Method CopyObjectPart

cmd/disk-cache.go:1116–1156

CopyObjectPart behaves similar to PutObjectPart - caches part to upload dir if writethrough mode is enabled.

(ctx context.Context, srcBucket, srcObject, dstBucket, dstObject, uploadID string, partID int, startOffset int64, length int64, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions)

// CopyObjectPart behaves similar to PutObjectPart - caches part to upload dir if writethrough mode is enabled.
func (c *cacheObjects) CopyObjectPart(ctx context.Context, srcBucket, srcObject, dstBucket, dstObject, uploadID string, partID int, startOffset int64, length int64, srcInfo ObjectInfo, srcOpts, dstOpts ObjectOptions) (pi PartInfo, e error) {
	copyObjectPartFn := c.InnerCopyObjectPartFn
	dcache, err := c.getCacheToLoc(ctx, dstBucket, dstObject)
	if err != nil {
		// disk cache could not be located,execute backend call.
		return copyObjectPartFn(ctx, srcBucket, srcObject, dstBucket, dstObject, uploadID, partID, startOffset, length, srcInfo, srcOpts, dstOpts)
	}

	if !c.commitWritethrough && !c.commitWriteback {
		return copyObjectPartFn(ctx, srcBucket, srcObject, dstBucket, dstObject, uploadID, partID, startOffset, length, srcInfo, srcOpts, dstOpts)
	}
	if err := dcache.uploadIDExists(dstBucket, dstObject, uploadID); err != nil {
		return copyObjectPartFn(ctx, srcBucket, srcObject, dstBucket, dstObject, uploadID, partID, startOffset, length, srcInfo, srcOpts, dstOpts)
	}
	partInfo, err := copyObjectPartFn(ctx, srcBucket, srcObject, dstBucket, dstObject, uploadID, partID, startOffset, length, srcInfo, srcOpts, dstOpts)
	if err != nil {
		return pi, toObjectErr(err, dstBucket, dstObject)
	}
	go func() {
		isSuffixLength := false
		if startOffset < 0 {
			isSuffixLength = true
		}

		rs := &HTTPRangeSpec{
			IsSuffixLength: isSuffixLength,
			Start:          startOffset,
			End:            startOffset + length,
		}
		// fill cache in the background
		bReader, bErr := c.InnerGetObjectNInfoFn(GlobalContext, srcBucket, srcObject, rs, http.Header{}, readLock, ObjectOptions{})
		if bErr != nil {
			return
		}
		defer bReader.Close()
		// avoid cache overwrite if another background routine filled cache
		dcache.PutObjectPart(GlobalContext, dstBucket, dstObject, uploadID, partID, bReader, length, ObjectOptions{UserDefined: getMetadata(bReader.ObjInfo)})
	}()
	// Success.
	return partInfo, nil
}

// CompleteMultipartUpload - completes multipart upload operation on the backend. If writethrough mode is enabled, this also
// finalizes the upload saved in cache multipart dir.