package backup import ( "code.laria.me/petrific/cache" "code.laria.me/petrific/fs" "code.laria.me/petrific/objects" "code.laria.me/petrific/storage" "io" "runtime" "sort" "time" ) type filesLast []fs.File func (fl filesLast) Len() int { return len(fl) } func (fl filesLast) Less(i, j int) bool { return fl[i].Type() != fs.FFile && fl[j].Type() == fs.FFile } func (fl filesLast) Swap(i, j int) { fl[i], fl[j] = fl[j], fl[i] } type writeFileTaskResult struct { file fs.RegularFile file_id objects.ObjectId err error } type writeFileTask struct { file fs.RegularFile result *chan writeFileTaskResult } func (task writeFileTask) process(store storage.Storage) { var result writeFileTaskResult result.file = task.file rwc, err := task.file.Open() if err != nil { result.err = err *(task.result) <- result return } defer rwc.Close() result.file_id, result.err = WriteFile(store, rwc) *(task.result) <- result } type writeDirProcess struct { queue chan writeFileTask store storage.Storage } func (proc writeDirProcess) worker() { for task := range proc.queue { task.process(proc.store) } } func (proc writeDirProcess) enqueue(file fs.RegularFile, result *chan writeFileTaskResult) { go func() { proc.queue <- writeFileTask{file, result} }() } func (proc writeDirProcess) stop() { close(proc.queue) } func WriteDir( store storage.Storage, abspath string, d fs.Dir, pcache cache.Cache, ) (objects.ObjectId, error) { proc := writeDirProcess{ make(chan writeFileTask), store, } defer proc.stop() for i := 0; i < runtime.NumCPU(); i++ { go proc.worker() } return proc.writeDir(abspath, d, pcache) } func (proc writeDirProcess) writeDir( abspath string, d fs.Dir, pcache cache.Cache, ) (objects.ObjectId, error) { _children, err := d.Readdir() if err != nil { return objects.ObjectId{}, err } file_results := make(chan writeFileTaskResult) wait_for_files := 0 // fs.FFile entries must be processed at the end, since they are processed concurrently and might otherwise lock us up children := filesLast(_children) sort.Sort(children) infos := make(objects.Tree) for _, c := range children { var info objects.TreeEntry = nil switch c.Type() { case fs.FFile: mtime, file_id, ok := pcache.PathUpdated(abspath) if !ok || mtime.Before(c.ModTime()) { // According to cache the file was changed proc.enqueue(c.(fs.RegularFile), &file_results) wait_for_files++ } else { info = objects.NewTreeEntryFile(file_id, c.Executable()) } case fs.FDir: subtree_id, err := proc.writeDir(abspath+"/"+c.Name(), c.(fs.Dir), pcache) if err != nil { return objects.ObjectId{}, err } info = objects.NewTreeEntryDir(subtree_id, c.Executable()) case fs.FSymlink: target, err := c.(fs.Symlink).Readlink() if err != nil { return objects.ObjectId{}, err } info = objects.NewTreeEntrySymlink(target, c.Executable()) } if info != nil { infos[c.Name()] = info } } for ; wait_for_files > 0; wait_for_files-- { result := <-file_results if result.err != nil { err = result.err wait_for_files-- break } pcache.SetPathUpdated(abspath+"/"+result.file.Name(), result.file.ModTime(), result.file_id) infos[result.file.Name()] = objects.NewTreeEntryFile(result.file_id, result.file.Executable()) } for ; wait_for_files > 0; wait_for_files-- { // Drain remaining results in case of error <-file_results } if err != nil { return objects.ObjectId{}, err } return storage.SetObject(proc.store, objects.ToRawObject(infos)) } const BlobChunkSize = 16 * 1024 * 1024 // 16MB func WriteFile(store storage.Storage, r io.Reader) (objects.ObjectId, error) { // Right now we will create the file as fixed chunks of size BlobChunkSize // It Would be more efficient to use a dynamic/content aware chunking method but this can be added later. // The way files are serialized allows for any chunk size and addition of more properties in the future while staying compatible fragments := make(objects.File, 0) read_buf := make([]byte, BlobChunkSize) for { n, err := io.ReadFull(r, read_buf) if err == nil || err == io.ErrUnexpectedEOF { content := objects.Blob(read_buf[:n]) blob_id, err := storage.SetObject(store, objects.ToRawObject(&content)) if err != nil { return objects.ObjectId{}, err } fragments = append(fragments, objects.FileFragment{Blob: blob_id, Size: uint64(n)}) } else if err == io.EOF { break } else { return objects.ObjectId{}, err } } return storage.SetObject(store, objects.ToRawObject(&fragments)) } func CreateSnapshot( store storage.Storage, tree_id objects.ObjectId, date time.Time, archive string, comment string, ) (objects.ObjectId, error) { return storage.SetObject(store, objects.ToRawObject(&objects.Snapshot{ Tree: tree_id, Date: date, Archive: archive, Comment: comment, })) }