diff --git a/table.go b/table.go index 922aa81..370ec38 100644 --- a/table.go +++ b/table.go @@ -1,12 +1,21 @@ package cuckoo import ( + "errors" "fmt" "iter" "math/bits" "strings" ) +// ErrBadHash occurs when the hashes given to a [Table] cause too many key +// collisions. If you get this error, try using: +// +// 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 is hash table that uses cuckoo hashing to resolve collision. Create // one with [NewTable]. Or if you want more granularity, use [NewTableBy] or // [NewCustomTable]. @@ -128,7 +137,7 @@ func (t *Table[K, V]) Put(key K, value V) (err error) { } if t.load() < t.minLoadFactor { - return fmt.Errorf("bad hash: resize on load %d/%d = %f", t.Size(), t.TotalCapacity(), t.load()) + return fmt.Errorf("hash functions produced a cycle at load %d/%d: %w", t.Size(), t.TotalCapacity(), ErrBadHash) } if err := t.grow(); err != nil {