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Diffstat (limited to 'vendor/dario.cat/mergo/merge.go')
-rw-r--r-- | vendor/dario.cat/mergo/merge.go | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/vendor/dario.cat/mergo/merge.go b/vendor/dario.cat/mergo/merge.go new file mode 100644 index 0000000..0ef9b21 --- /dev/null +++ b/vendor/dario.cat/mergo/merge.go @@ -0,0 +1,409 @@ +// 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 ( + "fmt" + "reflect" +) + +func hasMergeableFields(dst reflect.Value) (exported bool) { + for i, n := 0, dst.NumField(); i < n; i++ { + field := dst.Type().Field(i) + if field.Anonymous && dst.Field(i).Kind() == reflect.Struct { + exported = exported || hasMergeableFields(dst.Field(i)) + } else if isExportedComponent(&field) { + exported = exported || len(field.PkgPath) == 0 + } + } + return +} + +func isExportedComponent(field *reflect.StructField) bool { + pkgPath := field.PkgPath + if len(pkgPath) > 0 { + return false + } + c := field.Name[0] + if 'a' <= c && c <= 'z' || c == '_' { + return false + } + return true +} + +type Config struct { + Transformers Transformers + Overwrite bool + ShouldNotDereference bool + AppendSlice bool + TypeCheck bool + overwriteWithEmptyValue bool + overwriteSliceWithEmptyValue bool + sliceDeepCopy bool + debug bool +} + +type Transformers interface { + Transformer(reflect.Type) func(dst, src reflect.Value) error +} + +// 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, config *Config) (err error) { + overwrite := config.Overwrite + typeCheck := config.TypeCheck + overwriteWithEmptySrc := config.overwriteWithEmptyValue + overwriteSliceWithEmptySrc := config.overwriteSliceWithEmptyValue + sliceDeepCopy := config.sliceDeepCopy + + 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{typ, seen, addr} + } + + if config.Transformers != nil && !isReflectNil(dst) && dst.IsValid() { + if fn := config.Transformers.Transformer(dst.Type()); fn != nil { + err = fn(dst, src) + return + } + } + + switch dst.Kind() { + case reflect.Struct: + if hasMergeableFields(dst) { + for i, n := 0, dst.NumField(); i < n; i++ { + if err = deepMerge(dst.Field(i), src.Field(i), visited, depth+1, config); err != nil { + return + } + } + } else { + if dst.CanSet() && (isReflectNil(dst) || overwrite) && (!isEmptyValue(src, !config.ShouldNotDereference) || overwriteWithEmptySrc) { + dst.Set(src) + } + } + case reflect.Map: + if dst.IsNil() && !src.IsNil() { + if dst.CanSet() { + dst.Set(reflect.MakeMap(dst.Type())) + } else { + dst = src + return + } + } + + if src.Kind() != reflect.Map { + if overwrite && dst.CanSet() { + dst.Set(src) + } + return + } + + 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.Interface, reflect.Slice: + if srcElement.IsNil() { + if overwrite { + dst.SetMapIndex(key, srcElement) + } + continue + } + fallthrough + default: + if !srcElement.CanInterface() { + continue + } + switch reflect.TypeOf(srcElement.Interface()).Kind() { + case reflect.Struct: + fallthrough + case reflect.Ptr: + fallthrough + case reflect.Map: + srcMapElm := srcElement + dstMapElm := dstElement + if srcMapElm.CanInterface() { + srcMapElm = reflect.ValueOf(srcMapElm.Interface()) + if dstMapElm.IsValid() { + dstMapElm = reflect.ValueOf(dstMapElm.Interface()) + } + } + if err = deepMerge(dstMapElm, srcMapElm, visited, depth+1, config); err != nil { + return + } + case reflect.Slice: + srcSlice := reflect.ValueOf(srcElement.Interface()) + + var dstSlice reflect.Value + if !dstElement.IsValid() || dstElement.IsNil() { + dstSlice = reflect.MakeSlice(srcSlice.Type(), 0, srcSlice.Len()) + } else { + dstSlice = reflect.ValueOf(dstElement.Interface()) + } + + if (!isEmptyValue(src, !config.ShouldNotDereference) || overwriteWithEmptySrc || overwriteSliceWithEmptySrc) && (overwrite || isEmptyValue(dst, !config.ShouldNotDereference)) && !config.AppendSlice && !sliceDeepCopy { + if typeCheck && srcSlice.Type() != dstSlice.Type() { + return fmt.Errorf("cannot override two slices with different type (%s, %s)", srcSlice.Type(), dstSlice.Type()) + } + dstSlice = srcSlice + } else if config.AppendSlice { + if srcSlice.Type() != dstSlice.Type() { + return fmt.Errorf("cannot append two slices with different type (%s, %s)", srcSlice.Type(), dstSlice.Type()) + } + dstSlice = reflect.AppendSlice(dstSlice, srcSlice) + } else if sliceDeepCopy { + i := 0 + for ; i < srcSlice.Len() && i < dstSlice.Len(); i++ { + srcElement := srcSlice.Index(i) + dstElement := dstSlice.Index(i) + + if srcElement.CanInterface() { + srcElement = reflect.ValueOf(srcElement.Interface()) + } + if dstElement.CanInterface() { + dstElement = reflect.ValueOf(dstElement.Interface()) + } + + if err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil { + return + } + } + + } + dst.SetMapIndex(key, dstSlice) + } + } + + if dstElement.IsValid() && !isEmptyValue(dstElement, !config.ShouldNotDereference) { + if reflect.TypeOf(srcElement.Interface()).Kind() == reflect.Slice { + continue + } + if reflect.TypeOf(srcElement.Interface()).Kind() == reflect.Map && reflect.TypeOf(dstElement.Interface()).Kind() == reflect.Map { + continue + } + } + + if srcElement.IsValid() && ((srcElement.Kind() != reflect.Ptr && overwrite) || !dstElement.IsValid() || isEmptyValue(dstElement, !config.ShouldNotDereference)) { + if dst.IsNil() { + dst.Set(reflect.MakeMap(dst.Type())) + } + dst.SetMapIndex(key, srcElement) + } + } + + // Ensure that all keys in dst are deleted if they are not in src. + if overwriteWithEmptySrc { + for _, key := range dst.MapKeys() { + srcElement := src.MapIndex(key) + if !srcElement.IsValid() { + dst.SetMapIndex(key, reflect.Value{}) + } + } + } + case reflect.Slice: + if !dst.CanSet() { + break + } + if (!isEmptyValue(src, !config.ShouldNotDereference) || overwriteWithEmptySrc || overwriteSliceWithEmptySrc) && (overwrite || isEmptyValue(dst, !config.ShouldNotDereference)) && !config.AppendSlice && !sliceDeepCopy { + dst.Set(src) + } else if config.AppendSlice { + if src.Type() != dst.Type() { + return fmt.Errorf("cannot append two slice with different type (%s, %s)", src.Type(), dst.Type()) + } + dst.Set(reflect.AppendSlice(dst, src)) + } else if sliceDeepCopy { + for i := 0; i < src.Len() && i < dst.Len(); i++ { + srcElement := src.Index(i) + dstElement := dst.Index(i) + if srcElement.CanInterface() { + srcElement = reflect.ValueOf(srcElement.Interface()) + } + if dstElement.CanInterface() { + dstElement = reflect.ValueOf(dstElement.Interface()) + } + + if err = deepMerge(dstElement, srcElement, visited, depth+1, config); err != nil { + return + } + } + } + case reflect.Ptr: + fallthrough + case reflect.Interface: + if isReflectNil(src) { + if overwriteWithEmptySrc && dst.CanSet() && src.Type().AssignableTo(dst.Type()) { + dst.Set(src) + } + break + } + + if src.Kind() != reflect.Interface { + if dst.IsNil() || (src.Kind() != reflect.Ptr && overwrite) { + if dst.CanSet() && (overwrite || isEmptyValue(dst, !config.ShouldNotDereference)) { + dst.Set(src) + } + } else if src.Kind() == reflect.Ptr { + if !config.ShouldNotDereference { + if err = deepMerge(dst.Elem(), src.Elem(), visited, depth+1, config); err != nil { + return + } + } else { + if overwriteWithEmptySrc || (overwrite && !src.IsNil()) || dst.IsNil() { + dst.Set(src) + } + } + } else if dst.Elem().Type() == src.Type() { + if err = deepMerge(dst.Elem(), src, visited, depth+1, config); err != nil { + return + } + } else { + return ErrDifferentArgumentsTypes + } + break + } + + if dst.IsNil() || overwrite { + if dst.CanSet() && (overwrite || isEmptyValue(dst, !config.ShouldNotDereference)) { + dst.Set(src) + } + break + } + + if dst.Elem().Kind() == src.Elem().Kind() { + if err = deepMerge(dst.Elem(), src.Elem(), visited, depth+1, config); err != nil { + return + } + break + } + default: + mustSet := (isEmptyValue(dst, !config.ShouldNotDereference) || overwrite) && (!isEmptyValue(src, !config.ShouldNotDereference) || overwriteWithEmptySrc) + if mustSet { + if dst.CanSet() { + dst.Set(src) + } else { + dst = 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{}, opts ...func(*Config)) error { + return merge(dst, src, opts...) +} + +// MergeWithOverwrite will do the same as Merge except that non-empty dst attributes will be overridden by +// non-empty src attribute values. +// Deprecated: use Merge(…) with WithOverride +func MergeWithOverwrite(dst, src interface{}, opts ...func(*Config)) error { + return merge(dst, src, append(opts, WithOverride)...) +} + +// WithTransformers adds transformers to merge, allowing to customize the merging of some types. +func WithTransformers(transformers Transformers) func(*Config) { + return func(config *Config) { + config.Transformers = transformers + } +} + +// WithOverride will make merge override non-empty dst attributes with non-empty src attributes values. +func WithOverride(config *Config) { + config.Overwrite = true +} + +// WithOverwriteWithEmptyValue will make merge override non empty dst attributes with empty src attributes values. +func WithOverwriteWithEmptyValue(config *Config) { + config.Overwrite = true + config.overwriteWithEmptyValue = true +} + +// WithOverrideEmptySlice will make merge override empty dst slice with empty src slice. +func WithOverrideEmptySlice(config *Config) { + config.overwriteSliceWithEmptyValue = true +} + +// WithoutDereference prevents dereferencing pointers when evaluating whether they are empty +// (i.e. a non-nil pointer is never considered empty). +func WithoutDereference(config *Config) { + config.ShouldNotDereference = true +} + +// WithAppendSlice will make merge append slices instead of overwriting it. +func WithAppendSlice(config *Config) { + config.AppendSlice = true +} + +// WithTypeCheck will make merge check types while overwriting it (must be used with WithOverride). +func WithTypeCheck(config *Config) { + config.TypeCheck = true +} + +// WithSliceDeepCopy will merge slice element one by one with Overwrite flag. +func WithSliceDeepCopy(config *Config) { + config.sliceDeepCopy = true + config.Overwrite = true +} + +func merge(dst, src interface{}, opts ...func(*Config)) error { + if dst != nil && reflect.ValueOf(dst).Kind() != reflect.Ptr { + return ErrNonPointerArgument + } + var ( + vDst, vSrc reflect.Value + err error + ) + + config := &Config{} + + for _, opt := range opts { + opt(config) + } + + 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, config) +} + +// IsReflectNil is the reflect value provided nil +func isReflectNil(v reflect.Value) bool { + k := v.Kind() + switch k { + case reflect.Interface, reflect.Slice, reflect.Chan, reflect.Func, reflect.Map, reflect.Ptr: + // Both interface and slice are nil if first word is 0. + // Both are always bigger than a word; assume flagIndir. + return v.IsNil() + default: + return false + } +} |