From: David Bremner <david@tethera.net>
To: notmuch@notmuchmail.org
Subject: Re: [RFC2 Patch 5/5] lib: iterator API for message properties
In-Reply-To: <1464608999-14774-6-git-send-email-david@tethera.net>
References: <1463927339-5441-1-git-send-email-david@tethera.net>
 <1464608999-14774-1-git-send-email-david@tethera.net>
 <1464608999-14774-6-git-send-email-david@tethera.net>
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Date: Tue, 31 May 2016 22:12:21 -0300
Message-ID: <8760tthfuy.fsf@zancas.localnet>
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David Bremner <david@tethera.net> writes:

> +   notmuch_message_properties_t *list;
> +   RUN(notmuch_message_add_property (message, "testkey1", "bob"));
> +   RUN(notmuch_message_add_property (message, "testkey1", "testvalue2"));
> +   RUN(notmuch_message_add_property (message, "testkey1", "alice"));
> +
> +   for (list = notmuch_message_get_properties (message, "testkey1", TRUE);
> +        notmuch_message_properties_valid (list); notmuch_message_properties_move_to_next (list)) {
> +      printf("%s\n", notmuch_message_properties_value(list));
> +   }
> +   notmuch_message_properties_destroy (list);

I was thinking a bit about how to dump/restore these.

The most upwardly compatible way that i thought of is something like

#= msg-id key=val key=val

i.e. duplicate the msg-id for messages with properties

This would be ignored by old notmuch-restore.

Otherwise, maybe something like

msg-id -- +tag +tag # key=val key=val

I'm not sure. this might crash old notmuch-restore.

How important is backward compatibility, and how important is minimizing
dump size? It's a bit hard to predict the things people might use
message properties for, but for thread surgery, I would expect a small
number of messages with properties.

d