buildkit/vendor/github.com/Microsoft/hcsshim/layerutils.go

112 lines
2.2 KiB
Go

package hcsshim
// This file contains utility functions to support storage (graph) related
// functionality.
import (
"path/filepath"
"syscall"
"github.com/sirupsen/logrus"
)
/* To pass into syscall, we need a struct matching the following:
enum GraphDriverType
{
DiffDriver,
FilterDriver
};
struct DriverInfo {
GraphDriverType Flavour;
LPCWSTR HomeDir;
};
*/
type DriverInfo struct {
Flavour int
HomeDir string
}
type driverInfo struct {
Flavour int
HomeDirp *uint16
}
func convertDriverInfo(info DriverInfo) (driverInfo, error) {
homedirp, err := syscall.UTF16PtrFromString(info.HomeDir)
if err != nil {
logrus.Debugf("Failed conversion of home to pointer for driver info: %s", err.Error())
return driverInfo{}, err
}
return driverInfo{
Flavour: info.Flavour,
HomeDirp: homedirp,
}, nil
}
/* To pass into syscall, we need a struct matching the following:
typedef struct _WC_LAYER_DESCRIPTOR {
//
// The ID of the layer
//
GUID LayerId;
//
// Additional flags
//
union {
struct {
ULONG Reserved : 31;
ULONG Dirty : 1; // Created from sandbox as a result of snapshot
};
ULONG Value;
} Flags;
//
// Path to the layer root directory, null-terminated
//
PCWSTR Path;
} WC_LAYER_DESCRIPTOR, *PWC_LAYER_DESCRIPTOR;
*/
type WC_LAYER_DESCRIPTOR struct {
LayerId GUID
Flags uint32
Pathp *uint16
}
func layerPathsToDescriptors(parentLayerPaths []string) ([]WC_LAYER_DESCRIPTOR, error) {
// Array of descriptors that gets constructed.
var layers []WC_LAYER_DESCRIPTOR
for i := 0; i < len(parentLayerPaths); i++ {
// Create a layer descriptor, using the folder name
// as the source for a GUID LayerId
_, folderName := filepath.Split(parentLayerPaths[i])
g, err := NameToGuid(folderName)
if err != nil {
logrus.Debugf("Failed to convert name to guid %s", err)
return nil, err
}
p, err := syscall.UTF16PtrFromString(parentLayerPaths[i])
if err != nil {
logrus.Debugf("Failed conversion of parentLayerPath to pointer %s", err)
return nil, err
}
layers = append(layers, WC_LAYER_DESCRIPTOR{
LayerId: g,
Flags: 0,
Pathp: p,
})
}
return layers, nil
}