filer_http: support uploading file with offset

weed/server/filer_server_handlers_write_autochunk.go

@@ -126,10 +126,6 @@ func (fs *FilerServer) doPutAutoChunk(ctx context.Context, w http.ResponseWriter
 	return
 }
 
-func isAppend(r *http.Request) bool {
-	return r.URL.Query().Get("op") == "append"
-}
-
 func (fs *FilerServer) saveMetaData(ctx context.Context, r *http.Request, fileName string, contentType string, so *operation.StorageOption, md5bytes []byte, fileChunks []*filer_pb.FileChunk, chunkOffset int64, content []byte) (filerResult *FilerPostResult, replyerr error) {
 
 	// detect file mode
@@ -161,8 +157,11 @@ func (fs *FilerServer) saveMetaData(ctx context.Context, r *http.Request, fileNa
 
 	var entry *filer.Entry
 	var mergedChunks []*filer_pb.FileChunk
+
+	isAppend := r.URL.Query().Get("op") == "append"
+	isOffsetWrite := fileChunks[0].Offset > 0
 	// when it is an append
-	if isAppend(r) {
+	if isAppend || isOffsetWrite {
 		existingEntry, findErr := fs.filer.FindEntry(ctx, util.FullPath(path))
 		if findErr != nil && findErr != filer_pb.ErrNotFound {
 			glog.V(0).Infof("failing to find %s: %v", path, findErr)
@@ -173,11 +172,13 @@ func (fs *FilerServer) saveMetaData(ctx context.Context, r *http.Request, fileNa
 		entry.Mtime = time.Now()
 		entry.Md5 = nil
 		// adjust chunk offsets
-		for _, chunk := range fileChunks {
-			chunk.Offset += int64(entry.FileSize)
+		if isAppend {
+			for _, chunk := range fileChunks {
+				chunk.Offset += int64(entry.FileSize)
+			}
+			entry.FileSize += uint64(chunkOffset)
 		}
 		mergedChunks = append(entry.Chunks, fileChunks...)
-		entry.FileSize += uint64(chunkOffset)
 
 		// TODO
 		if len(entry.Content) > 0 {
@@ -215,6 +216,10 @@ func (fs *FilerServer) saveMetaData(ctx context.Context, r *http.Request, fileNa
 		return
 	}
 	entry.Chunks = mergedChunks
+	if isOffsetWrite {
+		entry.Md5 = nil
+		entry.FileSize = entry.Size()
+	}
 
 	filerResult = &FilerPostResult{
 		Name: fileName,

weed/server/filer_server_handlers_write_upload.go

@@ -3,10 +3,12 @@ package weed_server
 import (
 	"bytes"
 	"crypto/md5"
+	"fmt"
 	"hash"
 	"io"
 	"net/http"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -28,6 +30,22 @@ var bufPool = sync.Pool{
 }
 
 func (fs *FilerServer) uploadReaderToChunks(w http.ResponseWriter, r *http.Request, reader io.Reader, chunkSize int32, fileName, contentType string, contentLength int64, so *operation.StorageOption) (fileChunks []*filer_pb.FileChunk, md5Hash hash.Hash, chunkOffset int64, uploadErr error, smallContent []byte) {
+	query := r.URL.Query()
+	isAppend := query.Get("op") == "append"
+
+	if query.Has("offset") {
+		offset := query.Get("offset")
+		offsetInt, err := strconv.ParseInt(offset, 10, 64)
+		if err != nil || offsetInt < 0 {
+			err = fmt.Errorf("invalid 'offset': '%s'", offset)
+			return nil, nil, 0, err, nil
+		}
+		if isAppend && offsetInt > 0 {
+			err = fmt.Errorf("cannot set offset when op=append")
+			return nil, nil, 0, err, nil
+		}
+		chunkOffset = offsetInt
+	}
 
 	md5Hash = md5.New()
 	var partReader = io.NopCloser(io.TeeReader(reader, md5Hash))
@@ -63,7 +81,7 @@ func (fs *FilerServer) uploadReaderToChunks(w http.ResponseWriter, r *http.Reque
 			bytesBufferLimitCond.Signal()
 			break
 		}
-		if chunkOffset == 0 && !isAppend(r) {
+		if chunkOffset == 0 && !isAppend {
 			if dataSize < fs.option.SaveToFilerLimit || strings.HasPrefix(r.URL.Path, filer.DirectoryEtcRoot) {
 				chunkOffset += dataSize
 				smallContent = make([]byte, dataSize)