79 lines
1.8 KiB
Go
79 lines
1.8 KiB
Go
package inmem
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import (
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"github.com/hashicorp/go-memdb"
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"github.com/hashicorp/consul/proto-public/pbresource"
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)
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// Snapshot obtains a point-in-time snapshot of the store that can later be
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// persisted and restored later.
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func (s *Store) Snapshot() (*Snapshot, error) {
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tx := s.txn(false)
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iter, err := tx.Get(tableNameResources, indexNameID)
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if err != nil {
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return nil, err
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}
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return &Snapshot{iter: iter}, nil
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}
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// Snapshot is a point-in-time snapshot of a store.
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type Snapshot struct {
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iter memdb.ResultIterator
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}
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// Next returns the next resource in the snapshot. nil will be returned when
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// the end of the snapshot has been reached.
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func (s *Snapshot) Next() *pbresource.Resource {
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v := s.iter.Next()
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if v == nil {
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return nil
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}
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return v.(*pbresource.Resource)
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}
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// Restore starts the process of restoring a snapshot.
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//
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// Callers *must* call Abort or Commit when done, to free resources.
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func (s *Store) Restore() (*Restoration, error) {
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db, err := newDB()
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if err != nil {
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return nil, err
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}
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return &Restoration{
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s: s,
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db: db,
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tx: db.Txn(true),
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}, nil
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}
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// Restoration is a handle that can be used to restore a snapshot.
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type Restoration struct {
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s *Store
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db *memdb.MemDB
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tx *memdb.Txn
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}
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// Apply the given resource to the store.
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func (r *Restoration) Apply(res *pbresource.Resource) error {
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return r.tx.Insert(tableNameResources, res)
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}
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// Commit the restoration. Replaces the in-memory database wholesale and closes
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// any watches.
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func (r *Restoration) Commit() {
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r.tx.Commit()
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r.s.mu.Lock()
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defer r.s.mu.Unlock()
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r.s.db = r.db
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r.s.pub.RefreshTopic(eventTopic)
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}
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// Abort the restoration. It's safe to always call this in a defer statement
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// because aborting a committed restoration is a no-op.
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func (r *Restoration) Abort() { r.tx.Abort() }
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