distribution/docs/storage/filereader_test.go

194 lines
5 KiB
Go
Raw Normal View History

package storage
import (
"bytes"
"crypto/rand"
"io"
mrand "math/rand"
"os"
"testing"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/registry/storage/driver/inmemory"
)
func TestSimpleRead(t *testing.T) {
content := make([]byte, 1<<20)
n, err := rand.Read(content)
if err != nil {
t.Fatalf("unexpected error building random data: %v", err)
}
if n != len(content) {
t.Fatalf("random read did't fill buffer")
}
dgst, err := digest.FromReader(bytes.NewReader(content))
if err != nil {
t.Fatalf("unexpected error digesting random content: %v", err)
}
driver := inmemory.New()
path := "/random"
if err := driver.PutContent(path, content); err != nil {
t.Fatalf("error putting patterned content: %v", err)
}
fr, err := newFileReader(driver, path)
if err != nil {
t.Fatalf("error allocating file reader: %v", err)
}
verifier := digest.NewDigestVerifier(dgst)
io.Copy(verifier, fr)
if !verifier.Verified() {
t.Fatalf("unable to verify read data")
}
}
func TestFileReaderSeek(t *testing.T) {
driver := inmemory.New()
pattern := "01234567890ab" // prime length block
repititions := 1024
path := "/patterned"
content := bytes.Repeat([]byte(pattern), repititions)
if err := driver.PutContent(path, content); err != nil {
t.Fatalf("error putting patterned content: %v", err)
}
fr, err := newFileReader(driver, path)
if err != nil {
t.Fatalf("unexpected error creating file reader: %v", err)
}
// Seek all over the place, in blocks of pattern size and make sure we get
// the right data.
for _, repitition := range mrand.Perm(repititions - 1) {
targetOffset := int64(len(pattern) * repitition)
// Seek to a multiple of pattern size and read pattern size bytes
offset, err := fr.Seek(targetOffset, os.SEEK_SET)
if err != nil {
t.Fatalf("unexpected error seeking: %v", err)
}
if offset != targetOffset {
t.Fatalf("did not seek to correct offset: %d != %d", offset, targetOffset)
}
p := make([]byte, len(pattern))
n, err := fr.Read(p)
if err != nil {
t.Fatalf("error reading pattern: %v", err)
}
if n != len(pattern) {
t.Fatalf("incorrect read length: %d != %d", n, len(pattern))
}
if string(p) != pattern {
t.Fatalf("incorrect read content: %q != %q", p, pattern)
}
// Check offset
current, err := fr.Seek(0, os.SEEK_CUR)
if err != nil {
t.Fatalf("error checking current offset: %v", err)
}
if current != targetOffset+int64(len(pattern)) {
t.Fatalf("unexpected offset after read: %v", err)
}
}
start, err := fr.Seek(0, os.SEEK_SET)
if err != nil {
t.Fatalf("error seeking to start: %v", err)
}
if start != 0 {
t.Fatalf("expected to seek to start: %v != 0", start)
}
end, err := fr.Seek(0, os.SEEK_END)
if err != nil {
t.Fatalf("error checking current offset: %v", err)
}
if end != int64(len(content)) {
t.Fatalf("expected to seek to end: %v != %v", end, len(content))
}
// 4. Seek before start, ensure error.
// seek before start
before, err := fr.Seek(-1, os.SEEK_SET)
if err == nil {
t.Fatalf("error expected, returned offset=%v", before)
}
// 5. Seek after end,
after, err := fr.Seek(1, os.SEEK_END)
if err != nil {
t.Fatalf("unexpected error expected, returned offset=%v", after)
}
p := make([]byte, 16)
n, err := fr.Read(p)
if n != 0 {
t.Fatalf("bytes reads %d != %d", n, 0)
}
if err != io.EOF {
t.Fatalf("expected io.EOF, got %v", err)
}
}
// TestFileReaderNonExistentFile ensures the reader behaves as expected with a
// missing or zero-length remote file. While the file may not exist, the
// reader should not error out on creation and should return 0-bytes from the
// read method, with an io.EOF error.
func TestFileReaderNonExistentFile(t *testing.T) {
driver := inmemory.New()
fr, err := newFileReader(driver, "/doesnotexist")
if err != nil {
t.Fatalf("unexpected error initializing reader: %v", err)
}
var buf [1024]byte
n, err := fr.Read(buf[:])
if n != 0 {
t.Fatalf("non-zero byte read reported: %d != 0", n)
}
if err != io.EOF {
t.Fatalf("read on missing file should return io.EOF, got %v", err)
}
}
// TestLayerReadErrors covers the various error return type for different
// conditions that can arise when reading a layer.
func TestFileReaderErrors(t *testing.T) {
// TODO(stevvooe): We need to cover error return types, driven by the
// errors returned via the HTTP API. For now, here is a incomplete list:
//
// 1. Layer Not Found: returned when layer is not found or access is
// denied.
// 2. Layer Unavailable: returned when link references are unresolved,
// but layer is known to the registry.
// 3. Layer Invalid: This may more split into more errors, but should be
// returned when name or tarsum does not reference a valid error. We
// may also need something to communication layer verification errors
// for the inline tarsum check.
// 4. Timeout: timeouts to backend. Need to better understand these
// failure cases and how the storage driver propagates these errors
// up the stack.
}