The message store¶
The message store is a collection of messages keyed off of Message-ID
and
X-Message-ID-Hash
headers. Either of these values can be combined with
the message’s List-Archive
header to create a globally unique URI to the
message object in the internet facing interface of the message store. The
X-Message-ID-Hash
is the base-32 SHA1 hash of the Message-ID
.
>>> from mailman.interfaces.messages import IMessageStore
>>> from zope.component import getUtility
>>> message_store = getUtility(IMessageStore)
A message with a Message-ID
header can be stored.
>>> msg = message_from_string("""\
... Subject: An important message
... Message-ID: <87myycy5eh.fsf@uwakimon.sk.tsukuba.ac.jp>
...
... This message is very important.
... """)
>>> x_message_id_hash = message_store.add(msg)
>>> print(x_message_id_hash)
AGDWSNXXKCWEILKKNYTBOHRDQGOX3Y35
>>> print(msg.as_string())
Subject: An important message
Message-ID: <87myycy5eh.fsf@uwakimon.sk.tsukuba.ac.jp>
X-Message-ID-Hash: AGDWSNXXKCWEILKKNYTBOHRDQGOX3Y35
<BLANKLINE>
This message is very important.
<BLANKLINE>
Finding messages¶
There are several ways to find a message given either the Message-ID
or
X-Message-ID-Hash
headers. In either case, if no matching message is
found, None
is returned.
>>> print(message_store.get_message_by_id('nothing'))
None
>>> print(message_store.get_message_by_hash('nothing'))
None
Given an existing Message-ID
, the message can be found.
>>> message = message_store.get_message_by_id(msg['message-id'])
>>> print(message.as_string())
Subject: An important message
Message-ID: <87myycy5eh.fsf@uwakimon.sk.tsukuba.ac.jp>
X-Message-ID-Hash: AGDWSNXXKCWEILKKNYTBOHRDQGOX3Y35
<BLANKLINE>
This message is very important.
<BLANKLINE>
Similarly, we can find messages by the X-Message-ID-Hash
:
>>> message = message_store.get_message_by_hash(msg['x-message-id-hash'])
>>> print(message.as_string())
Subject: An important message
Message-ID: <87myycy5eh.fsf@uwakimon.sk.tsukuba.ac.jp>
X-Message-ID-Hash: AGDWSNXXKCWEILKKNYTBOHRDQGOX3Y35
<BLANKLINE>
This message is very important.
<BLANKLINE>
Iterating over all messages¶
The message store provides a means to iterate over all the messages it contains.
>>> messages = list(message_store.messages)
>>> len(messages)
1
>>> print(messages[0].as_string())
Subject: An important message
Message-ID: <87myycy5eh.fsf@uwakimon.sk.tsukuba.ac.jp>
X-Message-ID-Hash: AGDWSNXXKCWEILKKNYTBOHRDQGOX3Y35
<BLANKLINE>
This message is very important.
<BLANKLINE>
Deleting messages from the store¶
You delete a message from the storage service by providing the Message-ID
for the message you want to delete.
>>> message_id = message['message-id']
>>> message_store.delete_message(message_id)
>>> list(message_store.messages)
[]
>>> print(message_store.get_message_by_id(message_id))
None
>>> print(message_store.get_message_by_hash(message['x-message-id-hash']))
None