diff options
Diffstat (limited to 'identity/identityhash.go')
-rw-r--r-- | identity/identityhash.go | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/identity/identityhash.go b/identity/identityhash.go new file mode 100644 index 000000000..ef7b5afa7 --- /dev/null +++ b/identity/identityhash.go @@ -0,0 +1,69 @@ +// Copyright 2023 The Hugo Authors. All rights reserved. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package identity + +import ( + "strconv" + + "github.com/mitchellh/hashstructure" +) + +// HashString returns a hash from the given elements. +// It will panic if the hash cannot be calculated. +// Note that this hash should be used primarily for identity, not for change detection as +// it in the more complex values (e.g. Page) will not hash the full content. +func HashString(vs ...any) string { + hash := HashUint64(vs...) + return strconv.FormatUint(hash, 10) +} + +// HashUint64 returns a hash from the given elements. +// It will panic if the hash cannot be calculated. +// Note that this hash should be used primarily for identity, not for change detection as +// it in the more complex values (e.g. Page) will not hash the full content. +func HashUint64(vs ...any) uint64 { + var o any + if len(vs) == 1 { + o = toHashable(vs[0]) + } else { + elements := make([]any, len(vs)) + for i, e := range vs { + elements[i] = toHashable(e) + } + o = elements + } + + hash, err := hashstructure.Hash(o, nil) + if err != nil { + panic(err) + } + return hash +} + +type keyer interface { + Key() string +} + +// For structs, hashstructure.Hash only works on the exported fields, +// so rewrite the input slice for known identity types. +func toHashable(v any) any { + switch t := v.(type) { + case Provider: + return t.GetIdentity() + case keyer: + return t.Key() + default: + return v + } +} |