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package wkfscache
import (
"context"
"os"
"path/filepath"
"go4.org/wkfs"
"golang.org/x/crypto/acme/autocert"
)
type Cache string
// Get reads a certificate data from the specified file name.
func (d Cache) Get(ctx context.Context, name string) ([]byte, error) {
name = filepath.Join(string(d), name)
var (
data []byte
err error
done = make(chan struct{})
)
go func() {
data, err = wkfs.ReadFile(name)
close(done)
}()
select {
case <-ctx.Done():
return nil, ctx.Err()
case <-done:
}
if os.IsNotExist(err) {
return nil, autocert.ErrCacheMiss
}
return data, err
}
// Put writes the certificate data to the specified file name.
// The file will be created with 0600 permissions.
func (d Cache) Put(ctx context.Context, name string, data []byte) error {
if err := wkfs.MkdirAll(string(d), 0700); err != nil {
return err
}
done := make(chan struct{})
var err error
go func() {
defer close(done)
if err := wkfs.WriteFile(filepath.Join(string(d), name), data, 0600); err != nil {
return
}
// prevent overwriting the file if the context was cancelled
if ctx.Err() != nil {
return // no need to set err
}
}()
select {
case <-ctx.Done():
return ctx.Err()
case <-done:
}
return err
}
// Delete removes the specified file name.
func (d Cache) Delete(ctx context.Context, name string) error {
name = filepath.Join(string(d), name)
var (
err error
done = make(chan struct{})
)
go func() {
err = wkfs.Remove(name)
close(done)
}()
select {
case <-ctx.Done():
return ctx.Err()
case <-done:
}
if err != nil && !os.IsNotExist(err) {
return err
}
return nil
}
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