93 lines
2 KiB
Go
93 lines
2 KiB
Go
package parser
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import (
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"fmt"
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"sort"
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"strings"
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)
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// DecodeToNode converts the labels to a tree of nodes.
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// If any filters are present, labels which do not match the filters are skipped.
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func DecodeToNode(labels map[string]string, rootName string, filters ...string) (*Node, error) {
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sortedKeys := sortKeys(labels, filters)
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var node *Node
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for i, key := range sortedKeys {
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split := strings.Split(key, ".")
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if split[0] != rootName {
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return nil, fmt.Errorf("invalid label root %s", split[0])
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}
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var parts []string
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for _, v := range split {
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if v[0] == '[' {
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return nil, fmt.Errorf("invalid leading character '[' in field name (bracket is a slice delimiter): %s", v)
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}
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if strings.HasSuffix(v, "]") && v[0] != '[' {
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indexLeft := strings.Index(v, "[")
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parts = append(parts, v[:indexLeft], v[indexLeft:])
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} else {
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parts = append(parts, v)
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}
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}
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if i == 0 {
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node = &Node{}
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}
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decodeToNode(node, parts, labels[key])
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}
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return node, nil
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}
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func decodeToNode(root *Node, path []string, value string) {
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if len(root.Name) == 0 {
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root.Name = path[0]
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}
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// it's a leaf or not -> children
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if len(path) > 1 {
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if n := containsNode(root.Children, path[1]); n != nil {
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// the child already exists
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decodeToNode(n, path[1:], value)
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} else {
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// new child
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child := &Node{Name: path[1]}
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decodeToNode(child, path[1:], value)
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root.Children = append(root.Children, child)
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}
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} else {
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root.Value = value
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}
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}
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func containsNode(nodes []*Node, name string) *Node {
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for _, n := range nodes {
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if strings.EqualFold(name, n.Name) {
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return n
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}
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}
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return nil
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}
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func sortKeys(labels map[string]string, filters []string) []string {
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var sortedKeys []string
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for key := range labels {
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if len(filters) == 0 {
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sortedKeys = append(sortedKeys, key)
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continue
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}
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for _, filter := range filters {
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if len(key) >= len(filter) && strings.EqualFold(key[:len(filter)], filter) {
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sortedKeys = append(sortedKeys, key)
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continue
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}
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}
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}
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sort.Strings(sortedKeys)
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return sortedKeys
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}
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