From 473596a5736b3f5a0b0997d05b1e9b2be7b50c0d Mon Sep 17 00:00:00 2001
From: Markus Unterwaditzer <markus@unterwaditzer.net>
Date: Sun, 16 Feb 2014 15:35:51 +0100
Subject: [PATCH] Storage API improvements

---
 vdirsyncer/storage/base.py       | 23 ++++++++++++++++-------
 vdirsyncer/storage/filesystem.py | 21 ++++++++++++---------
 vdirsyncer/storage/memory.py     | 25 ++++++++++++++++---------
 3 files changed, 44 insertions(+), 25 deletions(-)

diff --git a/vdirsyncer/storage/base.py b/vdirsyncer/storage/base.py
index 6c1a313..1ebeaf0 100644
--- a/vdirsyncer/storage/base.py
+++ b/vdirsyncer/storage/base.py
@@ -29,20 +29,28 @@ class Storage(object):
         self.fileext = fileext
         self.item_class = item_class
 
-    def list_items(self):
+    def list(self):
         '''
         :returns: list of (uid, etag)
         '''
         raise NotImplementedError()
 
-    def get_items(self, uids):
+    def get(self, uid):
         '''
-        :param uids: list of uids to fetch
-        :returns: list of (object, uid, etag)
+        :param uid: uid to fetch
+        :returns: (object, uid, etag)
         '''
         raise NotImplementedError()
 
-    def item_exists(self, uid):
+    def get_multi(self, uids):
+        '''
+        :param uids: list of uids to fetch
+        :returns: iterable of (object, uid, etag)
+        '''
+        for uid in uids:
+            yield self.get(uid)
+
+    def has(self, uid):
         '''
         check if item exists
         :returns: True or False
@@ -67,8 +75,9 @@ class Storage(object):
         '''
         raise NotImplementedError()
 
-    def delete(self, uid):
+    def delete(self, uid, etag):
         '''
-        Delete the object, raise exceptions on error, no return value
+        Delete the object, raise exceptions when etag doesn't match, no return
+        value
         '''
         raise NotImplementedError()
diff --git a/vdirsyncer/storage/filesystem.py b/vdirsyncer/storage/filesystem.py
index 9a6948b..8a94f21 100644
--- a/vdirsyncer/storage/filesystem.py
+++ b/vdirsyncer/storage/filesystem.py
@@ -23,20 +23,19 @@ class FilesystemStorage(Storage):
     def _get_filepath(self, uid):
         return os.path.join(self.path, uid + self.fileext)
 
-    def list_items(self):
+    def list(self):
         for fname in os.listdir(self.path):
             fpath = os.path.join(self.path, fname)
             if os.path.isfile(fpath) and fname.endswith(self.fileext):
                 uid = fname[:-len(self.fileext)]
                 yield uid, os.path.getmtime(fpath)
 
-    def get_items(self, uids):
-        for uid in uids:
-            fpath = self._get_filepath(uid)
-            with open(fpath, 'rb') as f:
-                yield Item(f.read()), uid, os.path.getmtime(fpath)
+    def get(self, uid):
+        fpath = self._get_filepath(uid)
+        with open(fpath, 'rb') as f:
+            return Item(f.read()), uid, os.path.getmtime(fpath)
 
-    def item_exists(self, uid):
+    def has(self, uid):
         return os.path.isfile(self._get_filepath(uid))
 
     def upload(self, obj):
@@ -54,9 +53,13 @@ class FilesystemStorage(Storage):
         actual_etag = os.path.getmtime(fpath)
         if etag != actual_etag:
             raise exceptions.WrongEtagError(etag, actual_etag)
+
         with open(fpath, 'wb') as f:
             f.write(obj.raw)
         return os.path.getmtime(fpath)
 
-    def delete(self, uid):
-        os.remove(self._get_filepath(uid))
+    def delete(self, uid, etag):
+        fpath = self._get_filepath(uid)
+        if etag != os.path.getmtime(fpath):
+            raise exceptions.WrongEtagError(etag, actual_etag)
+        os.remove(fpath)
diff --git a/vdirsyncer/storage/memory.py b/vdirsyncer/storage/memory.py
index 8485c84..92c263a 100644
--- a/vdirsyncer/storage/memory.py
+++ b/vdirsyncer/storage/memory.py
@@ -19,16 +19,15 @@ class MemoryStorage(Storage):
         self.items = {}  # uid => (etag, object)
         super(MemoryStorage, self).__init__(**kwargs)
 
-    def list_items(self):
+    def list(self):
         for uid, (etag, obj) in self.items.items():
             yield uid, etag
 
-    def get_items(self, uids):
-        for uid in uids:
-            etag, obj = self.items[uid]
-            yield obj, uid, etag
+    def get(self, uid):
+        etag, obj = self.items[uid]
+        return obj, uid, etag
 
-    def item_exists(self, uid):
+    def has(self, uid):
         return uid in self.items
 
     def upload(self, obj):
@@ -41,9 +40,17 @@ class MemoryStorage(Storage):
     def update(self, obj, etag):
         if obj.uid not in self.items:
             raise exceptions.NotFoundError(obj)
-        etag = datetime.datetime.now()
-        self.items[obj.uid] = (etag, obj)
+        actual_etag, _ = self.items[obj.uid]
+        if etag != actual_etag:
+            raise exceptions.WrongEtagError(etag, actual_etag)
+
+        new_etag = datetime.datetime.now()
+        self.items[obj.uid] = (new_etag, obj)
         return etag
 
-    def delete(self, uid):
+    def delete(self, uid, etag):
+        if not self.has(uid):
+            raise exceptions.NotFoundError(uid)
+        if etag != self.items[uid][0]:
+            raise exceptions.WrongEtagError(etag)
         del self.items[uid]