summary refs log tree commit diff
path: root/synapse/util
diff options
context:
space:
mode:
Diffstat (limited to 'synapse/util')
-rw-r--r--synapse/util/caches/stream_change_cache.py125
-rw-r--r--synapse/util/metrics.py4
-rw-r--r--synapse/util/patch_inline_callbacks.py36
-rw-r--r--synapse/util/stringutils.py21
4 files changed, 122 insertions, 64 deletions
diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py
index 235f64049c..e54f80d76e 100644
--- a/synapse/util/caches/stream_change_cache.py
+++ b/synapse/util/caches/stream_change_cache.py
@@ -14,17 +14,22 @@
 # limitations under the License.
 
 import logging
+from typing import Dict, FrozenSet, List, Mapping, Optional, Set, Union
 
 from six import integer_types
 
 from sortedcontainers import SortedDict
 
+from synapse.types import Collection
 from synapse.util import caches
 
 logger = logging.getLogger(__name__)
 
+# for now, assume all entities in the cache are strings
+EntityType = str
 
-class StreamChangeCache(object):
+
+class StreamChangeCache:
     """Keeps track of the stream positions of the latest change in a set of entities.
 
     Typically the entity will be a room or user id.
@@ -34,10 +39,23 @@ class StreamChangeCache(object):
     old then the cache will simply return all given entities.
     """
 
-    def __init__(self, name, current_stream_pos, max_size=10000, prefilled_cache=None):
+    def __init__(
+        self,
+        name: str,
+        current_stream_pos: int,
+        max_size=10000,
+        prefilled_cache: Optional[Mapping[EntityType, int]] = None,
+    ):
         self._max_size = int(max_size * caches.CACHE_SIZE_FACTOR)
-        self._entity_to_key = {}
-        self._cache = SortedDict()
+        self._entity_to_key = {}  # type: Dict[EntityType, int]
+
+        # map from stream id to the a set of entities which changed at that stream id.
+        self._cache = SortedDict()  # type: SortedDict[int, Set[EntityType]]
+
+        # the earliest stream_pos for which we can reliably answer
+        # get_all_entities_changed. In other words, one less than the earliest
+        # stream_pos for which we know _cache is valid.
+        #
         self._earliest_known_stream_pos = current_stream_pos
         self.name = name
         self.metrics = caches.register_cache("cache", self.name, self._cache)
@@ -46,7 +64,7 @@ class StreamChangeCache(object):
             for entity, stream_pos in prefilled_cache.items():
                 self.entity_has_changed(entity, stream_pos)
 
-    def has_entity_changed(self, entity, stream_pos):
+    def has_entity_changed(self, entity: EntityType, stream_pos: int) -> bool:
         """Returns True if the entity may have been updated since stream_pos
         """
         assert type(stream_pos) in integer_types
@@ -67,22 +85,27 @@ class StreamChangeCache(object):
         self.metrics.inc_hits()
         return False
 
-    def get_entities_changed(self, entities, stream_pos):
+    def get_entities_changed(
+        self, entities: Collection[EntityType], stream_pos: int
+    ) -> Union[Set[EntityType], FrozenSet[EntityType]]:
         """
         Returns subset of entities that have had new things since the given
         position.  Entities unknown to the cache will be returned.  If the
         position is too old it will just return the given list.
         """
-        assert type(stream_pos) is int
-
-        if stream_pos >= self._earliest_known_stream_pos:
-            changed_entities = {
-                self._cache[k]
-                for k in self._cache.islice(start=self._cache.bisect_right(stream_pos))
-            }
-
-            result = changed_entities.intersection(entities)
-
+        changed_entities = self.get_all_entities_changed(stream_pos)
+        if changed_entities is not None:
+            # We now do an intersection, trying to do so in the most efficient
+            # way possible (some of these sets are *large*). First check in the
+            # given iterable is already set that we can reuse, otherwise we
+            # create a set of the *smallest* of the two iterables and call
+            # `intersection(..)` on it (this can be twice as fast as the reverse).
+            if isinstance(entities, (set, frozenset)):
+                result = entities.intersection(changed_entities)
+            elif len(changed_entities) < len(entities):
+                result = set(changed_entities).intersection(entities)
+            else:
+                result = set(entities).intersection(changed_entities)
             self.metrics.inc_hits()
         else:
             result = set(entities)
@@ -90,13 +113,13 @@ class StreamChangeCache(object):
 
         return result
 
-    def has_any_entity_changed(self, stream_pos):
+    def has_any_entity_changed(self, stream_pos: int) -> bool:
         """Returns if any entity has changed
         """
         assert type(stream_pos) is int
 
         if not self._cache:
-            # If we have no cache, nothing can have changed.
+            # If the cache is empty, nothing can have changed.
             return False
 
         if stream_pos >= self._earliest_known_stream_pos:
@@ -106,42 +129,58 @@ class StreamChangeCache(object):
             self.metrics.inc_misses()
             return True
 
-    def get_all_entities_changed(self, stream_pos):
-        """Returns all entites that have had new things since the given
+    def get_all_entities_changed(self, stream_pos: int) -> Optional[List[EntityType]]:
+        """Returns all entities that have had new things since the given
         position. If the position is too old it will return None.
+
+        Returns the entities in the order that they were changed.
         """
         assert type(stream_pos) is int
 
-        if stream_pos >= self._earliest_known_stream_pos:
-            return [
-                self._cache[k]
-                for k in self._cache.islice(start=self._cache.bisect_right(stream_pos))
-            ]
-        else:
+        if stream_pos < self._earliest_known_stream_pos:
             return None
 
-    def entity_has_changed(self, entity, stream_pos):
+        changed_entities = []  # type: List[EntityType]
+
+        for k in self._cache.islice(start=self._cache.bisect_right(stream_pos)):
+            changed_entities.extend(self._cache[k])
+        return changed_entities
+
+    def entity_has_changed(self, entity: EntityType, stream_pos: int) -> None:
         """Informs the cache that the entity has been changed at the given
         position.
         """
         assert type(stream_pos) is int
 
-        if stream_pos > self._earliest_known_stream_pos:
-            old_pos = self._entity_to_key.get(entity, None)
-            if old_pos is not None:
-                stream_pos = max(stream_pos, old_pos)
-                self._cache.pop(old_pos, None)
-            self._cache[stream_pos] = entity
-            self._entity_to_key[entity] = stream_pos
-
-            while len(self._cache) > self._max_size:
-                k, r = self._cache.popitem(0)
-                self._earliest_known_stream_pos = max(
-                    k, self._earliest_known_stream_pos
-                )
-                self._entity_to_key.pop(r, None)
-
-    def get_max_pos_of_last_change(self, entity):
+        if stream_pos <= self._earliest_known_stream_pos:
+            return
+
+        old_pos = self._entity_to_key.get(entity, None)
+        if old_pos is not None:
+            if old_pos >= stream_pos:
+                # nothing to do
+                return
+            e = self._cache[old_pos]
+            e.remove(entity)
+            if not e:
+                # cache at this point is now empty
+                del self._cache[old_pos]
+
+        e1 = self._cache.get(stream_pos)
+        if e1 is None:
+            e1 = self._cache[stream_pos] = set()
+        e1.add(entity)
+        self._entity_to_key[entity] = stream_pos
+
+        # if the cache is too big, remove entries
+        while len(self._cache) > self._max_size:
+            k, r = self._cache.popitem(0)
+            self._earliest_known_stream_pos = max(k, self._earliest_known_stream_pos)
+            for entity in r:
+                del self._entity_to_key[entity]
+
+    def get_max_pos_of_last_change(self, entity: EntityType) -> int:
+
         """Returns an upper bound of the stream id of the last change to an
         entity.
         """
diff --git a/synapse/util/metrics.py b/synapse/util/metrics.py
index 7b18455469..ec61e14423 100644
--- a/synapse/util/metrics.py
+++ b/synapse/util/metrics.py
@@ -21,7 +21,7 @@ from prometheus_client import Counter
 
 from twisted.internet import defer
 
-from synapse.logging.context import LoggingContext
+from synapse.logging.context import LoggingContext, current_context
 from synapse.metrics import InFlightGauge
 
 logger = logging.getLogger(__name__)
@@ -106,7 +106,7 @@ class Measure(object):
             raise RuntimeError("Measure() objects cannot be re-used")
 
         self.start = self.clock.time()
-        parent_context = LoggingContext.current_context()
+        parent_context = current_context()
         self._logging_context = LoggingContext(
             "Measure[%s]" % (self.name,), parent_context
         )
diff --git a/synapse/util/patch_inline_callbacks.py b/synapse/util/patch_inline_callbacks.py
index 3925927f9f..fdff195771 100644
--- a/synapse/util/patch_inline_callbacks.py
+++ b/synapse/util/patch_inline_callbacks.py
@@ -32,7 +32,7 @@ def do_patch():
     Patch defer.inlineCallbacks so that it checks the state of the logcontext on exit
     """
 
-    from synapse.logging.context import LoggingContext
+    from synapse.logging.context import current_context
 
     global _already_patched
 
@@ -43,35 +43,35 @@ def do_patch():
     def new_inline_callbacks(f):
         @functools.wraps(f)
         def wrapped(*args, **kwargs):
-            start_context = LoggingContext.current_context()
+            start_context = current_context()
             changes = []  # type: List[str]
             orig = orig_inline_callbacks(_check_yield_points(f, changes))
 
             try:
                 res = orig(*args, **kwargs)
             except Exception:
-                if LoggingContext.current_context() != start_context:
+                if current_context() != start_context:
                     for err in changes:
                         print(err, file=sys.stderr)
 
                     err = "%s changed context from %s to %s on exception" % (
                         f,
                         start_context,
-                        LoggingContext.current_context(),
+                        current_context(),
                     )
                     print(err, file=sys.stderr)
                     raise Exception(err)
                 raise
 
             if not isinstance(res, Deferred) or res.called:
-                if LoggingContext.current_context() != start_context:
+                if current_context() != start_context:
                     for err in changes:
                         print(err, file=sys.stderr)
 
                     err = "Completed %s changed context from %s to %s" % (
                         f,
                         start_context,
-                        LoggingContext.current_context(),
+                        current_context(),
                     )
                     # print the error to stderr because otherwise all we
                     # see in travis-ci is the 500 error
@@ -79,23 +79,23 @@ def do_patch():
                     raise Exception(err)
                 return res
 
-            if LoggingContext.current_context() != LoggingContext.sentinel:
+            if current_context():
                 err = (
                     "%s returned incomplete deferred in non-sentinel context "
                     "%s (start was %s)"
-                ) % (f, LoggingContext.current_context(), start_context)
+                ) % (f, current_context(), start_context)
                 print(err, file=sys.stderr)
                 raise Exception(err)
 
             def check_ctx(r):
-                if LoggingContext.current_context() != start_context:
+                if current_context() != start_context:
                     for err in changes:
                         print(err, file=sys.stderr)
                     err = "%s completion of %s changed context from %s to %s" % (
                         "Failure" if isinstance(r, Failure) else "Success",
                         f,
                         start_context,
-                        LoggingContext.current_context(),
+                        current_context(),
                     )
                     print(err, file=sys.stderr)
                     raise Exception(err)
@@ -127,7 +127,7 @@ def _check_yield_points(f: Callable, changes: List[str]):
         function
     """
 
-    from synapse.logging.context import LoggingContext
+    from synapse.logging.context import current_context
 
     @functools.wraps(f)
     def check_yield_points_inner(*args, **kwargs):
@@ -136,7 +136,7 @@ def _check_yield_points(f: Callable, changes: List[str]):
         last_yield_line_no = gen.gi_frame.f_lineno
         result = None  # type: Any
         while True:
-            expected_context = LoggingContext.current_context()
+            expected_context = current_context()
 
             try:
                 isFailure = isinstance(result, Failure)
@@ -145,7 +145,7 @@ def _check_yield_points(f: Callable, changes: List[str]):
                 else:
                     d = gen.send(result)
             except (StopIteration, defer._DefGen_Return) as e:
-                if LoggingContext.current_context() != expected_context:
+                if current_context() != expected_context:
                     # This happens when the context is lost sometime *after* the
                     # final yield and returning. E.g. we forgot to yield on a
                     # function that returns a deferred.
@@ -159,7 +159,7 @@ def _check_yield_points(f: Callable, changes: List[str]):
                         % (
                             f.__qualname__,
                             expected_context,
-                            LoggingContext.current_context(),
+                            current_context(),
                             f.__code__.co_filename,
                             last_yield_line_no,
                         )
@@ -173,13 +173,13 @@ def _check_yield_points(f: Callable, changes: List[str]):
                 # This happens if we yield on a deferred that doesn't follow
                 # the log context rules without wrapping in a `make_deferred_yieldable`.
                 # We raise here as this should never happen.
-                if LoggingContext.current_context() is not LoggingContext.sentinel:
+                if current_context():
                     err = (
                         "%s yielded with context %s rather than sentinel,"
                         " yielded on line %d in %s"
                         % (
                             frame.f_code.co_name,
-                            LoggingContext.current_context(),
+                            current_context(),
                             frame.f_lineno,
                             frame.f_code.co_filename,
                         )
@@ -191,7 +191,7 @@ def _check_yield_points(f: Callable, changes: List[str]):
             except Exception as e:
                 result = Failure(e)
 
-            if LoggingContext.current_context() != expected_context:
+            if current_context() != expected_context:
 
                 # This happens because the context is lost sometime *after* the
                 # previous yield and *after* the current yield. E.g. the
@@ -206,7 +206,7 @@ def _check_yield_points(f: Callable, changes: List[str]):
                     % (
                         frame.f_code.co_name,
                         expected_context,
-                        LoggingContext.current_context(),
+                        current_context(),
                         last_yield_line_no,
                         frame.f_lineno,
                         frame.f_code.co_filename,
diff --git a/synapse/util/stringutils.py b/synapse/util/stringutils.py
index 2c0dcb5208..6899bcb788 100644
--- a/synapse/util/stringutils.py
+++ b/synapse/util/stringutils.py
@@ -13,10 +13,11 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+import itertools
 import random
 import re
 import string
+from collections import Iterable
 
 import six
 from six import PY2, PY3
@@ -126,3 +127,21 @@ def assert_valid_client_secret(client_secret):
         raise SynapseError(
             400, "Invalid client_secret parameter", errcode=Codes.INVALID_PARAM
         )
+
+
+def shortstr(iterable: Iterable, maxitems: int = 5) -> str:
+    """If iterable has maxitems or fewer, return the stringification of a list
+    containing those items.
+
+    Otherwise, return the stringification of a a list with the first maxitems items,
+    followed by "...".
+
+    Args:
+        iterable: iterable to truncate
+        maxitems: number of items to return before truncating
+    """
+
+    items = list(itertools.islice(iterable, maxitems + 1))
+    if len(items) <= maxitems:
+        return str(items)
+    return "[" + ", ".join(repr(r) for r in items[:maxitems]) + ", ...]"