Modernize APIs and speed up slice codecs by kelindar · Pull Request #24 · kelindar/binary

kelindar · 2026-07-20T19:13:48Z

Summary

Apply gopls modernize suggestions across the module (any, range-over-int, reflect.TypeFor, drop obsolete +build line)
Fix reflect.SliceHeader vet warnings without regressing nocopy zero-copy decode
Speed up slice decode (capacity reuse), varint batch encodes, and sorted integer codecs

Benchmarks

name                 time/op      ops/s        allocs/op    vs prev           
-------------------- ------------ ------------ ------------ ------------------
binary/enc           124.1 ns     8.1M         🟰 2          ✅ +15%                               
binary/enc-to        91.0 ns      11.0M        🟰 0          ✅ +14%                               
binary/dec           94.5 ns      10.6M        ✅ 1          ✅ +78%                               
binary/map-enc       8.1 µs       123.3K       ✅ 209        ✅ +14%                               
binary/map-dec       12.4 µs      80.4K        ✅ 500        ✅ +12%                               
binary/slice-enc     8.5 µs       118.1K       🟰 9          ✅ +7%                                
binary/slice-dec     6.9 µs       145.2K       ✅ 100        ✅ +2.1x                              
binary/nest-enc      4.4 µs       227.2K       ✅ 13         ✅ +9%                                
binary/nest-dec      3.8 µs       260.2K       ✅ 63         ✅ +2.1x                              
binary/bytes-enc     823.4 ns     1.2M         🟰 3          🟰 similar                            
binary/bytes-dec     166.3 ns     6.0M         ✅ 0          ✅ +5.0x                              
binary/u64-enc       37.7 µs      26.5K        ✅ 3          ✅ +87%                               
binary/u64-dec       55.5 µs      18.0K        ✅ 0          🟰 similar                            
binary/reuse-enc     90.6 ns      11.0M        🟰 0          ✅ +22%                               
binary/stream-dec    143.1 ns     7.0M         ✅ 1          ✅ +72%                               
nocopy/str-enc       103.1 ns     9.7M         🟰 3          ✅ +7%                                
nocopy/str-dec       32.1 ns      31.2M        🟰 0          ✅ +17%                               
nocopy/dict-enc      178.6 ns     5.6M         🟰 2          🟰 similar                            
nocopy/dict-dec      147.2 ns     6.8M         🟰 2          🟰 similar                            
nocopy/bmap-enc      312.5 ns     3.2M         🟰 5          🟰 similar                            
nocopy/bmap-dec      153.6 ns     6.5M         🟰 2          🟰 similar                            
nocopy/hmap-enc      307.1 ns     3.3M         🟰 5          🟰 similar                            
nocopy/hmap-dec      138.5 ns     7.2M         🟰 2          🟰 similar                            
nocopy/bytes-enc     848.7 ns     1.2M         🟰 3          🟰 similar                            
nocopy/bytes-dec     34.0 ns      29.4M        🟰 0          ✅ +22%                               
nocopy/u64-enc       5.2 µs       192.6K       🟰 3          🟰 similar                            
nocopy/u64-dec       30.8 ns      32.5M        🟰 0          ✅ +23%                               
nocopy/col-enc       482.9 ns     2.1M         ✅ 8          ✅ +8%                                
nocopy/col-dec       344.4 ns     2.9M         ✅ 6          ✅ +41%                               
nocopy/struct-enc    155.8 ns     6.4M         🟰 3          🟰 similar                            
nocopy/struct-dec    69.5 ns      14.4M        🟰 0          ✅ +12%                               
sorted/i32-enc       79.4 µs      12.6K        🟰 5          🟰 similar                            
sorted/i32-dec       55.5 µs      18.0K        ✅ 0          ✅ +9.9x                              
sorted/u32-enc       75.6 µs      13.2K        🟰 5          🟰 similar                            
sorted/u32-dec       49.3 µs      20.3K        ✅ 0          ✅ +11x                               
sorted/ts-enc        49.3 µs      20.3K        🟰 6          🟰 similar                            
sorted/ts-dec        21.8 µs      45.9K        🟰 2          🟰 similar                            
sorted/tsz-enc       125.7 µs     8.0K         🟰 7          🟰 similar                            
sorted/tsz-dec       116.6 µs     8.6K         🟰 3          🟰 similar                            
sorted/tcz-enc       87.0 µs      11.5K        🟰 6          ✅ +95%                               
sorted/tcz-dec       76.2 µs      13.1K        🟰 3          ✅ +51%                               
unsafe/u64-enc       471.9 ns     2.1M         🟰 3          🟰 similar                            
unsafe/u64-dec       447.7 ns     2.2M         🟰 2          🟰 similar

Test plan

go test ./... passes
go vet ./... is clean
cd bench && go run . looks consistent with the numbers above

Replace interface{} with any, use range-over-int and reflect.TypeFor, and drop the obsolete +build line now that the module requires Go 1.25. Co-authored-by: Cursor <cursoragent@cursor.com>

github-actions · 2026-07-20T19:14:18Z

`███████████████████░` 96.0% on changed lines

172 lines changed 6 uncovered 10 files

📂 10 files changed

	File	Coverage	Uncovered Lines
🟡	`decoder.go`	84.6%	58, 59

| 🟡 | encoder.go | 85.7% | 81, 82 |

| 🟢 | codecs.go | 96.7% | 212, 250 |

| 🟢 | nocopy/types.go | 100.0% | — |

| 🟢 | sorted/codecs.go | 100.0% | — |

| 🟢 | sorted/types.go | 100.0% | — |

| 🟢 | unsafe/types.go | 100.0% | — |

| 🟢 | scanner.go | 100.0% | — |

| 🟢 | sorted/timeseries.go | 100.0% | — |

| 🟢 | convert.go | 100.0% | — |

📋 Full diff-cover report

Diff Coverage

Diff: origin/master...HEAD, staged and unstaged changes

codecs.go (96.7%): Missing lines 212,250
convert.go (100%)
decoder.go (84.6%): Missing lines 58-59
encoder.go (85.7%): Missing lines 81-82
nocopy/types.go (100%)
scanner.go (100%)
sorted/codecs.go (100%)
sorted/timeseries.go (100%)
sorted/types.go (100%)
unsafe/types.go (100%)

Summary

Total: 172 lines
Missing: 6 lines
Coverage: 96%

codecs.go

  208 		}
  209 		e.Write(buffer)
  210 		return
  211 	}
! 212 	for i := range l {
  213 		e.WriteVarint(rv.Index(i).Int())
  214 	}
  215 	return
  216 }

  246 		}
  247 		e.Write(buffer)
  248 		return
  249 	}
! 250 	for i := range l {
  251 		e.WriteUvarint(rv.Index(i).Uint())
  252 	}
  253 	return
  254 }

decoder.go

  54 	t := rv.Type()
  55 	c := d.codec
  56 	if t != d.last {
  57 		if c, err = scan(t); err != nil {
! 58 			return
! 59 		}
  60 		d.last = t
  61 		d.codec = c
  62 	}
  63 	err = c.DecodeTo(d, rv)

encoder.go

  77 	t := rv.Type()
  78 	c := e.codec
  79 	if t != e.last {
  80 		if c, err = scan(t); err != nil {
! 81 			return
! 82 		}
  83 		e.last = t
  84 		e.codec = c
  85 	}

_{🛡️ diff-cover-action}

coveralls · 2026-07-20T19:15:18Z

Coverage Report for CI Build 29774811568

Coverage decreased (-0.3%) to 91.578%

Details

Coverage decreased (-0.3%) from the base build.
Patch coverage: 6 uncovered changes across 3 files (166 of 172 lines covered, 96.51%).
6 coverage regressions across 1 file.

Uncovered Changes

File	Changed	Covered	%
codecs.go	61	59	96.72%
decoder.go	13	11	84.62%
encoder.go	14	12	85.71%
Total (10 files)	172	166	96.51%

Coverage Regressions

6 previously-covered lines in 1 file lost coverage.

File	Lines Losing Coverage	Coverage
codecs.go	6	92.36%

Coverage Stats


Relevant Lines:	1591
Covered Lines:	1457
Line Coverage:	91.58%
Coverage Strength:	626.3 hits per line

💛 - Coveralls

Replace deprecated SliceHeader/StringHeader casting with unsafe.Slice and unsafe.StringData so go vet stays clean on Go 1.25. Co-authored-by: Cursor <cursoragent@cursor.com>

rv.Set(reflect.NewAt(...)) allocated on decode and regressed nocopy/u64-dec. Mutate the slice header in place again without using deprecated reflect.SliceHeader. Co-authored-by: Cursor <cursoragent@cursor.com>

Reuse slice capacity on decode, batch varint writes into bytes.Buffer, and decode sorted integer slices without reflect.Append so hot paths allocate less and run faster. Co-authored-by: Cursor <cursoragent@cursor.com>

Remove vs-ref (JSON and safe baselines) so benches only report absolute timing and vs-prev deltas. Co-authored-by: Cursor <cursoragent@cursor.com>

Apply gopls modernize fixes

dd85654

Replace interface{} with any, use range-over-int and reflect.TypeFor, and drop the obsolete +build line now that the module requires Go 1.25. Co-authored-by: Cursor <cursoragent@cursor.com>

kelindar and others added 3 commits July 20, 2026 20:15

Fix reflect.SliceHeader vet warnings

efc12c8

Replace deprecated SliceHeader/StringHeader casting with unsafe.Slice and unsafe.StringData so go vet stays clean on Go 1.25. Co-authored-by: Cursor <cursoragent@cursor.com>

Restore zero-copy nocopy integer slice decode

6becb0f

rv.Set(reflect.NewAt(...)) allocated on decode and regressed nocopy/u64-dec. Mutate the slice header in place again without using deprecated reflect.SliceHeader. Co-authored-by: Cursor <cursoragent@cursor.com>

Speed up slice decode and sorted varint codecs

d532855

Reuse slice capacity on decode, batch varint writes into bytes.Buffer, and decode sorted integer slices without reflect.Append so hot paths allocate less and run faster. Co-authored-by: Cursor <cursoragent@cursor.com>

kelindar changed the title ~~Apply gopls modernize fixes~~ Modernize APIs and speed up slice codecs Jul 20, 2026

kelindar and others added 2 commits July 20, 2026 21:00

Drop benchmark reference comparisons

625d80c

Remove vs-ref (JSON and safe baselines) so benches only report absolute timing and vs-prev deltas. Co-authored-by: Cursor <cursoragent@cursor.com>

preallocate map

f8edf19

kelindar enabled auto-merge (squash) July 20, 2026 20:07

kelindar merged commit dfcd154 into master Jul 20, 2026
1 check passed

kelindar deleted the modernize branch July 20, 2026 20:08

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Modernize APIs and speed up slice codecs#24

Modernize APIs and speed up slice codecs#24
kelindar merged 6 commits into
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kelindar commented Jul 20, 2026 •

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Diff Coverage

Diff: origin/master...HEAD, staged and unstaged changes

Summary

codecs.go

decoder.go

encoder.go

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Diff: origin/master...HEAD, staged and unstaged changes

Summary

codecs.go

decoder.go

encoder.go

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Coverage Report for CI Build 29774811568

Coverage decreased (-0.3%) to 91.578%

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