fix(proxy): offload OpenAI and Gemini tokenizer counting off the event loop (#2498)

## Description

The OpenAI and Gemini handlers resolved the tokenizer and counted the
conversation inline on the event loop. When a model resolves to a
HuggingFace tokenizer (the registry routes qwen, deepseek, llama, phi,
falcon, and more there) a cold cache runs
`AutoTokenizer.from_pretrained` behind a 10s `thread.join`, which
freezes the whole server. That is the GH #1701 stall, now reachable from
OpenAI and Gemini because `/v1/chat/completions` and `/v1/responses` are
documented multi-provider passthroughs and receive those models.

Anthropic already routed the same call through a fail-open
`_count_tokens_offloaded` helper. This hoists that helper to the shared
`HeadroomProxy` base and sends the OpenAI and Gemini sites through it
too.

No linked issue. This is the OpenAI and Gemini follow-on to #1738, which
offloaded the Anthropic and batch paths. GH #1701 is the original freeze
report.

## Type of Change

- [x] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update
- [ ] Performance improvement
- [ ] Code refactoring (no functional changes)

## Changes Made

- Hoisted `_count_tokens_offloaded` from `AnthropicHandlerMixin` to the
shared `HeadroomProxy` base, next to `_run_compression_in_executor`. It
resolves and counts on the bounded compression executor and fails open
to estimation on timeout, error, or executor quarantine.
- Routed 6 inline sites through it: `handle_openai_chat`,
`handle_openai_responses`, `handle_gemini_generate_content`,
`handle_google_cloudcode_stream`, `handle_gemini_count_tokens`, and
`handle_gemini_stream_generate_content` (resolve only, keeps its
per-part `count_text` loop).
- Removed 6 now-dead local `get_tokenizer` imports.
- Left batch's per-line counts inline on purpose. They run on an
already-warm tokenizer, so offloading them adds executor churn without
touching the cold load. Batch's `pipeline.apply` was already offloaded
in #1738.
- Extended the wiring guard to all 7 provider handlers, added a
quarantine fail-open test and a `count_text` fail-open test, and stubbed
the method on 2 mixin-only handler doubles.

## Testing

- [x] Unit tests pass (`pytest`)
- [x] Linting passes (`ruff check .`)
- [ ] Type checking passes (`mypy headroom`)
- [x] New tests added for new functionality
- [x] Manual testing performed

### Test Output

```text
$ ruff check headroom/proxy/server.py headroom/proxy/handlers/{anthropic,openai,gemini}.py tests/test_tokenizer_count_offload.py
All checks passed!

$ pytest tests/test_tokenizer_count_offload.py
6 passed in 4.39s

# offload suite + all 26 handler-calling test files + handler-helpers/batch/tokenizers
$ pytest tests/test_tokenizer_count_offload.py tests/test_openai_codex_routing.py tests/test_gemini_nonjson_status.py ... tests/test_tokenizers.py
377 passed, 15 skipped, 15 warnings in 86.60s (0:01:26)
```

## Real Behavior Proof

- Environment: macOS (Darwin), Python 3.13, proxy built from this
branch. A synthetic tokenizer that sleeps 0.5s on resolve+count stands
in for a cold HuggingFace `from_pretrained` load, with a 10ms asyncio
loop-canary running alongside.
- Exact command / steps: monkeypatch `headroom.tokenizers.get_tokenizer`
to the 0.5s-sleeping tokenizer, then time a concurrent canary across two
counts, the offloaded `await
proxy._count_tokens_offloaded("qwen2.5-coder", messages)` and the old
inline `get_tokenizer(model).count_messages(messages)`.
- Observed result: the offloaded path kept the loop live at 41 canary
ticks during the 509ms count, the inline path froze it to 0 ticks over
502ms, and both returned the same token count. Full run was 377 passed,
15 skipped, 0 failed. The new quarantine test confirms an unrelated
compression timeout downgrades counting to estimation instead of raising
a 500.
- Not tested: live HuggingFace downloads and real qwen/deepseek traffic.
No API keys in this environment, so the Gemini and OpenAI integration
tests skip on `GEMINI_API_KEY`/`OPENAI_API_KEY`. `mypy headroom` did not
finish locally (cold-times-out past 10 minutes on this box), so
type-checking is left to CI.

## Review Readiness

- [x] I have performed a self-review
- [x] This PR is ready for human review

## Checklist

- [x] My code follows the project's style guidelines
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [x] I did **not** edit `CHANGELOG.md` — it is generated by
release-please from my Conventional Commit PR title (a CI guard enforces
this)

## Additional Notes

- No linked issue. Follow-on to #1738.
- Batch per-line counts stay inline: they run on an already-warm
tokenizer, so offloading them adds executor churn without addressing the
cold load.
- Found a 6th site mid-implementation.
`handle_gemini_stream_generate_content` also resolved the tokenizer
inline but counts via a `count_text` loop, so it takes the resolve-only
path. Verified `EstimatingTokenCounter.count_text` exists, so its
fail-open branch does not crash.
- `mypy headroom` cold-times-out locally (server.py pulls the full
graph). Deferred to CI's Linux shards, same as prior PRs on this file.
`ruff` and `pytest` run clean.
- Documentation checkbox left unchecked: this change ships no
user-facing doc update.

---------

Co-authored-by: JerrettDavis <mxjerrett@gmail.com>
This commit is contained in:
inix 2026-07-23 12:01:05 +08:00 committed by GitHub
parent 5d23a0aec2
commit 806d2e468a
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7 changed files with 291 additions and 73 deletions

View file

@ -72,46 +72,9 @@ class AnthropicHandlerMixin:
"""Mixin providing Anthropic API handler methods for HeadroomProxy."""
async def _count_tokens_offloaded(self, model, messages): # noqa: ANN001, ANN201
"""Resolve a tokenizer and count messages off the event loop.
from headroom.proxy.token_counting import count_tokens_offloaded
Tokenizer resolution can be expensive on first use (HuggingFace
backends may download vocab files) and counting a full Claude Code
conversation is CPU-bound, so both run on the compression executor
bounded by ``COMPRESSION_TIMEOUT_SECONDS`` (GH #1701: an unbounded
on-loop load froze the whole server). On timeout or error this
fails open to character-based estimation.
Returns:
Tuple of ``(tokenizer, token_count)``. The tokenizer is fully
initialized, so later ``count_messages`` calls on it are pure
CPU work.
"""
from headroom.proxy.helpers import COMPRESSION_TIMEOUT_SECONDS
from headroom.tokenizers import EstimatingTokenCounter, get_tokenizer
def _resolve_and_count(): # noqa: ANN202
tokenizer = get_tokenizer(model)
return tokenizer, tokenizer.count_messages(messages)
try:
return await self._run_compression_in_executor(
_resolve_and_count,
timeout=float(COMPRESSION_TIMEOUT_SECONDS),
)
except Exception as e: # fail open — includes asyncio.TimeoutError
# Log the downgrade once per model, not per request.
fallback_models = getattr(self, "_token_count_fallback_models", None)
if fallback_models is None:
fallback_models = set()
self._token_count_fallback_models = fallback_models
if model not in fallback_models:
fallback_models.add(model)
logger.warning(
f"Token counting for model {model} failed or timed out "
f"({e.__class__.__name__}); falling back to estimation"
)
estimator = EstimatingTokenCounter()
return estimator, estimator.count_messages(messages)
return await count_tokens_offloaded(self, model, messages)
@staticmethod
def _resolve_ccr_workspace(

View file

@ -38,6 +38,16 @@ def _usage_int(value: Any, default: int = 0) -> int:
class GeminiHandlerMixin:
"""Mixin providing Gemini API handler methods for HeadroomProxy."""
async def _count_tokens_offloaded(self, model, messages): # noqa: ANN001, ANN201
from headroom.proxy.token_counting import count_tokens_offloaded
return await count_tokens_offloaded(self, model, messages)
async def _count_texts_offloaded(self, model, texts): # noqa: ANN001, ANN201
from headroom.proxy.token_counting import count_texts_offloaded
return await count_texts_offloaded(self, model, texts)
def _is_cloudcode_antigravity_request(
self, body: dict[str, Any], headers: dict[str, str]
) -> bool:
@ -259,7 +269,6 @@ class GeminiHandlerMixin:
from fastapi.responses import JSONResponse, Response
from headroom.proxy.helpers import MAX_REQUEST_BODY_SIZE, _read_request_json
from headroom.tokenizers import get_tokenizer
from headroom.utils import extract_user_query
start_time = time.time()
@ -491,9 +500,8 @@ class GeminiHandlerMixin:
headers=response_headers,
)
# Token counting
tokenizer = get_tokenizer(model)
original_tokens = tokenizer.count_messages(messages)
# Token counting (offloaded off the event loop — GH #1701)
tokenizer, original_tokens = await self._count_tokens_offloaded(model, messages)
# Optimization
transforms_applied: list[str] = []
@ -816,7 +824,6 @@ class GeminiHandlerMixin:
from fastapi.responses import JSONResponse
from headroom.proxy.helpers import _read_request_json
from headroom.tokenizers import get_tokenizer
from headroom.utils import extract_user_query
start_time = time.time()
@ -880,8 +887,10 @@ class GeminiHandlerMixin:
if isinstance(contents, list) and idx < len(contents)
}
tokenizer = get_tokenizer(model)
original_tokens = tokenizer.count_messages(messages) if messages else 0
# Token counting (offloaded off the event loop — GH #1701)
tokenizer, original_tokens = await self._count_tokens_offloaded(model, messages)
if not messages:
original_tokens = 0
optimized_messages = messages
optimized_tokens = original_tokens
transforms_applied: list[str] = []
@ -981,7 +990,6 @@ class GeminiHandlerMixin:
from fastapi.responses import JSONResponse
from headroom.proxy.helpers import _read_request_json
from headroom.tokenizers import get_tokenizer
start_time = time.time()
request_id = await self._next_request_id()
@ -1019,14 +1027,17 @@ class GeminiHandlerMixin:
request_id=request_id,
)
# Token counting
tokenizer = get_tokenizer(model)
original_tokens = 0
for content in contents:
parts = content.get("parts", [])
for part in parts:
if "text" in part:
original_tokens += tokenizer.count_text(part["text"])
# Token counting (offloaded off the event loop — GH #1701). Reuse the
# shared _dict_parts coercion and keep only str text values: count_text
# raises on a non-str part value and the fail-open path re-runs the same
# input, so a malformed part would otherwise 500 the streaming request.
text_parts = [
part["text"]
for content in (contents if isinstance(contents, list) else [])
for part in self._dict_parts(content)
if isinstance(part.get("text"), str)
]
_, original_tokens = await self._count_texts_offloaded(model, text_parts)
optimization_latency = (time.time() - start_time) * 1000
@ -1069,7 +1080,6 @@ class GeminiHandlerMixin:
from fastapi.responses import JSONResponse, Response
from headroom.proxy.helpers import _read_request_json
from headroom.tokenizers import get_tokenizer
from headroom.utils import extract_user_query
start_time = time.time()
@ -1140,9 +1150,8 @@ class GeminiHandlerMixin:
headers=response_headers,
)
# Token counting (original)
tokenizer = get_tokenizer(model)
original_tokens = tokenizer.count_messages(messages)
# Token counting (original, offloaded off the event loop — GH #1701)
tokenizer, original_tokens = await self._count_tokens_offloaded(model, messages)
# Apply compression using the same pipeline as generateContent
transforms_applied: list[str] = []

View file

@ -1316,6 +1316,11 @@ def _prefers_http1_passthrough(base_url: str) -> bool:
class OpenAIHandlerMixin:
"""Mixin providing OpenAI API handler methods for HeadroomProxy."""
async def _count_tokens_offloaded(self, model, messages): # noqa: ANN001, ANN201
from headroom.proxy.token_counting import count_tokens_offloaded
return await count_tokens_offloaded(self, model, messages)
OPENAI_RESPONSES_ROUTER_MIN_BYTES = 512
OPENAI_RESPONSES_OUTPUT_TYPES = _RESPONSES_OUTPUT_ITEM_TYPES
@ -2576,7 +2581,6 @@ class OpenAIHandlerMixin:
_read_request_json,
)
from headroom.proxy.modes import is_cache_mode, is_token_mode
from headroom.tokenizers import get_tokenizer
from headroom.utils import extract_user_query
start_time = time.time()
@ -2905,9 +2909,8 @@ class OpenAIHandlerMixin:
return Response(content=cached.response_body, headers=response_headers)
# Token counting
tokenizer = get_tokenizer(model)
original_tokens = tokenizer.count_messages(messages)
# Token counting (offloaded off the event loop — GH #1701)
tokenizer, original_tokens = await self._count_tokens_offloaded(model, messages)
# Hook: pre_compress
_hook_biases = None
@ -4257,7 +4260,6 @@ class OpenAIHandlerMixin:
MAX_REQUEST_BODY_SIZE,
read_request_json_with_bytes,
)
from headroom.tokenizers import get_tokenizer
from headroom.utils import extract_user_query
start_time = time.time()
@ -4474,9 +4476,8 @@ class OpenAIHandlerMixin:
detail=f"Rate limited. Retry after {wait_seconds:.1f}s",
)
# Token counting on converted messages
tokenizer = get_tokenizer(model)
original_tokens = tokenizer.count_messages(messages)
# Token counting on converted messages (offloaded off the event loop — GH #1701)
tokenizer, original_tokens = await self._count_tokens_offloaded(model, messages)
# Defaults below feed downstream telemetry and memory injection.
# If optimization remains enabled, the Responses payload is compressed

View file

@ -0,0 +1,79 @@
"""Offloaded token-count helpers shared by proxy handlers.
Tokenizer resolution can be expensive on first use (HuggingFace backends may
download vocab files) and counting a full Claude Code conversation is CPU-bound,
so both run on the caller's compression executor bounded by
``COMPRESSION_TIMEOUT_SECONDS`` (GH #1701: an unbounded on-loop load froze the
whole server). On timeout, error, or a missing executor this fails open to
character-based estimation.
Shared by every provider handler mixin (Anthropic, OpenAI, Gemini): the OpenAI
``/v1/chat/completions`` and ``/v1/responses`` endpoints are multi-provider
passthroughs, so an HF-routed model (qwen, deepseek, llama, ...) can reach them
and trigger the same cold load.
"""
from __future__ import annotations
import logging
from collections.abc import Callable
from typing import Any, cast
logger = logging.getLogger("headroom.proxy")
def _record_fallback_model(owner: Any, model: Any, message: str) -> None:
fallback_models = getattr(owner, "_token_count_fallback_models", None)
if fallback_models is None:
fallback_models = set()
owner._token_count_fallback_models = fallback_models
if model not in fallback_models:
fallback_models.add(model)
logger.warning(message)
async def _count_offloaded(owner: Any, model: Any, count: Callable[[Any], int]) -> tuple[Any, int]:
"""Resolve a tokenizer and apply ``count`` off the event loop when possible.
``count`` maps a resolved tokenizer to a token total. Returns
``(tokenizer, total)``; the returned tokenizer is fully initialized, so later
counts on it are pure CPU work. Fails open to ``EstimatingTokenCounter`` when
the owner has no compression executor, or on timeout/error.
"""
from headroom.proxy.helpers import COMPRESSION_TIMEOUT_SECONDS
from headroom.tokenizers import EstimatingTokenCounter, get_tokenizer
runner = getattr(owner, "_run_compression_in_executor", None)
if runner is None:
estimator = EstimatingTokenCounter()
return estimator, count(estimator)
def _resolve_and_count() -> tuple[Any, int]:
tokenizer = get_tokenizer(model)
return tokenizer, count(tokenizer)
try:
result = await runner(_resolve_and_count, timeout=float(COMPRESSION_TIMEOUT_SECONDS))
return cast(tuple[Any, int], result)
except Exception as e: # fail open — includes asyncio.TimeoutError
_record_fallback_model(
owner,
model,
f"Token counting for model {model} failed or timed out "
f"({e.__class__.__name__}); falling back to estimation",
)
estimator = EstimatingTokenCounter()
return estimator, count(estimator)
async def count_tokens_offloaded(owner: Any, model: Any, messages: Any) -> tuple[Any, int]:
"""Resolve a tokenizer and count ``messages`` off the event loop when possible."""
return await _count_offloaded(owner, model, lambda counter: counter.count_messages(messages))
async def count_texts_offloaded(owner: Any, model: Any, texts: Any) -> tuple[Any, int]:
"""Resolve a tokenizer and count text fragments off the event loop when possible."""
text_list = list(texts)
return await _count_offloaded(
owner, model, lambda counter: sum(counter.count_text(text) for text in text_list)
)

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@ -57,6 +57,14 @@ class _Handler(GeminiHandlerMixin):
async def _record_request_outcome(self, outcome) -> None: # noqa: ANN001
self.outcomes.append(outcome)
async def _count_tokens_offloaded(self, model, messages): # noqa: ANN001, ANN201
# Test stub for HeadroomProxy._count_tokens_offloaded: resolve the
# tokenizer and count inline (the real method offloads to the executor).
from headroom.tokenizers import get_tokenizer
tokenizer = get_tokenizer(model)
return tokenizer, tokenizer.count_messages(messages)
@pytest.mark.asyncio
async def test_generate_content_forwards_non_json_upstream_status(

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@ -205,6 +205,14 @@ class _DummyOpenAIHandler(OpenAIHandlerMixin):
# synchronously so MagicMock call_count assertions fire.
return fn()
async def _count_tokens_offloaded(self, model, messages): # noqa: ANN001, ANN201
# Test stub for HeadroomProxy._count_tokens_offloaded: resolve the
# tokenizer and count inline (the real method offloads to the executor).
from headroom.tokenizers import get_tokenizer
tokenizer = get_tokenizer(model)
return tokenizer, tokenizer.count_messages(messages)
async def _record_request_outcome(self, outcome) -> None:
# Test stub: delegates to the production funnel so wire shape
# matches HeadroomProxy._record_request_outcome.

View file

@ -4,8 +4,10 @@ handler. For HF-backed models (e.g. deepseek-*) first use triggers an unbounded
network download, freezing the whole server (610s request, then /livez, /readyz
and /health hang until kill). The fix routes resolution + counting through
HeadroomProxy._count_tokens_offloaded (compression executor, bounded by
COMPRESSION_TIMEOUT_SECONDS, fail-open to estimation), and offloads the inline
batch pipeline.apply() calls the same way.
COMPRESSION_TIMEOUT_SECONDS, fail-open to estimation) shared by every provider
handler (Anthropic, OpenAI, Gemini), since the OpenAI passthrough endpoints
receive the same HF-backed models and offloads the inline batch
pipeline.apply() calls the same way.
"""
from __future__ import annotations
@ -17,7 +19,18 @@ import time
from headroom.proxy.handlers.anthropic import AnthropicHandlerMixin
from headroom.proxy.handlers.batch import BatchHandlerMixin
from headroom.proxy.server import ProxyConfig, create_app
from headroom.proxy.handlers.gemini import GeminiHandlerMixin
from headroom.proxy.handlers.openai import OpenAIHandlerMixin
from headroom.proxy.server import (
CompressionQuarantinedError,
ProxyConfig,
create_app,
)
from headroom.proxy.token_counting import (
_count_offloaded,
count_texts_offloaded,
count_tokens_offloaded,
)
from headroom.tokenizers import EstimatingTokenCounter
@ -36,11 +49,36 @@ def _make_proxy(): # noqa: ANN202 — returns the internal HeadroomProxy
def test_handlers_offload_token_counting_and_batch_apply() -> None:
"""Wiring guard: the request paths must use the offloaded helpers, not inline
get_tokenizer/count_messages or pipeline.apply on the event loop."""
fn = AnthropicHandlerMixin.handle_anthropic_messages
# Every provider handler that counts the original conversation must route
# resolution + counting through the shared fail-open helper, never inline on
# the loop. OpenAI /chat + /responses are multi-provider passthroughs, so an
# HF-routed model (qwen, deepseek, llama, ...) can reach them and cold-load.
for mixin, method in (
(AnthropicHandlerMixin, "handle_anthropic_messages"),
(OpenAIHandlerMixin, "handle_openai_chat"),
(OpenAIHandlerMixin, "handle_openai_responses"),
(GeminiHandlerMixin, "handle_gemini_generate_content"),
(GeminiHandlerMixin, "handle_google_cloudcode_stream"),
(GeminiHandlerMixin, "handle_gemini_count_tokens"),
):
fn = getattr(mixin, method)
assert inspect.iscoroutinefunction(fn), f"{method} must be async"
src = inspect.getsource(fn)
assert "_count_tokens_offloaded(" in src, f"{method}: token counting not offloaded"
assert "tokenizer = get_tokenizer(" not in src, (
f"{method}: tokenizer resolved inline on the loop"
)
fn = GeminiHandlerMixin.handle_gemini_stream_generate_content
assert inspect.iscoroutinefunction(fn)
src = inspect.getsource(fn)
assert "_count_tokens_offloaded(" in src, "token counting not offloaded"
assert "_count_texts_offloaded(" in src, "streaming Gemini text counting not offloaded"
assert "tokenizer = get_tokenizer(" not in src, "tokenizer resolved inline on the loop"
assert "count_text(" not in src, "streaming Gemini count_text still runs on the loop"
assert "_dict_parts(" in src, "streaming Gemini must reuse the shared _dict_parts coercion"
assert 'isinstance(part.get("text"), str)' in src, (
"streaming Gemini must skip non-str text so count_text can't 500"
)
for mixin, method in (
(AnthropicHandlerMixin, "handle_anthropic_batch_create"),
@ -54,7 +92,7 @@ def test_handlers_offload_token_counting_and_batch_apply() -> None:
assert "_run_compression_in_executor(" in src, f"{method}: apply() not offloaded"
assert "COMPRESSION_TIMEOUT_SECONDS" in src, f"{method}: offload missing timeout"
helper_src = inspect.getsource(AnthropicHandlerMixin._count_tokens_offloaded)
helper_src = inspect.getsource(_count_offloaded)
assert "COMPRESSION_TIMEOUT_SECONDS" in helper_src
assert "EstimatingTokenCounter" in helper_src, "helper must fail open to estimation"
@ -124,3 +162,115 @@ async def test_count_tokens_offloaded_fails_open(monkeypatch) -> None: # noqa:
assert tokens > 0
# Logged-once bookkeeping records the downgraded model.
assert "deepseek-chat" in proxy._token_count_fallback_models
async def test_count_tokens_offloaded_fails_open_on_executor_quarantine() -> None:
"""Now that OpenAI/Gemini counting shares the compression executor, an
unrelated request's compression timeout can quarantine it — the next
``_run_compression_in_executor`` call raises ``CompressionQuarantinedError``
immediately (process-wide state). A request that is only counting tokens
must not 500 on that; it fails open to estimation like any other error."""
# The executor's ``except Exception`` fail-open only catches the quarantine
# error because it subclasses Exception — pin that contract.
assert issubclass(CompressionQuarantinedError, Exception)
proxy = _make_proxy()
# Record a concurrent compression as timed out so the real executor guard
# quarantines the next call — no mock of the helper itself.
proxy._compression_timed_out_in_flight = 1
tokenizer, tokens = await proxy._count_tokens_offloaded(
"qwen2.5-coder", [{"role": "user", "content": "hello world"}]
)
assert isinstance(tokenizer, EstimatingTokenCounter)
assert tokens > 0
assert "qwen2.5-coder" in proxy._token_count_fallback_models
async def test_count_tokens_offloaded_returns_count_text_capable_tokenizer() -> None:
"""The fail-open tokenizer should still support text counting for callers
that need per-fragment accounting."""
proxy = _make_proxy()
# Quarantine forces the fail-open branch (an EstimatingTokenCounter).
proxy._compression_timed_out_in_flight = 1
# The empty-messages count is intentionally discarded by that handler
# (it sums text parts itself), so only the tokenizer matters here.
tokenizer, _ = await proxy._count_tokens_offloaded("qwen2.5-coder", [])
assert isinstance(tokenizer, EstimatingTokenCounter)
# The streaming handler's per-part loop must not raise on the fallback.
assert tokenizer.count_text("hello world") > 0
async def test_count_texts_offloaded_runs_on_worker_thread(monkeypatch) -> None: # noqa: ANN001
proxy = _make_proxy()
loop_thread = threading.current_thread().name
seen: dict[str, str] = {}
class _SpyTokenizer(EstimatingTokenCounter):
def count_text(self, text): # noqa: ANN001, ANN201
seen["thread"] = threading.current_thread().name
return super().count_text(text)
monkeypatch.setattr("headroom.tokenizers.get_tokenizer", lambda *a, **k: _SpyTokenizer())
_, tokens = await proxy._count_texts_offloaded("gemini-pro", ["hello", "world"])
assert tokens > 0
assert seen["thread"].startswith("headroom-compress")
assert seen["thread"] != loop_thread
async def test_count_texts_offloaded_fails_open(monkeypatch) -> None: # noqa: ANN001
"""The texts variant downgrades to estimation on a resolution error, the same
as the messages variant (its fail-open branch was previously uncovered)."""
proxy = _make_proxy()
def _boom(*a, **k): # noqa: ANN002, ANN003, ANN202
raise RuntimeError("tokenizer backend exploded")
monkeypatch.setattr("headroom.tokenizers.get_tokenizer", _boom)
tokenizer, tokens = await proxy._count_texts_offloaded("deepseek-chat", ["hello", "world"])
assert isinstance(tokenizer, EstimatingTokenCounter)
assert tokens > 0
assert "deepseek-chat" in proxy._token_count_fallback_models
async def test_count_offloaded_without_executor_estimates() -> None:
"""An owner with no compression executor (a lightweight caller or test double)
fails open to estimation inline instead of crashing on the missing runner."""
class _NoExecutorOwner:
pass
owner = _NoExecutorOwner()
tok, n_msg = await count_tokens_offloaded(
owner, "gpt-4", [{"role": "user", "content": "hello world"}]
)
assert isinstance(tok, EstimatingTokenCounter)
assert n_msg > 0
tok2, n_txt = await count_texts_offloaded(owner, "gemini-pro", ["hello", "world"])
assert isinstance(tok2, EstimatingTokenCounter)
assert n_txt > 0
async def test_count_texts_offloaded_sums_fragments(monkeypatch) -> None: # noqa: ANN001
"""The streaming rewrite sums per-fragment counts, matching the old per-part
count_text loop it replaced."""
proxy = _make_proxy()
monkeypatch.setattr(
"headroom.tokenizers.get_tokenizer", lambda *a, **k: EstimatingTokenCounter()
)
fragments = ["hello", "world", "foo"]
_, total = await proxy._count_texts_offloaded("gemini-pro", fragments)
est = EstimatingTokenCounter()
assert total == sum(est.count_text(f) for f in fragments)
assert total > 0