Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

optimize parsing ulid #116

Open
wants to merge 5 commits into
base: main
Choose a base branch
from
Open

optimize parsing ulid #116

Changes from 2 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
5f985ca
optimize parsing ulid
shogo82148 Mar 1, 2024
a67312a
s/-1/0xFF/
peterbourgon Mar 13, 2024
2ac659b
s/int8/byte/
peterbourgon Mar 13, 2024
7414e91
Revert my changes
peterbourgon Mar 13, 2024
25fa2cb
Add some comments about the reason for using -1.
shogo82148 Apr 7, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
95 changes: 48 additions & 47 deletions ulid.go
View file
Open in desktop
Expand Up @@ -175,35 +175,39 @@
return ErrDataSize
}

// Use an optimized unrolled loop to decode a base32 ULID.
h := uint64(dec[v[0]])<<45 |
uint64(dec[v[1]])<<40 |
uint64(dec[v[2]])<<35 |
uint64(dec[v[3]])<<30 |
uint64(dec[v[4]])<<25 |
uint64(dec[v[5]])<<20 |
uint64(dec[v[6]])<<15 |
uint64(dec[v[7]])<<10 |
uint64(dec[v[8]])<<5 |
uint64(dec[v[9]])

m := uint64(dec[v[10]])<<35 |
uint64(dec[v[11]])<<30 |
uint64(dec[v[12]])<<25 |
uint64(dec[v[13]])<<20 |
uint64(dec[v[14]])<<15 |
uint64(dec[v[15]])<<10 |
uint64(dec[v[16]])<<5 |
uint64(dec[v[17]])

l := uint64(dec[v[18]])<<35 |
uint64(dec[v[19]])<<30 |
uint64(dec[v[20]])<<25 |
uint64(dec[v[21]])<<20 |
uint64(dec[v[22]])<<15 |
uint64(dec[v[23]])<<10 |
uint64(dec[v[24]])<<5 |
uint64(dec[v[25]])

// Check if all the characters in a base32 encoded ULID are part of the
// expected base32 character set.
if strict &&
(dec[v[0]] == 0xFF ||
dec[v[1]] == 0xFF ||
dec[v[2]] == 0xFF ||
dec[v[3]] == 0xFF ||
dec[v[4]] == 0xFF ||
dec[v[5]] == 0xFF ||
dec[v[6]] == 0xFF ||
dec[v[7]] == 0xFF ||
dec[v[8]] == 0xFF ||
dec[v[9]] == 0xFF ||
dec[v[10]] == 0xFF ||
dec[v[11]] == 0xFF ||
dec[v[12]] == 0xFF ||
dec[v[13]] == 0xFF ||
dec[v[14]] == 0xFF ||
dec[v[15]] == 0xFF ||
dec[v[16]] == 0xFF ||
dec[v[17]] == 0xFF ||
dec[v[18]] == 0xFF ||
dec[v[19]] == 0xFF ||
dec[v[20]] == 0xFF ||
dec[v[21]] == 0xFF ||
dec[v[22]] == 0xFF ||
dec[v[23]] == 0xFF ||
dec[v[24]] == 0xFF ||
dec[v[25]] == 0xFF) {
if strict && (h|m|l)&(1<<63) != 0 {
return ErrInvalidCharacters
}

Expand All @@ -216,28 +220,25 @@
return ErrOverflow
}

// Use an optimized unrolled loop (from https://github.com/RobThree/NUlid)
// to decode a base32 ULID.

// 6 bytes timestamp (48 bits)
(*id)[0] = (dec[v[0]] << 5) | dec[v[1]]
(*id)[1] = (dec[v[2]] << 3) | (dec[v[3]] >> 2)
(*id)[2] = (dec[v[3]] << 6) | (dec[v[4]] << 1) | (dec[v[5]] >> 4)
(*id)[3] = (dec[v[5]] << 4) | (dec[v[6]] >> 1)
(*id)[4] = (dec[v[6]] << 7) | (dec[v[7]] << 2) | (dec[v[8]] >> 3)
(*id)[5] = (dec[v[8]] << 5) | dec[v[9]]
(*id)[0] = byte(h >> 40)
(*id)[1] = byte(h >> 32)
(*id)[2] = byte(h >> 24)
(*id)[3] = byte(h >> 16)
(*id)[4] = byte(h >> 8)
(*id)[5] = byte(h)

// 10 bytes of entropy (80 bits)
(*id)[6] = (dec[v[10]] << 3) | (dec[v[11]] >> 2)
(*id)[7] = (dec[v[11]] << 6) | (dec[v[12]] << 1) | (dec[v[13]] >> 4)
(*id)[8] = (dec[v[13]] << 4) | (dec[v[14]] >> 1)
(*id)[9] = (dec[v[14]] << 7) | (dec[v[15]] << 2) | (dec[v[16]] >> 3)
(*id)[10] = (dec[v[16]] << 5) | dec[v[17]]
(*id)[11] = (dec[v[18]] << 3) | dec[v[19]]>>2
(*id)[12] = (dec[v[19]] << 6) | (dec[v[20]] << 1) | (dec[v[21]] >> 4)
(*id)[13] = (dec[v[21]] << 4) | (dec[v[22]] >> 1)
(*id)[14] = (dec[v[22]] << 7) | (dec[v[23]] << 2) | (dec[v[24]] >> 3)
(*id)[15] = (dec[v[24]] << 5) | dec[v[25]]
(*id)[6] = byte(m >> 32)
(*id)[7] = byte(m >> 24)
(*id)[8] = byte(m >> 16)
(*id)[9] = byte(m >> 8)
(*id)[10] = byte(m)
(*id)[11] = byte(l >> 32)
(*id)[12] = byte(l >> 24)
(*id)[13] = byte(l >> 16)
(*id)[14] = byte(l >> 8)
(*id)[15] = byte(l)

return nil
}
Expand Down Expand Up @@ -361,17 +362,17 @@

// Byte to index table for O(1) lookups when unmarshaling.
// We use 0xFF as sentinel value for invalid indexes.
var dec = [...]byte{
var dec = [...]int8{
peterbourgon marked this conversation as resolved.
Show resolved Hide resolved
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

Check failure on line 366 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 366 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 366 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

Check failure on line 367 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 367 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 367 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

Check failure on line 368 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 368 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 368 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,

Check failure on line 369 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 369 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 369 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x01,

Check failure on line 370 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 370 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 370 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0xFF, 0xFF,

Check failure on line 371 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 371 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 371 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,

Check failure on line 372 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 372 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 372 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0x0F, 0x10, 0x11, 0xFF, 0x12, 0x13, 0xFF, 0x14, 0x15, 0xFF,

Check failure on line 373 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 373 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 373 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0x16, 0x17, 0x18, 0x19, 0x1A, 0xFF, 0x1B, 0x1C, 0x1D, 0x1E,

Check failure on line 374 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 374 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 374 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0x1F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x0A, 0x0B, 0x0C,

Check failure on line 375 in ulid.go

View workflow job for this annotation

GitHub Actions / lint 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 375 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, ubuntu-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)

Check failure on line 375 in ulid.go

View workflow job for this annotation

GitHub Actions / test (1.x, macos-latest) 

cannot use 0xFF (untyped int constant 255) as int8 value in array or slice literal (overflows)
0x0D, 0x0E, 0x0F, 0x10, 0x11, 0xFF, 0x12, 0x13, 0xFF, 0x14,
0x15, 0xFF, 0x16, 0x17, 0x18, 0x19, 0x1A, 0xFF, 0x1B, 0x1C,
0x1D, 0x1E, 0x1F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
Expand Down