DockerCLI/vendor/github.com/Microsoft/hcsshim/internal/wclayer/layerutils.go

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package wclayer
// This file contains utility functions to support storage (graph) related
// functionality.
import (
"syscall"
"github.com/Microsoft/hcsshim/internal/guid"
"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
HomeDirp *uint16
}
var (
utf16EmptyString uint16
stdDriverInfo = driverInfo{1, &utf16EmptyString}
)
/* 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.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++ {
g, err := LayerID(parentLayerPaths[i])
if err != nil {
logrus.WithError(err).Debug("Failed to convert name to guid")
return nil, err
}
p, err := syscall.UTF16PtrFromString(parentLayerPaths[i])
if err != nil {
logrus.WithError(err).Debug("Failed conversion of parentLayerPath to pointer")
return nil, err
}
layers = append(layers, WC_LAYER_DESCRIPTOR{
LayerId: g,
Flags: 0,
Pathp: p,
})
}
return layers, nil
}