44167aa47a
* upgrade k8s package version Signed-off-by: hongzhouzi <hongzhouzi@kubesphere.io> * Script upgrade and code formatting. Signed-off-by: hongzhouzi <hongzhouzi@kubesphere.io> Signed-off-by: hongzhouzi <hongzhouzi@kubesphere.io>
57 lines
1.7 KiB
Go
57 lines
1.7 KiB
Go
/*
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Copyright The ORAS 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 content
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import (
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"context"
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"fmt"
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"io"
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"github.com/containerd/containerd/remotes"
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ocispec "github.com/opencontainers/image-spec/specs-go/v1"
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)
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// MultiReader store to read content from multiple stores. It finds the content by asking each underlying
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// store to find the content, which it does based on the hash.
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//
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// Example:
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// fileStore := NewFileStore(rootPath)
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// memoryStore := NewMemoryStore()
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// // load up content in fileStore and memoryStore
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// multiStore := MultiReader([]content.Provider{fileStore, memoryStore})
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//
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// You now can use multiStore anywhere that content.Provider is accepted
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type MultiReader struct {
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stores []remotes.Fetcher
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}
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// AddStore add a store to read from
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func (m *MultiReader) AddStore(store ...remotes.Fetcher) {
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m.stores = append(m.stores, store...)
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}
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// ReaderAt get a reader
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func (m MultiReader) Fetch(ctx context.Context, desc ocispec.Descriptor) (io.ReadCloser, error) {
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for _, store := range m.stores {
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r, err := store.Fetch(ctx, desc)
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if r != nil && err == nil {
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return r, nil
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}
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}
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// we did not find any
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return nil, fmt.Errorf("not found")
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}
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