aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/cli/internal/xxhash/xxhash.go
diff options
context:
space:
mode:
Diffstat (limited to 'cli/internal/xxhash/xxhash.go')
-rw-r--r--cli/internal/xxhash/xxhash.go202
1 files changed, 0 insertions, 202 deletions
diff --git a/cli/internal/xxhash/xxhash.go b/cli/internal/xxhash/xxhash.go
deleted file mode 100644
index 642ac73..0000000
--- a/cli/internal/xxhash/xxhash.go
+++ /dev/null
@@ -1,202 +0,0 @@
-// Package xxhash implements the 64-bit variant of xxHash (XXH64) as described
-// at http://cyan4973.github.io/xxHash/.
-
-// Adapted from https://cs.github.com/evanw/esbuild/blob/0c9ced59c8b3ea3bd8dd5feebafed1f47ed279dd/internal/xxhash
-// Copyright (c) 2016 Caleb Spare. All rights reserved.
-// SPDX-License-Identifier: MIT
-package xxhash
-
-import (
- "encoding/binary"
- "math/bits"
-)
-
-const (
- prime1 uint64 = 11400714785074694791
- prime2 uint64 = 14029467366897019727
- prime3 uint64 = 1609587929392839161
- prime4 uint64 = 9650029242287828579
- prime5 uint64 = 2870177450012600261
-)
-
-// NOTE(caleb): I'm using both consts and vars of the primes. Using consts where
-// possible in the Go code is worth a small (but measurable) performance boost
-// by avoiding some MOVQs. Vars are needed for the asm and also are useful for
-// convenience in the Go code in a few places where we need to intentionally
-// avoid constant arithmetic (e.g., v1 := prime1 + prime2 fails because the
-// result overflows a uint64).
-var prime1v = prime1
-
-// Digest implements hash.Hash64.
-type Digest struct {
- v1 uint64
- v2 uint64
- v3 uint64
- v4 uint64
- total uint64
- mem [32]byte
- n int // how much of mem is used
-}
-
-// New creates a new Digest that computes the 64-bit xxHash algorithm.
-func New() *Digest {
- var d Digest
- d.Reset()
- return &d
-}
-
-// Reset clears the Digest's state so that it can be reused.
-func (d *Digest) Reset() {
- d.v1 = prime1v + prime2
- d.v2 = prime2
- d.v3 = 0
- d.v4 = -prime1v
- d.total = 0
- d.n = 0
-}
-
-// Size always returns 8 bytes.
-func (d *Digest) Size() int { return 8 }
-
-// BlockSize always returns 32 bytes.
-func (d *Digest) BlockSize() int { return 32 }
-
-// Write adds more data to d. It always returns len(b), nil.
-func (d *Digest) Write(b []byte) (n int, err error) {
- n = len(b)
- d.total += uint64(n)
-
- if d.n+n < 32 {
- // This new data doesn't even fill the current block.
- copy(d.mem[d.n:], b)
- d.n += n
- return
- }
-
- if d.n > 0 {
- // Finish off the partial block.
- copy(d.mem[d.n:], b)
- d.v1 = round(d.v1, u64(d.mem[0:8]))
- d.v2 = round(d.v2, u64(d.mem[8:16]))
- d.v3 = round(d.v3, u64(d.mem[16:24]))
- d.v4 = round(d.v4, u64(d.mem[24:32]))
- b = b[32-d.n:]
- d.n = 0
- }
-
- if len(b) >= 32 {
- // One or more full blocks left.
- nw := writeBlocks(d, b)
- b = b[nw:]
- }
-
- // Store any remaining partial block.
- copy(d.mem[:], b)
- d.n = len(b)
-
- return
-}
-
-// Sum appends the current hash to b and returns the resulting slice.
-func (d *Digest) Sum(b []byte) []byte {
- s := d.Sum64()
- return append(
- b,
- byte(s>>56),
- byte(s>>48),
- byte(s>>40),
- byte(s>>32),
- byte(s>>24),
- byte(s>>16),
- byte(s>>8),
- byte(s),
- )
-}
-
-// Sum64 returns the current hash.
-func (d *Digest) Sum64() uint64 {
- var h uint64
-
- if d.total >= 32 {
- v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4
- h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4)
- h = mergeRound(h, v1)
- h = mergeRound(h, v2)
- h = mergeRound(h, v3)
- h = mergeRound(h, v4)
- } else {
- h = d.v3 + prime5
- }
-
- h += d.total
-
- i, end := 0, d.n
- for ; i+8 <= end; i += 8 {
- k1 := round(0, u64(d.mem[i:i+8]))
- h ^= k1
- h = rol27(h)*prime1 + prime4
- }
- if i+4 <= end {
- h ^= uint64(u32(d.mem[i:i+4])) * prime1
- h = rol23(h)*prime2 + prime3
- i += 4
- }
- for i < end {
- h ^= uint64(d.mem[i]) * prime5
- h = rol11(h) * prime1
- i++
- }
-
- h ^= h >> 33
- h *= prime2
- h ^= h >> 29
- h *= prime3
- h ^= h >> 32
-
- return h
-}
-
-const (
- magic = "xxh\x06"
- marshaledSize = len(magic) + 8*5 + 32
-)
-
-func u64(b []byte) uint64 { return binary.LittleEndian.Uint64(b) }
-func u32(b []byte) uint32 { return binary.LittleEndian.Uint32(b) }
-
-func round(acc, input uint64) uint64 {
- acc += input * prime2
- acc = rol31(acc)
- acc *= prime1
- return acc
-}
-
-func mergeRound(acc, val uint64) uint64 {
- val = round(0, val)
- acc ^= val
- acc = acc*prime1 + prime4
- return acc
-}
-
-func rol1(x uint64) uint64 { return bits.RotateLeft64(x, 1) }
-func rol7(x uint64) uint64 { return bits.RotateLeft64(x, 7) }
-func rol11(x uint64) uint64 { return bits.RotateLeft64(x, 11) }
-func rol12(x uint64) uint64 { return bits.RotateLeft64(x, 12) }
-func rol18(x uint64) uint64 { return bits.RotateLeft64(x, 18) }
-func rol23(x uint64) uint64 { return bits.RotateLeft64(x, 23) }
-func rol27(x uint64) uint64 { return bits.RotateLeft64(x, 27) }
-func rol31(x uint64) uint64 { return bits.RotateLeft64(x, 31) }
-
-func writeBlocks(d *Digest, b []byte) int {
- v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4
- n := len(b)
- for len(b) >= 32 {
- v1 = round(v1, u64(b[0:8:len(b)]))
- v2 = round(v2, u64(b[8:16:len(b)]))
- v3 = round(v3, u64(b[16:24:len(b)]))
- v4 = round(v4, u64(b[24:32:len(b)]))
- b = b[32:len(b):len(b)]
- }
- d.v1, d.v2, d.v3, d.v4 = v1, v2, v3, v4
- return n - len(b)
-}