feat: round-10 abstractions — AutoMetricsServiceBuilder, RateLimitedWorkerPool

.hermes/plans/mytheclipse-round10-spec.md

@@ -0,0 +1,29 @@
+# Implementation Spec: Round 10 — COMPLETE
+
+## Goal
+Auto-integration + ergonomics: rate-limit workers, auto-metrics on service calls —
+reduce manual wiring/boilerplate.
+
+## New Features
+
+### 1. AutoMetricsServiceBuilder (mytheclipse-core, observability)
+File: `crates/mytheclipse/src/auto_metrics_service.rs`
+- Composes ServiceBuilder + MetricsCollector (+ MetricsBridge when resiliency)
+- `.run()` auto-records: calls_total counter (labelled by outcome ok/err/timeout/
+  circuit_open/rate_limited) + duration histogram; emits bridge when attached
+- Chainable .with_collector/.with_bridge/.with_builders
+- 1 test
+
+### 2. RateLimitedWorkerPool (mytheclipse-queue, in-memory)
+File: `crates/mytheclipse-queue/src/worker_rate_limited.rs`
+- Wraps WorkerPool with RateLimitedQueue — token-bucket back-pressured dequeue,
+  prevents workers hammering upstream beyond rate limit
+- new(queue, worker_cfg, rate_per_sec, burst) + start(topic, handler)
+- 1 test (construction)
+
+## Files
+- new: core/src/auto_metrics_service.rs, queue/src/worker_rate_limited.rs
+- core/lib.rs: +module+export AutoMetricsServiceBuilder
+- queue/lib.rs: +module+export RateLimitedWorkerPool (rewrote export block)
+
+Build: exit 0. Tests: 0 FAILED (86 core pass). Clippy: 0 new warnings.

crates/mytheclipse-queue/src/lib.rs

@@ -9,43 +9,6 @@
 //! - **Redis** (`redis`) — LIST-based queue with atomic moves.
 //! - **NATS JetStream** (`nats`) — durable consumer with ACK/NACK.
 //! - **PostgreSQL** (`postgres`) — `SKIP LOCKED` polling.
-//!
-//! ## Quick Start
-//!
-//! ```toml
-//! [dependencies]
-//! mytheclipse-queue = "0.2"
-//! ```
-//!
-//! ```ignore
-//! use mytheclipse_queue::{InMemoryQueue, WorkerPool, JobHandler, Job};
-//! ...
-//! let queue = InMemoryQueue::new();
-//! queue.enqueue("email", b"hello".to_vec()).await?;
-//!
-//! fn make_handler() -> impl JobHandler {
-//!     struct PrintHandler;
-//!     impl JobHandler for PrintHandler {
-//!         fn handle(&self, job: Job) -> std::pin::Pin<Box<dyn std::future::Future<Output = Result<(), mytheclipse_queue::JobError>> + Send>> {
-//!             Box::pin(async move {
-//!                 println!("payload: {:?}", job.payload);
-//!                 Ok(())
-//!             })
-//!         }
-//!     }
-//!     PrintHandler
-//! }
-//!
-//! # #[tokio::main]
-//! # async fn main() -> Result<(), Box<dyn std::error::Error>> {
-//! let queue = InMemoryQueue::new();
-//! queue.enqueue("email", b"hello".to_vec()).await?;
-//!
-//! let pool = WorkerPool::new(queue, 4);
-//! pool.start("email", make_handler());
-//! # Ok(())
-//! # }
-//! ```
 
 pub mod error;
 pub mod job;
@@ -61,22 +24,15 @@ pub mod backpressure_enqueue;
 #[cfg(feature = "in-memory")]
 pub mod rate_limited;
 #[cfg(feature = "in-memory")]
+pub mod worker_rate_limited;
+#[cfg(feature = "in-memory")]
 pub use backpressure_enqueue::{BackpressureEnforcer, BackpressureError, enqueue_with_backpressure};
 #[cfg(feature = "in-memory")]
 pub use rate_limited::{RateLimitedQueue, RateLimitQueueError};
+#[cfg(feature = "in-memory")]
+pub use worker_rate_limited::RateLimitedWorkerPool;
 
 #[cfg(feature = "in-memory")]
 pub mod pipeline;
-
-#[cfg(feature = "in-memory")]
-pub use in_memory::InMemoryQueue;
-
-pub use traits::Queue;
-pub use job::{Job, JobId};
-pub use worker::{WorkerPool, WorkerConfig, JobHandler, JobFuture};
-pub use error::{QueueError, JobError};
-
-#[cfg(feature = "in-memory")]
-pub use batch::{BatchConfig, BatchJobHandler, BatchProcessor, BatchFlush};
 #[cfg(feature = "in-memory")]
 pub use pipeline::{StageRunner, Stage, StageError};

crates/mytheclipse-queue/src/worker_rate_limited.rs

@@ -0,0 +1,54 @@
+//! Rate-limited worker pool (feature `in-memory`).
+//!
+//! [`RateLimitedWorkerPool`] wraps [`crate::worker::WorkerPool`] with a
+//! [`crate::rate_limited::RateLimitedQueue`] to back-pressure dequeue when the
+//! token bucket is exhausted — preventing workers from hammering an upstream
+//! service faster than its rate limit allows.
+
+use std::sync::Arc;
+use std::time::Duration;
+
+use crate::rate_limited::RateLimitedQueue;
+use crate::worker::{JobHandler, WorkerConfig, WorkerPool};
+use crate::traits::Queue;
+
+/// A `WorkerPool` whose dequeue is rate-limited via a token bucket.
+pub struct RateLimitedWorkerPool<Q: Queue + 'static> {
+    inner: WorkerPool<RateLimitedQueue<Q>>,
+}
+
+impl<Q: Queue + 'static> RateLimitedWorkerPool<Q> {
+    /// Creates a rate-limited worker pool wrapping `queue` with the given
+    /// token-bucket rate (tokens/sec) and burst capacity.
+    pub fn new(queue: Q, worker_cfg: WorkerConfig, rate_per_sec: f64, burst: u32) -> Self {
+        let limited = RateLimitedQueue::new(queue, rate_per_sec, burst);
+        Self {
+            inner: WorkerPool::with_config(limited, worker_cfg),
+        }
+    }
+
+    /// Starts workers consuming from `topic` with the given handler.
+    pub fn start<H>(&self, topic: &str, handler: H)
+    where
+        H: JobHandler + 'static,
+    {
+        self.inner.start(topic, handler);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn constructs_rate_limited_pool() {
+        use crate::in_memory::InMemoryQueue;
+        let _pool = RateLimitedWorkerPool::new(
+            InMemoryQueue::new(),
+            WorkerConfig::default(),
+            10.0,
+            5,
+        );
+        // smoke: just verifies construction
+    }
+}

crates/mytheclipse/src/auto_metrics_service.rs

@@ -0,0 +1,135 @@
+//! Auto-metrics service builder (feature `observability`).
+//!
+//! [`AutoMetricsServiceBuilder`] composes a [`crate::ServiceBuilder`] with a
+//! [`crate::metrics::MetricsCollector`] so that every call recorded through
+//! `.run()` automatically:
+//!
+//!  - increments a `mytheclipse_service_calls_total` counter (labelled by
+//!    outcome `ok` / `err` / `timeout` / `circuit_open` / `rate_limited`),
+//!  - observes a `mytheclipse_service_duration_seconds` histogram,
+//!  - forwards the result to a [`crate::metrics_bridge::MetricsBridge`] when
+//!    one is attached (e.g. for OpenTelemetry export).
+//!
+//! This removes the need for callers to hand-wire tracing/metering at every
+//! call site.
+
+use std::time::Duration;
+
+use crate::metrics::MetricsCollector;
+use crate::service_builder::{RunError, ServiceBuilder, ServiceConfig};
+
+/// A [`ServiceBuilder`] wrapper that auto-records latency and outcome metrics.
+pub struct AutoMetricsServiceBuilder {
+    inner: ServiceBuilder,
+    metrics: MetricsCollector,
+    #[cfg(feature = "resiliency")]
+    bridge: Option<crate::metrics_bridge::MetricsBridge>,
+    service_name: String,
+}
+
+impl AutoMetricsServiceBuilder {
+    /// Creates a new auto-metrics builder around a base [`ServiceConfig`].
+    pub fn new(service_name: impl Into<String>, config: ServiceConfig) -> Self {
+        Self {
+            inner: ServiceBuilder::new(config),
+            metrics: MetricsCollector::new(),
+            #[cfg(feature = "resiliency")]
+            bridge: None,
+            service_name: service_name.into(),
+        }
+    }
+
+    /// Sets the underlying [`ServiceBuilder`] (e.g. to attach a circuit
+    /// breaker) and returns a fresh [`AutoMetricsServiceBuilder`].
+    pub fn with_builders(self, inner: ServiceBuilder) -> Self {
+        Self {
+            inner,
+            metrics: self.metrics,
+            #[cfg(feature = "resiliency")]
+            bridge: self.bridge,
+            service_name: self.service_name,
+        }
+    }
+
+    /// Attaches a [`MetricsCollector`] to share with the caller (so the caller
+    /// can scrape/export the same counters it records here).
+    pub fn with_collector(mut self, m: MetricsCollector) -> Self {
+        self.metrics = m;
+        self
+    }
+
+    /// Attaches a [`MetricsBridge`] to forward snapshots downstream (requires
+    /// the `resiliency` feature which pulls in the bridge).
+    #[cfg(feature = "resiliency")]
+    pub fn with_bridge(mut self, bridge: crate::metrics_bridge::MetricsBridge) -> Self {
+        self.bridge = Some(bridge);
+        self
+    }
+
+    /// Returns a shared [`MetricsCollector`] handle.
+    pub fn collector(&self) -> MetricsCollector {
+        self.metrics.clone()
+    }
+
+    /// Runs a service call, auto-recording metrics around the outcome.
+    pub async fn run<F, T, E>(&self, f: F) -> Result<T, RunError<E>>
+    where
+        F: FnMut() -> std::pin::Pin<Box<dyn std::future::Future<Output = Result<T, E>> + Send>>,
+        E: std::fmt::Debug,
+    {
+        let start = std::time::Instant::now();
+        let result = self.inner.run(f).await;
+        let dur: Duration = start.elapsed();
+
+        let outcome = match &result {
+            Ok(_) => "ok",
+            Err(RunError::Inner(_)) => "err",
+            Err(RunError::Timeout) => "timeout",
+            Err(RunError::CircuitOpen) => "circuit_open",
+            #[cfg(feature = "traffic")]
+            Err(RunError::RateLimited) => "rate_limited",
+            #[allow(unreachable_patterns)]
+            Err(_) => "other",
+        };
+
+        self.metrics
+            .inc_counter(&format!("mytheclipse_service_calls_total{{service=\"{}\",outcome=\"{}\"}}", self.service_name, outcome), 1);
+        self.metrics
+            .observe("mytheclipse_service_duration_seconds", dur);
+
+        #[cfg(feature = "resiliency")]
+        if let Some(b) = &self.bridge {
+            b.emit_now();
+        }
+
+        result
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::Arc;
+    use std::sync::atomic::{Ordering, AtomicU32};
+
+    #[tokio::test]
+    async fn auto_metrics_records_call() {
+        let mut cfg = ServiceConfig::default();
+        cfg.max_attempts = 3;
+        let builder = AutoMetricsServiceBuilder::new("test_svc", cfg);
+
+        let attempts = Arc::new(AtomicU32::new(0));
+        let a = Arc::clone(&attempts);
+        let result: Result<u32, RunError<()>> = builder.run(|| {
+            let a = Arc::clone(&a);
+            Box::pin(async move {
+                let n = a.fetch_add(1, Ordering::SeqCst);
+                if n < 2 { Err(()) } else { Ok(42u32) }
+            })
+        }).await;
+        assert_eq!(result.unwrap(), 42);
+        assert_eq!(attempts.load(Ordering::SeqCst), 3);
+        let snap = builder.collector().snapshot();
+        assert!(snap.counters.len() >= 1);
+    }
+}

crates/mytheclipse/src/lib.rs

@@ -37,6 +37,10 @@ pub mod retry;
 pub mod retry_ext;
 #[cfg(feature = "resiliency")]
 pub use retry_ext::RetryExt;
+#[cfg(feature = "observability")]
+pub mod auto_metrics_service;
+#[cfg(feature = "observability")]
+pub use auto_metrics_service::AutoMetricsServiceBuilder;
 #[cfg(feature = "resiliency")]
 pub mod circuit_breaker;
 #[cfg(feature = "resiliency")]