Add consume_from_share method to HostState class

Modify FilterScheduler._schedule_share to call new new method
consume_from_share (it was calling consume_from_volume).

Add HostState.consume_from_share to host_manager.

Change-Id: I124674afe739ccf9648f91fcfbc63fd3be7caecc
Closes-Bug: #1253860

bin/manila-all

@@ -64,7 +64,7 @@ if __name__ == '__main__':
     except (Exception, SystemExit):
         LOG.exception(_('Failed to load osapi_share'))
 
-    for binary in ['manila-share', 'manila-scheduler']:
+    for binary in ['manila-share', 'manila-scheduler', 'manila-api']:
         try:
             servers.append(service.Service.create(binary=binary))
         except (Exception, SystemExit):

manila/scheduler/filter_scheduler.py

@@ -156,7 +156,7 @@ class FilterScheduler(driver.Scheduler):
         best_host = weighed_hosts[0]
         LOG.debug(_("Choosing for share: %(best_host)s") % locals())
         #NOTE(rushiagr): updating the available space parameters at same place
-        best_host.obj.consume_from_volume(share_properties)
+        best_host.obj.consume_from_share(share_properties)
         return best_host
 
     def _populate_retry_share(self, filter_properties, properties):

manila/scheduler/host_manager.py

@@ -132,6 +132,19 @@ class HostState(object):
 
             self.updated = capability['timestamp']
 
+    def consume_from_share(self, share):
+        """Incrementally update host state from an share"""
+        share_gb = share['size']
+        if self.free_capacity_gb == 'infinite':
+            # There's virtually infinite space on back-end
+            pass
+        elif self.free_capacity_gb == 'unknown':
+            # Unable to determine the actual free space on back-end
+            pass
+        else:
+            self.free_capacity_gb -= share_gb
+        self.updated = timeutils.utcnow()
+
 
 class HostManager(object):
     """Base HostManager class."""

manila/tests/scheduler/test_host_manager.py

@@ -201,3 +201,49 @@ class HostStateTestCase(test.TestCase):
         fake_host.update_from_share_capability(share_capability)
         self.assertEqual(fake_host.total_capacity_gb, 'infinite')
         self.assertEqual(fake_host.free_capacity_gb, 'unknown')
+
+    def test_consume_from_share_capability(self):
+        fake_host = host_manager.HostState('host1')
+        share_size = 10
+        free_capacity = 100
+        fake_share = {'id': 'foo', 'size': share_size}
+
+        share_capability = {'total_capacity_gb': free_capacity * 2,
+                             'free_capacity_gb': free_capacity,
+                             'reserved_percentage': 0,
+                             'timestamp': None}
+
+        fake_host.update_from_share_capability(share_capability)
+        fake_host.consume_from_share(fake_share)
+        self.assertEqual(fake_host.free_capacity_gb,
+                         free_capacity - share_size)
+
+    def test_consume_from_share_infinite_capability(self):
+        fake_host = host_manager.HostState('host1')
+        share_size = 1000
+        fake_share = {'id': 'foo', 'size': share_size}
+
+        share_capability = {'total_capacity_gb': 'infinite',
+                             'free_capacity_gb': 'infinite',
+                             'reserved_percentage': 0,
+                             'timestamp': None}
+
+        fake_host.update_from_share_capability(share_capability)
+        fake_host.consume_from_share(fake_share)
+        self.assertEqual(fake_host.total_capacity_gb, 'infinite')
+        self.assertEqual(fake_host.free_capacity_gb, 'infinite')
+
+    def test_consume_from_share_unknown_capability(self):
+        fake_host = host_manager.HostState('host1')
+        share_size = 1000
+        fake_share = {'id': 'foo', 'size': share_size}
+
+        share_capability = {'total_capacity_gb': 'infinite',
+                             'free_capacity_gb': 'unknown',
+                             'reserved_percentage': 0,
+                             'timestamp': None}
+
+        fake_host.update_from_share_capability(share_capability)
+        fake_host.consume_from_share(fake_share)
+        self.assertEqual(fake_host.total_capacity_gb, 'infinite')
+        self.assertEqual(fake_host.free_capacity_gb, 'unknown')