forked from TrueCloudLab/distribution
65b0d73cb7
This change is slightly more complex than previous package maves in that the package name changed. To address this, we simply always reference the package driver as storagedriver to avoid compatbility issues with existing code. While unfortunate, this can be cleaned up over time. Signed-off-by: Stephen J Day <stephen.day@docker.com>
118 lines
4.1 KiB
Go
118 lines
4.1 KiB
Go
package driver
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import (
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"errors"
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"fmt"
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"io"
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"regexp"
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"strconv"
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"strings"
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)
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// Version is a string representing the storage driver version, of the form
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// Major.Minor.
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// The registry must accept storage drivers with equal major version and greater
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// minor version, but may not be compatible with older storage driver versions.
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type Version string
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// Major returns the major (primary) component of a version.
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func (version Version) Major() uint {
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majorPart := strings.Split(string(version), ".")[0]
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major, _ := strconv.ParseUint(majorPart, 10, 0)
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return uint(major)
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}
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// Minor returns the minor (secondary) component of a version.
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func (version Version) Minor() uint {
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minorPart := strings.Split(string(version), ".")[1]
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minor, _ := strconv.ParseUint(minorPart, 10, 0)
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return uint(minor)
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}
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// CurrentVersion is the current storage driver Version.
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const CurrentVersion Version = "0.1"
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// StorageDriver defines methods that a Storage Driver must implement for a
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// filesystem-like key/value object storage.
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type StorageDriver interface {
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// GetContent retrieves the content stored at "path" as a []byte.
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// This should primarily be used for small objects.
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GetContent(path string) ([]byte, error)
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// PutContent stores the []byte content at a location designated by "path".
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// This should primarily be used for small objects.
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PutContent(path string, content []byte) error
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// ReadStream retrieves an io.ReadCloser for the content stored at "path"
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// with a given byte offset.
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// May be used to resume reading a stream by providing a nonzero offset.
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ReadStream(path string, offset int64) (io.ReadCloser, error)
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// WriteStream stores the contents of the provided io.ReadCloser at a
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// location designated by the given path.
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// May be used to resume writing a stream by providing a nonzero offset.
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// The offset must be no larger than the CurrentSize for this path.
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WriteStream(path string, offset int64, reader io.Reader) (nn int64, err error)
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// Stat retrieves the FileInfo for the given path, including the current
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// size in bytes and the creation time.
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Stat(path string) (FileInfo, error)
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// List returns a list of the objects that are direct descendants of the
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//given path.
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List(path string) ([]string, error)
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// Move moves an object stored at sourcePath to destPath, removing the
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// original object.
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// Note: This may be no more efficient than a copy followed by a delete for
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// many implementations.
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Move(sourcePath string, destPath string) error
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// Delete recursively deletes all objects stored at "path" and its subpaths.
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Delete(path string) error
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// URLFor returns a URL which may be used to retrieve the content stored at
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// the given path, possibly using the given options.
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// May return an UnsupportedMethodErr in certain StorageDriver
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// implementations.
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URLFor(path string, options map[string]interface{}) (string, error)
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}
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// PathRegexp is the regular expression which each file path must match. A
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// file path is absolute, beginning with a slash and containing a positive
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// number of path components separated by slashes, where each component is
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// restricted to lowercase alphanumeric characters or a period, underscore, or
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// hyphen.
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var PathRegexp = regexp.MustCompile(`^(/[a-z0-9._-]+)+$`)
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// UnsupportedMethodErr may be returned in the case where a StorageDriver implementation does not support an optional method.
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var ErrUnsupportedMethod = errors.New("Unsupported method")
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// PathNotFoundError is returned when operating on a nonexistent path.
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type PathNotFoundError struct {
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Path string
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}
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func (err PathNotFoundError) Error() string {
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return fmt.Sprintf("Path not found: %s", err.Path)
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}
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// InvalidPathError is returned when the provided path is malformed.
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type InvalidPathError struct {
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Path string
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}
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func (err InvalidPathError) Error() string {
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return fmt.Sprintf("Invalid path: %s", err.Path)
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}
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// InvalidOffsetError is returned when attempting to read or write from an
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// invalid offset.
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type InvalidOffsetError struct {
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Path string
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Offset int64
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}
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func (err InvalidOffsetError) Error() string {
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return fmt.Sprintf("Invalid offset: %d for path: %s", err.Offset, err.Path)
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}
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