[tracker-miners/sam/test-runner-fix: 14/24] functional-tests: Add a way to track MinerFS status changes

[Sam Thursfield <sthursfield src gnome org>]

commit 5d6ee7c1a129305c41496aed34f96829c31e1bf0
Author: Sam Thursfield <sam afuera me uk>
Date:   Fri Jan 4 19:52:47 2019 +0100

    functional-tests: Add a way to track MinerFS status changes
    
    This re-introduces a feature that I previously removed, as it turns out
    the 601-applications-sync test requires this feature. In general, tests
    that trigger miner-fs operations should continue to use
    await_resource_inserted() and await_resource_deleted(). For cases where
    we expect the miner to wake up but to not make any database changes
    (because they have already been made) it's now possible to use the new
    MinerFsHelper.await_wakeup_count() function.

 tests/functional-tests/common/utils/helpers.py | 70 ++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
---
diff --git a/tests/functional-tests/common/utils/helpers.py b/tests/functional-tests/common/utils/helpers.py
index 3faa9593d..4e1d45203 100644
--- a/tests/functional-tests/common/utils/helpers.py
+++ b/tests/functional-tests/common/utils/helpers.py
@@ -572,6 +572,10 @@ class StoreHelper (Helper):
             raise Exception ("Something fishy is going on")
 
 
+class WakeupCycleTimeoutException(RuntimeError):
+    pass
+
+
 class MinerFsHelper (Helper):
 
     PROCESS_NAME = 'tracker-miner-fs'
@@ -580,6 +584,13 @@ class MinerFsHelper (Helper):
 
     FLAGS = ['--initial-sleep=0']
 
+    def __init__ (self):
+        Helper.__init__(self)
+        self._progress_handler_id = 0
+        self._wakeup_count = 0
+        self._previous_status = None
+        self._target_wakeup_count = None
+
     def start (self):
         Helper.start (self)
 
@@ -590,9 +601,68 @@ class MinerFsHelper (Helper):
             self.bus, Gio.DBusProxyFlags.DO_NOT_AUTO_START, None,
             cfg.MINERFS_BUSNAME, cfg.MINERFS_INDEX_OBJ_PATH, cfg.MINER_INDEX_IFACE)
 
+        def signal_handler(proxy, sender_name, signal_name, parameters):
+            if signal_name == 'Progress':
+                self._progress_cb(*parameters.unpack())
+
+        self._progress_handler_id = self.miner_fs.connect('g-signal', signal_handler)
+
     def stop (self):
         Helper.stop (self)
 
+        if self._progress_handler_id != 0:
+            self.miner_fs.disconnect(self._progress_handler_id)
+
+    def _progress_cb (self, status, progress, remaining_time):
+        if self._previous_status is None:
+            self._previous_status = status
+        if self._previous_status != 'Idle' and status == 'Idle':
+            self._wakeup_count += 1
+
+        if self._target_wakeup_count is not None and self._wakeup_count >= self._target_wakeup_count:
+            self.loop.quit()
+
+    def wakeup_count(self):
+        """Return the number of wakeup-to-idle cycles the miner-fs completed."""
+        return self._wakeup_count
+
+    def await_wakeup_count (self, target_wakeup_count, timeout=REASONABLE_TIMEOUT):
+        """Block until the miner has completed N wakeup-and-idle cycles.
+
+        This function is for use by miner-fs tests that should trigger an
+        operation in the miner, but which do not cause a new resource to be
+        inserted. These tests can instead wait for the status to change from
+        Idle to Processing... and then back to Idle.
+
+        The miner may change its status any number of times, but you can use
+        this function reliably as follows:
+
+            wakeup_count = miner_fs.wakeup_count()
+            # Trigger a miner-fs operation somehow ...
+            miner_fs.await_wakeup_count(wakeup_count + 1)
+            # The miner has probably finished processing the operation now.
+
+        If the timeout is reached before enough wakeup cycles complete, an
+        exception will be raised.
+
+        """
+
+        assert self._target_wakeup_count is None
+
+        if self._wakeup_count >= target_wakeup_count:
+            log ("miner-fs wakeup count is at %s (target is %s). No need to wait" % (self._wakeup_count, 
target_wakeup_count))
+        else:
+            def _timeout_cb ():
+                raise WakeupCycleTimeoutException()
+            timeout_id = GLib.timeout_add_seconds (timeout, _timeout_cb)
+
+            log ("Waiting for miner-fs wakeup count of %s (currently %s)" % (target_wakeup_count, 
self._wakeup_count))
+            self._target_wakeup_count = target_wakeup_count
+            self.loop.run_checked()
+
+            self._target_wakeup_count = None
+            GLib.source_remove(timeout_id)
+
     def index_file (self, uri):
         return self.index.IndexFile('(s)', uri)