description

Documentation

Index

• Constants
• func CompareTopologyVersion(currentTV, responseTV *TopologyVersion) int
• func MaxStalenessSupported(wireVersion *VersionRange) error
• func ScramSHA1Supported(wireVersion *VersionRange) error
• func SessionsSupported(wireVersion *VersionRange) bool
• type HostlistDiff
• type SelectedServer
• type Server
  • func NewDefaultServer(addr address.Address) Server
  • func NewServer(addr address.Address, response bsoncore.Document) Server
  • func NewServerFromError(addr address.Address, err error, tv *TopologyVersion) Server
  • func (s Server) DataBearing() bool
  • func (s Server) SelectServer(_ Topology, candidates []Server) ([]Server, error)
  • func (s Server) SetAverageRTT(rtt time.Duration) Server
  • func (s Server) SupportsRetryWrites() bool
• type ServerKind
  • func (kind ServerKind) String() string
• type ServerSelector
  • func CompositeSelector(selectors []ServerSelector) ServerSelector
  • func LatencySelector(latency time.Duration) ServerSelector
  • func ReadPrefSelector(rp *readpref.ReadPref) ServerSelector
  • func WriteSelector() ServerSelector
• type ServerSelectorFunc
  • func (ssf ServerSelectorFunc) SelectServer(t Topology, s []Server) ([]Server, error)
• type Topology
  • func (t Topology) DiffHostlist(hostlist []string) HostlistDiff
  • func (t Topology) Server(addr address.Address) (Server, bool)
• type TopologyDiff
  • func DiffTopology(old, new Topology) TopologyDiff
• type TopologyKind
  • func (kind TopologyKind) String() string
• type TopologyVersion
  • func NewTopologyVersion(doc bsoncore.Document) (*TopologyVersion, error)
• type Version
  • func (v Version) AtLeast(other ...uint8) bool
  • func (v Version) String() string
• type VersionRange
  • func NewVersionRange(min, max int32) VersionRange
  • func (vr VersionRange) Includes(v int32) bool
  • func (vr VersionRange) String() string

Constants

const Unknown = 0

Unknown is an unknown server or topology kind.

const UnsetRTT = -1 * time.Millisecond

UnsetRTT is the unset value for a round trip time.

Functions

func CompareTopologyVersion

func CompareTopologyVersion(currentTV, responseTV *TopologyVersion) int

CompareTopologyVersion returns -1 if currentTV<responseTV, 0 if currentTV==responseTV, 1 if currentTV>responseTV. This comparsion is not commutative so the original TopologyVersion should be first.

func MaxStalenessSupported

func MaxStalenessSupported(wireVersion *VersionRange) error

MaxStalenessSupported returns an error if the given server version does not support max staleness.

func ScramSHA1Supported

func ScramSHA1Supported(wireVersion *VersionRange) error

ScramSHA1Supported returns an error if the given server version does not support scram-sha-1.

func SessionsSupported

func SessionsSupported(wireVersion *VersionRange) bool

SessionsSupported returns true of the given server version indicates that it supports sessions.

Types

type HostlistDiff

type HostlistDiff struct {
	Added   []string
	Removed []string
}

HostlistDiff is the difference between a topology and a host list.

type SelectedServer

type SelectedServer struct {
	Server
	Kind TopologyKind
}

SelectedServer represents a selected server that is a member of a topology.

type Server

type Server struct {
	Addr address.Address

	AverageRTT              time.Duration
	AverageRTTSet           bool
	Compression             []string // compression methods returned by server
	CanonicalAddr           address.Address
	ElectionID              primitive.ObjectID
	HeartbeatInterval       time.Duration
	LastError               error
	LastUpdateTime          time.Time
	LastWriteTime           time.Time
	MaxBatchCount           uint32
	MaxDocumentSize         uint32
	MaxMessageSize          uint32
	Members                 []address.Address
	ReadOnly                bool
	SessionTimeoutMinutes   uint32
	SetName                 string
	SetVersion              uint32
	SpeculativeAuthenticate bsoncore.Document
	Tags                    tag.Set
	TopologyVersion         *TopologyVersion
	Kind                    ServerKind
	WireVersion             *VersionRange

	SaslSupportedMechs []string // user-specific from server handshake
}

Server represents a description of a server. This is created from an isMaster command.

func NewDefaultServer

func NewDefaultServer(addr address.Address) Server

NewDefaultServer creates a new unknown server description with the given address.

func NewServer

func NewServer(addr address.Address, response bsoncore.Document) Server

NewServer creates a new server description from the given parameters.

func NewServerFromError

func NewServerFromError(addr address.Address, err error, tv *TopologyVersion) Server

NewServerFromError creates a new unknown server description with the given parameters.

func (Server) DataBearing

func (s Server) DataBearing() bool

DataBearing returns true if the server is a data bearing server.

func (Server) SelectServer

func (s Server) SelectServer(_ Topology, candidates []Server) ([]Server, error)

SelectServer selects this server if it is in the list of given candidates.

func (Server) SetAverageRTT

func (s Server) SetAverageRTT(rtt time.Duration) Server

SetAverageRTT sets the average round trip time for this server description.

func (Server) SupportsRetryWrites

func (s Server) SupportsRetryWrites() bool

SupportsRetryWrites returns true if this description represents a server that supports retryable writes.

type ServerKind

type ServerKind uint32

ServerKind represents the type of a server.

const (
	Standalone  ServerKind = 1
	RSMember    ServerKind = 2
	RSPrimary   ServerKind = 4 + RSMember
	RSSecondary ServerKind = 8 + RSMember
	RSArbiter   ServerKind = 16 + RSMember
	RSGhost     ServerKind = 32 + RSMember
	Mongos      ServerKind = 256
)

These constants are the possible types of servers.

func (ServerKind) String

func (kind ServerKind) String() string

String implements the fmt.Stringer interface.

type ServerSelector

type ServerSelector interface {
	SelectServer(Topology, []Server) ([]Server, error)
}

ServerSelector is an interface implemented by types that can select a server given a topology description.

func CompositeSelector

func CompositeSelector(selectors []ServerSelector) ServerSelector

CompositeSelector combines multiple selectors into a single selector.

func LatencySelector

func LatencySelector(latency time.Duration) ServerSelector

LatencySelector creates a ServerSelector which selects servers based on their latency.

func ReadPrefSelector

func ReadPrefSelector(rp *readpref.ReadPref) ServerSelector

ReadPrefSelector selects servers based on the provided read preference.

func WriteSelector

func WriteSelector() ServerSelector

WriteSelector selects all the writable servers.

type ServerSelectorFunc

type ServerSelectorFunc func(Topology, []Server) ([]Server, error)

ServerSelectorFunc is a function that can be used as a ServerSelector.

func (ServerSelectorFunc) SelectServer

func (ssf ServerSelectorFunc) SelectServer(t Topology, s []Server) ([]Server, error)

SelectServer implements the ServerSelector interface.

type Topology

type Topology struct {
	Servers               []Server
	Kind                  TopologyKind
	SessionTimeoutMinutes uint32
}

Topology represents a description of a mongodb topology

func (Topology) DiffHostlist

func (t Topology) DiffHostlist(hostlist []string) HostlistDiff

DiffHostlist compares the topology description and host list and returns the difference.

func (Topology) Server

func (t Topology) Server(addr address.Address) (Server, bool)

Server returns the server for the given address. Returns false if the server could not be found.

type TopologyDiff

type TopologyDiff struct {
	Added   []Server
	Removed []Server
}

TopologyDiff is the difference between two different topology descriptions.

func DiffTopology

func DiffTopology(old, new Topology) TopologyDiff

DiffTopology compares the two topology descriptions and returns the difference.

type TopologyKind

type TopologyKind uint32

TopologyKind represents a specific topology configuration.

const (
	Single                TopologyKind = 1
	ReplicaSet            TopologyKind = 2
	ReplicaSetNoPrimary   TopologyKind = 4 + ReplicaSet
	ReplicaSetWithPrimary TopologyKind = 8 + ReplicaSet
	Sharded               TopologyKind = 256
)

These constants are the available topology configurations.

func (TopologyKind) String

func (kind TopologyKind) String() string

String implements the fmt.Stringer interface.

type TopologyVersion

type TopologyVersion struct {
	ProcessID primitive.ObjectID
	Counter   int64
}

TopologyVersion represents a software version.

func NewTopologyVersion

func NewTopologyVersion(doc bsoncore.Document) (*TopologyVersion, error)

NewTopologyVersion creates a TopologyVersion based on doc

type Version

type Version struct {
	Desc  string
	Parts []uint8
}

Version represents a software version.

func (Version) AtLeast

func (v Version) AtLeast(other ...uint8) bool

AtLeast ensures that the version is at least as large as the "other" version.

func (Version) String

func (v Version) String() string

String provides the string represtation of the Version.

type VersionRange

type VersionRange struct {
	Min int32
	Max int32
}

VersionRange represents a range of versions.

func NewVersionRange

func NewVersionRange(min, max int32) VersionRange

NewVersionRange creates a new VersionRange given a min and a max.

func (VersionRange) Includes

func (vr VersionRange) Includes(v int32) bool

Includes returns a bool indicating whether the supplied integer is included in the range.

func (VersionRange) String

func (vr VersionRange) String() string

String implements the fmt.Stringer interface.