storage

Documentation

Overview

Package storage contains abstractions and implementations for an object backend.

Index

• Variables
• func Register(scheme string, factory Factory)
• type Backend
  • func Connect(ctx context.Context, urlString string, hlp *riposo.Helpers) (Backend, error)
• type CountOptions
• type Factory
• type Inclusion
• type ListOptions
• type Transaction
• type UpdateHandle

Variables

var (
	// ErrNotFound is returned when an object is not found.
	ErrNotFound = errors.New("object not found")
	// ErrObjectExists is returned when trying to create an object that already exists.
	ErrObjectExists = errors.New("object already exists")
	// ErrInvalidPath is returned when an invalid path is used for the method.
	ErrInvalidPath = errors.New("invalid path")
)

Functions

func Register

func Register(scheme string, factory Factory)

Register registers a new backend by scheme. It will panic if multiple backends are registered under the same scheme.

Types

type Backend

type Backend interface {
	// Ping returns an error if offline.
	Ping(context.Context) error

	// Begin starts a new Transation.
	Begin(context.Context) (Transaction, error)

	// Close closes the backend.
	Close() error
}

Backend defines the abstract storage interface.

func Connect

func Connect(ctx context.Context, urlString string, hlp *riposo.Helpers) (Backend, error)

Connect connects a backend via URL.

type CountOptions

type CountOptions struct {
	// Condition are AND'ed.
	Condition params.Condition
}

CountOptions contain options for bulk-counting.

type Factory

type Factory func(context.Context, *url.URL, *riposo.Helpers) (Backend, error)

Factory initializes a new backend at runtime.

type Inclusion

type Inclusion uint8

Inclusion allows to include objects by state.

const (
	IncludeLive Inclusion = iota
	IncludeAll
)

Inclusion enum.

type ListOptions

type ListOptions struct {
	// Condition are AND'ed.
	Condition params.Condition
	// Pagination are are OR'd.
	Pagination params.ConditionSet
	// Include live/all objects in the output.
	Include Inclusion
	// Sort are applied sequentially.
	Sort []params.SortOrder
	// Limits the number of objects returned.
	Limit int
}

ListOptions contain options for bulk-listing.

type Transaction

type Transaction interface {
	// Commit commits the transaction.
	Commit() error
	// Rollback aborts the transaction.
	Rollback() error

	// Flush removes every object from this backend.
	Flush() error
	// Purge purges all deleted objects olderThan epoch.
	Purge(olderThan riposo.Epoch) (int64, error)

	// ModTime returns the maximum epoch of the given node.
	ModTime(path riposo.Path) (riposo.Epoch, error)
	// ListAll appends matching objects within a node and returns the resulting slice.
	ListAll(objs []*schema.Object, node riposo.Path, opt ListOptions) ([]*schema.Object, error)
	// CountAll counts all matching objects within a node and returns the resulting number.
	CountAll(node riposo.Path, opt CountOptions) (int64, error)
	// DeleteAll recursively deletes given paths and returns the
	// maximum modTime of the deleted objects.
	DeleteAll(paths ...riposo.Path) (riposo.Epoch, error)

	// Exists returns true if a path exists.
	// Accepts elementary paths only.
	Exists(path riposo.Path) (bool, error)
	// Get returns a stored object. May return ErrNotFound.
	// Accepts elementary paths only.
	Get(path riposo.Path) (*schema.Object, error)
	// GetForUpdate returns a stored object with a lock. May return ErrNotFound.
	GetForUpdate(path riposo.Path) (UpdateHandle, error)

	// Create stores a new object under a node.
	Create(node riposo.Path, obj *schema.Object) error
	// Update updates an existing object.
	Update(h UpdateHandle) error
	// Delete deletes the given path and returns the affected object.
	Delete(path riposo.Path) (*schema.Object, error)
}

Transaction is a transaction.

type UpdateHandle

type UpdateHandle interface {
	// Object returns the transactional object.
	Object() *schema.Object
}

UpdateHandle is an update handle.