Bound nostr event cache TTL and size

[alltheseas]

addresses

#14

Summary

• set cache TTL default to 30m, configurable via env
• add hard cap on cache entries with oldest-first eviction and eager pruning
• add tests covering pruning and cap eviction

Testing

• cargo test

Summary by CodeRabbit

• New Features

  • Added configurable cache entry limit (default: 10,000) to optimize memory usage and system performance. This can be customized via environment configuration.

• Chores

  • Reduced default event cache retention period from 1 hour to 30 minutes for improved data freshness and reduced memory overhead.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[jb55]

whats this for?

[jb55]

• oh for Memory leak or creeping memory usage over time #14, nice

[alltheseas]

cargo test passed, but needs to be tested in production.

the cache clearing variables can be adjusted accordingly

[alltheseas]

@coderabbitai review please

[coderabbitai]

@alltheseas, I'll review the changes in this PR for you.

✅ Actions performed

Review triggered.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.

[coderabbitai]

📝 Walkthrough

Walkthrough

This pull request adds cache entry count limiting functionality to the Nostr event cache system. A new configuration parameter DEFAULT_NOSTR_EVENT_CACHE_MAX_ENTRIES (10,000) is introduced, threaded through environment initialization and the notification manager stack, and integrated into the Cache with supporting eviction logic. The default cache age is also reduced from 1 hour to 30 minutes.

Changes

Cohort / File(s)	Summary
Configuration & Environment src/notepush_env.rs	Adds DEFAULT_NOSTR_EVENT_CACHE_MAX_ENTRIES constant (10,000), new field nostr_event_cache_max_entries to NotePushEnv, reduces DEFAULT_NOSTR_EVENT_CACHE_MAX_AGE from 1 hour to 30 minutes, reads NOSTR_EVENT_CACHE_MAX_ENTRIES environment variable.
Initialization & Manager src/main.rs, src/notification_manager/mod.rs	Threads nostr_event_cache_max_entries from environment through NotificationManager::new() and into NostrNetworkHelper::new().
Cache Implementation src/notification_manager/nostr_event_cache.rs, src/notification_manager/nostr_network_helper.rs	Adds max_entries field to Cache, introduces prune_expired_entries(), remove_expired_from(), and enforce_cap() methods for expiration and eviction management. Cache::new() constructor updated to accept both max_age and max_entries parameters. Eviction logic wired into add/get paths.
Utilities src/utils/time_delta.rs	Adds #[allow(dead_code)] attribute to suppress warnings on TimeDelta::subtracting() function.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~28 minutes

Poem

🐰 A cache with limits, now bounded and lean,
Ten thousand entries—no overflow scene!
With pruning and eviction in every command,
Our memory stays tidy across the land! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 48.15% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The pull request title 'Bound nostr event cache TTL and size' directly and concisely summarizes the main changes: adding TTL (time-to-live) bounds and size limits to the nostr event cache.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[alltheseas]

@coderabbitai review please

[coderabbitai]

@alltheseas, I'll review the changes in this PR for you.

✅ Actions performed

Review triggered.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.