restic/internal/index/index_parallel.go

37 lines
1.1 KiB
Go

package index
import (
"context"
"runtime"
"sync"
"github.com/restic/restic/internal/restic"
)
// ForAllIndexes loads all index files in parallel and calls the given callback.
// It is guaranteed that the function is not run concurrently. If the callback
// returns an error, this function is cancelled and also returns that error.
func ForAllIndexes(ctx context.Context, repo restic.Repository,
fn func(id restic.ID, index *Index, oldFormat bool, err error) error) error {
// decoding an index can take quite some time such that this can be both CPU- or IO-bound
// as the whole index is kept in memory anyways, a few workers too much don't matter
workerCount := repo.Connections() + uint(runtime.GOMAXPROCS(0))
var m sync.Mutex
return restic.ParallelList(ctx, repo.Backend(), restic.IndexFile, workerCount, func(ctx context.Context, id restic.ID, size int64) error {
var err error
var idx *Index
oldFormat := false
buf, err := repo.LoadUnpacked(ctx, restic.IndexFile, id)
if err == nil {
idx, oldFormat, err = DecodeIndex(buf, id)
}
m.Lock()
defer m.Unlock()
return fn(id, idx, oldFormat, err)
})
}