[#462] Implement PATCH for regular objects

Signed-off-by: Marina Biryukova <m.biryukova@yadro.com>

api/handler/patch.go

@@ -0,0 +1,186 @@
+package handler
+
+import (
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api"
+	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
+	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/errors"
+	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/layer"
+	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/middleware"
+	"go.uber.org/zap"
+)
+
+const maxPatchSize = 5 * 1024 * 1024 * 1024 // 5GB
+
+func (h *handler) PatchObjectHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	reqInfo := middleware.GetReqInfo(ctx)
+
+	if _, ok := r.Header[api.ContentRange]; !ok {
+		h.logAndSendError(w, "missing Content-Range", reqInfo, errors.GetAPIError(errors.ErrMissingContentRange))
+		return
+	}
+
+	if _, ok := r.Header[api.ContentLength]; !ok {
+		h.logAndSendError(w, "missing Content-Length", reqInfo, errors.GetAPIError(errors.ErrMissingContentLength))
+		return
+	}
+
+	conditional, err := parsePatchConditionalHeaders(r.Header)
+	if err != nil {
+		h.logAndSendError(w, "could not parse conditional headers", reqInfo, err)
+		return
+	}
+
+	bktInfo, err := h.getBucketAndCheckOwner(r, reqInfo.BucketName)
+	if err != nil {
+		h.logAndSendError(w, "could not get bucket info", reqInfo, err)
+		return
+	}
+
+	settings, err := h.obj.GetBucketSettings(ctx, bktInfo)
+	if err != nil {
+		h.logAndSendError(w, "could not get bucket settings", reqInfo, err)
+		return
+	}
+
+	srcObjPrm := &layer.HeadObjectParams{
+		Object:    reqInfo.ObjectName,
+		BktInfo:   bktInfo,
+		VersionID: reqInfo.URL.Query().Get(api.QueryVersionID),
+	}
+
+	extendedSrcObjInfo, err := h.obj.GetExtendedObjectInfo(ctx, srcObjPrm)
+	if err != nil {
+		h.logAndSendError(w, "could not find object", reqInfo, err)
+		return
+	}
+	srcObjInfo := extendedSrcObjInfo.ObjectInfo
+
+	if err = checkPreconditions(srcObjInfo, conditional, h.cfg.MD5Enabled()); err != nil {
+		h.logAndSendError(w, "precondition failed", reqInfo, err)
+		return
+	}
+
+	srcSize, err := layer.GetObjectSize(srcObjInfo)
+	if err != nil {
+		h.logAndSendError(w, "failed to get source object size", reqInfo, err)
+		return
+	}
+
+	byteRange, err := parsePatchByteRange(r.Header.Get(api.ContentRange), srcSize)
+	if err != nil {
+		h.logAndSendError(w, "could not parse byte range", reqInfo, errors.GetAPIError(errors.ErrInvalidRange), zap.Error(err))
+		return
+	}
+
+	if maxPatchSize < byteRange.End-byteRange.Start+1 {
+		h.logAndSendError(w, "byte range length is longer than allowed", reqInfo, errors.GetAPIError(errors.ErrInvalidRange), zap.Error(err))
+		return
+	}
+
+	if uint64(r.ContentLength) != (byteRange.End - byteRange.Start + 1) {
+		h.logAndSendError(w, "content-length must be equal to byte range length", reqInfo, errors.GetAPIError(errors.ErrInvalidRangeLength))
+		return
+	}
+
+	if byteRange.Start > srcSize {
+		h.logAndSendError(w, "start byte is greater than object size", reqInfo, errors.GetAPIError(errors.ErrRangeOutOfBounds))
+		return
+	}
+
+	params := &layer.PatchObjectParams{
+		Object:            srcObjInfo,
+		BktInfo:           bktInfo,
+		NewBytes:          r.Body,
+		Range:             byteRange,
+		VersioningEnabled: settings.VersioningEnabled(),
+	}
+
+	extendedObjInfo, err := h.obj.PatchObject(ctx, params)
+	if err != nil {
+		if isErrObjectLocked(err) {
+			h.logAndSendError(w, "object is locked", reqInfo, errors.GetAPIError(errors.ErrAccessDenied))
+		} else {
+			h.logAndSendError(w, "could not patch object", reqInfo, err)
+		}
+		return
+	}
+
+	w.Header().Set(api.AmzVersionID, extendedObjInfo.ObjectInfo.VersionID())
+	w.Header().Set(api.ETag, data.Quote(extendedObjInfo.ObjectInfo.ETag(h.cfg.MD5Enabled())))
+
+	resp := PatchObjectResult{
+		Object: PatchObject{
+			LastModified: extendedObjInfo.ObjectInfo.Created.UTC().Format(time.RFC3339),
+			ETag:         data.Quote(extendedObjInfo.ObjectInfo.ETag(h.cfg.MD5Enabled())),
+		},
+	}
+
+	if err = middleware.EncodeToResponse(w, resp); err != nil {
+		h.logAndSendError(w, "could not encode PatchObjectResult to response", reqInfo, err)
+		return
+	}
+}
+
+func parsePatchConditionalHeaders(headers http.Header) (*conditionalArgs, error) {
+	var err error
+	args := &conditionalArgs{
+		IfMatch: data.UnQuote(headers.Get(api.IfMatch)),
+	}
+
+	if args.IfUnmodifiedSince, err = parseHTTPTime(headers.Get(api.IfUnmodifiedSince)); err != nil {
+		return nil, err
+	}
+
+	return args, nil
+}
+
+func parsePatchByteRange(rangeStr string, objSize uint64) (*layer.RangeParams, error) {
+	const prefix = "bytes "
+
+	if rangeStr == "" {
+		return nil, fmt.Errorf("empty range")
+	}
+
+	if !strings.HasPrefix(rangeStr, prefix) {
+		return nil, fmt.Errorf("unknown unit in range header")
+	}
+
+	rangeStr, _, found := strings.Cut(strings.TrimPrefix(rangeStr, prefix), "/") // value after / is ignored
+	if !found {
+		return nil, fmt.Errorf("invalid range: %s", rangeStr)
+	}
+
+	startStr, endStr, found := strings.Cut(rangeStr, "-")
+	if !found {
+		return nil, fmt.Errorf("invalid range: %s", rangeStr)
+	}
+
+	start, err := strconv.ParseUint(startStr, 10, 64)
+	if err != nil {
+		return nil, fmt.Errorf("invalid start byte: %s", startStr)
+	}
+
+	end := objSize - 1
+	if len(endStr) > 0 {
+		end, err = strconv.ParseUint(endStr, 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("invalid end byte: %s", endStr)
+		}
+	}
+
+	if start > end {
+		return nil, fmt.Errorf("start byte is greater than end byte")
+	}
+
+	return &layer.RangeParams{
+		Start: start,
+		End:   end,
+	}, nil
+}