From 1aa300c53f070436888150ae582dad23cddac03b Mon Sep 17 00:00:00 2001

From: David Kupka <dkupka@redhat.com>

Date: Mon, 15 Aug 2016 08:01:59 +0200

Subject: [PATCH] schema cache: Store API schema cache in memory

Read whole cache into memory and keep it there for lifetime of api

object. This removes the need to repetitively open/close the cache and

speeds up every access to it.

https://fedorahosted.org/freeipa/ticket/6048

Reviewed-By: Jan Cholasta <jcholast@redhat.com>

---

 ipaclient/remote_plugins/schema.py | 51 +++++++++++++++++++++-----------------

 1 file changed, 28 insertions(+), 23 deletions(-)

diff --git a/ipaclient/remote_plugins/schema.py b/ipaclient/remote_plugins/schema.py

index aadc891750782b0961bc46989e3693d1d3ed0ecb..2fc6cce3eca392447cd4230216900116002934f4 100644

--- a/ipaclient/remote_plugins/schema.py

+++ b/ipaclient/remote_plugins/schema.py

@@ -3,6 +3,7 @@

 #

 import collections

+import contextlib

 import errno

 import fcntl

 import json

@@ -315,24 +316,6 @@ class _SchemaObjectPlugin(_SchemaPlugin):

     schema_key = 'classes'

-class _LockedZipFile(zipfile.ZipFile):

-    """ Add locking to zipfile.ZipFile

-    Shared lock is used with read mode, exclusive with write mode.

-    """

-    def __enter__(self):

-        if 'r' in self.mode:

-            fcntl.flock(self.fp, fcntl.LOCK_SH)

-        elif 'w' in self.mode or 'a' in self.mode:

-            fcntl.flock(self.fp, fcntl.LOCK_EX)

-

-        return super(_LockedZipFile, self).__enter__()

-

-    def __exit__(self, type_, value, traceback):

-        fcntl.flock(self.fp, fcntl.LOCK_UN)

-

-        return super(_LockedZipFile, self).__exit__(type_, value, traceback)

-

-

 class _SchemaNameSpace(collections.Mapping):

     def __init__(self, schema, name):

@@ -450,6 +433,7 @@ class Schema(object):

         self._dict = {}

         self._namespaces = {}

         self._help = None

+        self._file = six.StringIO()

         for ns in self.namespaces:

             self._dict[ns] = {}

@@ -486,9 +470,20 @@ class Schema(object):

             except AttributeError:

                 pass

-    def _open_schema(self, filename, mode):

+    @contextlib.contextmanager

+    def _open(self, filename, mode):

         path = os.path.join(self._DIR, filename)

-        return _LockedZipFile(path, mode)

+

+        with open(path, mode) as f:

+            if mode.startswith('r'):

+                fcntl.flock(f, fcntl.LOCK_SH)

+            else:

+                fcntl.flock(f, fcntl.LOCK_EX)

+

+            try:

+                yield f

+            finally:

+                fcntl.flock(f, fcntl.LOCK_UN)

     def _fetch(self, client):

         if not client.isconnected():

@@ -523,7 +518,11 @@ class Schema(object):

         self._expiration = ttl + time.time()

     def _read_schema(self):

-        with self._open_schema(self._fingerprint, 'r') as schema:

+        self._file.truncate(0)

+        with self._open(self._fingerprint, 'r') as f:

+            self._file.write(f.read())

+

+        with zipfile.ZipFile(self._file, 'r') as schema:

             self._dict['fingerprint'] = self._fingerprint

             for name in schema.namelist():

@@ -566,7 +565,8 @@ class Schema(object):

                 logger.warning("Failed to write schema: {}".format(e))

                 return

-        with self._open_schema(self._fingerprint, 'w') as schema:

+        self._file.truncate(0)

+        with zipfile.ZipFile(self._file, 'w', zipfile.ZIP_DEFLATED) as schema:

             for key, value in self._dict.items():

                 if key in self.namespaces:

                     ns = value

@@ -579,8 +579,13 @@ class Schema(object):

             schema.writestr('_help',

                             json.dumps(self._generate_help(self._dict)))

+        self._file.seek(0)

+        with self._open(self._fingerprint, 'w') as f:

+            f.truncate(0)

+            f.write(self._file.read())

+

     def _read(self, path):

-        with self._open_schema(self._fingerprint, 'r') as zf:

+        with zipfile.ZipFile(self._file, 'r') as zf:

             return json.loads(zf.read(path))

     def read_namespace_member(self, namespace, member):

-- 

2.7.4