history

Documentation

Overview

Package history provides a store for historical records. This package contains the interfaces and general types, see various foostore packages for actual store implementations.

Index

• type Record
  • func (r Record) IsZero() bool
• type Slice
• type Store

Types

type Record

type Record struct {
	ID         string
	CreateTime time.Time
	Payload    []byte
}

Record is a payload as it was at a point in time.

func (Record) IsZero

func (r Record) IsZero() bool

IsZero returns whether r is equivalent to Record{}, the zero record.

type Slice

type Slice interface {
	// Slice creates a new slice including records >= from and < to.
	// If from is zero then it is treated as the first record available,
	// if to is zero then it is the record immediately after the last record,
	// just like with go slices.
	// The record should have either ID and/or CreateTime set.
	Slice(from, to Record) Slice
	// Read reads records from the slice starting at the first record available, ending when into is full (according to len).
	// Read returns the number of records actually read.
	// The first record read will be places into index 0, the second into index 1, and so on.
	Read(ctx context.Context, into []Record) (int, error)
	// Len returns the number of records this slice represents.
	Len(ctx context.Context) (int, error)
}

Slice describes a read-only ordered segment of a Store.

type Store

type Store interface {
	// Append adds the given payload to the store, returning the Record as recorded.
	// The context can be used to abort the append operation if needed.
	Append(ctx context.Context, payload []byte) (Record, error)
	Slice
}

Store defines an append-only collection of ordered records. The store can be sliced, like a go slice, to query for a range of records which can then be read.