feat: add webpush topics

Add's webpush topics with versioned sort key.

Closes #643

autopush/db.py

@@ -1,4 +1,34 @@
-"""Database Interaction"""
+"""Database Interaction
+
+WebPush Sort Keys
+-----------------
+
+Messages for WebPush are stored using a partition key + sort key, originally
+the sort key was:
+
+    CHID : Encrypted(UAID: CHID)
+
+The encrypted portion was returned as the Location to the Application Server.
+Decrypting it resulted in enough information to create the sort key so that
+the message could be deleted and located again.
+
+For WebPush Topic messages, a new scheme was needed since the only way to
+locate the prior message is the UAID + CHID + Topic. Using Encryption in
+the sort key is therefore not useful since it would change every update.
+
+The sort key scheme for WebPush messages is:
+
+    VERSION : CHID : TOPIC
+
+To ensure updated messages are not deleted, each message will still have an
+update-id key/value in its item.
+
+Non-versioned messages are assumed to be original messages from before this
+scheme was adopted.
+
+``VERSION`` is a 2-digit 0-padded number, starting at 01 for Topic messages.
+
+"""
 from __future__ import absolute_import
 
 import datetime
@@ -19,7 +49,11 @@
 from boto.dynamodb2.types import NUMBER
 
 from autopush.exceptions import AutopushException
-from autopush.utils import generate_hash
+from autopush.utils import (
+    generate_hash,
+    normalize_id,
+    WebPushNotification,
+)
 
 key_hash = ""
 TRACK_DB_CALLS = False
@@ -63,16 +97,6 @@ def dump_uaid(uaid_data):
         return repr(uaid_data)
 
 
-def normalize_id(ident):
-    if (len(ident) == 36 and
-            ident[8] == ident[13] == ident[18] == ident[23] == '-'):
-        return ident.lower()
-    raw = filter(lambda x: x in '0123456789abcdef', ident.lower())
-    if len(raw) != 32:
-        raise ValueError("Invalid UUID")
-    return '-'.join((raw[:8], raw[8:12], raw[12:16], raw[16:20], raw[20:]))
-
-
 def make_rotating_tablename(prefix, delta=0, date=None):
     """Creates a tablename for table rotation based on a prefix with a given
     month delta."""
@@ -417,130 +441,62 @@ def save_channels(self, uaid, channels):
         ), overwrite=True)
 
     @track_provisioned
-    def store_message(self, uaid, channel_id, message_id, ttl, data=None,
-                      headers=None, timestamp=None):
-        """Stores a message in the message table for the given uaid/channel
-        with the message id"""
+    def store_message(self, notification):
+        """Stores a WebPushNotification in the message table
+
+        :type notification: WebPushNotification
+        :type timestamp: int
+
+        """
         item = dict(
-            uaid=hasher(uaid),
-            chidmessageid="%s:%s" % (normalize_id(channel_id), message_id),
-            data=data,
-            headers=headers,
-            ttl=ttl,
-            timestamp=timestamp or int(time.time()),
-            updateid=uuid.uuid4().hex
+            uaid=hasher(notification.uaid.hex),
+            chidmessageid=notification.sort_key,
+            data=notification.data,
+            headers=notification.headers,
+            ttl=notification.ttl,
+            timestamp=notification.timestamp,
+            updateid=notification.update_id
         )
-        if data:
-            item["headers"] = headers
-            item["data"] = data
         self.table.put_item(data=item, overwrite=True)
         return True
 
     @track_provisioned
-    def update_message(self, uaid, channel_id, message_id, ttl, data=None,
-                       headers=None, timestamp=None):
-        """Updates a message in the message table for the given uaid/channel
-        /message_id.
+    def delete_message(self, notification):
+        """Deletes a specific message
 
-        If the message is not present, False is returned.
+        :type notification: WebPushNotification
 
         """
-        conn = self.table.connection
-        item = dict(
-            ttl=ttl,
-            timestamp=timestamp or int(time.time()),
-            updateid=uuid.uuid4().hex
-        )
-        if data:
-            item["headers"] = headers
-            item["data"] = data
-        try:
-            chidmessageid = "%s:%s" % (normalize_id(channel_id), message_id)
-            db_key = self.encode({"uaid": hasher(uaid),
-                                  "chidmessageid": chidmessageid})
-            expr = ("SET #tl=:ttl, #ts=:timestamp,"
-                    " updateid=:updateid")
-            if data:
-                expr += ", #dd=:data, headers=:headers"
-            else:
-                expr += " REMOVE #dd, headers"
-            expr_values = self.encode({":%s" % k: v for k, v in item.items()})
-            conn.update_item(
-                self.table.table_name,
-                db_key,
-                condition_expression="attribute_exists(updateid)",
-                update_expression=expr,
-                expression_attribute_names={"#tl": "ttl",
-                                            "#ts": "timestamp",
-                                            "#dd": "data"},
-                expression_attribute_values=expr_values,
-            )
-        except ConditionalCheckFailedException:
-            return False
-        return True
-
-    @track_provisioned
-    def delete_message(self, uaid, channel_id, message_id, updateid=None):
-        """Deletes a specific message"""
-        if updateid:
+        if notification.update_id:
             try:
                 self.table.delete_item(
-                    uaid=hasher(uaid),
-                    chidmessageid="%s:%s" % (normalize_id(channel_id),
-                                             message_id),
-                    expected={'updateid__eq': updateid})
+                    uaid=hasher(notification.uaid.hex),
+                    chidmessageid=notification.sort_key,
+                    expected={'updateid__eq': notification.update_id})
             except ConditionalCheckFailedException:
                 return False
         else:
             self.table.delete_item(
-                uaid=hasher(uaid),
-                chidmessageid="%s:%s" % (normalize_id(channel_id),
-                                         message_id))
+                uaid=hasher(notification.uaid.hex),
+                chidmessageid=notification.sort_key,
+            )
         return True
 
-    def delete_messages(self, uaid, chidmessageids):
-        with self.table.batch_write() as batch:
-            for chidmessageid in chidmessageids:
-                if chidmessageid:
-                    batch.delete_item(
-                        uaid=hasher(uaid),
-                        chidmessageid=chidmessageid
-                    )
-
     @track_provisioned
-    def delete_messages_for_channel(self, uaid, channel_id):
-        """Deletes all messages for a uaid/channel_id"""
-        results = self.table.query_2(
-            uaid__eq=hasher(uaid),
-            chidmessageid__beginswith="%s:" % normalize_id(channel_id),
-            consistent=True,
-            attributes=("chidmessageid",),
-        )
-        chidmessageids = [x["chidmessageid"] for x in results]
-        if chidmessageids:
-            self.delete_messages(uaid, chidmessageids)
-        return len(chidmessageids) > 0
+    def fetch_messages(self, uaid, limit=10):
+        """Fetches messages for a uaid
 
-    @track_provisioned
-    def delete_user(self, uaid):
-        """Deletes all messages and channel info for a given uaid"""
-        results = self.table.query_2(
-            uaid__eq=hasher(uaid),
-            chidmessageid__gte=" ",
-            consistent=True,
-            attributes=("chidmessageid",),
-        )
-        chidmessageids = [x["chidmessageid"] for x in results]
-        if chidmessageids:
-            self.delete_messages(uaid, chidmessageids)
+        :type uaid: uuid.UUID
+        :type limit: int
 
-    @track_provisioned
-    def fetch_messages(self, uaid, limit=10):
-        """Fetches messages for a uaid"""
+        """
         # Eagerly fetches all results in the result set.
-        return list(self.table.query_2(uaid__eq=hasher(uaid),
-                                       chidmessageid__gt=" ",
-                                       consistent=True, limit=limit))
+        results = list(self.table.query_2(uaid__eq=hasher(uaid.hex),
+                                          chidmessageid__gt=" ",
+                                          consistent=True, limit=limit))
+        return [
+            WebPushNotification.from_message_table(uaid, x) for x in results
+        ]
 
 
 class Router(object):