bitbake: bitbake: cooker: add a new function to retrieve task signatures

adding a new command in cooker to compute and get task signatures

this commit also add the associated command and event needed to get the
signatures using tinfoil

(Bitbake rev: 05c15162de90c41dad67e37a95ec9fdb440a7864)

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/command.py

@@ -781,3 +781,9 @@ class CommandsAsync:
         bb.event.fire(bb.event.FindSigInfoResult(res), command.cooker.databuilder.mcdata[mc])
         command.finishAsyncCommand()
     findSigInfo.needcache = False
+
+    def getTaskSignatures(self, command, params):
+        res = command.cooker.getTaskSignatures(params[0], params[1])
+        bb.event.fire(bb.event.GetTaskSignatureResult(res), command.cooker.data)
+        command.finishAsyncCommand()
+    getTaskSignatures.needcache = True

bitbake/lib/bb/cooker.py

@@ -1442,6 +1442,37 @@ class BBCooker:
 
         self.idleCallBackRegister(buildFileIdle, rq)
 
+    def getTaskSignatures(self, target, tasks):
+        sig = []
+        getAllTaskSignatures = False
+
+        if not tasks:
+            tasks = ["do_build"]
+            getAllTaskSignatures = True
+
+        for task in tasks:
+            taskdata, runlist = self.buildTaskData(target, task, self.configuration.halt)
+            rq = bb.runqueue.RunQueue(self, self.data, self.recipecaches, taskdata, runlist)
+            rq.rqdata.prepare()
+
+            for l in runlist:
+                mc, pn, taskname, fn = l
+
+                taskdep = rq.rqdata.dataCaches[mc].task_deps[fn]
+                for t in taskdep['tasks']:
+                    if t in taskdep['nostamp'] or "setscene" in t:
+                        continue
+                    tid = bb.runqueue.build_tid(mc, fn, t)
+
+                    if t in task or getAllTaskSignatures:
+                        try:
+                            rq.rqdata.prepare_task_hash(tid)
+                            sig.append([pn, t, rq.rqdata.get_task_unihash(tid)])
+                        except KeyError:
+                            sig.append(self.getTaskSignatures(target, [t])[0])
+
+        return sig
+
     def buildTargets(self, targets, task):
         """
         Attempt to build the targets specified

bitbake/lib/bb/event.py

@@ -857,6 +857,14 @@ class FindSigInfoResult(Event):
         Event.__init__(self)
         self.result = result
 
+class GetTaskSignatureResult(Event):
+    """
+    Event to return results from GetTaskSignatures command
+    """
+    def __init__(self, sig):
+        Event.__init__(self)
+        self.sig = sig
+
 class ParseError(Event):
     """
     Event to indicate parse failed