qcow2

package
v0.1.1 Latest Latest
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This package is not in the latest version of its module.

 Go to latest Published: May 22, 2023 License: Apache-2.0 Imports: 12 Imported by: 2

Documentation

Index

Constants

View Source 
const (
	CryptMethodNone = CryptMethod(0)
	CryptMethodAES  = CryptMethod(1)
	CryptMethodLUKS = CryptMethod(2)
)
View Source 
const (
	IncompatibleFeaturesDirtyBit             = 0
	IncompatibleFeaturesCorruptBit           = 1
	IncompatibleFeaturesExternalDataFileBit  = 2
	IncompatibleFeaturesCompressionTypeBit   = 3
	IncompatibleFeaturesExtendedL2EntriesBit = 4
)
View Source 
const (
	AutoclearFeaturesBitmapsExtensionBit = 0
	AutoclearFeaturesRawExternalBit      = 1
)
View Source 
const (
	// CompressionTypeZlib is a misnomer. It is actually deflate without zlib header.
	CompressionTypeZlib = CompressionType(0)
	CompressionTypeZstd = CompressionType(1)
)
View Source 
const (
	HeaderExtensionTypeEnd                             = HeaderExtensionType(0x00000000)
	HeaderExtensionTypeBackingFileFormatNameString     = HeaderExtensionType(0xe2792aca)
	HeaderExtensionTypeFeatureNameTable                = HeaderExtensionType(0x6803f857)
	HeaderExtensionTypeBitmapsExtension                = HeaderExtensionType(0x23852875)
	HeaderExtensionTypeFullDiskEncryptionHeaderPointer = HeaderExtensionType(0x0537be77)
	HeaderExtensionTypeExternalDataFileNameString      = HeaderExtensionType(0x44415441)
)
View Source 
const (
	FeatureNameTableEntryTypeIncompatible = FeatureNameTableEntryType(0)
	FeatureNameTableEntryTypeCompatible   = FeatureNameTableEntryType(1)
	FeatureNameTableEntryTypeAutoclear    = FeatureNameTableEntryType(2)
)
View Source 
const (
	CompatibleFeaturesLazyRefcountsBit = 0
)
View Source 
const Magic = "QFI\xfb"

Magic is the qcow2 magic string.

View Source 
const Type = "qcow2"

Variables

View Source 
var (
	ErrNotQcow2               = fmt.Errorf("%w: image is not qcow2", image.ErrWrongType)
	ErrUnsupportedBackingFile = errors.New("unsupported backing file")
	ErrUnsupportedEncryption  = errors.New("unsupported encryption method")
	ErrUnsupportedCompression = errors.New("unsupported compression type")
	ErrUnsupportedFeature     = errors.New("unsupported feature")
)
View Source 
var AutoclearFeaturesNames = []string{
	"bitmaps",
	"raw external data",
}
View Source 
var CompatibleFeaturesNames = []string{
	"lazy refcounts",
}
View Source 
var IncompatibleFeaturesNames = []string{
	"dirty bit",
	"corrupt bit",
	"external data file",
	"compression type",
	"extended L2 entries",
}

Functions

func SetDecompressor 

func SetDecompressor(t CompressionType, d Decompressor)

SetDecompressor sets a custom decompressor. By default, flate.NewReader is registered for CompressionTypeZlib. No decompressor is registered by default for CompressionTypeZstd.

Types

type AutoclearFeatures 

type AutoclearFeatures uint64

func (AutoclearFeatures) MarshalJSON 

func (x AutoclearFeatures) MarshalJSON() ([]byte, error)

type CompatibleFeatures 

type CompatibleFeatures uint64

func (CompatibleFeatures) MarshalJSON 

func (x CompatibleFeatures) MarshalJSON() ([]byte, error)

type CompressionType 

type CompressionType uint8

func (CompressionType) MarshalText 

func (x CompressionType) MarshalText() ([]byte, error)

func (CompressionType) String 

func (x CompressionType) String() string

type CryptMethod 

type CryptMethod uint32

func (CryptMethod) MarshalText 

func (x CryptMethod) MarshalText() ([]byte, error)

func (CryptMethod) String 

func (x CryptMethod) String() string

type Decompressor 

type Decompressor func(r io.Reader) (io.ReadCloser, error)

type FeatureName 

type FeatureName [46]byte

type FeatureNameTableEntry 

type FeatureNameTableEntry struct {
	Type FeatureNameTableEntryType `json:"type"`
	Bit  uint8                     `json:"bit"`
	Name string                    `json:"name"`
}

type FeatureNameTableEntryType 

type FeatureNameTableEntryType uint8

func (FeatureNameTableEntryType) MarshalText 

func (x FeatureNameTableEntryType) MarshalText() ([]byte, error)

func (FeatureNameTableEntryType) String 

func (x FeatureNameTableEntryType) String() string

type Features 

type Features struct {
	Raw   uint64   `json:"raw"`
	Names []string `json:"names"`
}
type Header struct {
	HeaderFieldsV2
	*HeaderFieldsV3
	*HeaderFieldsAdditional
}

func (*Header) Length 

func (header *Header) Length() int

func (*Header) Readable 

func (header *Header) Readable() error

Readable returns nil if the image is readable, otherwise returns an error.

type HeaderExtension 

type HeaderExtension struct {
	Type   HeaderExtensionType `json:"type"`
	Length uint32              `json:"length"`
	Data   interface{}         `json:"data,omitempty"`
}

type HeaderExtensionType 

type HeaderExtensionType uint32

func (HeaderExtensionType) MarshalText 

func (x HeaderExtensionType) MarshalText() ([]byte, error)

func (HeaderExtensionType) String 

func (x HeaderExtensionType) String() string

type HeaderFieldsAdditional 

type HeaderFieldsAdditional struct {
	CompressionType CompressionType `json:"compression_type"`
	// Pad is exposed to avoid `panic: reflect: reflect.Value.SetUint using value obtained using unexported field` during [binary.Read].
	Pad [7]byte `json:"-"`
}

type HeaderFieldsV2 

type HeaderFieldsV2 struct {
	Magic                 MagicType   `json:"magic"`
	Version               uint32      `json:"version"`             // 2 or 3
	BackingFileOffset     uint64      `json:"backing_file_offset"` // offset of file name (not null terminated)
	BackingFileSize       uint32      `json:"backing_file_size"`   // length of file name (<= 1023)
	ClusterBits           uint32      `json:"cluster_bits"`
	Size                  uint64      `json:"size"` // Virtual disk size in bytes
	CryptMethod           CryptMethod `json:"crypt_method"`
	L1Size                uint32      `json:"l1_size"`         // Number of entries
	L1TableOffset         uint64      `json:"l1_table_offset"` // Offset into the image file
	RefcountTableOffset   uint64      `json:"refcount_table_offset"`
	RefcountTableClusters uint32      `json:"refcount_table_clusters"`
	NbSnapshots           uint32      `json:"nb_snapshots"` // Number of snapshots
	SnapshotsOffset       uint64      `json:"snapshots_offset"`
}

type HeaderFieldsV3 

type HeaderFieldsV3 struct {
	IncompatibleFeatures IncompatibleFeatures `json:"incompatible_features"`
	CompatibleFeatures   CompatibleFeatures   `json:"compatible_features"`
	AutoclearFeatures    AutoclearFeatures    `json:"autoclear_features"`
	RefcountOrder        uint32               `json:"refcount_order"`
	HeaderLength         uint32               `json:"header_length"`
}

type IncompatibleFeatures 

type IncompatibleFeatures uint64

func (IncompatibleFeatures) MarshalJSON 

func (x IncompatibleFeatures) MarshalJSON() ([]byte, error)

type MagicType 

type MagicType [4]byte

MagicType wraps magic bytes.

func (MagicType) MarshalText 

func (x MagicType) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler.

func (MagicType) String 

func (x MagicType) String() string

String implements fmt.Stringer.

type Namer 

type Namer interface {
	Name() string
}

Namer is implemented by os.File.

type OffsetLengthPair64 

type OffsetLengthPair64 struct {
	Offset uint64 `json:"offset"`
	Length uint64 `json:"length"`
}

type Qcow2 

type Qcow2 struct {
	*Header          `json:"header"`
	HeaderExtensions []HeaderExtension `json:"header_extensions"`

	BackingFile         string     `json:"backing_file"`
	BackingFileFullPath string     `json:"backing_file_full_path"`
	BackingFileFormat   image.Type `json:"backing_file_format"`
	// contains filtered or unexported fields
}

Qcow2 implements image.Image.

func Open 

func Open(ra io.ReaderAt, openWithType image.OpenWithType) (*Qcow2, error)

Open opens an qcow2 image.

To open an image with backing files, ra must implement Namer, and openWithType must be non-nil.

func (*Qcow2) Close 

func (img *Qcow2) Close() error

func (*Qcow2) ReadAt 

func (img *Qcow2) ReadAt(p []byte, off int64) (n int, err error)

ReadAt implements io.ReaderAt.

func (*Qcow2) Readable 

func (img *Qcow2) Readable() error

func (*Qcow2) Size 

func (img *Qcow2) Size() int64

func (*Qcow2) Type 

func (img *Qcow2) Type() image.Type

Source Files

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