1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
pub(crate) mod confirmed_anchor;
#[cfg(feature = "decode")]
pub(crate) mod decode;
use super::CompiledScanner;
#[cfg(feature = "decode")]
use crate::types::MAX_SCAN_CHUNK_BYTES;
use keyhog_core::{Chunk, RawMatch};
/// Deduplicate a literal into a shared `literals` Vec, returning its index.
/// Avoids the `entry(lit.clone()).or_insert_with(|| push(lit.clone()))`
/// double-clone by checking `get` first: zero clones when the literal is
/// already known, two clones only on first insertion (one for the Vec, one
/// for the HashMap key).
pub(crate) fn register_literal(
literals: &mut Vec<String>,
ids: &mut std::collections::HashMap<String, usize>,
lit: &str,
) -> usize {
if let Some(&id) = ids.get(lit) {
return id;
}
let id = literals.len();
let owned = lit.to_string();
literals.push(owned.clone());
ids.insert(owned, id);
id
}
// Re-export the post-processing satellites through their established engine paths.
// Scanner tuning owns enablement; the suffix-gate satellite only builds the gate.
pub use super::scan_postprocess_profile::{
confirmed_postprocess_profile_from_typed, format_confirmed_postprocess_profile,
ConfirmedPostprocessProfile,
};
#[cfg(feature = "decode")]
pub(crate) use super::scan_postprocess_profile::{
decode_recursion_from_typed, format_decode_recursion,
};
#[cfg(feature = "ml")]
pub(crate) use super::scan_postprocess_profile::{
format_ml_batch_profile, ml_batch_profile_from_parts,
};
pub(crate) use super::scan_postprocess_suffix_gate::build_confirmed_suffix_gate_with_hints;
impl CompiledScanner {
pub(crate) fn post_process_matches(
&self,
chunk: &Chunk,
matches: &mut Vec<RawMatch>,
deadline: Option<std::time::Instant>,
route: crate::ScanExecutionRoute,
) -> crate::error::Result<()> {
self.post_process_matches_with_decoder_absence(chunk, matches, deadline, route, false)
}
pub(crate) fn post_process_matches_with_decoder_absence(
&self,
chunk: &Chunk,
matches: &mut Vec<RawMatch>,
deadline: Option<std::time::Instant>,
route: crate::ScanExecutionRoute,
_decoder_absence: bool,
) -> crate::error::Result<()> {
if crate::deadline::expired(deadline) {
return Ok(());
}
// No stopwatch here. This region is inclusive of the `Stage::Decode`
// span opened below and of the phase-2 leaves the resolution tail
// re-enters, so its wall was never an addend of anything. It also used
// to be gated on a tracing LEVEL rather than on the measurement switch,
// which made `tracing` a second place that decided whether to measure.
self.scan_cross_chunk_fragments(chunk, matches, deadline, route)?;
if crate::deadline::expired(deadline) {
return Ok(());
}
#[cfg(feature = "decode")]
{
let decode_parent = |chunk: &Chunk,
matches: &mut Vec<RawMatch>|
-> crate::error::Result<()> {
// Generation time is owned by the profile runtime's Decode stage
// span; rescan time by its Decoded attribution on every leaf span
// inside the rescans below. The counts/bytes are typed counters in
// the same runtime (no-ops when no runtime is active).
let decoded_chunks = {
let _g = super::profile::span(keyhog_profile::Stage::Decode);
crate::decode::decode_chunk_with_policy(
chunk,
self.detector_plans.decode_transforms(),
self.detector_plans.decoder_plan(),
self.config.max_decode_depth,
self.config.validate_decode,
deadline,
self.route_classification.alphabet_screen.as_ref(),
)
};
if crate::deadline::expired(deadline) {
return Ok(());
}
// Empty decode-through on this line vocabulary: later windows
// with the same unique-line fingerprint can skip the pipeline.
// Only record proofs for parent filesystem/windowed slices so
// unrelated sources cannot fill/clear the shared memo.
if decoded_chunks.is_empty()
&& chunk.metadata.decoded_span.is_none()
&& chunk.metadata.source_type.as_ref() == "filesystem/windowed"
{
super::scan::mark_decode_vocab_empty(
&self.vocab_stage_absence_cache,
self.detector_digest,
self.entropy_evidence_config_digest(),
super::scan::vocab_path_class(
chunk.metadata.source_type.as_ref(),
chunk.metadata.path.as_deref(),
),
&chunk.data,
);
}
if !decoded_chunks.is_empty() {
keyhog_profile::add_counter(keyhog_profile::CounterId::DecodeParentChunks, 1);
keyhog_profile::add_counter(
keyhog_profile::CounterId::DecodeDerivedChunks,
decoded_chunks.len() as u64,
);
}
// Avoid allocating dedup state when decoding produced no sub-chunks.
if !decoded_chunks.is_empty() {
// Buffer, then sort by source offset so synthesized aliases cannot
// win `(detector, credential)` dedup over a real source coordinate.
let mut decoded_candidates: Vec<RawMatch> = Vec::new();
for decoded_chunk in decoded_chunks {
if crate::deadline::expired(deadline) {
break;
}
if decoded_chunk.data.len() > self.config.max_decode_bytes {
crate::telemetry::record_decode_truncation();
// LAW10: decode truncation is counted in scanner coverage
// telemetry before this debug detail is emitted.
tracing::debug!(
path = ?chunk.metadata.path,
decoded_len = decoded_chunk.data.len(),
ceiling = self.config.max_decode_bytes,
"decoded chunk exceeds max_decode_bytes; skipping"
);
continue;
}
keyhog_profile::add_counter(
keyhog_profile::CounterId::DecodeDerivedBytes,
decoded_chunk.data.len() as u64,
);
// Track recursive decode work separately and preserve the
// calibrated route's explicit small-buffer backend.
let restore_rescan = super::profile::set_in_decode(true);
let decoded_backend = route.decode_backend;
let decoded_result = if decoded_chunk.data.len() > MAX_SCAN_CHUNK_BYTES {
self.scan_windowed(&decoded_chunk, decoded_backend, deadline, route)
} else {
self.scan_inner(&decoded_chunk, decoded_backend, deadline, route)
};
super::profile::set_in_decode(restore_rescan);
let decoded_matches = decoded_result?;
if crate::deadline::expired(deadline) {
break;
}
for m in decoded_matches {
// Generic decoded matches retain structural assignment evidence.
let path = chunk.metadata.path.as_deref();
let is_entropy = self.detector_plans.is_entropy(m.detector_id.as_ref());
let suppressed = crate::adjudicate::record_decoded_unanchored_entropy_suppression(
&m, path, is_entropy,
) || crate::adjudicate::record_decoded_parent_example_suppression(
&m, path, chunk.data.as_ref(),
) || crate::adjudicate::record_decoded_reverse_placeholder_suppression(
&m,
decoded_chunk.metadata.path.as_deref().or(path),
&decoded_chunk.metadata.source_type,
);
if suppressed {
continue;
}
decoded_candidates.push(m);
}
}
if decoded_candidates.is_empty() {
return Ok(());
}
keyhog_profile::add_counter(
keyhog_profile::CounterId::PostprocessDedupCalls,
1,
);
let _dedup_span =
keyhog_profile::counter_span(keyhog_profile::CounterId::PostprocessDedupNs);
// Decoding is monotonic: keep raw findings and union resolved decoded evidence.
let raw_findings = matches.clone();
decoded_candidates.sort_by(|a, b| {
a.location
.offset
.cmp(&b.location.offset)
.then_with(|| a.cmp(b))
});
decode::union_unique_matches(matches, decoded_candidates);
let resolved = crate::resolution::try_resolve_matches_with_compiled_plan(
std::mem::take(matches),
&self.detector_plans,
)
.map_err(|error| {
crate::ScanError::Config(format!(
"compiled detector resolution failed: {error}"
))
})?;
let mut merged = raw_findings;
decode::union_unique_matches(&mut merged, resolved);
*matches = merged;
}
Ok(())
};
if chunk.data.len() <= self.config.max_decode_bytes
&& self.chunk_needs_decode_postprocess_with_absence(chunk, _decoder_absence)
{
decode_parent(chunk, matches)?;
} else if self.chunk_uses_bounded_decode_windows(chunk) {
let overlap = self.decode_window_overlap_bytes();
decode::decode_source_windows(self.config.max_decode_bytes, chunk, overlap, |w| {
self.chunk_needs_decode_postprocess(w)
.then(|| decode_parent(w, matches))
.unwrap_or(Ok(()))
})?;
}
}
tracing::debug!(
target: "keyhog::routing",
chunk_bytes = chunk.data.len(),
matches = matches.len(),
"post_process_matches done",
);
Ok(())
}
pub(crate) fn expand_triggered_patterns(&self, triggered_patterns: &[u64]) -> Vec<u64> {
// Propagate ONLY via `same_prefix_patterns`: when AC matches a
// literal prefix shared by patterns X and Y, both X and Y need
// to be evaluated since they're different regexes that happen
// to share the same fixed prefix.
//
// The previous flow ALSO propagated via `detector_to_patterns`,
// expanding to every other pattern of the same detector. That
// was wasted work: each pattern is in `ac_map` *because* it has
// a literal AC prefix, and if Y's prefix was not matched in
// this chunk, Y's regex (which starts with that prefix) can't
// match either. The expansion forced full-text regex passes on
// patterns that were guaranteed to return no matches - the
// dominant cost of the per-detector regex pass on chunks that
// trigger multiple AC patterns of multi-pattern detectors.
// No-trigger fast path: if no AC pattern fired, every word is
// zero, so same-prefix expansion has nothing to propagate. Bail
// BEFORE the `to_vec()` clone and the O(words) bit-scan loop -
// the caller's `expanded.iter().any(|&w| w != 0)` would be false
// anyway, so an empty vec is an equivalent (and cheaper) "no
// patterns" signal. On the dominant no-hit chunk this drops the
// expansion clone + scan to a single all-zero pass.
if !triggered_patterns.iter().any(|&w| w != 0) {
return Vec::new();
}
let mut expanded = triggered_patterns.to_vec();
super::trigger_bitmap::for_each_set_bit(triggered_patterns, |pat_idx| {
if pat_idx >= self.ac_map.len() {
crate::telemetry::record_invalid_pattern_index_skip();
return;
}
let Some(siblings) = self.same_prefix_patterns.get(pat_idx) else {
crate::telemetry::record_invalid_pattern_index_skip();
return;
};
for &other_idx in siblings {
let other_idx = other_idx as usize;
let bucket = other_idx / 64;
if let Some(slot) = expanded.get_mut(bucket) {
*slot |= 1u64 << (other_idx % 64);
} else {
crate::telemetry::record_invalid_pattern_index_skip();
}
}
});
expanded
}
}