rusmes-storage

Storage abstraction layer for RusMES. Defines traits for mailbox, message, and metadata storage, with pluggable backend implementations.

Architecture

StorageBackend (trait)
├── mailbox_store()  -> Arc<dyn MailboxStore>
├── message_store()  -> Arc<dyn MessageStore>
└── metadata_store() -> Arc<dyn MetadataStore>

Backends:
├── FilesystemBackend  (maildir format)
└── PostgresBackend    (SQL, schema defined)

Storage Traits

MailboxStore

create_mailbox() / delete_mailbox() / rename_mailbox()
get_mailbox() / list_mailboxes()

MessageStore

append_message() - store a new message
get_message() / delete_messages()
set_flags() - update message flags (Seen, Answered, Flagged, etc.)
search() - search by SearchCriteria

MetadataStore

get_user_quota() / set_user_quota()
get_mailbox_counters() - message count, unread count, total size

Types

Type	Description
`Mailbox`	Mailbox with ID, path, and message count
`MailboxId`	UUID-based mailbox identifier
`MailboxPath`	Hierarchical mailbox path (user + name)
`MessageMetadata`	UID, flags, internal date, size
`MessageFlags`	Seen, Answered, Flagged, Deleted, Draft, Recent
`Quota`	Storage quota (bytes used / limit, message count / limit)
`SearchCriteria`	Search filters for message queries
`MailboxCounters`	Total messages, unread count, total size

Backends

Filesystem (`backends::filesystem`)

Stores messages in maildir-compatible directory structure:

/var/lib/rusmes/mailboxes/
└── <user>/
    └── <mailbox>/
        ├── new/     (unread messages)
        ├── cur/     (read messages)
        └── tmp/     (delivery in progress)

PostgreSQL (`backends::postgres`)

Schema with tables: mailboxes, messages, user_quotas. Full implementation with connection pooling (sqlx), full-text search, quota enforcement, and MODSEQ tracking (2,592 lines).

AmateRS (`backends::amaters`)

All trait methods implemented as a mock (1,390 lines). Real distributed client integration is pending.

Dependencies

rusmes-proto - core types
tokio - async filesystem I/O
async-trait - async traits
uuid - mailbox/message IDs

Tests

cargo test -p rusmes-storage   # 166 tests

rusmes-storage 0.1.1