blevesearch / bleve / 30118928861

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github

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Commit Message

MB-72489: fuzzy/regexp candidate-collection optimizations (#2382)

Split out from #2381 per review — the fuzzy/regexp candidate-collection
optimizations, as their own PR. No functional/API changes.

### Changes

- **Trim fuzzy candidate-collection overhead**
(`search/searcher/search_fuzzy.go`): skip the per-candidate dedup map
when the field has no synonyms (the dictionary iterator already yields
each term once; the map only exists to de-dup synonym terms), replace
the O(n²) `prefixTerm` rune-concat with a zero-alloc slice, and hoist
repeated `ctx.Value` lookups.
- **Omit postings-count read for fuzzy/regexp candidate collection**
(`index/scorch/snapshot_index*.go`): fuzzy/regexp collectors use only
the term + edit distance and discard `DictEntry.Count`, yet the segment
iterator read each candidate's postings list to compute it. A new opt-in
`AutomatonIteratorOmitCount` path skips that read, wired via a graceful
type-assertion fallback. `FieldDict`/`FieldDictPrefix`/`FieldDictRange`
still populate counts.

**Depends on** blevesearch/zapx#436 — the omit-count optimization
activates once the `zapx/v17` dependency is bumped to a release that
includes `AutomatonIteratorOmitCount`. Until then the wiring falls back
to the count-reading path (the wiring test skips), so this is safe to
merge independently.

### Benchmark

`BenchmarkFuzzyCandidateCollection` (scorch index, 1000 terms / 3000
docs, fuzziness-2 query matching 280 candidates), original → both
commits, Apple M4 Pro, count=12 via benchstat:

| | sec/op | B/op | allocs/op |
|---|---|---|---|
| micro-opts | −5.9% | −3.8% | −1.3% (988→975) |
| omit-count wiring | −9.7% | −1.1% | −29.1% (975→691) |
| **combined** | **−15.0%** | **−4.8%** | **−30.1%** (988→691) |

All p=0.000, n=12. Verified with the full fuzzy + synonym search suites
and `-race`.

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: Thejas-bhat <thejas.orkombu@couchbase.com>

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19877 of 37989 relevant lines covered (52.32%)

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