docs: information about recommended minimum load

- This always causes errors, it should not be possible.

.claude/settings.json

@@ -0,0 +1,7 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(curl -s -w \"\\\\n---HTTP_STATUS:%{http_code}---\" https://raw.githubusercontent.com/kubernetes/kubernetes/master/.markdownlint.yaml)"
+    ]
+  }
+}

.gitea/workflows/ci.yml

@@ -39,6 +39,14 @@ jobs:
       - 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

.markdownlint.yml

@@ -0,0 +1,17 @@
+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

Makefile

@@ -1,4 +1,4 @@
-.PHONY: all help install clean test-unit test-mutation test-fuzz test docs lint-go lint-makefile lint
+.PHONY: all help install clean test-unit test-mutation test-fuzz test docs lint-go lint-makefile lint-markdown lint
 
 help: ## Show this help
 	@grep -E '^[a-zA-Z_-]+:.*##' $(MAKEFILE_LIST) | awk -F ':.*## ' '{printf "  %-15s %s\n", $$1, $$2}'
@@ -32,7 +32,10 @@ lint-go: ## Lint Go code
 lint-makefile: ## Lint the Makefile
 	checkmake Makefile
 
-lint: lint-go lint-makefile ## Lint all code
+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)"

README.md

@@ -1,3 +1,3 @@
-# go-cuckoo
+# <img height="30" src="assets/logo.svg" alt="Go Cuckoo, by `mvhutz`."> Go Cuckoo
 
-A hash table that uses cuckoo hashing to achieve a worst-case O(1) lookup time.
+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).

assets/logo.svg

@@ -0,0 +1 @@
+<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>

cuckoo_fuzz_test.go

@@ -1,7 +1,10 @@
 package cuckoo_test
 
 import (
+	"fmt"
 	"maps"
+	"math"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -26,6 +29,8 @@ type fuzzStep struct {
 
 type fuzzScenario struct {
 	seedA, seedB           uint32
+	capacity, growthFactor uint8
+	load                   float64
 	steps                  []fuzzStep
 }
 
@@ -40,14 +45,33 @@ func FuzzInsertLookup(f *testing.F) {
 			return
 		}
 
-		if scenario.seedA == scenario.seedB {
-			return
+		seedA, seedB := scenario.seedA, scenario.seedB
+		growthFactor := max(2, int(scenario.growthFactor))
+		capacity := int(scenario.capacity)
+		minimumLoad := math.Abs(math.Mod(scenario.load, 1.0))
+
+		// If they are the same number, the hashes will clash, always causing an
+		// error.
+		if seedA == seedB {
+			t.Skip()
 		}
 
+		// If the load is too high, the hashs will not be able to allocate
+		// properly.
+		if minimumLoad > 0.20 {
+			t.Skip()
+		}
+
+		fmt.Fprintf(os.Stderr, "seedA=%d seedB=%d capacity=%d growthFactor=%d minimumLoad=%f\n",
+			seedA, seedB, capacity, growthFactor, minimumLoad)
+
 		actual := cuckoo.NewCustomTable[uint32, uint32](
-			offsetHash(scenario.seedA),
-			offsetHash(scenario.seedB),
+			offsetHash(seedA),
+			offsetHash(seedB),
 			func(a, b uint32) bool { return a == b },
+			cuckoo.Capacity(capacity),
+			cuckoo.GrowthFactor(growthFactor),
+			cuckoo.MinimumLoad(minimumLoad),
 		)
 
 		expected := map[uint32]uint32{}

settings.go

@@ -1,5 +1,7 @@
 package cuckoo
 
+import "fmt"
+
 // DefaultCapacity is the initial capacity of a [Table]. It is inspired from
 // Java's [HashMap] implementation, which also uses 16.
 //
@@ -27,19 +29,34 @@ type settings struct {
 type Option func(*settings)
 
 // Capacity modifies the starting capacity of each bucket of the [Table]. The
-// value must be greater than 0.
+// value must be non-negative.
 func Capacity(value int) Option {
+	if value < 0 {
+		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.
+//
+// The higher the minimum load, the more likely that a [Table.Put] will not
+// succeed. Minimum loads above 20% are not tested.
 func MinimumLoad(value float64) Option {
+	if value < 0.00 || value > 1.00 {
+		panic(fmt.Sprintf("go-cuckoo: MinimumLoad must be between 0.00 and 1.00, got %f", value))
+	}
+
 	return func(s *settings) { s.minLoadFactor = value }
 }
 
 // GrowthFactor controls how much the capacity of the [Table] multiplies when
 // it must resize. The value must be greater than 1.
 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) }
 }