2 Commits

Author SHA1 Message Date
9726670dea feat: only one CI job at a time per PR
All checks were successful
CI / lint (pull_request) Successful in 52s
CI / unit-test (pull_request) Successful in 26s
CI / fuzz-test (pull_request) Successful in 1m3s
CI / mutation-test (pull_request) Successful in 43s
This prevents the Gitea runner from getting clogged up with stale CI checks.
2026-03-17 19:51:19 -04:00
62bc15a979 refactor: rename lint.yml to ci.yml
The `lint.yml` workflow contains more than just linting jobs. Renaming it to `ci.yml`, which is more general, and common practice.
2026-03-17 19:49:21 -04:00
27 changed files with 247 additions and 705 deletions

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@@ -1,26 +0,0 @@
# yaml-language-server: $schema=https://www.schemastore.org/gitea-issue-forms.json
name: 🐛 Bug Report
about: Report a bug in this project
title: "[BUG]: "
body:
- type: textarea
id: context
attributes:
label: Context
placeholder: What circumstances led to the bug?
validations:
required: true
- type: textarea
id: expected-behavior
attributes:
label: Expected Behavior
placeholder: What did you expect would happen?
validations:
required: true
- type: textarea
id: actual-behavior
attributes:
label: Actual Behavior
placeholder: What happened, and why was it unexpected?
validations:
required: true

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@@ -1,37 +0,0 @@
# 'Feature Request Template' By @cheehwatang
# https://github.com/cheehwatang/.github/blob/master/.github/ISSUE_TEMPLATE/feature_request.yml
#
# yaml-language-server: $schema=https://www.schemastore.org/gitea-issue-forms.json
name: ✨ Feature Request
about: Suggest an idea for this project
title: "[FEATURE]: "
body:
- type: dropdown
attributes:
multiple: false
label: Feature Type
options:
- "✨ New Feature"
- "📝 Documentation"
- "🎨 Style and UI"
- "🔨 Code Refactor"
- "⚡ Performance Improvements"
- "✅ New Test"
validations:
required: true
- type: textarea
id: description
attributes:
label: Description
placeholder: |
Give us a brief description of the feature or enhancement you would
like!
validations:
required: true
- type: textarea
id: additional-information
attributes:
label: Additional Information
placeholder: |
Give us some additional information on the feature request like proposed
solutions, links, screenshots, etc.

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@@ -1,2 +0,0 @@
# yaml-language-server: $schema=https://www.schemastore.org/gitea-issue-config.json
blank_issues_enabled: false

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@@ -1,17 +0,0 @@
---
name: "New Pull Request"
about: "Standard PR template"
title: ""
ref: "main"
---
## Description
## Changes
### Design Decisions
## Checklist
- [ ] Tests pass
- [ ] Docs updated

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@@ -1,26 +1,16 @@
name: CI name: CI
concurrency:
group: ${{ github.workflow }}-${{ github.ref }}
cancel-in-progress: true
on: on:
push: push:
branches: [main] branches: [main]
pull_request: pull_request:
jobs: jobs:
check-pr-title: lint:
name: Check PR Title
runs-on: ubuntu-latest
if: github.event_name == 'pull_request'
env:
TITLE: ${{ gitea.event.pull_request.title }}
steps:
- run: |
if ! echo "$TITLE" | grep -qE '^(WIP: )?(feat|fix|docs|chore|ci|test|refactor|perf|build|style|revert)(\(.+\))?(!)?: .+'; then
echo "::error::Pull Request title must follow conventional commits"
exit 1
fi
lint-go:
name: Go Lint
runs-on: ubuntu-latest runs-on: ubuntu-latest
steps: steps:
- uses: actions/checkout@v4 - uses: actions/checkout@v4
@@ -29,39 +19,11 @@ jobs:
with: with:
go-version-file: go.mod go-version-file: go.mod
- name: Check go mod tidy
run: go mod tidy && git diff --exit-code go.mod go.sum
- uses: golangci/golangci-lint-action@v7 - uses: golangci/golangci-lint-action@v7
with: with:
version: latest version: latest
lint-makefile: unit-test:
name: Makefile Lint
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: actions/setup-go@v5
with:
go-version-file: go.mod
- name: Install gremlins
run: go install github.com/checkmake/checkmake/cmd/checkmake@latest
- name: Run mutation tests
run: make lint-makefile
lint-markdown:
name: Markdown Lint
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
- uses: DavidAnson/markdownlint-cli2-action@v19
test-unit:
name: Unit Tests
runs-on: ubuntu-latest runs-on: ubuntu-latest
steps: steps:
- uses: actions/checkout@v4 - uses: actions/checkout@v4
@@ -71,10 +33,9 @@ jobs:
go-version-file: go.mod go-version-file: go.mod
- name: Run unit tests - name: Run unit tests
run: make test-unit run: go test ./... -cover -v
test-fuzz: fuzz-test:
name: Fuzz Tests
runs-on: ubuntu-latest runs-on: ubuntu-latest
steps: steps:
- uses: actions/checkout@v4 - uses: actions/checkout@v4
@@ -84,10 +45,12 @@ jobs:
go-version-file: go.mod go-version-file: go.mod
- name: Run fuzz tests - name: Run fuzz tests
run: make test-fuzz run: |
for func in $(grep -r --include='*_test.go' -oh 'func Fuzz\w*' . | sed 's/func //'); do
go test ./... -fuzz="^${func}$" -fuzztime=30s
done
test-mutation: mutation-test:
name: Mutation Tests
runs-on: ubuntu-latest runs-on: ubuntu-latest
steps: steps:
- uses: actions/checkout@v4 - uses: actions/checkout@v4
@@ -100,4 +63,4 @@ jobs:
run: go install github.com/go-gremlins/gremlins/cmd/gremlins@latest run: go install github.com/go-gremlins/gremlins/cmd/gremlins@latest
- name: Run mutation tests - name: Run mutation tests
run: make test-mutation run: gremlins unleash

1
.gitignore vendored
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@@ -24,3 +24,4 @@ go.work.sum
# env file # env file
.env .env

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@@ -114,9 +114,6 @@ linters:
# Reports uses of functions with replacement inside the testing package. # Reports uses of functions with replacement inside the testing package.
- usetesting - usetesting
# Reports mixed receiver types in structs/interfaces.
- recvcheck
settings: settings:
revive: revive:
rules: rules:

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@@ -5,5 +5,3 @@ unleash:
workers: 4 workers: 4
dry-run: false dry-run: false
threshold:
efficacy: 1.0

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@@ -1,17 +0,0 @@
default: true
heading-style:
style: atx
ul-indent:
indent: 2
line-length: false
no-duplicate-heading:
siblings_only: true
no-inline-html:
allowed_elements:
- br
- details
- summary
- img
- picture
- source
first-line-heading: true

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@@ -1,47 +1,12 @@
.PHONY: all help install clean test-unit test-mutation test-fuzz test docs lint-go lint-makefile lint-markdown lint unit:
help: ## Show this help
@grep -E '^[a-zA-Z_-]+:.*##' $(MAKEFILE_LIST) | awk -F ':.*## ' '{printf " %-15s %s\n", $$1, $$2}'
install: ## Install dev tools
go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
go install github.com/checkmake/checkmake/cmd/checkmake@latest
go install github.com/go-gremlins/gremlins/cmd/gremlins@latest
go install golang.org/x/tools/cmd/godoc@latest
go install golang.org/x/vuln/cmd/govulncheck@latest
test-unit: ## Run unit tests with coverage
go test ./... -cover -v go test ./... -cover -v
test-mutation: ## Run mutation tests with gremlins mutation:
gremlins unleash gremlins unleash
FUZZ_TIME ?= 30 fuzz:
go test ./... -fuzz=$(FN)
test-fuzz: ## Run all fuzz tests for 30s each docs:
@for func in $$(grep -r --include='*_test.go' -oh 'func Fuzz\w*' . | sed 's/func //'); do \ @echo ">>> Visit: http://localhost:6060/pkg/git.maximhutz.com/tools/dsa/"
echo "Fuzzing $$func..."; \
go test ./... -fuzz="^$$func$$" -fuzztime=$(FUZZ_TIME)s; \
done
test: test-unit test-mutation test-fuzz ## Run all tests
lint-go: ## Lint Go code
golangci-lint run ./...
lint-makefile: ## Lint the Makefile
checkmake Makefile
lint-markdown: ## Lint Markdown files
docker run --rm -v $(CURDIR):/workdir davidanson/markdownlint-cli2 "**/*.md"
lint: lint-go lint-makefile lint-markdown ## Lint all code
docs: ## Serve godoc locally
@echo ">>> Visit: http://localhost:6060/pkg/$$(go list -m)"
godoc -http=:6060 godoc -http=:6060
clean: ## Clean build and test caches
go clean -cache -testcache
all: lint test ## Run all checks and tests

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@@ -1,3 +1,3 @@
# <img height="30" src="assets/logo.svg" alt="Go Cuckoo, by `mvhutz`."> Go Cuckoo # go-cuckoo
A hash table that uses cuckoo hashing to achieve a worst-case O(1) lookup time. Read more about it in [the package documentation](https://pkg.go.dev/git.maximhutz.com/tools/go-cuckoo). A hash table that uses cuckoo hashing to achieve a worst-case O(1) lookup time.

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@@ -1 +0,0 @@
<svg width="16" height="16" xmlns="http://www.w3.org/2000/svg" shape-rendering="crispEdges"><path fill="#2a1512" d="M3,6h1v1h-1v-1M2,7h1v1h-1v-1M12,7h1v1h-1v-1M1,8h1v1h-1v-1M4,8h1v2h-1v-2M14,8h1v1h-1v-1M11,9h1v2h-2v-1h1v-1M5,10h1v1h-1v-1M1,13h2v1h1v1h-2v-1h-1v-1M13,13h2v1h-1v1h-1v1h-1v-2h1v-1M4,15h1v1h-1v-1"/><path fill="#38231f" d="M4,6h1v1h-1v-1M11,6h1v1h-1v-1M13,7h1v1h-1v-1M1,9h1v2h-1v-2M14,9h1v1h-1v-1M14,11h1v2h-1v-2M1,12h1v1h-1v-1M5,15h3v1h-3v-1M10,15h2v1h-2v-1"/><path fill="#3f3f74" d="M7,3h2v1h-2v-1M6,4h1v1h-1v-1M9,4h1v1h-1v-1M5,5h1v5h-1v-5M10,5h1v5h-1v-5M6,10h4v1h-4v-1"/><path fill="#6262ab" d="M9,5h1v1h-1v-1M6,9h1v1h-1v-1M9,9h1v1h-1v-1"/><path fill="#663931" d="M11,8h1v1h-1v-1M2,9h1v1h-1v-1M14,10h1v1h-1v-1M1,11h1v1h-1v-1M3,11h2v1h-2v-1M13,11h1v1h-1v-1M2,12h1v1h-1v-1M5,12h1v1h-1v-1M10,12h3v2h-1v-1h-2v-1M3,13h1v1h-1v-1M8,13h2v1h-2v-1M4,14h3v1h-3v-1M10,14h2v1h-2v-1M8,15h2v1h-2v-1"/><path fill="#8d8dcb" d="M9,6h1v3h-1v1h-2v-1h1v-1h1v-2M6,8h1v1h-1v-1"/><path fill="#8f563b" d="M2,8h1v1h-1v-1M12,9h1v1h-1v-1M2,10h1v1h-1v-1M13,10h1v1h-1v-1M7,11h1v1h-1v-1M11,11h2v1h-2v-1M4,12h1v1h1v-1h1v2h-3v-2M13,12h1v1h-1v-1M10,13h2v1h-2v-1M7,14h3v1h-3v-1"/><path fill="#a4a4d5" d="M8,4h1v4h-1v1h-1v-1h-1v-2h1v-1h1v-1"/><path fill="#ab764a" d="M4,7h1v1h-1v-1M3,8h1v2h-1v-2M12,10h1v1h-1v-1M2,11h1v1h-1v-1M8,11h1v1h-1v-1M3,12h1v1h-1v-1M7,12h1v2h-1v-2"/><path fill="#cacaea" d="M7,4h1v1h-1v-1M6,5h1v1h-1v-1"/><path fill="#d9a066" d="M3,7h1v1h-1v-1M11,7h1v1h-1v-1M12,8h2v2h-1v-1h-1v-1M3,10h2v1h-2v-1M5,11h2v1h-2v-1M9,11h2v1h-1v1h-2v-1h1v-1"/></svg>

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73
bucket.go Normal file
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@@ -0,0 +1,73 @@
package cuckoo
type entry[K, V any] struct {
key K
value V
}
type slot[K, V any] struct {
entry[K, V]
occupied bool
}
type bucket[K, V any] struct {
hash Hash[K]
slots []slot[K, V]
capacity, size uint64
compare EqualFunc[K]
}
func (b bucket[K, V]) location(key K) uint64 {
return b.hash(key) % b.capacity
}
func (b bucket[K, V]) get(key K) (value V, found bool) {
slot := b.slots[b.location(key)]
return slot.value, slot.occupied && b.compare(slot.key, key)
}
func (b *bucket[K, V]) resize(capacity uint64) {
b.slots = make([]slot[K, V], capacity)
b.capacity = capacity
b.size = 0
}
func (b bucket[K, V]) update(key K, value V) (updated bool) {
slot := &b.slots[b.location(key)]
if slot.occupied && b.compare(slot.key, key) {
slot.value = value
return true
}
return false
}
func (b *bucket[K, V]) evict(insertion entry[K, V]) (evicted entry[K, V], eviction bool) {
slot := &b.slots[b.location(insertion.key)]
if !slot.occupied {
slot.entry = insertion
slot.occupied = true
b.size++
return
}
if b.compare(slot.key, insertion.key) {
slot.value = insertion.value
return
}
insertion, slot.entry = slot.entry, insertion
return insertion, true
}
func newBucket[K, V any](capacity uint64, hash Hash[K], compare EqualFunc[K]) bucket[K, V] {
return bucket[K, V]{
hash: hash,
capacity: capacity,
compare: compare,
size: 0,
slots: make([]slot[K, V], capacity),
}
}

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@@ -2,7 +2,7 @@ package cuckoo
// An EqualFunc determines whethers two keys are 'equal'. Keys that are 'equal' // An EqualFunc determines whethers two keys are 'equal'. Keys that are 'equal'
// are teated as the same by the [Table]. A good EqualFunc is pure, // are teated as the same by the [Table]. A good EqualFunc is pure,
// deterministic, and fast. By default, [New] uses [DefaultEqualFunc]. // deterministic, and fast. By default, [NewTable] uses [DefaultEqualFunc].
// //
// This function MUST NOT return true if the [Hash] digest of two keys // This function MUST NOT return true if the [Hash] digest of two keys
// are different: the [Table] will not work. // are different: the [Table] will not work.

View File

@@ -28,7 +28,7 @@ func ExampleEqualFunc_badEqualFunc() {
// Two users with the same ID are equal. // Two users with the same ID are equal.
isEqual := func(a, b User) bool { return a.ID == b.ID } isEqual := func(a, b User) bool { return a.ID == b.ID }
userbase := cuckoo.NewCustom[User, bool](makeHash(1), makeHash(2), isEqual) userbase := cuckoo.NewCustomTable[User, bool](makeHash(1), makeHash(2), isEqual)
(userbase.Put(User{"1", "Robert Doe"}, true)) (userbase.Put(User{"1", "Robert Doe"}, true))

View File

@@ -1,13 +1,11 @@
package cuckoo_test package cuckoo_test
import ( import (
"fmt" "bytes"
"maps" "encoding/binary"
"os"
"testing" "testing"
"github.com/stretchr/testify/assert" "github.com/stretchr/testify/assert"
go_fuzz_utils "github.com/trailofbits/go-fuzz-utils"
"git.maximhutz.com/tools/go-cuckoo" "git.maximhutz.com/tools/go-cuckoo"
) )
@@ -21,73 +19,31 @@ func offsetHash(seed uint32) cuckoo.Hash[uint32] {
} }
} }
type fuzzStep struct {
drop bool
key, value uint32
}
type fuzzScenario struct {
seedA, seedB uint32
capacity, growthFactor uint8
steps []fuzzStep
}
func FuzzInsertLookup(f *testing.F) { func FuzzInsertLookup(f *testing.F) {
f.Fuzz(func(t *testing.T, data []byte) { f.Fuzz(func(t *testing.T, data []byte, seedA, seedB uint32) {
var scenario fuzzScenario
assert := assert.New(t) assert := assert.New(t)
if tp, err := go_fuzz_utils.NewTypeProvider(data); err != nil { table := cuckoo.NewCustomTable[uint32, uint32](
return
} else if err := tp.Fill(&scenario); err != nil {
return
}
seedA, seedB := scenario.seedA, scenario.seedB
growthFactor := max(2, int(scenario.growthFactor))
capacity := int(scenario.capacity)
// If they are the same number, the hashes will clash, always causing an
// error.
if seedA == seedB {
t.Skip()
}
fmt.Fprintf(os.Stderr, "seedA=%d seedB=%d capacity=%d growthFactor=%d\n",
seedA, seedB, capacity, growthFactor)
actual := cuckoo.NewCustom[uint32, uint32](
offsetHash(seedA), offsetHash(seedA),
offsetHash(seedB), offsetHash(seedB),
func(a, b uint32) bool { return a == b }, func(a, b uint32) bool { return a == b },
cuckoo.Capacity(capacity),
cuckoo.GrowthFactor(growthFactor),
) )
expected := map[uint32]uint32{} if seedA == seedB {
return
for _, step := range scenario.steps {
if step.drop {
ok := actual.Drop(step.key)
_, has := expected[step.key]
assert.Equal(ok, has)
delete(expected, step.key)
_, ok = actual.Get(step.key)
assert.False(ok)
} else {
err := actual.Put(step.key, step.value)
assert.NoError(err)
expected[step.key] = step.value
found, ok := actual.Get(step.key)
assert.True(ok)
assert.Equal(step.value, found)
} }
assert.Equal(expected, maps.Collect(actual.Entries())) r := bytes.NewReader(data)
var key, value uint32
for binary.Read(r, binary.LittleEndian, &key) == nil &&
binary.Read(r, binary.LittleEndian, &value) == nil {
err := table.Put(key, value)
assert.NoError(err)
found, err := table.Get(key)
assert.NoError(err)
assert.Equal(value, found)
} }
}) })
} }

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@@ -11,7 +11,7 @@ func TestMaxEvictions(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
for i := 16; i < 116; i++ { for i := 16; i < 116; i++ {
table := New[int, bool](Capacity(i / 2)) table := NewTable[int, bool](Capacity(i / 2))
expectedEvictions := 3 * math.Floor(math.Log2(float64(i))) expectedEvictions := 3 * math.Floor(math.Log2(float64(i)))
assert.Equal(table.maxEvictions(), int(expectedEvictions)) assert.Equal(table.maxEvictions(), int(expectedEvictions))
@@ -20,11 +20,11 @@ func TestMaxEvictions(t *testing.T) {
func TestLoad(t *testing.T) { func TestLoad(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
table := New[int, bool](Capacity(8)) table := NewTable[int, bool](Capacity(8))
for i := range 16 { for i := range 16 {
err := table.Put(i, true) err := table.Put(i, true)
assert.NoError(err) assert.NoError(err)
assert.Equal(float64(table.Size())/float64(table.TotalCapacity()), table.load()) assert.Equal(float64(table.Size())/float64(table.Capacity()), table.load())
} }
} }

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@@ -1,7 +1,6 @@
package cuckoo_test package cuckoo_test
import ( import (
"errors"
"maps" "maps"
"math/rand/v2" "math/rand/v2"
"testing" "testing"
@@ -14,7 +13,7 @@ import (
func TestNewTable(t *testing.T) { func TestNewTable(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
table := cuckoo.New[int, bool]() table := cuckoo.NewTable[int, bool]()
assert.NotNil(table) assert.NotNil(table)
assert.Zero(table.Size()) assert.Zero(table.Size())
@@ -23,7 +22,7 @@ func TestNewTable(t *testing.T) {
func TestAddItem(t *testing.T) { func TestAddItem(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
key, value := 0, true key, value := 0, true
table := cuckoo.New[int, bool]() table := cuckoo.NewTable[int, bool]()
err := table.Put(key, value) err := table.Put(key, value)
@@ -35,7 +34,7 @@ func TestAddItem(t *testing.T) {
func TestPutOverwrite(t *testing.T) { func TestPutOverwrite(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
key, value, newValue := 0, 1, 2 key, value, newValue := 0, 1, 2
table := cuckoo.New[int, int]() table := cuckoo.NewTable[int, int]()
(table.Put(key, value)) (table.Put(key, value))
err := table.Put(key, newValue) err := table.Put(key, newValue)
@@ -50,7 +49,7 @@ func TestPutOverwrite(t *testing.T) {
func TestSameHash(t *testing.T) { func TestSameHash(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
hash := func(int) uint64 { return 0 } hash := func(int) uint64 { return 0 }
table := cuckoo.NewCustom[int, bool](hash, hash, cuckoo.DefaultEqualFunc[int]) table := cuckoo.NewCustomTable[int, bool](hash, hash, cuckoo.DefaultEqualFunc[int])
errA := table.Put(0, true) errA := table.Put(0, true)
errB := table.Put(1, true) errB := table.Put(1, true)
@@ -63,29 +62,29 @@ func TestSameHash(t *testing.T) {
func TestStartingCapacity(t *testing.T) { func TestStartingCapacity(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
table := cuckoo.New[int, bool](cuckoo.Capacity(64)) table := cuckoo.NewTable[int, bool](cuckoo.Capacity(64))
assert.Equal(uint64(128), table.TotalCapacity()) assert.Equal(uint64(128), table.Capacity())
} }
func TestResizeCapacity(t *testing.T) { func TestResizeCapacity(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
table := cuckoo.New[int, bool]( table := cuckoo.NewTable[int, bool](
cuckoo.Capacity(8), cuckoo.Capacity(8),
cuckoo.GrowthFactor(2), cuckoo.GrowthFactor(2),
) )
for table.TotalCapacity() == 16 { for table.Capacity() == 16 {
err := table.Put(rand.Int(), true) err := table.Put(rand.Int(), true)
assert.NoError(err) assert.NoError(err)
} }
assert.Equal(uint64(32), table.TotalCapacity()) assert.Equal(uint64(32), table.Capacity())
} }
func TestPutMany(t *testing.T) { func TestPutMany(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
expected, actual := map[int]bool{}, cuckoo.New[int, bool]() expected, actual := map[int]bool{}, cuckoo.NewTable[int, bool]()
for i := range 1_000 { for i := range 1_000 {
expected[i] = true expected[i] = true
@@ -100,7 +99,7 @@ func TestPutMany(t *testing.T) {
func TestGetMany(t *testing.T) { func TestGetMany(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
table := cuckoo.New[int, bool]() table := cuckoo.NewTable[int, bool]()
for i := range 1_000 { for i := range 1_000 {
err := table.Put(i, true) err := table.Put(i, true)
@@ -108,119 +107,24 @@ func TestGetMany(t *testing.T) {
} }
for i := range 2_000 { for i := range 2_000 {
value, ok := table.Get(i) value, err := table.Get(i)
if i < 1_000 { if i < 1_000 {
assert.True(ok) assert.NoError(err)
assert.Equal(value, true) assert.Equal(value, true)
} else { } else {
assert.False(ok) assert.Error(err)
} }
} }
} }
func TestDropExistingItem(t *testing.T) { func TestRemove(t *testing.T) {
assert := assert.New(t) assert := assert.New(t)
key, value := 0, true table := cuckoo.NewTable[int, bool]()
table := cuckoo.New[int, bool]()
(table.Put(key, value))
had := table.Drop(key) assert.False(table.Has(0))
assert.True(had)
assert.Equal(0, table.Size())
assert.False(table.Has(key))
}
func TestDropNoItem(t *testing.T) {
assert := assert.New(t)
key := 0
table := cuckoo.New[int, bool]()
had := table.Drop(key)
assert.False(had)
assert.Equal(0, table.Size())
assert.False(table.Has(key))
}
func TestDropItemCapacity(t *testing.T) {
assert := assert.New(t)
key := 0
table := cuckoo.New[int, bool](
cuckoo.Capacity(64),
cuckoo.GrowthFactor(2),
)
startingCapacity := table.TotalCapacity()
table.Drop(key)
endingCapacity := table.TotalCapacity()
assert.Equal(0, table.Size())
assert.Equal(uint64(128), startingCapacity)
assert.Equal(uint64(64), endingCapacity)
}
func TestPutNoCapacity(t *testing.T) {
assert := assert.New(t)
key, value := 0, true
table := cuckoo.New[int, bool](
cuckoo.Capacity(0),
)
err := table.Put(key, value)
err := table.Put(0, true)
assert.NoError(err) assert.NoError(err)
assert.Equal(1, table.Size())
assert.True(table.Has(key)) assert.True(table.Has(0))
}
func TestBadHashCapacity(t *testing.T) {
assert := assert.New(t)
table := cuckoo.NewCustom[int, bool](
func(int) uint64 { return 0 },
func(int) uint64 { return 0 },
func(a, b int) bool { return a == b },
cuckoo.Capacity(20),
)
err1 := table.Put(0, true)
err2 := table.Put(1, true)
err3 := table.Put(2, true)
assert.NoError(err1)
assert.NoError(err2)
assert.Error(err3)
assert.Equal(uint64(80), table.TotalCapacity())
}
func TestDropResizeCapacity(t *testing.T) {
assert := assert.New(t)
table := cuckoo.New[int, bool](
cuckoo.Capacity(10),
)
err1 := table.Put(0, true)
err2 := table.Put(1, true)
table.Drop(1)
assert.NoError(errors.Join(err1, err2))
assert.Equal(uint64(20), table.TotalCapacity())
}
func TestNewTableBy(t *testing.T) {
type User struct {
_ func()
id string
name string
}
assert := assert.New(t)
table := cuckoo.NewBy[User, bool](func(u User) string { return u.id })
err := table.Put(User{nil, "1", "Robert"}, true)
assert.NoError(err)
assert.Equal(1, table.Size())
assert.True(table.Has(User{nil, "1", "Robbie"}))
} }

7
doc.go
View File

@@ -1,12 +1,9 @@
// Package cuckoo provides a hash table that uses cuckoo hashing to achieve // Package cuckoo provides a hash table that uses cuckoo hashing to achieve
// a worst-case O(1) lookup time. // a worst-case O(1) lookup time.
// //
// While a [New] only supports comparable keys by default, you can create // While a [NewTable] only supports comparable keys by default, you can create
// a table with any key type using [NewCustom]. Custom [Hash] functions and // a table with any key type using [NewCustomTable]. Custom [Hash] functions and
// key comparison are also supported. // key comparison are also supported.
// //
// NOTE: The [Table] is a look-up structure, and not a source of truth. If
// [ErrBadHash] occurs, the data cannot be restored.
//
// See more: https://en.wikipedia.org/wiki/Cuckoo_hashing // See more: https://en.wikipedia.org/wiki/Cuckoo_hashing
package cuckoo package cuckoo

View File

@@ -8,25 +8,25 @@ import (
) )
func Example_basic() { func Example_basic() {
table := cuckoo.New[int, string]() table := cuckoo.NewTable[int, string]()
if err := table.Put(1, "Hello, World!"); err != nil { if err := table.Put(1, "Hello, World!"); err != nil {
fmt.Println("Put error:", err) fmt.Println("Put error:", err)
} }
if item, ok := table.Get(1); !ok { if item, err := table.Get(1); err != nil {
fmt.Println("Not Found 1!") fmt.Println("Error:", err)
} else { } else {
fmt.Println("Found 1:", item) fmt.Println("Found 1:", item)
} }
if item, ok := table.Get(0); !ok { if item, err := table.Get(0); err != nil {
fmt.Println("Not Found 0!") fmt.Println("Error:", err)
} else { } else {
fmt.Println("Found 0:", item) fmt.Println("Found 0:", item)
} }
// Output: // Output:
// Found 1: Hello, World! // Found 1: Hello, World!
// Not Found 0! // Error: key '0' not found
} }

3
go.mod
View File

@@ -4,11 +4,8 @@ go 1.25.6
require github.com/stretchr/testify v1.11.1 require github.com/stretchr/testify v1.11.1
require github.com/kr/pretty v0.3.1 // indirect
require ( require (
github.com/davecgh/go-spew v1.1.1 // indirect github.com/davecgh/go-spew v1.1.1 // indirect
github.com/pmezard/go-difflib v1.0.0 // indirect github.com/pmezard/go-difflib v1.0.0 // indirect
github.com/trailofbits/go-fuzz-utils v0.0.0-20260318143407-0907cafe7589
gopkg.in/yaml.v3 v3.0.1 // indirect gopkg.in/yaml.v3 v3.0.1 // indirect
) )

12
go.sum
View File

@@ -1,21 +1,9 @@
github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c= github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38= github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM= github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4= github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U= github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U= github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
github.com/trailofbits/go-fuzz-utils v0.0.0-20260318143407-0907cafe7589 h1:UmBZCTPdDYore2IEHN+U4eIqEaRq6METh9pKiPumkqc=
github.com/trailofbits/go-fuzz-utils v0.0.0-20260318143407-0907cafe7589/go.mod h1:zh+T+w9XT/3o4E0WLEGCdmLJ8Yqx/zY3o538tQY3OjY=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0= gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA= gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM= gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

View File

@@ -1,7 +1,5 @@
package cuckoo package cuckoo
import "fmt"
// DefaultCapacity is the initial capacity of a [Table]. It is inspired from // DefaultCapacity is the initial capacity of a [Table]. It is inspired from
// Java's [HashMap] implementation, which also uses 16. // Java's [HashMap] implementation, which also uses 16.
// //
@@ -9,20 +7,14 @@ import "fmt"
const DefaultCapacity uint64 = 16 const DefaultCapacity uint64 = 16
// DefaultGrowthFactor is the standard resize multiplier for a [Table]. Most // DefaultGrowthFactor is the standard resize multiplier for a [Table]. Most
// implementations use 2. // hash table implementations use 2.
const DefaultGrowthFactor uint64 = 2 const DefaultGrowthFactor uint64 = 2
// defaultMinimumLoad is the default lowest acceptable occupancy of a [Table]. // DefaultMinimumLoad is the default lowest acceptable occupancy of a [Table].
// The higher the minimum load, the more likely that a [Table.Put] will not // The value of 5% is taken from [libcuckoo].
// succeed. The value of 5% is taken from [libcuckoo].
// //
// [libcuckoo]: https://github.com/efficient/libcuckoo/blob/656714705a055df2b7a605eb3c71586d9da1e119/libcuckoo/cuckoohash_config.hh#L21 // [libcuckoo]: https://github.com/efficient/libcuckoo/blob/656714705a055df2b7a605eb3c71586d9da1e119/libcuckoo/cuckoohash_config.hh#L21
const defaultMinimumLoad float64 = 0.05 const DefaultMinimumLoad float64 = 0.05
// defaultGrowthLimit is the maximum number of times a [Table] can grow in a
// single [Table.Put], before the library infers it will lead to a stack
// overflow. The value of '64' was chosen arbirarily.
const defaultGrowthLimit uint64 = 64
type settings struct { type settings struct {
growthFactor uint64 growthFactor uint64
@@ -31,25 +23,23 @@ type settings struct {
} }
// An Option modifies the settings of a [Table]. It is used in its constructors // An Option modifies the settings of a [Table]. It is used in its constructors
// like [New], for example. // like [NewTable], for example.
type Option func(*settings) type Option func(*settings)
// Capacity modifies the starting capacity of each subtable of the [Table]. The // Capacity modifies the starting capacity of each bucket of the [Table]. The
// value must be non-negative. // value must be greater than 0.
func Capacity(value int) Option { func Capacity(value int) Option {
if value < 0 { return func(s *settings) { s.bucketSize = uint64(value) }
panic(fmt.Sprintf("go-cuckoo: Capacity must be non-negative, got %d", value))
} }
return func(s *settings) { s.bucketSize = uint64(value) } // MinimumLoad modifies the [DefaultMinimumLoad] of the [Table]. The value must
// be between 0.00 and 1.00.
func MinimumLoad(value float64) Option {
return func(s *settings) { s.minLoadFactor = value }
} }
// GrowthFactor controls how much the capacity of the [Table] multiplies when // GrowthFactor controls how much the capacity of the [Table] multiplies when
// it must resize. The value must be greater than 1. // it must resize. The value must be greater than 1.
func GrowthFactor(value int) Option { func GrowthFactor(value int) Option {
if value < 2 {
panic(fmt.Sprintf("go-cuckoo: GrowthFactor must be greater than 1, got %d", value))
}
return func(s *settings) { s.growthFactor = uint64(value) } return func(s *settings) { s.growthFactor = uint64(value) }
} }

View File

@@ -1,107 +0,0 @@
package cuckoo
// An entry is a key-value pair.
type entry[K, V any] struct {
key K
value V
}
type slot[K, V any] struct {
entry[K, V]
occupied bool
}
type subtable[K, V any] struct {
hash Hash[K]
slots []slot[K, V]
capacity, size uint64
compare EqualFunc[K]
}
// location determines where in the subtable a certain key would be placed. If
// the capacity is 0, this will panic.
func (t *subtable[K, V]) location(key K) uint64 {
return t.hash(key) % t.capacity
}
func (t *subtable[K, V]) get(key K) (value V, found bool) {
if t.capacity == 0 {
return
}
slot := t.slots[t.location(key)]
return slot.value, slot.occupied && t.compare(slot.key, key)
}
func (t *subtable[K, V]) drop(key K) (occupied bool) {
if t.capacity == 0 {
return
}
slot := &t.slots[t.location(key)]
if slot.occupied && t.compare(slot.key, key) {
slot.occupied = false
t.size--
return true
}
return false
}
func (t *subtable[K, V]) resized(capacity uint64) *subtable[K, V] {
return &subtable[K, V]{
slots: make([]slot[K, V], capacity),
capacity: capacity,
hash: t.hash,
compare: t.compare,
}
}
func (t *subtable[K, V]) update(key K, value V) (updated bool) {
if t.capacity == 0 {
return
}
slot := &t.slots[t.location(key)]
if slot.occupied && t.compare(slot.key, key) {
slot.value = value
return true
}
return false
}
func (t *subtable[K, V]) insert(insertion entry[K, V]) (evicted entry[K, V], eviction bool) {
if t.capacity == 0 {
return insertion, true
}
slot := &t.slots[t.location(insertion.key)]
if !slot.occupied {
slot.entry = insertion
slot.occupied = true
t.size++
return
}
if t.compare(slot.key, insertion.key) {
slot.value = insertion.value
return
}
insertion, slot.entry = slot.entry, insertion
return insertion, true
}
func newSubtable[K, V any](capacity uint64, hash Hash[K], compare EqualFunc[K]) *subtable[K, V] {
return &subtable[K, V]{
hash: hash,
capacity: capacity,
compare: compare,
size: 0,
slots: make([]slot[K, V], capacity),
}
}

240
table.go
View File

@@ -1,206 +1,126 @@
package cuckoo package cuckoo
import ( import (
"errors"
"fmt" "fmt"
"iter" "iter"
"math/bits" "math/bits"
"strings" "strings"
) )
// ErrBadHash occurs when the hashes given to a [Table] cause too many key // A Table is hash table that uses cuckoo hashing to resolve collision. Create
// collisions. Discard the old table, rebuild it from your source data, and try: // one with [NewTable]. Or if you want more granularity, use [NewTableBy] or
// // [NewCustomTable].
// 1. Different hash seeds. Equal seeds produce equal hash functions, which
// always cycle.
// 2. A different [Hash] algorithm.
var ErrBadHash = errors.New("bad hash")
// A Table which uses cuckoo hashing to resolve collision. Create
// one with [New]. Or if you want more granularity, use [NewBy] or
// [NewCustom].
type Table[K, V any] struct { type Table[K, V any] struct {
tableA, tableB *subtable[K, V] bucketA, bucketB bucket[K, V]
growthFactor uint64 growthFactor uint64
minLoadFactor float64 minLoadFactor float64
} }
// TotalCapacity returns the number of slots allocated for the [Table]. To get the // Capacity returns the number of slots allocated for the [Table]. To get the
// number of slots filled, look at [Table.Size]. // number of slots filled, look at [Table.Size].
func (t *Table[K, V]) TotalCapacity() uint64 { func (t Table[K, V]) Capacity() uint64 {
return t.tableA.capacity + t.tableB.capacity return t.bucketA.capacity + t.bucketB.capacity
} }
// Size returns how many slots are filled in the [Table]. // Size returns how many slots are filled in the [Table].
func (t *Table[K, V]) Size() int { func (t Table[K, V]) Size() int {
return int(t.tableA.size + t.tableB.size) return int(t.bucketA.size + t.bucketB.size)
} }
func log2(n uint64) (m int) { func log2(n uint64) (m int) {
return max(0, bits.Len64(n)-1) return bits.Len64(n) - 1
} }
func (t *Table[K, V]) maxEvictions() int { func (t Table[K, V]) maxEvictions() int {
return 3 * log2(t.TotalCapacity()) return 3 * log2(t.Capacity())
} }
func (t *Table[K, V]) load() float64 { func (t Table[K, V]) load() float64 {
// When there are no slots in the table, we still treat the load as 100%. return float64(t.Size()) / float64(t.Capacity())
// Every slot in the table is full.
if t.TotalCapacity() == 0 {
return 1.0
} }
return float64(t.Size()) / float64(t.TotalCapacity()) func (t *Table[K, V]) resize() error {
} entries := make([]entry[K, V], 0, t.Size())
// insert attempts to put/update an entry in the table, without modifying the
// size of the table. Returns a displaced entry and 'homeless = true' if an
// entry could not be placed after exhausting evictions.
func (t *Table[K, V]) insert(entry entry[K, V]) (displaced entry[K, V], homeless bool) {
if t.tableA.update(entry.key, entry.value) {
return
}
if t.tableB.update(entry.key, entry.value) {
return
}
for range t.maxEvictions() {
if entry, homeless = t.tableA.insert(entry); !homeless {
return
}
if entry, homeless = t.tableB.insert(entry); !homeless {
return
}
}
return entry, true
}
// resized creates an empty copy of the table, with a new capacity for each
// bucket.
func (t *Table[K, V]) resized(capacity uint64) *Table[K, V] {
return &Table[K, V]{
growthFactor: t.growthFactor,
minLoadFactor: t.minLoadFactor,
tableA: t.tableA.resized(capacity),
tableB: t.tableB.resized(capacity),
}
}
// resize creates a new [Table.resized] with 'capacity', inserts all items into
// the array, and replaces the current table. It is a helper function for
// [Table.grow] and [Table.shrink]; use them instead.
func (t *Table[K, V]) resize(capacity uint64) bool {
updated := t.resized(capacity)
for k, v := range t.Entries() { for k, v := range t.Entries() {
if _, failed := updated.insert(entry[K, V]{k, v}); failed { entries = append(entries, entry[K, V]{k, v})
return false }
t.bucketA.resize(t.growthFactor * t.bucketA.capacity)
t.bucketB.resize(t.growthFactor * t.bucketB.capacity)
for _, entry := range entries {
if err := t.Put(entry.key, entry.value); err != nil {
return err
} }
} }
*t = *updated return nil
return true
} }
// grow increases the table's capacity by the growth factor. If the // Get fetches the value for a key in the [Table]. Returns an error if no value
// capacity is 0, it increases it to 1. // is found.
func (t *Table[K, V]) grow() bool { func (t Table[K, V]) Get(key K) (value V, err error) {
var newCapacity uint64 if item, ok := t.bucketA.get(key); ok {
return item, nil
if t.TotalCapacity() == 0 {
newCapacity = 1
} else {
newCapacity = t.tableA.capacity * t.growthFactor
} }
return t.resize(newCapacity) if item, ok := t.bucketB.get(key); ok {
return item, nil
} }
// shrink reduces the table's capacity by the growth factor. It may return value, fmt.Errorf("key '%v' not found", key)
// reduce it down to 0.
func (t *Table[K, V]) shrink() bool {
return t.resize(t.tableA.capacity / t.growthFactor)
}
// Get fetches the value for a key in the [Table]. Matches the comma-ok pattern
// of a builtin map; see [Table.Find] for plain indexing.
func (t *Table[K, V]) Get(key K) (value V, ok bool) {
if item, ok := t.tableA.get(key); ok {
return item, true
}
if item, ok := t.tableB.get(key); ok {
return item, true
}
return
}
// Find fetches the value of a key. Matches direct indexing of a builtin map;
// see [Table.Get] for a comma-ok pattern.
func (t *Table[K, V]) Find(key K) (value V) {
value, _ = t.Get(key)
return
} }
// Has returns true if a key has a value in the table. // Has returns true if a key has a value in the table.
func (t *Table[K, V]) Has(key K) (exists bool) { func (t Table[K, V]) Has(key K) (exists bool) {
_, exists = t.Get(key) _, err := t.Get(key)
return return err == nil
} }
// Put sets the value for a key. If it cannot be set, an error is returned. // Put sets the value for a key. Returns error if its value cannot be set.
func (t *Table[K, V]) Put(key K, value V) (err error) { func (t *Table[K, V]) Put(key K, value V) (err error) {
var ( if t.bucketA.update(key, value) {
entry = entry[K, V]{key, value} return nil
homeless bool
)
for range defaultGrowthLimit {
if entry, homeless = t.insert(entry); !homeless {
return
} }
// Both this and the growth limit are necessary: this catches bad hashes if t.bucketB.update(key, value) {
// early when the table is sparse, while the latter catches cases where return nil
// growing never helps.
if t.load() < t.minLoadFactor {
return fmt.Errorf("hash functions produced a cycle at load %d/%d: %w", t.Size(), t.TotalCapacity(), ErrBadHash)
} }
// It is theoretically possible to have a table with a larger capacity entry, eviction := entry[K, V]{key, value}, false
// that is valid. But this chance is astronomically small, so we ignore for range t.maxEvictions() {
// it in this implementation. if entry, eviction = t.bucketA.evict(entry); !eviction {
if grew := t.grow(); !grew { return nil
return fmt.Errorf("could not redistribute entries into larger table: %w", ErrBadHash)
}
} }
return fmt.Errorf("could not place entry after %d resizes: %w", defaultGrowthLimit, ErrBadHash) if entry, eviction = t.bucketB.evict(entry); !eviction {
return nil
}
} }
// Drop removes a value for a key in the table. Returns whether the key had
// existed.
func (t *Table[K, V]) Drop(key K) bool {
occupied := t.tableA.drop(key) || t.tableB.drop(key)
if t.load() < t.minLoadFactor { if t.load() < t.minLoadFactor {
// The error is not handled here, because table-shrinking is an internal return fmt.Errorf("bad hash: resize on load %d/%d = %f", t.Size(), t.Capacity(), t.load())
// optimization.
t.shrink()
} }
return occupied if err := t.resize(); err != nil {
return err
}
return t.Put(entry.key, entry.value)
}
// Drop removes a value for a key in the table. Returns an error if its value
// cannot be removed.
//
// Deprecated: Do not use.
func (t Table[K, V]) Drop(_ K) {
panic("Not implemented")
} }
// Entries returns an unordered sequence of all key-value pairs in the table. // Entries returns an unordered sequence of all key-value pairs in the table.
func (t *Table[K, V]) Entries() iter.Seq2[K, V] { func (t Table[K, V]) Entries() iter.Seq2[K, V] {
return func(yield func(K, V) bool) { return func(yield func(K, V) bool) {
for _, slot := range t.tableA.slots { for _, slot := range t.bucketA.slots {
if slot.occupied { if slot.occupied {
if !yield(slot.key, slot.value) { if !yield(slot.key, slot.value) {
return return
@@ -208,7 +128,7 @@ func (t *Table[K, V]) Entries() iter.Seq2[K, V] {
} }
} }
for _, slot := range t.tableB.slots { for _, slot := range t.bucketB.slots {
if slot.occupied { if slot.occupied {
if !yield(slot.key, slot.value) { if !yield(slot.key, slot.value) {
return return
@@ -219,8 +139,8 @@ func (t *Table[K, V]) Entries() iter.Seq2[K, V] {
} }
// String returns the entries of the table as a string in the format: // String returns the entries of the table as a string in the format:
// "table[k1:v1 k2:v2 ...]". // "table[k1:v1 h2:v2 ...]".
func (t *Table[K, V]) String() string { func (t Table[K, V]) String() string {
var sb strings.Builder var sb strings.Builder
sb.WriteString("table[") sb.WriteString("table[")
@@ -238,13 +158,13 @@ func (t *Table[K, V]) String() string {
return sb.String() return sb.String()
} }
// NewCustom creates a [Table] with custom [Hash] and [EqualFunc] // NewCustomTable creates a [Table] with custom [Hash] and [EqualFunc]
// functions, along with any [Option] the user provides. // functions, along with any [Option] the user provides.
func NewCustom[K, V any](hashA, hashB Hash[K], compare EqualFunc[K], options ...Option) *Table[K, V] { func NewCustomTable[K, V any](hashA, hashB Hash[K], compare EqualFunc[K], options ...Option) *Table[K, V] {
settings := &settings{ settings := &settings{
growthFactor: DefaultGrowthFactor, growthFactor: DefaultGrowthFactor,
bucketSize: DefaultCapacity, bucketSize: DefaultCapacity,
minLoadFactor: defaultMinimumLoad, minLoadFactor: DefaultMinimumLoad,
} }
for _, option := range options { for _, option := range options {
@@ -254,8 +174,8 @@ func NewCustom[K, V any](hashA, hashB Hash[K], compare EqualFunc[K], options ...
return &Table[K, V]{ return &Table[K, V]{
growthFactor: settings.growthFactor, growthFactor: settings.growthFactor,
minLoadFactor: settings.minLoadFactor, minLoadFactor: settings.minLoadFactor,
tableA: newSubtable[K, V](settings.bucketSize, hashA, compare), bucketA: newBucket[K, V](settings.bucketSize, hashA, compare),
tableB: newSubtable[K, V](settings.bucketSize, hashB, compare), bucketB: newBucket[K, V](settings.bucketSize, hashB, compare),
} }
} }
@@ -263,10 +183,10 @@ func pipe[X, Y, Z any](a func(X) Y, b func(Y) Z) func(X) Z {
return func(x X) Z { return b(a(x)) } return func(x X) Z { return b(a(x)) }
} }
// NewBy creates a [Table] for any key type by using keyFunc to derive a // NewTableBy creates a [Table] for any key type by using keyFunc to derive a
// comparable key. Two keys with the same derived key are treated as equal. // comparable key. Two keys with the same derived key are treated as equal.
func NewBy[K, V any, C comparable](keyFunc func(K) C, options ...Option) *Table[K, V] { func NewTableBy[K, V any, C comparable](keyFunc func(K) C, options ...Option) *Table[K, V] {
return NewCustom[K, V]( return NewCustomTable[K, V](
pipe(keyFunc, NewDefaultHash[C]()), pipe(keyFunc, NewDefaultHash[C]()),
pipe(keyFunc, NewDefaultHash[C]()), pipe(keyFunc, NewDefaultHash[C]()),
func(a, b K) bool { return keyFunc(a) == keyFunc(b) }, func(a, b K) bool { return keyFunc(a) == keyFunc(b) },
@@ -274,10 +194,10 @@ func NewBy[K, V any, C comparable](keyFunc func(K) C, options ...Option) *Table[
) )
} }
// New creates a [Table] using the default [Hash] and [EqualFunc]. Use // NewTable creates a [Table] using the default [Hash] and [EqualFunc]. Use
// the [Option] functions to configure its behavior. Note that this constructor // the [Option] functions to configure its behavior. Note that this constructor
// is only provided for comparable keys. For arbitrary keys, consider // is only provided for comparable keys. For arbitrary keys, consider
// [NewBy] or [NewCustom]. // [NewTableBy] or [NewCustomTable].
func New[K comparable, V any](options ...Option) *Table[K, V] { func NewTable[K comparable, V any](options ...Option) *Table[K, V] {
return NewCustom[K, V](NewDefaultHash[K](), NewDefaultHash[K](), DefaultEqualFunc[K], options...) return NewCustomTable[K, V](NewDefaultHash[K](), NewDefaultHash[K](), DefaultEqualFunc[K], options...)
} }