offline_protocol_reliability/
constants.rs

1//! Reliability layer constants.
2
3/// Default ACK timeout in milliseconds.
4pub const DEFAULT_ACK_TIMEOUT_MS: u64 = 10000;
5
6/// Maximum number of pending ACKs to track.
7pub const DEFAULT_MAX_PENDING_ACKS: usize = 1000;
8
9/// Default maximum number of retries per message.
10pub const DEFAULT_MAX_RETRIES: u32 = 10;
11
12/// Initial retry delay in milliseconds.
13pub const DEFAULT_INITIAL_DELAY_MS: u64 = 1000;
14
15/// Maximum retry delay in milliseconds.
16///
17/// 5 minutes. Delivery latency does not ride on this ceiling: outbox
18/// flushes (start, transport reconnect, peer rediscovery, session
19/// establishment) bypass backoff timers entirely. The periodic retry is a
20/// safety net, and a lower ceiling only multiplies futile send attempts —
21/// and per-failure `MessageRetrying` events — while a peer stays offline
22/// within the 7-day outbox window.
23pub const DEFAULT_MAX_DELAY_MS: u64 = 300_000;
24
25/// Backoff multiplier for exponential backoff.
26pub const DEFAULT_BACKOFF_MULTIPLIER: f32 = 2.0;
27
28/// Maximum lifetime for messages in outbox (milliseconds).
29///
30/// 7 days, matching the app-layer presence-flush window: a peer is
31/// considered recoverable for up to 7 days offline, so queued messages
32/// must survive at least that long before the outbox gives up on them.
33pub const DEFAULT_OUTBOX_LIFETIME_MS: u64 = 604_800_000;
34
35/// How long one message id may be re-sent after its first send: 7 days.
36///
37/// The one window both ends of a delivery agree on. A sender drops an outbox
38/// entry the relay has pushed once it is this old, measured from its first
39/// send and never re-granted; a receiver's deduplicator remembers ids this
40/// long, so every replay inside the window is answered as a duplicate (with
41/// a re-ACK) instead of reaching a ratchet whose generation is already spent.
42///
43/// Pairs with the relay's push-claim TTL (one visible notification per
44/// message id) and its mailbox retention, both 7 days: past this age the
45/// relay would push the id again and its mailbox has already let it go.
46/// Fixed rather than read from `outbox_max_lifetime_ms`, because those relay
47/// windows do not move with an app's configuration.
48pub const REDELIVERY_WINDOW_MS: u64 = DEFAULT_OUTBOX_LIFETIME_MS;
49
50/// Maximum lifetime for messages waiting on MLS session establishment.
51///
52/// This is deliberately finite so an unresolved or permanently invalid
53/// recipient cannot remain in durable `pending_messages` forever.
54pub const DEFAULT_PENDING_MESSAGE_LIFETIME_MS: u64 = 604_800_000;
55
56/// Estimated size of an ACK entry in bytes (message ID + metadata).
57pub const ESTIMATED_ACK_SIZE_BYTES: usize = 40;
58
59/// Network size threshold below which all ACKs are relayed.
60pub const SMALL_NETWORK_RELAY_THRESHOLD: usize = 5;
61
62/// Density factor numerator for relay probability calculation.
63pub const RELAY_DENSITY_FACTOR_NUMERATOR: f32 = 5.0;
64
65#[cfg(test)]
66mod tests {
67    use super::*;
68
69    /// The RN native bridges rebuild the whole `RetryConfig` from JSON in
70    /// `updateRetryConfig`, filling absent fields from hardcoded fallbacks.
71    /// A fallback that drifts from the Rust defaults silently overrides the
72    /// SDK default for every field the app didn't set (this happened once:
73    /// `maxRetries` 3 vs 10). This test pins the bridge literals to the
74    /// constants above; when a default changes here, it fails until both
75    /// bridge files are updated.
76    #[test]
77    fn rn_bridge_retry_fallbacks_match_rust_defaults() {
78        let rn_root =
79            std::path::Path::new(env!("CARGO_MANIFEST_DIR")).join("../../bindings/react-native");
80        let kotlin_path =
81            rn_root.join("android/src/main/java/com/offlineprotocol/OfflineProtocolModule.kt");
82        let swift_path = rn_root.join("ios/OfflineProtocolModule.swift");
83
84        // The guard only applies in the repo checkout; skip when the
85        // bindings tree isn't present (e.g. a vendored crate).
86        let (Ok(kotlin), Ok(swift)) = (
87            std::fs::read_to_string(&kotlin_path),
88            std::fs::read_to_string(&swift_path),
89        ) else {
90            eprintln!("bindings tree not present, skipping RN fallback drift check");
91            return;
92        };
93
94        let ack_expected = [
95            (
96                format!("json.optLong(\"defaultTimeoutMs\", {DEFAULT_ACK_TIMEOUT_MS})"),
97                format!(
98                    "(config[\"defaultTimeoutMs\"] as? NSNumber)?.uint64Value ?? {DEFAULT_ACK_TIMEOUT_MS}"
99                ),
100            ),
101            (
102                format!("json.optLong(\"maxPendingAcks\", {DEFAULT_MAX_PENDING_ACKS})"),
103                format!(
104                    "(config[\"maxPendingAcks\"] as? NSNumber)?.uint64Value ?? {DEFAULT_MAX_PENDING_ACKS}"
105                ),
106            ),
107        ];
108        for (kotlin_fallback, swift_fallback) in &ack_expected {
109            assert!(
110                kotlin.contains(kotlin_fallback),
111                "RN Android bridge ACK fallback drifted from the Rust default: \
112                 expected `{kotlin_fallback}` in {}",
113                kotlin_path.display()
114            );
115            assert!(
116                swift.contains(swift_fallback),
117                "RN iOS bridge ACK fallback drifted from the Rust default: \
118                 expected `{swift_fallback}` in {}",
119                swift_path.display()
120            );
121        }
122
123        let kotlin_expected = [
124            format!("json.optInt(\"maxRetries\", {DEFAULT_MAX_RETRIES})"),
125            format!("json.optLong(\"initialDelayMs\", {DEFAULT_INITIAL_DELAY_MS})"),
126            format!("json.optLong(\"maxDelayMs\", {DEFAULT_MAX_DELAY_MS})"),
127            format!("json.optDouble(\"backoffMultiplier\", {DEFAULT_BACKOFF_MULTIPLIER:.1})"),
128            format!("json.optLong(\"outboxMaxLifetimeMs\", {DEFAULT_OUTBOX_LIFETIME_MS})"),
129            format!(
130                "json.optLong(\"pendingMessageMaxLifetimeMs\", {DEFAULT_PENDING_MESSAGE_LIFETIME_MS})"
131            ),
132        ];
133        for expected in &kotlin_expected {
134            assert!(
135                kotlin.contains(expected),
136                "RN Android bridge retry fallback drifted from the Rust default: \
137                 expected `{expected}` in {}",
138                kotlin_path.display()
139            );
140        }
141
142        let swift_expected = [
143            format!("(config[\"maxRetries\"] as? NSNumber)?.uint32Value ?? {DEFAULT_MAX_RETRIES}"),
144            format!(
145                "(config[\"initialDelayMs\"] as? NSNumber)?.uint64Value ?? {DEFAULT_INITIAL_DELAY_MS}"
146            ),
147            format!("(config[\"maxDelayMs\"] as? NSNumber)?.uint64Value ?? {DEFAULT_MAX_DELAY_MS}"),
148            format!(
149                "(config[\"backoffMultiplier\"] as? NSNumber)?.floatValue ?? {DEFAULT_BACKOFF_MULTIPLIER:.1}"
150            ),
151            format!(
152                "(config[\"outboxMaxLifetimeMs\"] as? NSNumber)?.uint64Value ?? {DEFAULT_OUTBOX_LIFETIME_MS}"
153            ),
154            format!(
155                "(config[\"pendingMessageMaxLifetimeMs\"] as? NSNumber)?.uint64Value ?? {DEFAULT_PENDING_MESSAGE_LIFETIME_MS}"
156            ),
157        ];
158        for expected in &swift_expected {
159            assert!(
160                swift.contains(expected),
161                "RN iOS bridge retry fallback drifted from the Rust default: \
162                 expected `{expected}` in {}",
163                swift_path.display()
164            );
165        }
166    }
167}
offline_protocol_reliability/constants.rs

offline_protocol_reliability/
constants.rs
