forgejo/services/pull/lfs.go
zeripath 5cb0c9aa0d
Propagate context and ensure git commands run in request context ()
This PR continues the work in  by progressively ensuring that git
commands run within the request context.

This now means that the if there is a git repo already open in the context it will be used instead of reopening it.

Signed-off-by: Andrew Thornton <art27@cantab.net>
2022-01-19 23:26:57 +00:00

136 lines
4.5 KiB
Go

// Copyright 2019 The Gitea Authors.
// All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package pull
import (
"bufio"
"context"
"io"
"strconv"
"sync"
"code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/git/pipeline"
"code.gitea.io/gitea/modules/lfs"
"code.gitea.io/gitea/modules/log"
)
// LFSPush pushes lfs objects referred to in new commits in the head repository from the base repository
func LFSPush(ctx context.Context, tmpBasePath, mergeHeadSHA, mergeBaseSHA string, pr *models.PullRequest) error {
// Now we have to implement git lfs push
// git rev-list --objects --filter=blob:limit=1k HEAD --not base
// pass blob shas in to git cat-file --batch-check (possibly unnecessary)
// ensure only blobs and <=1k size then pass in to git cat-file --batch
// to read each sha and check each as a pointer
// Then if they are lfs -> add them to the baseRepo
revListReader, revListWriter := io.Pipe()
shasToCheckReader, shasToCheckWriter := io.Pipe()
catFileCheckReader, catFileCheckWriter := io.Pipe()
shasToBatchReader, shasToBatchWriter := io.Pipe()
catFileBatchReader, catFileBatchWriter := io.Pipe()
errChan := make(chan error, 1)
wg := sync.WaitGroup{}
wg.Add(6)
// Create the go-routines in reverse order.
// 6. Take the output of cat-file --batch and check if each file in turn
// to see if they're pointers to files in the LFS store associated with
// the head repo and add them to the base repo if so
go createLFSMetaObjectsFromCatFileBatch(catFileBatchReader, &wg, pr)
// 5. Take the shas of the blobs and batch read them
go pipeline.CatFileBatch(ctx, shasToBatchReader, catFileBatchWriter, &wg, tmpBasePath)
// 4. From the provided objects restrict to blobs <=1k
go pipeline.BlobsLessThan1024FromCatFileBatchCheck(catFileCheckReader, shasToBatchWriter, &wg)
// 3. Run batch-check on the objects retrieved from rev-list
go pipeline.CatFileBatchCheck(ctx, shasToCheckReader, catFileCheckWriter, &wg, tmpBasePath)
// 2. Check each object retrieved rejecting those without names as they will be commits or trees
go pipeline.BlobsFromRevListObjects(revListReader, shasToCheckWriter, &wg)
// 1. Run rev-list objects from mergeHead to mergeBase
go pipeline.RevListObjects(ctx, revListWriter, &wg, tmpBasePath, mergeHeadSHA, mergeBaseSHA, errChan)
wg.Wait()
select {
case err, has := <-errChan:
if has {
return err
}
default:
}
return nil
}
func createLFSMetaObjectsFromCatFileBatch(catFileBatchReader *io.PipeReader, wg *sync.WaitGroup, pr *models.PullRequest) {
defer wg.Done()
defer catFileBatchReader.Close()
contentStore := lfs.NewContentStore()
bufferedReader := bufio.NewReader(catFileBatchReader)
buf := make([]byte, 1025)
for {
// File descriptor line: sha
_, err := bufferedReader.ReadString(' ')
if err != nil {
_ = catFileBatchReader.CloseWithError(err)
break
}
// Throw away the blob
if _, err := bufferedReader.ReadString(' '); err != nil {
_ = catFileBatchReader.CloseWithError(err)
break
}
sizeStr, err := bufferedReader.ReadString('\n')
if err != nil {
_ = catFileBatchReader.CloseWithError(err)
break
}
size, err := strconv.Atoi(sizeStr[:len(sizeStr)-1])
if err != nil {
_ = catFileBatchReader.CloseWithError(err)
break
}
pointerBuf := buf[:size+1]
if _, err := io.ReadFull(bufferedReader, pointerBuf); err != nil {
_ = catFileBatchReader.CloseWithError(err)
break
}
pointerBuf = pointerBuf[:size]
// Now we need to check if the pointerBuf is an LFS pointer
pointer, _ := lfs.ReadPointerFromBuffer(pointerBuf)
if !pointer.IsValid() {
continue
}
exist, _ := contentStore.Exists(pointer)
if !exist {
continue
}
// Then we need to check that this pointer is in the db
if _, err := models.GetLFSMetaObjectByOid(pr.HeadRepo.ID, pointer.Oid); err != nil {
if err == models.ErrLFSObjectNotExist {
log.Warn("During merge of: %d in %-v, there is a pointer to LFS Oid: %s which although present in the LFS store is not associated with the head repo %-v", pr.Index, pr.BaseRepo, pointer.Oid, pr.HeadRepo)
continue
}
_ = catFileBatchReader.CloseWithError(err)
break
}
// OK we have a pointer that is associated with the head repo
// and is actually a file in the LFS
// Therefore it should be associated with the base repo
meta := &models.LFSMetaObject{Pointer: pointer}
meta.RepositoryID = pr.BaseRepoID
if _, err := models.NewLFSMetaObject(meta); err != nil {
_ = catFileBatchReader.CloseWithError(err)
break
}
}
}