diff options
Diffstat (limited to 'vendor/github.com/imdario/mergo/map.go')
-rw-r--r-- | vendor/github.com/imdario/mergo/map.go | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/vendor/github.com/imdario/mergo/map.go b/vendor/github.com/imdario/mergo/map.go new file mode 100644 index 000000000..8e8c4ba8e --- /dev/null +++ b/vendor/github.com/imdario/mergo/map.go @@ -0,0 +1,156 @@ +// Copyright 2014 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 ( + "fmt" + "reflect" + "unicode" + "unicode/utf8" +) + +func changeInitialCase(s string, mapper func(rune) rune) string { + if s == "" { + return s + } + r, n := utf8.DecodeRuneInString(s) + return string(mapper(r)) + s[n:] +} + +func isExported(field reflect.StructField) bool { + r, _ := utf8.DecodeRuneInString(field.Name) + return r >= 'A' && r <= 'Z' +} + +// 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 deepMap(dst, src reflect.Value, visited map[uintptr]*visit, depth int, overwrite bool) (err error) { + 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} + } + zeroValue := reflect.Value{} + switch dst.Kind() { + case reflect.Map: + dstMap := dst.Interface().(map[string]interface{}) + for i, n := 0, src.NumField(); i < n; i++ { + srcType := src.Type() + field := srcType.Field(i) + if !isExported(field) { + continue + } + fieldName := field.Name + fieldName = changeInitialCase(fieldName, unicode.ToLower) + if v, ok := dstMap[fieldName]; !ok || (isEmptyValue(reflect.ValueOf(v)) || overwrite) { + dstMap[fieldName] = src.Field(i).Interface() + } + } + case reflect.Struct: + srcMap := src.Interface().(map[string]interface{}) + for key := range srcMap { + srcValue := srcMap[key] + fieldName := changeInitialCase(key, unicode.ToUpper) + dstElement := dst.FieldByName(fieldName) + if dstElement == zeroValue { + // We discard it because the field doesn't exist. + continue + } + srcElement := reflect.ValueOf(srcValue) + dstKind := dstElement.Kind() + srcKind := srcElement.Kind() + if srcKind == reflect.Ptr && dstKind != reflect.Ptr { + srcElement = srcElement.Elem() + srcKind = reflect.TypeOf(srcElement.Interface()).Kind() + } else if dstKind == reflect.Ptr { + // Can this work? I guess it can't. + if srcKind != reflect.Ptr && srcElement.CanAddr() { + srcPtr := srcElement.Addr() + srcElement = reflect.ValueOf(srcPtr) + srcKind = reflect.Ptr + } + } + if !srcElement.IsValid() { + continue + } + if srcKind == dstKind { + if err = deepMerge(dstElement, srcElement, visited, depth+1, overwrite); err != nil { + return + } + } else { + if srcKind == reflect.Map { + if err = deepMap(dstElement, srcElement, visited, depth+1, overwrite); err != nil { + return + } + } else { + return fmt.Errorf("type mismatch on %s field: found %v, expected %v", fieldName, srcKind, dstKind) + } + } + } + } + return +} + +// Map sets fields' values in dst from src. +// src can be a map with string keys or a struct. dst must be the opposite: +// if src is a map, dst must be a valid pointer to struct. If src is a struct, +// dst must be map[string]interface{}. +// It won't merge unexported (private) fields and will do recursively +// any exported field. +// If dst is a map, keys will be src fields' names in lower camel case. +// Missing key in src that doesn't match a field in dst will be skipped. This +// doesn't apply if dst is a map. +// This is separated method from Merge because it is cleaner and it keeps sane +// semantics: merging equal types, mapping different (restricted) types. +func Map(dst, src interface{}) error { + return _map(dst, src, false) +} + +// MapWithOverwrite will do the same as Map except that non-empty dst attributes will be overriden by +// non-empty src attribute values. +func MapWithOverwrite(dst, src interface{}) error { + return _map(dst, src, true) +} + +func _map(dst, src interface{}, overwrite bool) error { + var ( + vDst, vSrc reflect.Value + err error + ) + if vDst, vSrc, err = resolveValues(dst, src); err != nil { + return err + } + // To be friction-less, we redirect equal-type arguments + // to deepMerge. Only because arguments can be anything. + if vSrc.Kind() == vDst.Kind() { + return deepMerge(vDst, vSrc, make(map[uintptr]*visit), 0, overwrite) + } + switch vSrc.Kind() { + case reflect.Struct: + if vDst.Kind() != reflect.Map { + return ErrExpectedMapAsDestination + } + case reflect.Map: + if vDst.Kind() != reflect.Struct { + return ErrExpectedStructAsDestination + } + default: + return ErrNotSupported + } + return deepMap(vDst, vSrc, make(map[uintptr]*visit), 0, overwrite) +} |