1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
|
package filetree
import (
"fmt"
"github.com/satori/go.uuid"
"github.com/sirupsen/logrus"
"sort"
"strings"
)
const (
newLine = "\n"
noBranchSpace = " "
branchSpace = "│ "
middleItem = "├─"
lastItem = "└─"
whiteoutPrefix = ".wh."
doubleWhiteoutPrefix = ".wh..wh.."
uncollapsedItem = "─ "
collapsedItem = "⊕ "
)
// FileTree represents a set of files, directories, and their relations.
type FileTree struct {
Root *FileNode
Size int
FileSize uint64
Name string
Id uuid.UUID
}
// NewFileTree creates an empty FileTree
func NewFileTree() (tree *FileTree) {
tree = new(FileTree)
tree.Size = 0
tree.Root = new(FileNode)
tree.Root.Tree = tree
tree.Root.Children = make(map[string]*FileNode)
tree.Id = uuid.Must(uuid.NewV4())
return tree
}
// renderParams is a representation of a FileNode in the context of the greater tree. All
// data stored is necessary for rendering a single line in a tree format.
type renderParams struct {
node *FileNode
spaces []bool
childSpaces []bool
showCollapsed bool
isLast bool
}
// renderStringTreeBetween returns a string representing the given tree between the given rows. Since each node
// is rendered on its own line, the returned string shows the visible nodes not affected by a collapsed parent.
func (tree *FileTree) renderStringTreeBetween(startRow, stopRow int, showAttributes bool) string {
// generate a list of nodes to render
var params = make([]renderParams, 0)
var result string
// visit from the front of the list
var paramsToVisit = []renderParams{{node: tree.Root, spaces: []bool{}, showCollapsed: false, isLast: false}}
for currentRow := 0; len(paramsToVisit) > 0 && currentRow <= stopRow; currentRow++ {
// pop the first node
var currentParams renderParams
currentParams, paramsToVisit = paramsToVisit[0], paramsToVisit[1:]
// take note of the next nodes to visit later
var keys []string
for key := range currentParams.node.Children {
keys = append(keys, key)
}
// we should always visit nodes in order
sort.Strings(keys)
var childParams = make([]renderParams, 0)
for idx, name := range keys {
child := currentParams.node.Children[name]
// don't visit this node...
if child.Data.ViewInfo.Hidden || currentParams.node.Data.ViewInfo.Collapsed {
continue
}
// visit this node...
isLast := idx == (len(currentParams.node.Children) - 1)
showCollapsed := child.Data.ViewInfo.Collapsed && len(child.Children) > 0
// completely copy the reference slice
childSpaces := make([]bool, len(currentParams.childSpaces))
copy(childSpaces, currentParams.childSpaces)
if len(child.Children) > 0 && !child.Data.ViewInfo.Collapsed {
childSpaces = append(childSpaces, isLast)
}
childParams = append(childParams, renderParams{
node: child,
spaces: currentParams.childSpaces,
childSpaces: childSpaces,
showCollapsed: showCollapsed,
isLast: isLast,
})
}
// keep the child nodes to visit later
paramsToVisit = append(childParams, paramsToVisit...)
// never process the root node
if currentParams.node == tree.Root {
currentRow--
continue
}
// process the current node
if currentRow >= startRow && currentRow <= stopRow {
params = append(params, currentParams)
}
}
// render the result
for idx := range params {
currentParams := params[idx]
if showAttributes {
result += currentParams.node.MetadataString() + " "
}
result += currentParams.node.renderTreeLine(currentParams.spaces, currentParams.isLast, currentParams.showCollapsed)
}
return result
}
// String returns the entire tree in an ASCII representation.
func (tree *FileTree) String(showAttributes bool) string {
return tree.renderStringTreeBetween(0, tree.Size, showAttributes)
}
// StringBetween returns a partial tree in an ASCII representation.
func (tree *FileTree) StringBetween(start, stop uint, showAttributes bool) string {
return tree.renderStringTreeBetween(int(start), int(stop), showAttributes)
}
// Copy returns a copy of the given FileTree
func (tree *FileTree) Copy() *FileTree {
newTree := NewFileTree()
newTree.Size = tree.Size
newTree.FileSize = tree.FileSize
newTree.Root = tree.Root.Copy(newTree.Root)
// update the tree pointers
newTree.VisitDepthChildFirst(func(node *FileNode) error {
node.Tree = newTree
return nil
}, nil)
return newTree
}
// Visitor is a function that processes, observes, or otherwise transforms the given node
type Visitor func(*FileNode) error
// VisitEvaluator is a function that indicates whether the given node should be visited by a Visitor.
type VisitEvaluator func(*FileNode) bool
// VisitDepthChildFirst iterates the given tree depth-first, evaluating the deepest depths first (visit on bubble up)
func (tree *FileTree) VisitDepthChildFirst(visitor Visitor, evaluator VisitEvaluator) error {
return tree.Root.VisitDepthChildFirst(visitor, evaluator)
}
// VisitDepthParentFirst iterates the given tree depth-first, evaluating the shallowest depths first (visit while sinking down)
func (tree *FileTree) VisitDepthParentFirst(visitor Visitor, evaluator VisitEvaluator) error {
return tree.Root.VisitDepthParentFirst(visitor, evaluator)
}
// Stack takes two trees and combines them together. This is done by "stacking" the given tree on top of the owning tree.
func (tree *FileTree) Stack(upper *FileTree) error {
graft := func(node *FileNode) error {
if node.IsWhiteout() {
err := tree.RemovePath(node.Path())
if err != nil {
return fmt.Errorf("cannot remove node %s: %v", node.Path(), err.Error())
}
} else {
newNode, err := tree.AddPath(node.Path(), node.Data.FileInfo)
if err != nil {
return fmt.Errorf("cannot add node %s: %v", newNode.Path(), err.Error())
}
}
return nil
}
return upper.VisitDepthChildFirst(graft, nil)
}
// GetNode fetches a single node when given a slash-delimited string from root ('/') to the desired node (e.g. '/a/node/path')
func (tree *FileTree) GetNode(path string) (*FileNode, error) {
nodeNames := strings.Split(strings.Trim(path, "/"), "/")
node := tree.Root
for _, name := range nodeNames {
if name == "" {
continue
}
if node.Children[name] == nil {
return nil, fmt.Errorf("path does not exist: %s", path)
}
node = node.Children[name]
}
return node, nil
}
// AddPath adds a new node to the tree with the given payload
func (tree *FileTree) AddPath(path string, data FileInfo) (*FileNode, error) {
nodeNames := strings.Split(strings.Trim(path, "/"), "/")
node := tree.Root
for idx, name := range nodeNames {
if name == "" {
continue
}
// find or create node
if node.Children[name] != nil {
node = node.Children[name]
} else {
// don't attach the payload. The payload is destined for the
// Path's end node, not any intermediary node.
node = node.AddChild(name, FileInfo{})
if node == nil {
// the child could not be added
return node, fmt.Errorf(fmt.Sprintf("could not add child node '%s'", name))
}
}
// attach payload to the last specified node
if idx == len(nodeNames)-1 {
node.Data.FileInfo = data
}
}
return node, nil
}
// RemovePath removes a node from the tree given its path.
func
|