git-lfs/lfs/gitscanner_catfilebatchcheck.go
Lars Schneider 5bb498f0c2 move git cat-file invocation to git package using gitNoLFSBuffered
The only side effect of this refactoring should be that the Git LFS
is disabled for the Git subprocess. No other functional changes are
intended.
2017-08-22 19:34:29 +02:00

115 lines
2.5 KiB
Go

package lfs
import (
"bufio"
"fmt"
"io/ioutil"
"strconv"
"github.com/git-lfs/git-lfs/git"
)
// runCatFileBatchCheck uses 'git cat-file --batch-check' to get the type and
// size of a git object. Any object that isn't of type blob and under the
// blobSizeCutoff will be ignored, unless it's a locked file. revs is a channel
// over which strings containing git sha1s will be sent. It returns a channel
// from which sha1 strings can be read.
func runCatFileBatchCheck(smallRevCh chan string, lockableCh chan string, lockableSet *lockableNameSet, revs *StringChannelWrapper, errCh chan error) error {
cmd, err := git.CatFile()
if err != nil {
return err
}
go func() {
scanner := &catFileBatchCheckScanner{s: bufio.NewScanner(cmd.Stdout), limit: blobSizeCutoff}
for r := range revs.Results {
cmd.Stdin.Write([]byte(r + "\n"))
hasNext := scanner.Scan()
if err := scanner.Err(); err != nil {
errCh <- err
} else if b := scanner.LFSBlobOID(); len(b) > 0 {
smallRevCh <- b
} else if b := scanner.GitBlobOID(); len(b) > 0 {
if name, ok := lockableSet.Check(b); ok {
lockableCh <- name
}
}
if !hasNext {
break
}
}
if err := revs.Wait(); err != nil {
errCh <- err
}
cmd.Stdin.Close()
stderr, _ := ioutil.ReadAll(cmd.Stderr)
err := cmd.Wait()
if err != nil {
errCh <- fmt.Errorf("Error in git cat-file --batch-check: %v %v", err, string(stderr))
}
close(smallRevCh)
close(errCh)
}()
return nil
}
type catFileBatchCheckScanner struct {
s *bufio.Scanner
limit int
lfsBlobOID string
gitBlobOID string
}
func (s *catFileBatchCheckScanner) LFSBlobOID() string {
return s.lfsBlobOID
}
func (s *catFileBatchCheckScanner) GitBlobOID() string {
return s.gitBlobOID
}
func (s *catFileBatchCheckScanner) Err() error {
return s.s.Err()
}
func (s *catFileBatchCheckScanner) Scan() bool {
lfsBlobSha, gitBlobSha, hasNext := s.next()
s.lfsBlobOID = lfsBlobSha
s.gitBlobOID = gitBlobSha
return hasNext
}
func (s *catFileBatchCheckScanner) next() (string, string, bool) {
hasNext := s.s.Scan()
line := s.s.Text()
lineLen := len(line)
// Format is:
// <sha1> <type> <size>
// type is at a fixed spot, if we see that it's "blob", we can avoid
// splitting the line just to get the size.
if lineLen < 46 {
return "", "", hasNext
}
if line[41:45] != "blob" {
return "", "", hasNext
}
size, err := strconv.Atoi(line[46:lineLen])
if err != nil {
return "", "", hasNext
}
blobSha := line[0:40]
if size >= s.limit {
return "", blobSha, hasNext
}
return blobSha, "", hasNext
}