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perf(fast-browser): eliminate redundant browser protocol calls

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jb
2026-09-21 13:05:17 -04:00
parent 05793fe7b0
commit a79418efcb
2 changed files with 129 additions and 33 deletions
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extensions/fast-browser/browser_worker.py
+41 -33
View File
@@ -53,6 +53,9 @@ NAVIGATION_TIMEOUT_SECONDS = 10.0
# timeout returns a structured result instead of racing the parent deadline.
POPUP_WAIT_SECONDS = 4.75
EXPECTED_BROWSER_HARNESS_VERSION = "0.1.13"
_INTERNAL_TARGET_PREFIXES = (
"chrome://", "chrome-untrusted://", "devtools://", "chrome-extension://", "about:",
)
_TEXT_INPUT_TYPES = {"", "text", "search", "email", "url", "tel", "number", "password"}
_FILL_ROLES = {"textbox", "searchbox", "spinbutton"}
@@ -493,12 +496,12 @@ class BrowserWorker:
self.backend.fill(candidate.backend_id, text)
deadline = time.monotonic() + ACTION_TIMEOUT_SECONDS
while time.monotonic() < deadline:
self._post_action_state(snapshot, same_document=True)
tab = self._post_action_state(snapshot, same_document=True)
value_verified = self.backend.value_matches(candidate.backend_id, text)
condition_verified = True
if postcondition is not None:
if postcondition["kind"] == "url":
condition_verified = self.backend.current_tab().get("url") == postcondition["value"]
condition_verified = tab.get("url") == postcondition["value"]
else:
condition_verified = self.backend.visible_text(postcondition["value"])
if value_verified and condition_verified:
@@ -560,6 +563,7 @@ class RealBrowserBackend:
self._daemon_ready = False
self._process: subprocess.Popen | None = None
self._attached_target: str | None = None
self._select_all_modifier: int | None = None
self._configure_environment(cdp_url, self._sandbox)
try:
self._load_harness()
@@ -703,45 +707,46 @@ class RealBrowserBackend:
def switch_tab(self, target_id: str) -> None:
if not isinstance(target_id, str) or not target_id:
raise WorkerError("tab identity is unavailable")
# browser-harness 0.1.13 enables Page/DOM/Runtime/Network as part of
# its switch_tab set_session path. Re-enabling them here duplicates
# four CDP calls and can race the daemon's session setup.
self._session_id = self._helpers.switch_tab(target_id, activate=False)
self._attached_target = target_id
# The pinned helper does not enable these domains on every attach. Do
# so here once per target; drain_events is then a truthful source for
# the bounded diagnostics surface.
for method in ("Page.enable", "DOM.enable", "Runtime.enable", "Network.enable"):
try:
self._helpers.cdp(method)
except Exception:
# Diagnostics are best effort and never block a browser action.
pass
def list_tabs(self) -> list[dict[str, Any]]:
tabs = self._helpers.list_tabs(include_chrome=False)
opener_by_target: dict[str, str] = {}
try:
raw = self._helpers.cdp("Target.getTargets")
for info in raw.get("targetInfos", []) if isinstance(raw, dict) else []:
if not isinstance(info, dict) or info.get("type") != "page":
continue
target = info.get("targetId")
opener = info.get("openerId")
if isinstance(target, str) and isinstance(opener, str) and opener:
opener_by_target[target] = opener
except Exception:
pass
# helpers.list_tabs() and this opener lookup used to issue two identical
# Target.getTargets requests. Keep its page/internal filtering locally
# while deriving opener metadata from the same target inventory.
raw = self._helpers.cdp("Target.getTargets")
target_infos = raw.get("targetInfos", []) if isinstance(raw, dict) else []
if not isinstance(target_infos, list):
return []
result: list[dict[str, Any]] = []
for tab in tabs:
if not isinstance(tab, dict) or not isinstance(tab.get("url"), str):
for info in target_infos:
if not isinstance(info, dict) or info.get("type") != "page":
continue
target = tab.get("targetId") or tab.get("target_id")
url = info.get("url", "")
title = info.get("title", "")
if not isinstance(url, str) or not isinstance(title, str):
continue
# Match browser-harness helpers.list_tabs(include_chrome=False),
# including its startup-placeholder suppression.
if title.startswith("Starting agent ") and (
url in ("", "about:blank") or url.startswith("about:blank#")
):
continue
if url.startswith(_INTERNAL_TARGET_PREFIXES):
continue
target = info.get("targetId")
if not isinstance(target, str) or not target:
continue
opener = info.get("openerId")
result.append({
"targetId": target,
"target_id": target,
"url": tab.get("url", ""),
"title": tab.get("title", ""),
"openerTargetId": opener_by_target.get(target),
"url": url,
"title": title,
"openerTargetId": opener if isinstance(opener, str) and opener else None,
})
return result
@@ -948,9 +953,12 @@ class RealBrowserBackend:
raise WorkerError("candidate could not be focused")
# Select all without an arbitrary page script. Input.insertText is a
# single bounded browser operation and is substantially faster than
# dispatching up to 8,000 individual key events.
user_agent = self._helpers.cdp("Browser.getVersion").get("userAgent", "")
modifiers = 4 if "Mac OS X" in user_agent or "Macintosh" in user_agent else 2
# dispatching up to 8,000 individual key events. Browser.getVersion is
# stable for this backend, so cache the platform modifier for its life.
if getattr(self, "_select_all_modifier", None) is None:
user_agent = self._helpers.cdp("Browser.getVersion").get("userAgent", "")
self._select_all_modifier = 4 if "Mac OS X" in user_agent or "Macintosh" in user_agent else 2
modifiers = self._select_all_modifier
select_all = {"key": "a", "code": "KeyA", "modifiers": modifiers,
"windowsVirtualKeyCode": 65, "nativeVirtualKeyCode": 65,
"commands": ["SelectAll"]}
extensions/fast-browser/test_browser_worker.py
+88
View File
@@ -721,6 +721,26 @@ class BridgeRegressionTests(unittest.TestCase):
with self.assertRaisesRegex(WorkerError, "outside"):
worker.act({"observationId": obs["observationId"], "candidateId": "c-0", "action": "fill", "text": "Ada"})
def test_fill_url_postcondition_reuses_post_action_tab_state(self):
backend = FakeBackend()
original_fill = backend.fill
def fill_and_navigate(node, text):
original_fill(node, text)
backend.url = "http://fixture.test/done"
backend.fill = fill_and_navigate
current_tab = backend.current_tab
backend.current_tab = Mock(side_effect=current_tab)
worker = BrowserWorker(backend, ["http://fixture.test"])
observation = worker.observe()
result = worker.act({
"observationId": observation["observationId"], "candidateId": "c-0",
"action": "fill", "text": "Ada",
"postcondition": {"kind": "url", "value": "http://fixture.test/done"},
})
self.assertTrue(result["verified"])
# observe, fresh pre-mutation revalidation, and one post-action read.
self.assertEqual(backend.current_tab.call_count, 3)
def test_oversized_input_and_sensitive_error_are_not_echoed(self):
worker = BrowserWorker(FakeBackend(), ["http://fixture.test"])
out = io.BytesIO()
@@ -738,6 +758,74 @@ class BridgeRegressionTests(unittest.TestCase):
backend._load_harness()
spawn.assert_not_called()
def test_real_backend_list_tabs_uses_one_inventory_with_helper_filtering_and_openers(self):
helper = Mock()
helper.cdp.return_value = {"targetInfos": [
{"type": "page", "targetId": "page", "url": "http://fixture.test/form", "title": "Fixture",
"openerId": "opener"},
{"type": "page", "targetId": "internal", "url": "chrome://settings", "title": "Settings"},
{"type": "page", "targetId": "devtools", "url": "devtools://devtools", "title": "DevTools"},
{"type": "page", "targetId": "placeholder", "url": "about:blank#startup", "title": "Starting agent 1"},
{"type": "service_worker", "targetId": "worker", "url": "http://fixture.test/sw", "title": "Worker"},
{"type": "page", "targetId": "plain", "url": "https://other.test/", "title": "Other", "openerId": ""},
{"type": "page", "targetId": "malformed-opener", "url": "http://fixture.test/other", "title": "Other",
"openerId": 42},
]}
backend = RealBrowserBackend.__new__(RealBrowserBackend)
backend._helpers = helper
tabs = backend.list_tabs()
self.assertEqual([tab["targetId"] for tab in tabs], ["page", "plain", "malformed-opener"])
self.assertEqual(tabs[0]["openerTargetId"], "opener")
self.assertIsNone(tabs[1]["openerTargetId"])
self.assertIsNone(tabs[2]["openerTargetId"])
helper.cdp.assert_called_once_with("Target.getTargets")
helper.list_tabs.assert_not_called()
def test_real_backend_list_tabs_propagates_inventory_errors_without_fallback(self):
helper = Mock()
helper.cdp.side_effect = RuntimeError("inventory unavailable")
backend = RealBrowserBackend.__new__(RealBrowserBackend)
backend._helpers = helper
with self.assertRaisesRegex(RuntimeError, "inventory unavailable"):
backend.list_tabs()
helper.cdp.assert_called_once_with("Target.getTargets")
helper.list_tabs.assert_not_called()
def test_real_backend_switch_tab_does_not_reenable_harness_domains(self):
helper = Mock()
helper.switch_tab.return_value = "session-1"
backend = RealBrowserBackend.__new__(RealBrowserBackend)
backend._helpers = helper
backend.switch_tab("target-1")
self.assertEqual(backend._session_id, "session-1")
self.assertEqual(backend._attached_target, "target-1")
helper.switch_tab.assert_called_once_with("target-1", activate=False)
helper.cdp.assert_not_called()
def test_real_backend_caches_select_all_modifier_for_backend_lifetime(self):
helper = Mock()
calls = []
def cdp(method, **_kwargs):
calls.append(method)
return {"userAgent": "Macintosh"} if method == "Browser.getVersion" else {}
helper.cdp.side_effect = cdp
backend = RealBrowserBackend.__new__(RealBrowserBackend)
backend._helpers = helper
backend._call = Mock(return_value=True)
backend.fill(1, "first")
backend.fill(1, "second")
self.assertEqual(calls.count("Browser.getVersion"), 1)
keydowns = [call for call in helper.cdp.call_args_list
if call.args[0] == "Input.dispatchKeyEvent" and call.kwargs["type"] == "rawKeyDown"]
self.assertEqual([call.kwargs["modifiers"] for call in keydowns], [4, 4])
def test_real_backend_unrestricted_policy_still_requires_one_web_tab(self):
helper = Mock()
helper.list_tabs.return_value = [