.buildcache = buildcache
+ 
+     def getBuilders(self):
+         if self.builders is None:
+@@ -644,22 +643,19 @@ class SlaveJsonResource(JsonResource):
+                     self.builders.append(builderName)
+         return self.builders
+ 
+-    def mapSlavesToBuilds(self):
+-        for builderName in self.getBuilders():
+-            builder_status = self.status.getBuilder(builderName)
+-            for i in range(1, builder_status.buildCacheSize - 1):
+-                build_status = builder_status.getBuild(-i)
+-                if not build_status or not build_status.isFinished():
+-                    # If not finished, it will appear in runningBuilds.
+-                    break

[Isaac (away), 2013/04/06 01:35:08]

This does not look like the diff from origin.

+-                slave = self.buildcache[build_status.getSlavename()]
+-                slave.setdefault(builderName, []).append(
+-                        build_status.getNumber())
+-
+     def getSlaveBuildMap(self):
+         if not self.buildcache:
+-            self.mapSlavesToBuilds()
++            for builderName in self.getBuilders():
++                builds = []
++                builder_status = self.status.getBuilder(builderName)
++                for i in range(1, builder_status.buildCacheSize - 1):
++                    build_status = builder_status.getBuild(-i)
++                    if not build_status or not build_status.isFinished():
++                        # If not finished, it will appear in runningBuilds.
++                        break
++                    slave = self.buildcache[build_status.getSlavename()]
++                    slave.setdefault(builderName, []).append(
++                            build_status.getNumber())
+         return self.buildcache[self.name]
+ 
+     def asDict(self, request):