66 lines
1.3 KiB
Go
66 lines
1.3 KiB
Go
/*
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Copyright 2019 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package generator
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import "sort"
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type edge struct {
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from string
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to string
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}
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func transitiveClosure(in map[string][]string) map[string][]string {
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adj := make(map[edge]bool)
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imports := make(map[string]struct{})
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for from, tos := range in {
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for _, to := range tos {
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adj[edge{from, to}] = true
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imports[to] = struct{}{}
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}
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}
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// Warshal's algorithm
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for k := range in {
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for i := range in {
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if !adj[edge{i, k}] {
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continue
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}
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for j := range imports {
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if adj[edge{i, j}] {
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continue
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}
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if adj[edge{k, j}] {
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adj[edge{i, j}] = true
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}
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}
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}
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}
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out := make(map[string][]string, len(in))
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for i := range in {
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for j := range imports {
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if adj[edge{i, j}] {
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out[i] = append(out[i], j)
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}
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}
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sort.Strings(out[i])
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}
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return out
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}
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