/
exporter.go
60 lines (53 loc) · 1.44 KB
/
exporter.go
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package porting
import (
"context"
"fmt"
"github.com/brendoncarroll/go-state"
"github.com/brendoncarroll/go-state/cadata"
"github.com/brendoncarroll/go-state/posixfs"
"github.com/brendoncarroll/go-tai64"
"github.com/gotvc/got/pkg/gotfs"
"github.com/pkg/errors"
)
type Entry struct {
ModifiedAt tai64.TAI64N `json:"mtime"`
Root gotfs.Root `json:"root"`
}
type Cache = state.KVStore[string, Entry]
type Exporter struct {
gotfs *gotfs.Operator
cache Cache
fsx posixfs.FS
}
func NewExporter(gotfs *gotfs.Operator, cache Cache, fsx posixfs.FS) *Exporter {
return &Exporter{
gotfs: gotfs,
cache: cache,
fsx: fsx,
}
}
func (pr *Exporter) ExportFile(ctx context.Context, ms, ds cadata.Store, root gotfs.Root, p string) error {
md, err := pr.gotfs.GetInfo(ctx, ms, root, p)
if err != nil {
return err
}
mode := posixfs.FileMode(md.Mode)
if !mode.IsRegular() {
return errors.Errorf("ExportFile called for non-regular file %q: %v", p, mode)
}
// check if a file exists
if finfo, err := pr.fsx.Stat(p); err != nil && !posixfs.IsErrNotExist(err) {
return err
} else if err == nil {
if yes, err := needsUpdate(ctx, pr.cache, p, finfo); err != nil {
return err
} else if yes {
return fmt.Errorf("refusing to overwrite unknown file at path %q. current=%v", p, finfo.ModTime())
}
}
r, err := pr.gotfs.NewReader(ctx, ms, ds, root, p)
if err != nil {
return err
}
return posixfs.PutFile(ctx, pr.fsx, p, mode, r)
}