mutator

Documentation

Overview

Package mutator defines the operations to transform mutations into changes in the map as well as operations to write and read mutations to and from the database.

Index

• Variables
• type LogMessage
• type MapLogItemFn
• type ReduceMutationFn

Variables

var (
	// MaxMutationSize represent the maximum allowed mutation size in bytes.
	MaxMutationSize = 16 * 1024
	// ErrReplay occurs when two mutations acting on the same entry & revision
	// occur.
	ErrReplay = errors.New("mutation replay")
	// ErrSize occurs when the mutation size is larger than the allowed upper
	// bound.
	ErrSize = errors.New("mutation: too large")
	// ErrPreviousHash occurs when the mutation the hash of the previous
	// entry provided in the mutation does not match the previous entry
	// itself.
	ErrPreviousHash = errors.New("mutation: previous entry hash does not match the hash provided in the mutation")
	// ErrInvalidSig occurs when either the current or previous update entry
	// signature verification fails.
	ErrInvalidSig = errors.New("mutation: invalid signature")
	// ErrUnauthorized occurs when the mutation has not been signed by a key in the
	// previous entry.
	ErrUnauthorized = errors.New("mutation: unauthorized")
)

Types

type LogMessage

type LogMessage struct {
	ID        int64
	LocalID   int64
	Mutation  *pb.SignedEntry
	ExtraData *pb.Committed
}

LogMessage represents a change to a user, and associated data.

type MapLogItemFn

type MapLogItemFn func(logItem *LogMessage, emit func(index []byte, mutation *pb.EntryUpdate)) error

MapLogItemFn takes a log item and emits 0 or more KV<index, mutations> pairs.

type ReduceMutationFn

type ReduceMutationFn func(existingMapLeafValue, mutation *pb.SignedEntry) (*pb.SignedEntry, error)

ReduceMutationFn takes the existing mapleaf and a new mutation and returns the new value for that map leaf. ReduceMutationFn verifies that this is a valid mutation for this item. ReduceMutationFn must be idempotent.