| 1 | //! Shared stream entry seam for Chat Completions / Anthropic Messages / Responses. |
| 2 | //! |
| 3 | //! Scoped consolidation for v0.9.1: wire-protocol adapters stay at the edge |
| 4 | //! (`chat.rs`, `anthropic.rs`, `responses.rs`); this module owns the common |
| 5 | //! open path, HTTP/1.1 fallback policy, and idle-timeout envelope so providers |
| 6 | //! do not re-implement transport differently. |
| 7 | //! |
| 8 | //! Full piagent-style provider collapse is deferred — see |
| 9 | //! `docs/notes/post-0.9.1-thin-tui-and-stream.md`. |
| 10 | |
| 11 | use std::future::Future; |
| 12 | use std::time::Duration; |
| 13 | |
| 14 | use anyhow::Result; |
| 15 | use reqwest::Client; |
| 16 | |
| 17 | /// Default bounded wait for SSE response headers. Intentionally shorter than |
| 18 | /// the per-chunk idle timeout: it covers connection setup and upstream header |
| 19 | /// return only, never model thinking time after streaming has started. |
| 20 | pub(crate) const DEFAULT_STREAM_OPEN_TIMEOUT: Duration = Duration::from_secs(45); |
| 21 | |
| 22 | /// Env override (`CODEWHALE_STREAM_OPEN_TIMEOUT_SECS`, legacy |
| 23 | /// `DEEPSEEK_STREAM_OPEN_TIMEOUT_SECS`) for the response-header wait, |
| 24 | /// shared by every streaming adapter. |
| 25 | pub(crate) fn stream_open_timeout() -> Duration { |
| 26 | stream_open_timeout_from_env( |
| 27 | std::env::var("CODEWHALE_STREAM_OPEN_TIMEOUT_SECS") |
| 28 | .or_else(|_| std::env::var("DEEPSEEK_STREAM_OPEN_TIMEOUT_SECS")) |
| 29 | .ok() |
| 30 | .as_deref(), |
| 31 | ) |
| 32 | } |
| 33 | |
| 34 | pub(crate) fn stream_open_timeout_from_env(value: Option<&str>) -> Duration { |
| 35 | let secs = value |
| 36 | .and_then(|v| v.parse::<u64>().ok()) |
| 37 | .unwrap_or(DEFAULT_STREAM_OPEN_TIMEOUT.as_secs()) |
| 38 | .clamp(5, 300); |
| 39 | Duration::from_secs(secs) |
| 40 | } |
| 41 | |
| 42 | /// How the shared stream open path should pin HTTP version. |
| 43 | #[derive(Debug, Clone, Copy, PartialEq, Eq)] |
| 44 | pub enum StreamHttpPolicy { |
| 45 | /// Prefer the dual client (H2 primary, H1 twin for fallback). |
| 46 | DualWithH1Fallback, |
| 47 | /// Force HTTP/1.1 only (env pin or prior H2 stall). |
| 48 | Http1Only, |
| 49 | } |
| 50 | |
| 51 | /// Inputs shared by every streaming provider adapter at open time. |
| 52 | #[derive(Debug, Clone)] |
| 53 | pub struct StreamOpenRequest { |
| 54 | pub policy: StreamHttpPolicy, |
| 55 | pub open_timeout: Duration, |
| 56 | pub idle_timeout: Duration, |
| 57 | } |
| 58 | |
| 59 | impl StreamOpenRequest { |
| 60 | #[must_use] |
| 61 | pub fn new(open_timeout: Duration, idle_timeout: Duration) -> Self { |
| 62 | Self { |
| 63 | policy: if super::force_http1_from_env() { |
| 64 | StreamHttpPolicy::Http1Only |
| 65 | } else { |
| 66 | StreamHttpPolicy::DualWithH1Fallback |
| 67 | }, |
| 68 | open_timeout, |
| 69 | idle_timeout, |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | /// After an H2 stall, retry on the HTTP/1.1 twin. |
| 74 | #[must_use] |
| 75 | pub fn with_h1_only(mut self) -> Self { |
| 76 | self.policy = StreamHttpPolicy::Http1Only; |
| 77 | self |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | /// Select the HTTP client for a stream open attempt. |
| 82 | #[must_use] |
| 83 | pub fn client_for_policy<'a>( |
| 84 | primary: &'a Client, |
| 85 | http1_fallback: &'a Client, |
| 86 | policy: StreamHttpPolicy, |
| 87 | ) -> &'a Client { |
| 88 | match policy { |
| 89 | StreamHttpPolicy::DualWithH1Fallback => primary, |
| 90 | StreamHttpPolicy::Http1Only => http1_fallback, |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | /// Whether a transport error should trigger H1 fallback retry. |
| 95 | #[must_use] |
| 96 | pub fn should_retry_with_h1(policy: StreamHttpPolicy, err_text: &str) -> bool { |
| 97 | if policy != StreamHttpPolicy::DualWithH1Fallback { |
| 98 | return false; |
| 99 | } |
| 100 | let lower = err_text.to_ascii_lowercase(); |
| 101 | lower.contains("http2") |
| 102 | || lower.contains("h2 ") |
| 103 | || lower.contains("stream closed") |
| 104 | || lower.contains("connection reset") |
| 105 | || lower.contains("protocol error") |
| 106 | || lower.contains("frame size") |
| 107 | } |
| 108 | |
| 109 | /// Open an SSE response through the shared transport policy. |
| 110 | /// |
| 111 | /// `attempt` builds and sends one wire-specific request on the client |
| 112 | /// selected for the given policy (via [`client_for_policy`]); everything |
| 113 | /// transport-shared lives here: |
| 114 | /// |
| 115 | /// - the response-header wait is bounded by `open_req.open_timeout`; |
| 116 | /// - a header stall on the dual client retries exactly once on the |
| 117 | /// HTTP/1.1 twin ([`should_retry_with_h1`] classification); |
| 118 | /// - a stall on an already H1-pinned request never retries; |
| 119 | /// - once response headers have been received the seam never retries — |
| 120 | /// body/stream errors belong to the adapter's decode loop. |
| 121 | pub(crate) async fn open_sse_response<F, Fut>( |
| 122 | open_req: &StreamOpenRequest, |
| 123 | attempt: F, |
| 124 | ) -> Result<reqwest::Response> |
| 125 | where |
| 126 | F: Fn(StreamHttpPolicy) -> Fut, |
| 127 | Fut: Future<Output = Result<reqwest::Response>>, |
| 128 | { |
| 129 | match tokio::time::timeout(open_req.open_timeout, attempt(open_req.policy)).await { |
| 130 | Ok(result) => result, |
| 131 | Err(_elapsed) => { |
| 132 | // A header stall on the dual client is eligible for one explicit |
| 133 | // retry through the prebuilt HTTP/1.1 twin. |
| 134 | if should_retry_with_h1(open_req.policy, "http2 stream closed") { |
| 135 | let h1_req = open_req.clone().with_h1_only(); |
| 136 | crate::logging::warn( |
| 137 | "SSE stream headers timed out over HTTP/2; retrying once with HTTP/1.1", |
| 138 | ); |
| 139 | match tokio::time::timeout(h1_req.open_timeout, attempt(h1_req.policy)).await { |
| 140 | Ok(Ok(response)) => Ok(response), |
| 141 | Ok(Err(err)) => Err(anyhow::anyhow!( |
| 142 | "SSE stream request failed after HTTP/1.1 fallback: {err}. \ |
| 143 | `codewhale doctor` can still pass when non-streaming requests work; \ |
| 144 | on Windows or proxy networks, try `CODEWHALE_FORCE_HTTP1=1` and rerun `codewhale`." |
| 145 | )), |
| 146 | Err(_elapsed) => Err(anyhow::anyhow!( |
| 147 | "SSE stream request did not receive response headers after {}s \ |
| 148 | (HTTP/2 and HTTP/1.1). `codewhale doctor` can still pass when \ |
| 149 | non-streaming requests work; try `CODEWHALE_FORCE_HTTP1=1` and \ |
| 150 | rerun `codewhale`.", |
| 151 | open_req.open_timeout.as_secs() |
| 152 | )), |
| 153 | } |
| 154 | } else { |
| 155 | Err(anyhow::anyhow!( |
| 156 | "SSE stream request did not receive response headers after {}s. \ |
| 157 | `codewhale doctor` can still pass when non-streaming requests work; \ |
| 158 | on Windows or proxy networks, try `CODEWHALE_FORCE_HTTP1=1` and rerun `codewhale`.", |
| 159 | open_req.open_timeout.as_secs() |
| 160 | )) |
| 161 | } |
| 162 | } |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | /// Format a stable idle-timeout message shared across adapters. |
| 167 | #[must_use] |
| 168 | pub fn idle_timeout_message( |
| 169 | idle: Duration, |
| 170 | bytes_received: usize, |
| 171 | stream_age: Duration, |
| 172 | since_last_chunk: Duration, |
| 173 | ) -> String { |
| 174 | format!( |
| 175 | "SSE stream idle timeout after {}s — no data received \ |
| 176 | (bytes_received={}, stream_age_ms={}, ms_since_last_chunk={})", |
| 177 | idle.as_secs(), |
| 178 | bytes_received, |
| 179 | stream_age.as_millis(), |
| 180 | since_last_chunk.as_millis(), |
| 181 | ) |
| 182 | } |
| 183 | |
| 184 | #[cfg(test)] |
| 185 | mod tests { |
| 186 | use std::sync::Arc; |
| 187 | use std::sync::atomic::{AtomicUsize, Ordering}; |
| 188 | |
| 189 | use wiremock::matchers::method; |
| 190 | use wiremock::{Mock, MockServer, ResponseTemplate}; |
| 191 | |
| 192 | use super::*; |
| 193 | |
| 194 | fn open_req(policy: StreamHttpPolicy, open_timeout: Duration) -> StreamOpenRequest { |
| 195 | StreamOpenRequest { |
| 196 | policy, |
| 197 | open_timeout, |
| 198 | idle_timeout: Duration::from_secs(30), |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | async fn ok_server() -> MockServer { |
| 203 | let server = MockServer::start().await; |
| 204 | Mock::given(method("POST")) |
| 205 | .respond_with(ResponseTemplate::new(200)) |
| 206 | .mount(&server) |
| 207 | .await; |
| 208 | server |
| 209 | } |
| 210 | |
| 211 | #[tokio::test] |
| 212 | async fn open_returns_first_attempt_response_on_dual_policy() { |
| 213 | let server = ok_server().await; |
| 214 | let _ = rustls::crypto::ring::default_provider().install_default(); |
| 215 | let client = reqwest::Client::new(); |
| 216 | let attempts = Arc::new(AtomicUsize::new(0)); |
| 217 | let response = open_sse_response( |
| 218 | &open_req(StreamHttpPolicy::DualWithH1Fallback, Duration::from_secs(5)), |
| 219 | |policy| { |
| 220 | assert_eq!(policy, StreamHttpPolicy::DualWithH1Fallback); |
| 221 | let attempts = Arc::clone(&attempts); |
| 222 | let client = client.clone(); |
| 223 | let url = server.uri(); |
| 224 | async move { |
| 225 | attempts.fetch_add(1, Ordering::SeqCst); |
| 226 | Ok(client.post(url).send().await?) |
| 227 | } |
| 228 | }, |
| 229 | ) |
| 230 | .await |
| 231 | .expect("first attempt succeeds"); |
| 232 | assert_eq!(response.status(), 200); |
| 233 | assert_eq!(attempts.load(Ordering::SeqCst), 1); |
| 234 | } |
| 235 | |
| 236 | #[tokio::test] |
| 237 | async fn header_stall_on_dual_policy_retries_exactly_once_on_h1() { |
| 238 | let server = ok_server().await; |
| 239 | let _ = rustls::crypto::ring::default_provider().install_default(); |
| 240 | let client = reqwest::Client::new(); |
| 241 | let attempts = Arc::new(AtomicUsize::new(0)); |
| 242 | let response = open_sse_response( |
| 243 | &open_req( |
| 244 | StreamHttpPolicy::DualWithH1Fallback, |
| 245 | Duration::from_millis(150), |
| 246 | ), |
| 247 | |policy| { |
| 248 | let attempts = Arc::clone(&attempts); |
| 249 | let client = client.clone(); |
| 250 | let url = server.uri(); |
| 251 | async move { |
| 252 | let attempt = attempts.fetch_add(1, Ordering::SeqCst); |
| 253 | if attempt == 0 { |
| 254 | // First attempt stalls before response headers. |
| 255 | assert_eq!(policy, StreamHttpPolicy::DualWithH1Fallback); |
| 256 | std::future::pending::<()>().await; |
| 257 | } |
| 258 | assert_eq!(policy, StreamHttpPolicy::Http1Only); |
| 259 | Ok(client.post(url).send().await?) |
| 260 | } |
| 261 | }, |
| 262 | ) |
| 263 | .await |
| 264 | .expect("H1 fallback retry succeeds"); |
| 265 | assert_eq!(response.status(), 200); |
| 266 | assert_eq!( |
| 267 | attempts.load(Ordering::SeqCst), |
| 268 | 2, |
| 269 | "exactly one fallback retry" |
| 270 | ); |
| 271 | } |
| 272 | |
| 273 | #[tokio::test] |
| 274 | async fn header_stall_when_h1_pinned_never_retries_and_reports_timeout_text() { |
| 275 | let attempts = Arc::new(AtomicUsize::new(0)); |
| 276 | let err = open_sse_response( |
| 277 | &open_req(StreamHttpPolicy::Http1Only, Duration::from_millis(100)), |
| 278 | |_| { |
| 279 | let attempts = Arc::clone(&attempts); |
| 280 | async move { |
| 281 | attempts.fetch_add(1, Ordering::SeqCst); |
| 282 | std::future::pending::<()>().await; |
| 283 | unreachable!("stalled attempt never resolves") |
| 284 | } |
| 285 | }, |
| 286 | ) |
| 287 | .await |
| 288 | .expect_err("H1-pinned stall fails without retry"); |
| 289 | assert_eq!(attempts.load(Ordering::SeqCst), 1, "no retry when pinned"); |
| 290 | let text = err.to_string(); |
| 291 | assert!(text.contains("did not receive response headers"), "{text}"); |
| 292 | assert!(text.contains("CODEWHALE_FORCE_HTTP1=1"), "{text}"); |
| 293 | assert!( |
| 294 | !text.contains("HTTP/2 and HTTP/1.1"), |
| 295 | "single-protocol stall must not claim a dual-protocol attempt: {text}" |
| 296 | ); |
| 297 | } |
| 298 | |
| 299 | #[tokio::test] |
| 300 | async fn attempt_error_before_headers_is_not_h1_retried() { |
| 301 | let attempts = Arc::new(AtomicUsize::new(0)); |
| 302 | let err = open_sse_response( |
| 303 | &open_req(StreamHttpPolicy::DualWithH1Fallback, Duration::from_secs(5)), |
| 304 | |_| { |
| 305 | let attempts = Arc::clone(&attempts); |
| 306 | async move { |
| 307 | attempts.fetch_add(1, Ordering::SeqCst); |
| 308 | Err(anyhow::anyhow!("HTTP 401: invalid api key")) |
| 309 | } |
| 310 | }, |
| 311 | ) |
| 312 | .await |
| 313 | .expect_err("provider error propagates"); |
| 314 | assert_eq!( |
| 315 | attempts.load(Ordering::SeqCst), |
| 316 | 1, |
| 317 | "non-stall errors are never H1-retried" |
| 318 | ); |
| 319 | assert!(err.to_string().contains("HTTP 401"), "{err}"); |
| 320 | } |
| 321 | |
| 322 | #[tokio::test] |
| 323 | async fn double_stall_reports_both_protocols_in_timeout_text() { |
| 324 | let attempts = Arc::new(AtomicUsize::new(0)); |
| 325 | let err = open_sse_response( |
| 326 | &open_req( |
| 327 | StreamHttpPolicy::DualWithH1Fallback, |
| 328 | Duration::from_millis(100), |
| 329 | ), |
| 330 | |_| { |
| 331 | let attempts = Arc::clone(&attempts); |
| 332 | async move { |
| 333 | attempts.fetch_add(1, Ordering::SeqCst); |
| 334 | std::future::pending::<()>().await; |
| 335 | unreachable!("stalled attempt never resolves") |
| 336 | } |
| 337 | }, |
| 338 | ) |
| 339 | .await |
| 340 | .expect_err("double stall fails"); |
| 341 | assert_eq!(attempts.load(Ordering::SeqCst), 2, "one fallback, no more"); |
| 342 | let text = err.to_string(); |
| 343 | assert!(text.contains("HTTP/2 and HTTP/1.1"), "{text}"); |
| 344 | } |
| 345 | |
| 346 | #[test] |
| 347 | fn h1_retry_only_on_dual_policy() { |
| 348 | assert!(should_retry_with_h1( |
| 349 | StreamHttpPolicy::DualWithH1Fallback, |
| 350 | "http2 protocol error" |
| 351 | )); |
| 352 | assert!(!should_retry_with_h1( |
| 353 | StreamHttpPolicy::Http1Only, |
| 354 | "http2 protocol error" |
| 355 | )); |
| 356 | } |
| 357 | |
| 358 | #[test] |
| 359 | fn stream_open_timeout_defaults_and_clamps_env_values() { |
| 360 | assert_eq!(stream_open_timeout_from_env(None), Duration::from_secs(45)); |
| 361 | assert_eq!( |
| 362 | stream_open_timeout_from_env(Some("not-a-number")), |
| 363 | Duration::from_secs(45) |
| 364 | ); |
| 365 | assert_eq!( |
| 366 | stream_open_timeout_from_env(Some("1")), |
| 367 | Duration::from_secs(5) |
| 368 | ); |
| 369 | assert_eq!( |
| 370 | stream_open_timeout_from_env(Some("120")), |
| 371 | Duration::from_secs(120) |
| 372 | ); |
| 373 | assert_eq!( |
| 374 | stream_open_timeout_from_env(Some("999")), |
| 375 | Duration::from_secs(300) |
| 376 | ); |
| 377 | } |
| 378 | |
| 379 | #[test] |
| 380 | fn idle_message_is_stable() { |
| 381 | let msg = idle_timeout_message( |
| 382 | Duration::from_secs(30), |
| 383 | 0, |
| 384 | Duration::from_secs(30), |
| 385 | Duration::from_secs(30), |
| 386 | ); |
| 387 | assert!(msg.contains("idle timeout")); |
| 388 | assert!(msg.contains("bytes_received=0")); |
| 389 | } |
| 390 | } |
| 391 |