1ae5485998
The registry currently only accepts storage driver versions with the same major version and an equal or lower minor version as its own current storage driver api version, but this may be changed in the future if we decide to implement specific version cross-compatibility.
88 lines
3.1 KiB
Go
88 lines
3.1 KiB
Go
package storagedriver
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import (
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"fmt"
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"io"
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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 Major.Minor.
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// The registry must accept storage drivers with equal major version and greater minor version,
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// 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 filesystem-like
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// 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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// 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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// 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" with a given byte
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// 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 uint64) (io.ReadCloser, error)
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// WriteStream stores the contents of the provided io.ReadCloser at a location designated by
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// the given path
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// The driver will know it has received the full contents when it has read "size" bytes
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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 ResumeWritePosition for this path
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WriteStream(path string, offset, size uint64, readCloser io.ReadCloser) error
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// ResumeWritePosition retrieves the byte offset at which it is safe to continue writing at the
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// given path
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ResumeWritePosition(path string) (uint64, error)
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// List returns a list of the objects that are direct descendants of the 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 original object
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// Note: This may be no more efficient than a copy followed by a delete for 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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}
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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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// InvalidOffsetError is returned when attempting to read or write from an invalid offset
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type InvalidOffsetError struct {
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Path string
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Offset uint64
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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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