store

Documentation

Overview

Package store defines Store, a key-value CRDT store.

Index

• type Log
  • func (l *Log) Head() *common.VersionVector
  • func (l *Log) NewIterator(vec *common.VersionVector) *LogIterator
  • func (l *Log) Wait(vec *common.VersionVector)
• type LogIterator
  • func (it *LogIterator) Advance() bool
  • func (it *LogIterator) AgentId() uint32
  • func (it *LogIterator) AgentSeq() uint32
  • func (it *LogIterator) Err() error
  • func (it *LogIterator) Patch() *PatchEnvelope
  • func (it *LogIterator) VersionVector() *common.VersionVector
• type PatchEnvelope
• type Store
  • func OpenStore(mu *sync.Mutex) *Store
  • func (s *Store) ApplyClientPatch(agentId uint32, key, dtype, patch string) (uint32, error)
  • func (s *Store) ApplyServerPatch(agentId, agentSeq uint32, key, dtype, patch string) error
  • func (s *Store) NewIterator() *StoreIterator
• type StoreIterator
  • func (it *StoreIterator) Advance() bool
  • func (it *StoreIterator) Err() error
  • func (it *StoreIterator) Key() string
  • func (it *StoreIterator) Value() *ValueEnvelope
• type ValueEnvelope

Types

type Log

type Log struct {
	// contains filtered or unexported fields
}

func (*Log) Head

func (l *Log) Head() *common.VersionVector

Head returns a new version vector representing current knowledge. cond.L must be held.

func (*Log) NewIterator

func (l *Log) NewIterator(vec *common.VersionVector) *LogIterator

NewIterator returns an iterator for patches beyond the given version vector. Iteration order matches log order. cond.L must be held during calls to Advance, but need not be held at other times.

func (*Log) Wait

func (l *Log) Wait(vec *common.VersionVector)

Wait blocks until the log has patches beyond the given version vector. cond.L must not be held.

type LogIterator

type LogIterator struct {
	// contains filtered or unexported fields
}

func (*LogIterator) Advance

func (it *LogIterator) Advance() bool

Advance advances the iterator, staging the next patch. Must be called to stage the first value. Assumes cond.L is held.

func (*LogIterator) AgentId

func (it *LogIterator) AgentId() uint32

AgentId returns the agent id for the current patch.

func (*LogIterator) AgentSeq

func (it *LogIterator) AgentSeq() uint32

AgentSeq returns the agent sequence number for the current patch.

func (*LogIterator) Err

func (it *LogIterator) Err() error

Err returns a non-nil error iff the iterator encountered an error.

func (*LogIterator) Patch

func (it *LogIterator) Patch() *PatchEnvelope

Value returns the current patch.

func (*LogIterator) VersionVector

func (it *LogIterator) VersionVector() *common.VersionVector

VersionVector returns a copy of the current version vector, representing which patches the client has already seen.

type PatchEnvelope

type PatchEnvelope struct {
	LocalSeq uint32 // one-based position in local, cross-agent patch log
	Key      string
	DType    string
	Patch    string // encoded
}

PatchEnvelope represents a patch and its associated metadata. Key is of the form [AgentId]:[AgentSeq], where AgentId is the creator's agent id and [AgentSeq] is the creator's sequence number for this patch.

type Store

type Store struct {
	Log *Log
	// contains filtered or unexported fields
}

func OpenStore

func OpenStore(mu *sync.Mutex) *Store

OpenStore returns a store.

func (*Store) ApplyClientPatch

func (s *Store) ApplyClientPatch(agentId uint32, key, dtype, patch string) (uint32, error)

ApplyClientPatch applies the given encoded patch and returns the local sequence number for the written log record. Mutex must be held.

func (*Store) ApplyServerPatch

func (s *Store) ApplyServerPatch(agentId, agentSeq uint32, key, dtype, patch string) error

ApplyServerPatch applies the given encoded patch, if needed. Mutex must be held.

func (*Store) NewIterator

func (s *Store) NewIterator() *StoreIterator

NewIterator returns an iterator for stored key-value pairs. Iteration order matches lexicographic key order. The store must not be modified while the iterator is in use.

type StoreIterator

type StoreIterator struct {
	// contains filtered or unexported fields
}

func (*StoreIterator) Advance

func (it *StoreIterator) Advance() bool

Advance advances the iterator, staging the next value. Must be called to stage the first value.

func (*StoreIterator) Err

func (it *StoreIterator) Err() error

Err returns a non-nil error iff the iterator encountered an error.

func (*StoreIterator) Key

func (it *StoreIterator) Key() string

Key returns the current key.

func (*StoreIterator) Value

func (it *StoreIterator) Value() *ValueEnvelope

Value returns the current value.

type ValueEnvelope

type ValueEnvelope struct {
	DType string
	Value cvalue.CValue
}

ValueEnvelope represents a value and its associated metadata. Key is of the form [Key], where Key is the object key.