Files
DECNET/decnet/profiler/behave_shell/_parse.py
anti 65ddaaa681 fix(behave_shell/F.0): tighten prompt detector — log lines ending in '>' no longer vote
_detect_prompt_suffix accepted ANY line ending in $#%> as a PS1 prompt,
so a single `cat /var/log/dpkg.log` (195 lines closing in `<none>`)
flooded environmental.shell_type votes and flipped a plainly-bash
session to fish.

A prompt line now requires either a trailing space after the suffix
(default PS1 shape across bash/zsh/fish/PowerShell) or a PS1-shape
token (user@host, "PS " prefix, or a Windows drive-letter prefix).

Regression tests pin the dpkg.log false-positive and a $-terminated
prose line.
2026-05-09 02:57:40 -04:00

273 lines
9.7 KiB
Python

"""Asciinema event types + shard-line parsing helpers.
Shard lines are JSON objects ``{"sid": ..., "t": float, "ch": "i"|"o",
"d": str}`` produced by the DECNET PTY-recording wrapper and held in
sensor-side blob storage. The first line of each file is a header
(``{"sid": ..., "hdr": {...}}``) which carries no event payload — the
parser skips it.
The on-wire engine input is the simpler 3-tuple ``(t, kind, data)``
:data:`AsciinemaEvent`. Workers (``BEHAVE-INTEGRATION.md`` Phase 4)
either feed the 3-tuple directly or use :func:`parse_shard_line` to
turn a raw JSON string into one.
"""
from __future__ import annotations
import hashlib
import json
import re
from dataclasses import dataclass
from typing import Iterable, Iterator, Literal, Tuple
EventKind = Literal["i", "o"]
AsciinemaEvent = Tuple[float, EventKind, str]
# CSI / OSC / SGR / single-char escape sweeper. One pass, then we drop the
# stripped text on the floor — only the boolean error verdict (and the byte
# count, computed before stripping) leaves the helper. Full prompt-string
# parsing lives in Phase F.0; this is the slice cognitive.error_resilience.*
# needs to ship correctly.
_ANSI_RE = re.compile(
r"""
\x1B # ESC
(?:
\[ [0-?]* [ -/]* [@-~] # CSI
| \] [^\x07\x1B]* (?:\x07|\x1B\\)? # OSC, ST-or-BEL terminated
| [@-Z\\-_] # 2-byte escapes (ESC followed by 0x40-0x5F)
)
""",
re.VERBOSE,
)
def strip_ansi(data: str) -> str:
"""Remove ANSI escape sequences. Used pre-error-pattern match."""
return _ANSI_RE.sub("", data)
# Canonical bash/sh error fingerprints. v0.1 heuristic — Phase F.0's prompt
# parser will subsume this with PS1 + exit-code sniff. Any change here must
# leave the calibration grid green.
_OUTPUT_ERROR_PATTERNS: tuple[re.Pattern[str], ...] = (
re.compile(r"command not found"),
re.compile(r"No such file or directory"),
re.compile(r"Permission denied"),
re.compile(r": cannot "),
re.compile(r"Operation not permitted"),
re.compile(r"syntax error near unexpected token"),
)
def detect_error_in_output(stripped: str) -> bool:
"""True if any canonical error fingerprint matches the stripped output."""
return any(p.search(stripped) for p in _OUTPUT_ERROR_PATTERNS)
@dataclass(frozen=True, slots=True)
class PasteBurst:
"""Contiguous run of paste-class input events."""
start_ts: float
end_ts: float
char_count: int
event_count: int
@dataclass(frozen=True, slots=True)
class PromptLine:
"""One PS1 prompt line detected in the output stream.
PII trade-off (ANTI-authorised at Phase F): ``raw_line`` retains
the ANSI-stripped text of the prompt — hostnames / usernames /
cwd / etc. — because F.1 / F.3 / E.4 read off it. Capped at
``PROMPT_LINE_MAX_CHARS``. PromptLine instances live on
``SessionContext.prompt_lines``; only derived primitive values
(``bash`` / ``en-US`` / ``present``) leave the engine.
"""
ts: float
suffix_char: str # one of $ # % >
raw_line: str # ANSI stripped, capped at PROMPT_LINE_MAX_CHARS
is_root: bool # suffix_char == '#'
@dataclass(frozen=True, slots=True)
class Command:
"""One command-line invocation, segmented from the input stream.
PII discipline (per ``BEHAVE-INTEGRATION.md`` and the BEHAVE
envelope's pinned policy): only the *first token* of the command
is retained, and only as a sha256 hash. The full command body
never enters the engine's data structures, never goes to the bus,
never ends up in the database. ``first_token_hash`` lets
cognitive.command_branch_diversity (Step 6) count distinct
invocations without learning anything about argument values.
``end_ts`` is the timestamp of the ``\\r`` / ``\\n`` that
terminated the command; ``start_ts`` is the first character typed
or pasted into it.
``tab_count`` / ``shortcut_count`` / ``pipe_count`` are integer
counters populated by the context builder during the per-command
byte sweep. They feed the ``motor.shell_mastery.*`` primitives
(Phase C). The raw bytes themselves are read once during the
sweep and discarded — only the counters are retained.
``errored`` (Step D.0) is set when the output stream between this
command and the next contains a canonical bash/sh error fingerprint
(see :func:`detect_error_in_output`). ``output_bytes`` is the byte
count of that same window. Both are populated in the segmentation
walk; the underlying output text is stripped of ANSI then matched,
and the stripped text is discarded — only the bool and the int
leave the segmentation pass. Drives the ``cognitive.error_resilience.*``
family (Phase D) and the ``error_rate`` term of
``cognitive.cognitive_load``.
"""
start_ts: float
end_ts: float
first_token_hash: str
tab_count: int = 0
shortcut_count: int = 0
pipe_count: int = 0
errored: bool = False
output_bytes: int = 0
followed_by_prompt: bool = False
def hash_token(token: str) -> str:
"""sha256-hex of a token; the only PII-safe handle on a command."""
return hashlib.sha256(token.encode("utf-8")).hexdigest()
# Prompt-line detection (Step F.0). A prompt line ends with one of
# $/#/%/> followed by a space or end-of-line. The trailing space /
# newline is what tells us this is a *prompt* not just a sentence
# ending in those characters. We require either the space variant or
# the EOL variant to be present right after the suffix.
_PROMPT_LINE_RE = re.compile(
r"""
(?:^|\n) # line start
(?P<line> # capture the prompt line itself
[^\n]*? # any line content (non-greedy)
(?P<suffix>[$\#%>]) # prompt suffix
\ ? # optional trailing space (PS1 default has it)
)
(?=\n|\Z) # at end of line / end of buffer
""",
re.VERBOSE,
)
_PS1_SHAPE_RE = re.compile(
# A line that LOOKS like a PS1 prompt carries at least one of:
# - user@host (bash/zsh/fish defaults)
# - "PS " prefix (PowerShell)
# - drive-letter prefix "C:\" / "C:/" (cmd.exe / PowerShell)
# These tokens are extremely rare in the body of generic command
# output, so they discriminate prompts from log lines that
# incidentally end with one of $#%>.
r"(?:[\w.-]+@[\w.-]+|^\s*PS\s|[A-Za-z]:[\\/])"
)
def _detect_prompt_suffix(line: str) -> str | None:
"""Return the suffix character if ``line`` looks like a PS1 prompt.
``line`` is one logical output line, ANSI-stripped, trailing
whitespace included. The discriminating shape: a line ending in
one of ``$ # % >``, AND either
* the original line ends with the suffix followed by a trailing
space (the default PS1 shape across bash / zsh / fish /
PowerShell — ``$ ``, ``# ``, ``% ``, ``> ``), OR
* the line carries a recognisable PS1-shape token (``user@host``,
``PS `` prefix, or a Windows drive-letter prefix).
Without this guard, command output that incidentally ends in one
of the suffix characters — e.g. ``dpkg.log`` lines that close with
``<none>`` — was being voted into the shell-type mode and could
flip the result to ``fish`` for an obvious-bash session.
"""
stripped = line.rstrip()
if not stripped:
return None
last = stripped[-1]
if last not in ("$", "#", "%", ">"):
return None
# Prefer the cheap structural check: was there a trailing space
# after the suffix in the original line? (Default PS1s all carry
# one.) Falls back to a PS1-shape token search.
if len(line) > len(stripped) and line[len(stripped)] == " ":
return last
if _PS1_SHAPE_RE.search(stripped):
return last
return None
def extract_prompt_lines(
text: str,
*,
base_ts: float,
max_chars: int,
) -> Iterator[PromptLine]:
"""Yield prompt lines detected in ``text`` (already ANSI-stripped).
All emitted prompts share ``base_ts`` — the caller is responsible
for slicing output by event window before calling. A given output
chunk yields **at most one prompt line** (the trailing one), but
multi-line chunks containing multiple distinct prompts (mid-stream
redraws) yield each. ``raw_line`` is capped at ``max_chars`` and
leading/trailing whitespace stripped (preserving internal layout).
"""
if not text:
return
for raw in text.split("\n"):
suffix = _detect_prompt_suffix(raw)
if suffix is None:
continue
line = raw.strip()
if len(line) > max_chars:
line = line[-max_chars:]
yield PromptLine(
ts=base_ts,
suffix_char=suffix,
raw_line=line,
is_root=(suffix == "#"),
)
def parse_shard_line(line: str) -> AsciinemaEvent | None:
"""Turn one shard JSONL line into an :data:`AsciinemaEvent`.
Returns ``None`` for the header line and for any line that is not
a well-formed event record. Workers must filter ``None``s out
before passing to :func:`extract_session`.
"""
line = line.strip()
if not line:
return None
try:
rec = json.loads(line)
except (json.JSONDecodeError, ValueError):
return None
if not isinstance(rec, dict):
return None
if "hdr" in rec or "t" not in rec or "ch" not in rec:
return None
t = rec.get("t")
ch = rec.get("ch")
d = rec.get("d", "")
if not isinstance(t, (int, float)) or ch not in ("i", "o") or not isinstance(d, str):
return None
return (float(t), ch, d)
def parse_shard(lines: Iterable[str]) -> Iterator[AsciinemaEvent]:
"""Stream-parse a shard file's lines into events, skipping junk."""
for line in lines:
ev = parse_shard_line(line)
if ev is not None:
yield ev