sdb

type Attribute struct {
	Name  string
	Value string
}

type BatchDeleteMap map[ItemName][]DeleteUpdate

type BatchPutMap map[ItemName][]PutUpdate

type DeleteUpdate struct {
	// The name of the attribute.
	Name string

	// The particular value of the attribute to delete, if non-nil. Otherwise,
	// all values for the given name will be deleted.
	Value *string
}

type Domain interface {
	// Return the name of this domain.
	Name() string

	// Return the database connection to which this domain is attached.
	Db() SimpleDB

	// Atomically apply the supplied updates to the attributes of the named item,
	// but only if the supplied precondition holds. If no precondition is
	// desired, pass nil.
	//
	// The length of updates must be in [1, 256].
	PutAttributes(
		item ItemName,
		updates []PutUpdate,
		precondition *Precondition) error

	// Atomically apply updates to multiple items simultaneously.
	//
	// The length of the map must be in [1, 25]. The length of each of its values
	// must be in [1, 256]. An error may be returned if the underlying request to
	// SimpleDB is too large.
	BatchPutAttributes(updateMap BatchPutMap) error

	// Retrieve a set of attributes for the named item, or all attributes if the
	// attribute name slice is empty.
	//
	// If the named item doesn't exist, the empty set is returned.
	//
	// constistentRead specifies whether completely fresh data is needed or not.
	GetAttributes(
		item ItemName,
		constistentRead bool,
		attrNames []string) (attrs []Attribute, err error)

	// Atomically delete attributes from the named item, but only if the supplied
	// precondition holds. If no precondition is desired, pass nil.
	//
	// If deletes is empty, delete all attributes from the item. Otherwise
	// perform only the deletes is specifies. Deleting a non-existent attribute
	// does not result in an error.
	DeleteAttributes(
		item ItemName,
		deletes []DeleteUpdate,
		precondition *Precondition) error

	// Atomically delete attributes from multiple items simultaneously.
	//
	// If no updates are supplied for a particular item, delete all of its
	// attributes.
	BatchDeleteAttributes(deleteMap BatchDeleteMap) error
}

type ItemName string

type Precondition struct {
	// The name of the attribute to be inspected. Attributes with multiple values
	// are not supported.
	Name string

	// If non-nil, the value that the attribute must possess at the time of the
	// update. If nil, the attribute must not exist at the time of the update.
	Value *string
}

type PutUpdate struct {
	// The name of the attribute.
	Name string

	// The value to set for the attribute.
	Value string

	// If true, add this (name, value) attribute rather than replacing any
	// existing attributes with the given name (the default).
	Add bool
}

type Region string

type SelectedItem struct {
	Name       ItemName
	Attributes []Attribute
}

type SimpleDB interface {
	// Ensure that the domain with the specified name exists, then return it.
	OpenDomain(name string) (Domain, error)

	// Remove the supplied domain from the DB. Any domains previously opened with
	// this domain's name will no longer be valid. It is not an error to call
	// this method for a domain that has already been deleted.
	DeleteDomain(d Domain) error

	// Retrieve a set of items and their attributes based on a query string.
	//
	// constistentRead specifies whether completely fresh data is needed or not.
	//
	// If the selected result set is too large, a "next token" will be returned.
	// It can be passed to the Select method to resume where the previous result
	// set left off. For the initial query, use nil.
	//
	// For more info:
	//
	//     http://goo.gl/GTsSZ
	//
	Select(
		query string,
		constistentRead bool,
		nextToken []byte) (results []SelectedItem, tok []byte, err error)
}