Vendor opengcs and hcsshim

Signed-off-by: Darren Stahl <darst@microsoft.com>

vendor/github.com/Microsoft/opengcs/client/utilities.go

@@ -0,0 +1,99 @@
+// +build windows
+
+package client
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	modkernel32   = syscall.NewLazyDLL("kernel32.dll")
+	procCopyFileW = modkernel32.NewProc("CopyFileW")
+)
+
+// writeFileFromReader writes an output file from an io.Reader
+func writeFileFromReader(path string, reader io.Reader, timeoutSeconds int, context string) (int64, error) {
+	outFile, err := os.Create(path)
+	if err != nil {
+		return 0, fmt.Errorf("opengcs: writeFileFromReader: failed to create %s: %s", path, err)
+	}
+	defer outFile.Close()
+	return copyWithTimeout(outFile, reader, 0, timeoutSeconds, context)
+}
+
+// copyWithTimeout is a wrapper for io.Copy using a timeout duration
+func copyWithTimeout(dst io.Writer, src io.Reader, size int64, timeoutSeconds int, context string) (int64, error) {
+	logrus.Debugf("opengcs: copywithtimeout: size %d: timeout %d: (%s)", size, timeoutSeconds, context)
+
+	type resultType struct {
+		err   error
+		bytes int64
+	}
+
+	done := make(chan resultType, 1)
+	go func() {
+		result := resultType{}
+		result.bytes, result.err = io.Copy(dst, src)
+		done <- result
+	}()
+
+	var result resultType
+	timedout := time.After(time.Duration(timeoutSeconds) * time.Second)
+
+	select {
+	case <-timedout:
+		return 0, fmt.Errorf("opengcs: copyWithTimeout: timed out (%s)", context)
+	case result = <-done:
+		if result.err != nil && result.err != io.EOF {
+			// See https://github.com/golang/go/blob/f3f29d1dea525f48995c1693c609f5e67c046893/src/os/exec/exec_windows.go for a clue as to why we are doing this :)
+			if se, ok := result.err.(syscall.Errno); ok {
+				const (
+					errNoData     = syscall.Errno(232)
+					errBrokenPipe = syscall.Errno(109)
+				)
+				if se == errNoData || se == errBrokenPipe {
+					logrus.Debugf("opengcs: copyWithTimeout: hit NoData or BrokenPipe: %d: %s", se, context)
+					return result.bytes, nil
+				}
+			}
+			return 0, fmt.Errorf("opengcs: copyWithTimeout: error reading: '%s' after %d bytes (%s)", result.err, result.bytes, context)
+		}
+	}
+	logrus.Debugf("opengcs: copyWithTimeout: success - copied %d bytes (%s)", result.bytes, context)
+	return result.bytes, nil
+}
+
+// CopyFile is a utility for copying a file - used for the sandbox cache.
+// Uses CopyFileW win32 API for performance
+func CopyFile(srcFile, destFile string, overwrite bool) error {
+	var bFailIfExists uint32 = 1
+	if overwrite {
+		bFailIfExists = 0
+	}
+
+	lpExistingFileName, err := syscall.UTF16PtrFromString(srcFile)
+	if err != nil {
+		return err
+	}
+	lpNewFileName, err := syscall.UTF16PtrFromString(destFile)
+	if err != nil {
+		return err
+	}
+	r1, _, err := syscall.Syscall(
+		procCopyFileW.Addr(),
+		3,
+		uintptr(unsafe.Pointer(lpExistingFileName)),
+		uintptr(unsafe.Pointer(lpNewFileName)),
+		uintptr(bFailIfExists))
+	if r1 == 0 {
+		return fmt.Errorf("failed CopyFileW Win32 call from '%s' to '%s': %s", srcFile, destFile, err)
+	}
+	return nil
+}