blob: 83031a7f507053383de86971131d780f65ceefac [file] [log] [blame]
// Copyright 2019, 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.md file.
package cmp
import "reflect"
// valueNode represents a single node within a report, which is a
// structured representation of the value tree, containing information
// regarding which nodes are equal or not.
type valueNode struct {
parent *valueNode
Type reflect.Type
ValueX reflect.Value
ValueY reflect.Value
// NumSame is the number of leaf nodes that are equal.
// All descendants are equal only if NumDiff is 0.
NumSame int
// NumDiff is the number of leaf nodes that are not equal.
NumDiff int
// NumIgnored is the number of leaf nodes that are ignored.
NumIgnored int
// NumCompared is the number of leaf nodes that were compared
// using an Equal method or Comparer function.
NumCompared int
// NumTransformed is the number of non-leaf nodes that were transformed.
NumTransformed int
// NumChildren is the number of transitive descendants of this node.
// This counts from zero; thus, leaf nodes have no descendants.
NumChildren int
// MaxDepth is the maximum depth of the tree. This counts from zero;
// thus, leaf nodes have a depth of zero.
MaxDepth int
// Records is a list of struct fields, slice elements, or map entries.
Records []reportRecord // If populated, implies Value is not populated
// Value is the result of a transformation, pointer indirect, of
// type assertion.
Value *valueNode // If populated, implies Records is not populated
// TransformerName is the name of the transformer.
TransformerName string // If non-empty, implies Value is populated
}
type reportRecord struct {
Key reflect.Value // Invalid for slice element
Value *valueNode
}
func (parent *valueNode) PushStep(ps PathStep) (child *valueNode) {
vx, vy := ps.Values()
child = &valueNode{parent: parent, Type: ps.Type(), ValueX: vx, ValueY: vy}
switch s := ps.(type) {
case StructField:
assert(parent.Value == nil)
parent.Records = append(parent.Records, reportRecord{Key: reflect.ValueOf(s.Name()), Value: child})
case SliceIndex:
assert(parent.Value == nil)
parent.Records = append(parent.Records, reportRecord{Value: child})
case MapIndex:
assert(parent.Value == nil)
parent.Records = append(parent.Records, reportRecord{Key: s.Key(), Value: child})
case Indirect:
assert(parent.Value == nil && parent.Records == nil)
parent.Value = child
case TypeAssertion:
assert(parent.Value == nil && parent.Records == nil)
parent.Value = child
case Transform:
assert(parent.Value == nil && parent.Records == nil)
parent.Value = child
parent.TransformerName = s.Name()
parent.NumTransformed++
default:
assert(parent == nil) // Must be the root step
}
return child
}
func (r *valueNode) Report(rs Result) {
assert(r.MaxDepth == 0) // May only be called on leaf nodes
if rs.ByIgnore() {
r.NumIgnored++
} else {
if rs.Equal() {
r.NumSame++
} else {
r.NumDiff++
}
}
assert(r.NumSame+r.NumDiff+r.NumIgnored == 1)
if rs.ByMethod() {
r.NumCompared++
}
if rs.ByFunc() {
r.NumCompared++
}
assert(r.NumCompared <= 1)
}
func (child *valueNode) PopStep() (parent *valueNode) {
if child.parent == nil {
return nil
}
parent = child.parent
parent.NumSame += child.NumSame
parent.NumDiff += child.NumDiff
parent.NumIgnored += child.NumIgnored
parent.NumCompared += child.NumCompared
parent.NumTransformed += child.NumTransformed
parent.NumChildren += child.NumChildren + 1
if parent.MaxDepth < child.MaxDepth+1 {
parent.MaxDepth = child.MaxDepth + 1
}
return parent
}