Test for hardlink support on Windows before doing it.

pkg/runtime/depot.go

@@ -51,10 +51,11 @@ func (e ErrVolumeMismatch) Error() string {
 }
 
 type depot struct {
-	config    depotConfig
-	depotPath string
-	artifacts map[strfmt.UUID]struct{}
-	fsMutex   *sync.Mutex
+	config            depotConfig
+	depotPath         string
+	artifacts         map[strfmt.UUID]struct{}
+	fsMutex           *sync.Mutex
+	supportsHardLinks bool
 }
 
 func newDepot(runtimePath string) (*depot, error) {
@@ -74,9 +75,10 @@ func newDepot(runtimePath string) (*depot, error) {
 		config: depotConfig{
 			Deployments: map[strfmt.UUID][]deployment{},
 		},
-		depotPath: depotPath,
-		artifacts: map[strfmt.UUID]struct{}{},
-		fsMutex:   &sync.Mutex{},
+		depotPath:         depotPath,
+		artifacts:         map[strfmt.UUID]struct{}{},
+		fsMutex:           &sync.Mutex{},
+		supportsHardLinks: supportsHardLinks(depotPath),
 	}
 
 	if !fileutils.TargetExists(depotPath) {
@@ -146,6 +148,10 @@ func (d *depot) Put(id strfmt.UUID) error {
 
 // DeployViaLink will take an artifact from the depot and link it to the target path.
 func (d *depot) DeployViaLink(id strfmt.UUID, relativeSrc, absoluteDest string) error {
+	if !d.supportsHardLinks {
+		return d.DeployViaCopy(id, relativeSrc, absoluteDest)
+	}
+
 	d.fsMutex.Lock()
 	defer d.fsMutex.Unlock()
 

pkg/runtime/links_unix.go

@@ -0,0 +1,5 @@
+package runtime
+
+func supportsHardLinks(path string) bool {
+	return true
+}

pkg/runtime/links_windows.go

@@ -0,0 +1,70 @@
+package runtime
+
+import (
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/ActiveState/cli/internal/fileutils"
+	"github.com/ActiveState/cli/internal/logging"
+	"github.com/ActiveState/cli/internal/multilog"
+	"github.com/ActiveState/cli/internal/smartlink"
+)
+
+const linkTarget = "__target__"
+const link = "__link__"
+
+func supportsHardLinks(path string) (supported bool) {
+	logging.Debug("Determining if hard links are supported for drive associated with '%s'", path)
+	defer func() {
+		log := "Yes they are"
+		if !supported {
+			log = "No they are not"
+		}
+		logging.Debug(log)
+	}()
+
+	target := filepath.Join(path, linkTarget)
+	if !fileutils.TargetExists(target) {
+		err := fileutils.Touch(target)
+		if err != nil {
+			multilog.Error("Error touching target: %v", err)
+			return false
+		}
+	}
+
+	lnk := filepath.Join(path, link)
+	if !fileutils.TargetExists(target) {
+		err := smartlink.LinkContents(target, lnk)
+		if err != nil {
+			multilog.Error("Error creating link: %v", err)
+			return false
+		}
+	}
+
+	infoTarget, err := os.Stat(target)
+	if err != nil {
+		multilog.Error("Error reading target: %v", err)
+		return false
+	}
+
+	infoLink, err := os.Stat(lnk)
+	if err != nil {
+		multilog.Error("Error reading link: %v", err)
+		return false
+	}
+
+	statTarget, ok := infoTarget.Sys().(*syscall.Stat_t)
+	if !ok {
+		multilog.Error("Error casting target info")
+		return false
+	}
+
+	statLink, ok := infoLink.Sys().(*syscall.Stat_t)
+	if !ok {
+		multilog.Error("Error casting link info")
+		return false
+	}
+
+	return statTarget.Dev == statLink.Dev && statTarget.Ino == statLink.Ino
+}