chunker: implementation + required fstest patch

Note: chunker implements many irrelevant methods (UserInfo, Disconnect etc),
but they are required by TestIntegration/FsCheckWrap and cannot be removed.

Dropped API methods: MergeDirs DirCacheFlush PublicLink UserInfo Disconnect OpenWriterAt

Meta formats:
- renamed old simplejson format to wdmrcompat.
- new simplejson format supports hash sums and verification of chunk size/count.

Change list:
- split-chunking overlay for mailru
- add to all
- fix linter errors
- fix integration tests
- support chunks without meta object
- fix package paths
- propagate context
- fix formatting
- implement new required wrapper interfaces
- also test large file uploads
- simplify options
- user friendly name pattern
- set default chunk size 2G
- fix building with golang 1.9
- fix ci/cd on a separate branch
- fix updated object name (SyncUTFNorm failed)
- fix panic in Box overlay
- workaround: Box rename failed if name taken
- enhance comments in unit test
- fix formatting
- embed wrapped remote rather than inherit
- require wrapped remote to support move (or copy)
- implement 3 (keep fstest)
- drop irrelevant file system interfaces
- factor out Object.mainChunk
- refactor TestLargeUpload as InternalTest
- add unit test for chunk name formats
- new improved simplejson meta format
- tricky case in test FsIsFile (fix+ignore)
- remove debugging print
- hide temporary objects from listings
- fix bugs in chunking reader:
  - return EOF immediately when all data is sent
  - handle case when wrapped remote puts by hash (bug detected by TestRcat)
- chunked file hashing (feature)
- server-side copy across configs (feature)
- robust cleanup of temporary chunks in Put
- linear download strategy (no read-ahead, feature)
- fix unexpected EOF in the box multipart uploader
- throw error if destination ignores data

backend/chunker/chunker_internal_test.go

@@ -0,0 +1,146 @@
+package chunker
+
+import (
+	"flag"
+	"fmt"
+	"testing"
+
+	"github.com/rclone/rclone/fs"
+	"github.com/rclone/rclone/fstest"
+	"github.com/rclone/rclone/fstest/fstests"
+	"github.com/stretchr/testify/assert"
+)
+
+// Command line flags
+var (
+	UploadKilobytes = flag.Int("upload-kilobytes", 0, "Upload size in Kilobytes, set this to test large uploads")
+)
+
+// test that chunking does not break large uploads
+func (f *Fs) InternalTestPutLarge(t *testing.T, kilobytes int) {
+	t.Run(fmt.Sprintf("PutLarge%dk", kilobytes), func(t *testing.T) {
+		fstests.TestPutLarge(t, f, &fstest.Item{
+			ModTime: fstest.Time("2001-02-03T04:05:06.499999999Z"),
+			Path:    fmt.Sprintf("chunker-upload-%dk", kilobytes),
+			Size:    int64(kilobytes) * int64(fs.KibiByte),
+		})
+	})
+}
+
+func (f *Fs) InternalTestChunkNameFormat(t *testing.T) {
+	savedNameFormat := f.opt.NameFormat
+	savedStartFrom := f.opt.StartFrom
+	defer func() {
+		// restore original settings
+		_ = f.parseNameFormat(savedNameFormat)
+		f.opt.StartFrom = savedStartFrom
+	}()
+	var err error
+
+	err = f.parseNameFormat("*.rclone_chunk.###")
+	assert.NoError(t, err)
+	assert.Equal(t, `%s.rclone_chunk.%03d`, f.nameFormat)
+	assert.Equal(t, `^(.+)\.rclone_chunk\.([0-9]{3,})$`, f.nameRegexp.String())
+
+	err = f.parseNameFormat("*.rclone_chunk.#")
+	assert.NoError(t, err)
+	assert.Equal(t, `%s.rclone_chunk.%d`, f.nameFormat)
+	assert.Equal(t, `^(.+)\.rclone_chunk\.([0-9]+)$`, f.nameRegexp.String())
+
+	err = f.parseNameFormat("*_chunk_#####")
+	assert.NoError(t, err)
+	assert.Equal(t, `%s_chunk_%05d`, f.nameFormat)
+	assert.Equal(t, `^(.+)_chunk_([0-9]{5,})$`, f.nameRegexp.String())
+
+	err = f.parseNameFormat("*-chunk-#")
+	assert.NoError(t, err)
+	assert.Equal(t, `%s-chunk-%d`, f.nameFormat)
+	assert.Equal(t, `^(.+)-chunk-([0-9]+)$`, f.nameRegexp.String())
+
+	err = f.parseNameFormat("_*-chunk-##,")
+	assert.NoError(t, err)
+	assert.Equal(t, `_%s-chunk-%02d,`, f.nameFormat)
+	assert.Equal(t, `^_(.+)-chunk-([0-9]{2,}),$`, f.nameRegexp.String())
+
+	err = f.parseNameFormat(`*-chunk-#-%^$()[]{}.+-!?:\/`)
+	assert.NoError(t, err)
+	assert.Equal(t, `%s-chunk-%d-%%^$()[]{}.+-!?:\/`, f.nameFormat)
+	assert.Equal(t, `^(.+)-chunk-([0-9]+)-%\^\$\(\)\[\]\{\}\.\+-!\?:\\/$`, f.nameRegexp.String())
+
+	err = f.parseNameFormat("chunk-#")
+	assert.Error(t, err)
+
+	err = f.parseNameFormat("*-chunk")
+	assert.Error(t, err)
+
+	err = f.parseNameFormat("*-*-chunk-#")
+	assert.Error(t, err)
+
+	err = f.parseNameFormat("*-chunk-#-#")
+	assert.Error(t, err)
+
+	err = f.parseNameFormat("#-chunk-*")
+	assert.Error(t, err)
+
+	err = f.parseNameFormat("*#")
+	assert.NoError(t, err)
+
+	err = f.parseNameFormat("**#")
+	assert.Error(t, err)
+	err = f.parseNameFormat("#*")
+	assert.Error(t, err)
+	err = f.parseNameFormat("")
+	assert.Error(t, err)
+	err = f.parseNameFormat("-")
+	assert.Error(t, err)
+
+	f.opt.StartFrom = 2
+	err = f.parseNameFormat("*.chunk.###")
+	assert.NoError(t, err)
+	assert.Equal(t, `%s.chunk.%03d`, f.nameFormat)
+	assert.Equal(t, `^(.+)\.chunk\.([0-9]{3,})$`, f.nameRegexp.String())
+
+	assert.Equal(t, "fish.chunk.003", f.makeChunkName("fish", 1, -1))
+	assert.Equal(t, "fish.chunk.011..tmp_0000054321", f.makeChunkName("fish", 9, 54321))
+	assert.Equal(t, "fish.chunk.011..tmp_1234567890", f.makeChunkName("fish", 9, 1234567890))
+	assert.Equal(t, "fish.chunk.1916..tmp_123456789012345", f.makeChunkName("fish", 1914, 123456789012345))
+
+	name, chunkNo, tempNo := f.parseChunkName("fish.chunk.003")
+	assert.True(t, name == "fish" && chunkNo == 1 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.004..tmp_0000000021")
+	assert.True(t, name == "fish" && chunkNo == 2 && tempNo == 21)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.021")
+	assert.True(t, name == "fish" && chunkNo == 19 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.323..tmp_1234567890123456789")
+	assert.True(t, name == "fish" && chunkNo == 321 && tempNo == 1234567890123456789)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.3")
+	assert.True(t, name == "" && chunkNo == -1 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.001")
+	assert.True(t, name == "" && chunkNo == -1 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.21")
+	assert.True(t, name == "" && chunkNo == -1 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.-21")
+	assert.True(t, name == "" && chunkNo == -1 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.004.tmp_0000000021")
+	assert.True(t, name == "" && chunkNo == -1 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.003..tmp_123456789")
+	assert.True(t, name == "" && chunkNo == -1 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.003..tmp_012345678901234567890123456789")
+	assert.True(t, name == "" && chunkNo == -1 && tempNo == -1)
+	name, chunkNo, tempNo = f.parseChunkName("fish.chunk.003..tmp_-1")
+	assert.True(t, name == "" && chunkNo == -1 && tempNo == -1)
+}
+
+func (f *Fs) InternalTest(t *testing.T) {
+	t.Run("PutLarge", func(t *testing.T) {
+		if *UploadKilobytes <= 0 {
+			t.Skip("-upload-kilobytes is not set")
+		}
+		f.InternalTestPutLarge(t, *UploadKilobytes)
+	})
+	t.Run("ChunkNameFormat", func(t *testing.T) {
+		f.InternalTestChunkNameFormat(t)
+	})
+}
+
+var _ fstests.InternalTester = (*Fs)(nil)