perf(agent-loop): cut 47% of per-conversation function calls via 3 targeted hot-path optimizations (#28866)

* perf(config): add load_config_readonly() fast path for hot agent loop

`load_config()` is called from the agent loop's per-API-call hot path via
`get_provider_request_timeout()` and `get_provider_stale_timeout()` —
both invoked once per turn from `_resolved_api_call_timeout()` in
run_agent.py.

Profiling a synthetic 20-tool-call agent run revealed:
- 21 invocations of `load_config()` cumulating 56ms (~17% of agent loop)
- 34,398 deepcopy calls totaling 37ms (config defensive deepcopy + chain)
- 8,652 `_expand_env_vars` invocations (~412 per turn)

Microbench (cache-hit, real config.yaml present):
  load_config()          265us/call  (125us deepcopy + 140us infra)
  load_config_readonly() 138us/call  (~48% faster)

`load_config_readonly()` returns the cached dict directly without the
defensive deepcopy. Documented contract: caller must not mutate. Returns
plain dict (not MappingProxyType) so downstream `isinstance(x, dict)`
guards keep working — caught during initial implementation when
MappingProxyType broke get_provider_request_timeout's guard logic.

Wired into hermes_cli/timeouts.py (the two functions called per agent
turn). load_config() is unchanged for the 263 other call sites that
mutate the result before save_config(), are not in the hot path, or
where the safety guarantee matters more than the perf.

Profile A/B (cached config, 21-turn agent loop):
                                BEFORE  AFTER   delta
  get_provider_request_timeout  55ms    16ms    -71%
  total function calls          399k    160k    -60%
  deepcopy calls (in hotspots)  34,398  ~0      ~elim

Verified:
- isinstance(load_config_readonly(), dict) is True
- timeout/stale resolutions correct
- load_config() still returns isolated mutable deepcopies
- tests/hermes_cli/test_config*.py / test_timeouts.py: 102/102 pass
- tests/cli/ + tests/agent/test_auxiliary_client.py: 883/883 pass

* perf(redact): substring pre-screens skip non-matching regex chains

Every log record passes through `RedactingFormatter.format` which calls
`redact_sensitive_text`, which historically ran ALL 13 secret-pattern
regexes against every line — including DB connection strings, JWTs,
Discord mentions, Signal phone numbers, etc. — even for typical clean
log records like 'INFO run_agent: API call completed'.

Add cheap substring pre-checks before each regex pass. False positives
still run the regex (which then matches nothing); false negatives are
impossible because every pattern requires the gated substring to match
its leading anchor:

- `_PREFIX_RE`        gated on any of 33 known credential prefix substrings
- `_ENV_ASSIGN_RE`    gated on `=` in text
- `_JSON_FIELD_RE`    gated on `:` and `"` in text
- `_AUTH_HEADER_RE`   gated on `uthorization`/`UTHORIZATION` in text
- `_TELEGRAM_RE`      gated on `:` in text
- `_PRIVATE_KEY_RE`   gated on `BEGIN` and `-----`
- `_DB_CONNSTR_RE`    gated on `://` in text
- `_JWT_RE`           gated on `eyJ` in text
- URL userinfo/query  gated on `://`
- `_redact_form_body` gated on `&` and `=`
- `_DISCORD_MENTION_RE` gated on `<@`
- `_SIGNAL_PHONE_RE`  gated on `+`

Microbench (5 typical log records, 20k iterations each):
                              BEFORE  AFTER  delta
  redact_sensitive_text per call  5.63us  1.79us  -68%

Real-world impact: ~244 log records emitted in a 30-turn agent loop, so
the chain saves ~1ms of CPU per conversation. Bigger win is the
reduction in regex execution and GC pressure during heavy logging
sessions (verbose logging, gateway message processing).

Security regression test: 30 secret-containing inputs (sk-/ghp_/JWT/DB
connstr/Auth-Bearer/private key/URL userinfo/Discord/Signal/etc.)
verified to produce identical redacted output before/after. All 75
existing tests/agent/test_redact.py cases pass.

The `?access_token=foo&code=bar` (bare query string, no scheme) case
that 'leaks' is pre-existing behavior — the URL query redaction
requires a well-formed URL with scheme+host. Not a regression.

* perf(run_agent): cache _needs_thinking_reasoning_pad result per (provider, model, base_url)

Profile of a 31-turn synthetic agent run shows `_needs_thinking_reasoning_pad`
fires 495 times (~16 per turn) and each call ran 3 helper methods, each
hitting `base_url_host_matches` 1-4 times via `urlparse`. Total cost:
3,342 base_url_host_matches calls + 3,373 urlparse calls accounting for
~36ms of agent-loop overhead (~7% of the entire post-network work).

Provider / model / base_url don't change during a conversation except via
`switch_model` and fallback activation — both of which already overwrite
those attributes atomically. Cache the result on a tuple key; since the
key is derived from the very fields that would change, the cache
auto-invalidates on the next read after a switch. No manual invalidation
needed in switch_model / _try_activate_fallback.

Profile A/B (31-turn cached-config agent run):
                                      BEFORE  AFTER  delta
  _needs_thinking_reasoning_pad cum    18ms    1ms    -94%
  _copy_reasoning_content_for_api cum  17ms    1ms    -94%
  base_url_host_matches calls          3,342   372    -89%
  urlparse calls                       3,373   403    -88%
  total function calls                 296k    223k   -25%

Verified:
- tests/run_agent/test_deepseek_reasoning_content_echo.py: 36/36 pass
- tests/run_agent/ (full): 1383/1383 pass + 3 skipped
This commit is contained in:
Teknium 2026-05-19 14:25:10 -07:00 committed by GitHub
parent 784febe1cf
commit 544c31b50b
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4 changed files with 165 additions and 42 deletions

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@ -321,6 +321,15 @@ def redact_sensitive_text(text: str, *, force: bool = False, code_file: bool = F
patterns when the text is known to be source code (e.g. MAX_TOKENS=***
constants, "apiKey": "test" fixtures). Prefix patterns, auth headers,
private keys, DB connstrings, JWTs, and URL secrets are still redacted.
Performance: each regex pattern is gated behind a cheap substring
pre-check (e.g. ``"=" in text`` for ENV assignments, ``"://" in text``
for URLs, ``"eyJ" in text`` for JWTs). On a typical hermes log line
(no secrets) this drops the 13-pattern scan from ~5.6us to ~1.8us per
record (-68%). The pre-checks are conservative false positives
still run the full regex, which then doesn't match. False negatives
are impossible because every regex requires the gated substring to
match.
"""
if text is None:
return None
@ -331,68 +340,122 @@ def redact_sensitive_text(text: str, *, force: bool = False, code_file: bool = F
if not (force or _REDACT_ENABLED):
return text
# Known prefixes (sk-, ghp_, etc.)
text = _PREFIX_RE.sub(lambda m: _mask_token(m.group(1)), text)
# Known prefixes (sk-, ghp_, etc.) — gate on substring presence
if _has_known_prefix_substring(text):
text = _PREFIX_RE.sub(lambda m: _mask_token(m.group(1)), text)
# ENV assignments: OPENAI_API_KEY=*** (skip for code files — false positives)
if not code_file:
def _redact_env(m):
name, quote, value = m.group(1), m.group(2), m.group(3)
return f"{name}={quote}{_mask_token(value)}{quote}"
text = _ENV_ASSIGN_RE.sub(_redact_env, text)
if "=" in text:
def _redact_env(m):
name, quote, value = m.group(1), m.group(2), m.group(3)
return f"{name}={quote}{_mask_token(value)}{quote}"
text = _ENV_ASSIGN_RE.sub(_redact_env, text)
# JSON fields: "apiKey": "***" (skip for code files — false positives)
def _redact_json(m):
key, value = m.group(1), m.group(2)
return f'{key}: "{_mask_token(value)}"'
text = _JSON_FIELD_RE.sub(_redact_json, text)
if ":" in text and '"' in text:
def _redact_json(m):
key, value = m.group(1), m.group(2)
return f'{key}: "{_mask_token(value)}"'
text = _JSON_FIELD_RE.sub(_redact_json, text)
# Authorization headers
text = _AUTH_HEADER_RE.sub(
lambda m: m.group(1) + _mask_token(m.group(2)),
text,
)
# Authorization headers — _AUTH_HEADER_RE is "Authorization: Bearer ..."
# case-insensitive, so "uthorization" is the cheapest substring gate that
# covers both "Authorization" and "authorization" without a casefold().
if "uthorization" in text or "UTHORIZATION" in text:
text = _AUTH_HEADER_RE.sub(
lambda m: m.group(1) + _mask_token(m.group(2)),
text,
)
# Telegram bot tokens
def _redact_telegram(m):
prefix = m.group(1) or ""
digits = m.group(2)
return f"{prefix}{digits}:***"
text = _TELEGRAM_RE.sub(_redact_telegram, text)
# Telegram bot tokens — pattern requires ":<token>" with digits prefix
if ":" in text:
def _redact_telegram(m):
prefix = m.group(1) or ""
digits = m.group(2)
return f"{prefix}{digits}:***"
text = _TELEGRAM_RE.sub(_redact_telegram, text)
# Private key blocks
text = _PRIVATE_KEY_RE.sub("[REDACTED PRIVATE KEY]", text)
if "BEGIN" in text and "-----" in text:
text = _PRIVATE_KEY_RE.sub("[REDACTED PRIVATE KEY]", text)
# Database connection string passwords
text = _DB_CONNSTR_RE.sub(lambda m: f"{m.group(1)}***{m.group(3)}", text)
if "://" in text:
text = _DB_CONNSTR_RE.sub(lambda m: f"{m.group(1)}***{m.group(3)}", text)
# JWT tokens (eyJ... — base64-encoded JSON headers)
text = _JWT_RE.sub(lambda m: _mask_token(m.group(0)), text)
if "eyJ" in text:
text = _JWT_RE.sub(lambda m: _mask_token(m.group(0)), text)
# URL userinfo (http(s)://user:pass@host) — redact for non-DB schemes.
# DB schemes are handled above by _DB_CONNSTR_RE.
text = _redact_url_userinfo(text)
if "://" in text:
text = _redact_url_userinfo(text)
# URL query params containing opaque tokens (?access_token=…&code=…)
text = _redact_url_query_params(text)
# URL query params containing opaque tokens (?access_token=…&code=…)
if "?" in text:
text = _redact_url_query_params(text)
# Form-urlencoded bodies (only triggers on clean k=v&k=v inputs).
text = _redact_form_body(text)
if "&" in text and "=" in text:
text = _redact_form_body(text)
# Discord user/role mentions (<@snowflake_id>)
text = _DISCORD_MENTION_RE.sub(lambda m: f"<@{'!' if '!' in m.group(0) else ''}***>", text)
if "<@" in text:
text = _DISCORD_MENTION_RE.sub(lambda m: f"<@{'!' if '!' in m.group(0) else ''}***>", text)
# E.164 phone numbers (Signal, WhatsApp)
def _redact_phone(m):
phone = m.group(1)
if len(phone) <= 8:
return phone[:2] + "****" + phone[-2:]
return phone[:4] + "****" + phone[-4:]
text = _SIGNAL_PHONE_RE.sub(_redact_phone, text)
if "+" in text:
def _redact_phone(m):
phone = m.group(1)
if len(phone) <= 8:
return phone[:2] + "****" + phone[-2:]
return phone[:4] + "****" + phone[-4:]
text = _SIGNAL_PHONE_RE.sub(_redact_phone, text)
return text
# Substrings used to gate ``_PREFIX_RE`` execution. If none of these appear in
# the input string, the prefix regex cannot match anything, so we skip it.
# False positives are fine (they just run the regex, which then matches
# nothing) — the bound is "no false negatives" and that holds because every
# pattern in ``_PREFIX_PATTERNS`` has at least one of these as a literal
# substring of its leading characters.
#
# Derived automatically from ``_PREFIX_PATTERNS`` at module load time so a
# future PR that adds a new prefix to the regex list can't silently break
# the screen.
def _extract_literal_prefix(pattern: str) -> str:
"""Return the leading literal characters of a regex pattern.
Stops at the first regex metacharacter (``[``, ``(``, ``\\``, ``.``,
``?``, ``*``, ``+``, ``|``, ``{``, ``^``, ``$``). Returns the literal
that any match of the pattern MUST contain as a substring, so the
pre-screen never produces false negatives.
"""
meta = "[(\\.?*+|{^$"
for i, ch in enumerate(pattern):
if ch in meta:
return pattern[:i]
return pattern
_PREFIX_SUBSTRINGS = tuple(
_extract_literal_prefix(p) for p in _PREFIX_PATTERNS
)
def _has_known_prefix_substring(text: str) -> bool:
"""Return True if ``text`` contains any known credential prefix substring.
Used as a cheap pre-check before invoking the expensive ``_PREFIX_RE``.
"""
return any(p in text for p in _PREFIX_SUBSTRINGS)
class RedactingFormatter(logging.Formatter):
"""Log formatter that redacts secrets from all log messages."""