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Diffstat (limited to 'vendor/github.com/imdario/mergo/merge.go')
-rw-r--r-- | vendor/github.com/imdario/mergo/merge.go | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/vendor/github.com/imdario/mergo/merge.go b/vendor/github.com/imdario/mergo/merge.go new file mode 100644 index 000000000..11e55b1e2 --- /dev/null +++ b/vendor/github.com/imdario/mergo/merge.go @@ -0,0 +1,123 @@ +// Copyright 2013 Dario Castañé. All rights reserved. +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Based on src/pkg/reflect/deepequal.go from official +// golang's stdlib. + +package mergo + +import ( + "reflect" +) + +// Traverses recursively both values, assigning src's fields values to dst. +// The map argument tracks comparisons that have already been seen, which allows +// short circuiting on recursive types. +func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, overwrite bool) (err error) { + if !src.IsValid() { + return + } + if dst.CanAddr() { + addr := dst.UnsafeAddr() + h := 17 * addr + seen := visited[h] + typ := dst.Type() + for p := seen; p != nil; p = p.next { + if p.ptr == addr && p.typ == typ { + return nil + } + } + // Remember, remember... + visited[h] = &visit{addr, typ, seen} + } + switch dst.Kind() { + case reflect.Struct: + for i, n := 0, dst.NumField(); i < n; i++ { + if err = deepMerge(dst.Field(i), src.Field(i), visited, depth+1, overwrite); err != nil { + return + } + } + case reflect.Map: + for _, key := range src.MapKeys() { + srcElement := src.MapIndex(key) + if !srcElement.IsValid() { + continue + } + dstElement := dst.MapIndex(key) + switch srcElement.Kind() { + case reflect.Chan, reflect.Func, reflect.Map, reflect.Ptr, reflect.Interface, reflect.Slice: + if srcElement.IsNil() { + continue + } + fallthrough + default: + if !srcElement.CanInterface() { + continue + } + switch reflect.TypeOf(srcElement.Interface()).Kind() { + case reflect.Struct: + fallthrough + case reflect.Ptr: + fallthrough + case reflect.Map: + if err = deepMerge(dstElement, srcElement, visited, depth+1, overwrite); err != nil { + return + } + } + } + if !isEmptyValue(srcElement) && (overwrite || (!dstElement.IsValid() || isEmptyValue(dst))) { + if dst.IsNil() { + dst.Set(reflect.MakeMap(dst.Type())) + } + dst.SetMapIndex(key, srcElement) + } + } + case reflect.Ptr: + fallthrough + case reflect.Interface: + if src.IsNil() { + break + } else if dst.IsNil() { + if dst.CanSet() && (overwrite || isEmptyValue(dst)) { + dst.Set(src) + } + } else if err = deepMerge(dst.Elem(), src.Elem(), visited, depth+1, overwrite); err != nil { + return + } + default: + if dst.CanSet() && !isEmptyValue(src) && (overwrite || isEmptyValue(dst)) { + dst.Set(src) + } + } + return +} + +// Merge will fill any empty for value type attributes on the dst struct using corresponding +// src attributes if they themselves are not empty. dst and src must be valid same-type structs +// and dst must be a pointer to struct. +// It won't merge unexported (private) fields and will do recursively any exported field. +func Merge(dst, src interface{}) error { + return merge(dst, src, false) +} + +// MergeWithOverwrite will do the same as Merge except that non-empty dst attributes will be overriden by +// non-empty src attribute values. +func MergeWithOverwrite(dst, src interface{}) error { + return merge(dst, src, true) +} + +func merge(dst, src interface{}, overwrite bool) error { + var ( + vDst, vSrc reflect.Value + err error + ) + if vDst, vSrc, err = resolveValues(dst, src); err != nil { + return err + } + if vDst.Type() != vSrc.Type() { + return ErrDifferentArgumentsTypes + } + return deepMerge(vDst, vSrc, make(map[uintptr]*visit), 0, overwrite) +} |