policies.py
python
sha256:e6465e8a9b7fa8e6223ed4a3576e96c568c913ae2caeb9c31f15e7a81b250b40
docs: add | jq convention to --json section of agent-guide
Sonnet 4.6
1 day ago
| 1 | """Harmony policy persistence and matching — save, load, list, remove, match. |
| 2 | |
| 3 | Single responsibility: CRUD for Policy objects in the harmony store plus the |
| 4 | _condition_matches / match_policy evaluation helpers. |
| 5 | """ |
| 6 | |
| 7 | from __future__ import annotations |
| 8 | |
| 9 | import fnmatch |
| 10 | import json |
| 11 | import logging |
| 12 | import pathlib |
| 13 | from collections.abc import Mapping |
| 14 | |
| 15 | from muse.core.types import JsonValue, load_json_file |
| 16 | |
| 17 | from .fingerprint import _parse_dt |
| 18 | from .paths import policies_dir, _validate_policy_id |
| 19 | from .patterns import _write_atomic |
| 20 | from .types import ( |
| 21 | ConflictPattern, |
| 22 | Policy, |
| 23 | PolicyAction, |
| 24 | PolicyCondition, |
| 25 | PolicyScope, |
| 26 | _PolicyConditionDict, |
| 27 | _PolicyDict, |
| 28 | ) |
| 29 | |
| 30 | logger = logging.getLogger(__name__) |
| 31 | |
| 32 | #: Maximum bytes read from a policy JSON file. |
| 33 | _MAX_POLICY_BYTES: int = 8_192 # 8 KiB |
| 34 | |
| 35 | #: Maximum policies loaded in a single :func:`list_policies` call. |
| 36 | _MAX_POLICIES: int = 1_000 |
| 37 | |
| 38 | # --------------------------------------------------------------------------- |
| 39 | # Serialisation helpers |
| 40 | # --------------------------------------------------------------------------- |
| 41 | |
| 42 | def _policy_condition_to_dict(cond: PolicyCondition) -> _PolicyConditionDict: |
| 43 | return _PolicyConditionDict( |
| 44 | conflict_type=cond.conflict_type, |
| 45 | domain=cond.domain, |
| 46 | path_pattern=cond.path_pattern, |
| 47 | min_confidence=cond.min_confidence, |
| 48 | ) |
| 49 | |
| 50 | def _policy_to_dict(policy: Policy) -> _PolicyDict: |
| 51 | return _PolicyDict( |
| 52 | policy_id=policy.policy_id, |
| 53 | description=policy.description, |
| 54 | when=_policy_condition_to_dict(policy.when), |
| 55 | action=policy.action, |
| 56 | confidence=policy.confidence, |
| 57 | escalate_to=policy.escalate_to, |
| 58 | delegate_to=policy.delegate_to, |
| 59 | scope=policy.scope, |
| 60 | created_at=policy.created_at.isoformat(), |
| 61 | created_by=policy.created_by, |
| 62 | ) |
| 63 | |
| 64 | def _dict_to_policy(data: Mapping[str, JsonValue]) -> Policy | None: |
| 65 | """Deserialise a JSON dict to :class:`Policy`, returning ``None`` on error.""" |
| 66 | try: |
| 67 | when_data = data.get("when") or {} |
| 68 | condition = PolicyCondition( |
| 69 | conflict_type=when_data.get("conflict_type") or None, |
| 70 | domain=when_data.get("domain") or None, |
| 71 | path_pattern=when_data.get("path_pattern") or None, |
| 72 | min_confidence=when_data.get("min_confidence"), |
| 73 | ) |
| 74 | return Policy( |
| 75 | policy_id=str(data["policy_id"]), |
| 76 | description=str(data.get("description", "")), |
| 77 | when=condition, |
| 78 | action=str(data.get("action", PolicyAction.ESCALATE)), |
| 79 | confidence=float(data.get("confidence", 1.0)), |
| 80 | escalate_to=data.get("escalate_to") or None, |
| 81 | delegate_to=data.get("delegate_to") or None, |
| 82 | scope=str(data.get("scope", PolicyScope.REPO)), |
| 83 | created_at=_parse_dt(data.get("created_at")), |
| 84 | created_by=str(data.get("created_by", "unknown")), |
| 85 | ) |
| 86 | except (KeyError, TypeError, ValueError) as exc: |
| 87 | logger.warning("⚠️ harmony: failed to deserialise policy: %s", exc) |
| 88 | return None |
| 89 | |
| 90 | # --------------------------------------------------------------------------- |
| 91 | # Policy CRUD |
| 92 | # --------------------------------------------------------------------------- |
| 93 | |
| 94 | def save_policy(root: pathlib.Path, policy: Policy) -> None: |
| 95 | """Persist a :class:`Policy` to the harmony policy store. |
| 96 | |
| 97 | Stored at ``.muse/harmony/policies/<policy_id>.json``. **Overwrites** |
| 98 | any existing policy with the same ID — policies are versioned by |
| 99 | replacement, not by append. |
| 100 | |
| 101 | Args: |
| 102 | root: Repository root. |
| 103 | policy: Policy to save. |
| 104 | |
| 105 | Raises: |
| 106 | ValueError: If ``policy.policy_id`` is not URL-safe. |
| 107 | """ |
| 108 | _validate_policy_id(policy.policy_id) |
| 109 | dest = policies_dir(root) / f"{policy.policy_id}.json" |
| 110 | _write_atomic(dest, json.dumps(_policy_to_dict(policy), indent=2)) |
| 111 | logger.debug( |
| 112 | "harmony: saved policy %r (action=%s, scope=%s)", |
| 113 | policy.policy_id, |
| 114 | policy.action, |
| 115 | policy.scope, |
| 116 | ) |
| 117 | |
| 118 | def load_policy(root: pathlib.Path, policy_id: str) -> Policy | None: |
| 119 | """Load a single :class:`Policy` by ID. |
| 120 | |
| 121 | Returns ``None`` when *policy_id* is invalid, the file does not exist, |
| 122 | it exceeds :data:`_MAX_POLICY_BYTES`, or JSON parsing fails. |
| 123 | |
| 124 | Args: |
| 125 | root: Repository root. |
| 126 | policy_id: URL-safe policy identifier. |
| 127 | """ |
| 128 | try: |
| 129 | _validate_policy_id(policy_id) |
| 130 | except ValueError: |
| 131 | return None |
| 132 | |
| 133 | dest = policies_dir(root) / f"{policy_id}.json" |
| 134 | if not dest.exists(): |
| 135 | return None |
| 136 | |
| 137 | try: |
| 138 | size = dest.stat().st_size |
| 139 | except OSError as exc: |
| 140 | logger.warning("⚠️ harmony: failed to read policy %r: %s", policy_id, exc) |
| 141 | return None |
| 142 | if size > _MAX_POLICY_BYTES: |
| 143 | logger.warning( |
| 144 | "⚠️ harmony: policy %r is %d bytes — too large; skipping", |
| 145 | policy_id, |
| 146 | size, |
| 147 | ) |
| 148 | return None |
| 149 | data = load_json_file(dest) |
| 150 | if data is None: |
| 151 | logger.warning( |
| 152 | "⚠️ harmony: failed to read policy %r: unreadable or invalid JSON", policy_id |
| 153 | ) |
| 154 | return None |
| 155 | |
| 156 | return _dict_to_policy(data) |
| 157 | |
| 158 | def list_policies(root: pathlib.Path) -> list[Policy]: |
| 159 | """Return all :class:`Policy` entries from the harmony policy store. |
| 160 | |
| 161 | Sorted by scope order (workspace → repo → domain → file) then by |
| 162 | ``created_at`` ascending within each scope, so earlier policies take |
| 163 | precedence over later ones at the same scope level. |
| 164 | |
| 165 | Args: |
| 166 | root: Repository root. |
| 167 | """ |
| 168 | _SCOPE_ORDER = { |
| 169 | PolicyScope.WORKSPACE: 0, |
| 170 | PolicyScope.REPO: 1, |
| 171 | PolicyScope.DOMAIN: 2, |
| 172 | PolicyScope.FILE: 3, |
| 173 | } |
| 174 | |
| 175 | pdir = policies_dir(root) |
| 176 | if not pdir.exists(): |
| 177 | return [] |
| 178 | |
| 179 | results: list[Policy] = [] |
| 180 | count = 0 |
| 181 | |
| 182 | for f in pdir.iterdir(): |
| 183 | if count >= _MAX_POLICIES: |
| 184 | logger.warning( |
| 185 | "⚠️ harmony: >%d policies — scan truncated", _MAX_POLICIES |
| 186 | ) |
| 187 | break |
| 188 | count += 1 |
| 189 | if f.is_symlink() or not f.is_file(): |
| 190 | continue |
| 191 | if not f.name.endswith(".json"): |
| 192 | continue |
| 193 | pid = f.name[:-5] |
| 194 | p = load_policy(root, pid) |
| 195 | if p is not None: |
| 196 | results.append(p) |
| 197 | |
| 198 | results.sort(key=lambda p: (_SCOPE_ORDER.get(p.scope, 99), p.created_at)) |
| 199 | return results |
| 200 | |
| 201 | def remove_policy(root: pathlib.Path, policy_id: str) -> bool: |
| 202 | """Remove a policy from the harmony store. |
| 203 | |
| 204 | Args: |
| 205 | root: Repository root. |
| 206 | policy_id: URL-safe policy identifier. |
| 207 | |
| 208 | Returns: |
| 209 | ``True`` if the policy existed and was removed, ``False`` otherwise. |
| 210 | """ |
| 211 | try: |
| 212 | _validate_policy_id(policy_id) |
| 213 | except ValueError: |
| 214 | logger.warning( |
| 215 | "⚠️ harmony: invalid policy_id in remove_policy: %r", policy_id |
| 216 | ) |
| 217 | return False |
| 218 | |
| 219 | dest = policies_dir(root) / f"{policy_id}.json" |
| 220 | if not dest.exists(): |
| 221 | return False |
| 222 | |
| 223 | dest.unlink(missing_ok=True) |
| 224 | logger.debug("harmony: removed policy %r", policy_id) |
| 225 | return True |
| 226 | |
| 227 | # --------------------------------------------------------------------------- |
| 228 | # Policy matching |
| 229 | # --------------------------------------------------------------------------- |
| 230 | |
| 231 | def _condition_matches(condition: PolicyCondition, pattern: ConflictPattern) -> bool: |
| 232 | """Return ``True`` if *pattern* satisfies every non-``None`` field of *condition*. |
| 233 | |
| 234 | ``None`` fields are wildcards and match any value. ``path_pattern`` uses |
| 235 | :func:`fnmatch.fnmatch` glob semantics (e.g. ``"*.mid"``, ``"src/**"``). |
| 236 | |
| 237 | ``min_confidence`` is a proposal-time filter evaluated by the harmony |
| 238 | engine against the resolution confidence — not against any static field |
| 239 | of the pattern — so it is intentionally not checked here. |
| 240 | """ |
| 241 | if condition.conflict_type is not None: |
| 242 | if pattern.conflict_type != condition.conflict_type: |
| 243 | return False |
| 244 | |
| 245 | if condition.domain is not None: |
| 246 | if pattern.domain != condition.domain: |
| 247 | return False |
| 248 | |
| 249 | if condition.path_pattern is not None: |
| 250 | if not fnmatch.fnmatch(pattern.path, condition.path_pattern): |
| 251 | return False |
| 252 | |
| 253 | return True |
| 254 | |
| 255 | def match_policy( |
| 256 | policies: list[Policy], |
| 257 | pattern: ConflictPattern, |
| 258 | ) -> Policy | None: |
| 259 | """Return the first :class:`Policy` whose condition matches *pattern*. |
| 260 | |
| 261 | Evaluates policies in the order given. Callers should pass the list |
| 262 | returned by :func:`list_policies`, which is already sorted by scope |
| 263 | (workspace → repo → domain → file). |
| 264 | |
| 265 | Args: |
| 266 | policies: Ordered list of active policies to evaluate. |
| 267 | pattern: Incoming conflict pattern to match against. |
| 268 | |
| 269 | Returns: |
| 270 | The first matching :class:`Policy`, or ``None`` if no policy fires. |
| 271 | """ |
| 272 | for policy in policies: |
| 273 | if _condition_matches(policy.when, pattern): |
| 274 | return policy |
| 275 | return None |
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sha256:e6465e8a9b7fa8e6223ed4a3576e96c568c913ae2caeb9c31f15e7a81b250b40
docs: add | jq convention to --json section of agent-guide
Sonnet 4.6
1 day ago