v0.5.0

Breaking Changes

Why these changes? These breaking changes eliminate per-message serialization, deserialization, and heap allocations from the Signal protocol encrypt/decrypt hot path — matching WhatsApp Web's architecture where session and sender key objects are cached in memory and only serialized during periodic flush to storage. In benchmarks, this reduces ~70% of the CPU cost that was previously spent on protobuf encode/decode and unnecessary cloning on every message.

Trait signature changes

Downstream implementations of these traits must update:

• SessionStore::store_session — record: &SessionRecord → record: SessionRecord (takes ownership)
• SenderKeyStore::store_sender_key — record: &SenderKeyRecord → record: SenderKeyRecord (takes ownership)

SignalStoreCache API

All methods now accept typed addresses instead of &str:

Method	Before	After
get_session	&str → Option<Arc<[u8]>>	&ProtocolAddress → Option<SessionRecord>
put_session	&str, &[u8]	&ProtocolAddress, SessionRecord
delete_session	&str	&ProtocolAddress
has_session	&str	&ProtocolAddress
get_sender_key	&str → Option<Arc<[u8]>>	&SenderKeyName → Option<SenderKeyRecord>
put_sender_key	&str, &[u8]	&SenderKeyName, SenderKeyRecord

Struct changes

• ProtocolAddress — added private display field; struct literal construction no longer works, use ProtocolAddress::new()
• SenderKeyName — added private cache_key field; struct literal construction no longer works, use SenderKeyName::new()

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What's Changed

• fix: persist Device.account through serde by @jlucaso1 in #414
• perf: typed cache API + sender key object cache by @jlucaso1 in #415
• feat: MediaEncryptor streaming API + PortableCache fixes by @jlucaso1 in #416

Full Changelog: v0.4.3...v0.5.0