dydbassoc

Documentation

Overview

Package dydbassoc implements an assoc.Assoc based on AWS's DynamoDB.

Index

• type Assoc
  • func (a *Assoc) Get(ctx context.Context, kind assoc.Kind, k digest.Digest) (digest.Digest, digest.Digest, error)
  • func (a *Assoc) Put(ctx context.Context, kind assoc.Kind, expect, k, v digest.Digest) error

Types

type Assoc

type Assoc struct {
	DB        *dynamodb.DynamoDB
	Limiter   *limiter.Limiter
	TableName string
}

Assoc implements a DynamoDB-backed Assoc for use in caches. Each association entry is represented by a DynamoDB item with the attributes "ID" and "Value".

TODO(marius): support batch querying in this interface; it will be more efficient than relying on call concurrency.

func (*Assoc) Get

func (a *Assoc) Get(ctx context.Context, kind assoc.Kind, k digest.Digest) (digest.Digest, digest.Digest, error)

Lookup returns the digest associated with key digest k. Lookup returns an error flagged errors.NotExist when no such mapping exists. Lookup also modifies the item's last-accessed time, which can be used for LRU object garbage collection.

Get expands abbreviated keys by making use of a DynamoDB index.

func (*Assoc) Put

func (a *Assoc) Put(ctx context.Context, kind assoc.Kind, expect, k, v digest.Digest) error

Put associates the digest v with the key digest k in the dynamodb table. DynamoDB condtional expressions are used to implement compare-and-swap when expect is nonzero.