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51 lines
1.0 KiB
51 lines
1.0 KiB
package yamldb
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import (
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"github.com/pkg/errors"
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"io/ioutil"
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"os"
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"sync"
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log "github.com/sirupsen/logrus"
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)
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// YamlDB represents a YAML file database instance
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type YamlDB struct {
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Path string
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PathNew string
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lock sync.Mutex
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}
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// Transaction executes the given callback and safely saves
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// the data after they are modified within the callback
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func (db *YamlDB) Transaction(callback func() bool, marshaller func() ([]byte, error)) error {
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log.Debug("Enter transaction")
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db.lock.Lock()
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defer func() {
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db.lock.Unlock()
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log.Debug("Exit transaction")
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}()
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isDataChanged := callback()
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if isDataChanged {
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yamlData, err := marshaller()
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log.Debugf("Marshalled YAML: %#v", string(yamlData))
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if err != nil {
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return errors.Wrap(err, "Data marshalling error")
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}
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err = ioutil.WriteFile(db.PathNew, yamlData, 0644)
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if err != nil {
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return errors.Wrap(err, "YamlDB write failure")
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}
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err = os.Rename(db.PathNew, db.Path)
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if err != nil {
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return errors.Wrap(err, "Couldn't rewrite an old YamlDB file")
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}
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}
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return nil
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}
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