gocql

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README

gocql

Build Status GoDoc

Package gocql implements a fast and robust Cassandra client for the Go programming language.

Project Website: https://gocql.github.io/
API documentation: https://godoc.org/github.com/gocql/gocql
Discussions: https://groups.google.com/forum/#!forum/gocql

Supported Versions

The following matrix shows the versions of Go and Cassandra that are tested with the integration test suite as part of the CI build:

Go/Cassandra 2.1.x 2.2.x 3.0.x
1.6 yes yes yes
1.7 yes yes yes

Gocql has been tested in production against many different versions of Cassandra. Due to limits in our CI setup we only test against the latest 3 major releases, which coincide with the official support from the Apache project.

Sunsetting Model

In general, the gocql team will focus on supporting the current and previous versions of Go. gocql may still work with older versions of Go, but official support for these versions will have been sunset.

Installation

go get github.com/gocql/gocql

Features

  • Modern Cassandra client using the native transport
  • Automatic type conversions between Cassandra and Go
    • Support for all common types including sets, lists and maps
    • Custom types can implement a Marshaler and Unmarshaler interface
    • Strict type conversions without any loss of precision
    • Built-In support for UUIDs (version 1 and 4)
  • Support for logged, unlogged and counter batches
  • Cluster management
    • Automatic reconnect on connection failures with exponential falloff
    • Round robin distribution of queries to different hosts
    • Round robin distribution of queries to different connections on a host
    • Each connection can execute up to n concurrent queries (whereby n is the limit set by the protocol version the client chooses to use)
    • Optional automatic discovery of nodes
    • Policy based connection pool with token aware and round-robin policy implementations
  • Support for password authentication
  • Iteration over paged results with configurable page size
  • Support for TLS/SSL
  • Optional frame compression (using snappy)
  • Automatic query preparation
  • Support for query tracing
  • Support for Cassandra 2.1+ binary protocol version 3
    • Support for up to 32768 streams
    • Support for tuple types
    • Support for client side timestamps by default
    • Support for UDTs via a custom marshaller or struct tags
  • Support for Cassandra 3.0+ binary protocol version 4
  • An API to access the schema metadata of a given keyspace

Performance

While the driver strives to be highly performant, there are cases where it is difficult to test and verify. The driver is built with maintainability and code readability in mind first and then performance and features, as such every now and then performance may degrade, if this occurs please report and issue and it will be looked at and remedied. The only time the driver copies data from its read buffer is when it Unmarshal's data into supplied types.

Some tips for getting more performance from the driver:

  • Use the TokenAware policy
  • Use many goroutines when doing inserts, the driver is asynchronous but provides a synchronous API, it can execute many queries concurrently
  • Tune query page size
  • Reading data from the network to unmarshal will incur a large amount of allocations, this can adversely affect the garbage collector, tune GOGC
  • Close iterators after use to recycle byte buffers

Important Default Keyspace Changes

gocql no longer supports executing "use " statements to simplify the library. The user still has the ability to define the default keyspace for connections but now the keyspace can only be defined before a session is created. Queries can still access keyspaces by indicating the keyspace in the query:

SELECT * FROM example2.table;

Example of correct usage:

	cluster := gocql.NewCluster("192.168.1.1", "192.168.1.2", "192.168.1.3")
	cluster.Keyspace = "example"
	...
	session, err := cluster.CreateSession()

Example of incorrect usage:

	cluster := gocql.NewCluster("192.168.1.1", "192.168.1.2", "192.168.1.3")
	cluster.Keyspace = "example"
	...
	session, err := cluster.CreateSession()

	if err = session.Query("use example2").Exec(); err != nil {
		log.Fatal(err)
	}

This will result in an err being returned from the session.Query line as the user is trying to execute a "use" statement.

Example

/* Before you execute the program, Launch `cqlsh` and execute:
create keyspace example with replication = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };
create table example.tweet(timeline text, id UUID, text text, PRIMARY KEY(id));
create index on example.tweet(timeline);
*/
package main

import (
	"fmt"
	"log"

	"github.com/gocql/gocql"
)

func main() {
	// connect to the cluster
	cluster := gocql.NewCluster("192.168.1.1", "192.168.1.2", "192.168.1.3")
	cluster.Keyspace = "example"
	cluster.Consistency = gocql.Quorum
	session, _ := cluster.CreateSession()
	defer session.Close()

	// insert a tweet
	if err := session.Query(`INSERT INTO tweet (timeline, id, text) VALUES (?, ?, ?)`,
		"me", gocql.TimeUUID(), "hello world").Exec(); err != nil {
		log.Fatal(err)
	}

	var id gocql.UUID
	var text string

	/* Search for a specific set of records whose 'timeline' column matches
	 * the value 'me'. The secondary index that we created earlier will be
	 * used for optimizing the search */
	if err := session.Query(`SELECT id, text FROM tweet WHERE timeline = ? LIMIT 1`,
		"me").Consistency(gocql.One).Scan(&id, &text); err != nil {
		log.Fatal(err)
	}
	fmt.Println("Tweet:", id, text)

	// list all tweets
	iter := session.Query(`SELECT id, text FROM tweet WHERE timeline = ?`, "me").Iter()
	for iter.Scan(&id, &text) {
		fmt.Println("Tweet:", id, text)
	}
	if err := iter.Close(); err != nil {
		log.Fatal(err)
	}
}

Data Binding

There are various ways to bind application level data structures to CQL statements:

  • You can write the data binding by hand, as outlined in the Tweet example. This provides you with the greatest flexibility, but it does mean that you need to keep your application code in sync with your Cassandra schema.
  • You can dynamically marshal an entire query result into an []map[string]interface{} using the SliceMap() API. This returns a slice of row maps keyed by CQL column mames. This method requires no special interaction with the gocql API, but it does require your application to be able to deal with a key value view of your data.
  • As a refinement on the SliceMap() API you can also call MapScan() which returns map[string]interface{} instances in a row by row fashion.
  • The Bind() API provides a client app with a low level mechanism to introspect query meta data and extract appropriate field values from application level data structures.
  • Building on top of the gocql driver, cqlr adds the ability to auto-bind a CQL iterator to a struct or to bind a struct to an INSERT statement.
  • Another external project that layers on top of gocql is cqlc which generates gocql compliant code from your Cassandra schema so that you can write type safe CQL statements in Go with a natural query syntax.
  • gocassa is an external project that layers on top of gocql to provide convenient query building and data binding.
  • gocqltable provides an ORM-style convenience layer to make CRUD operations with gocql easier.

Ecosystem

The following community maintained tools are known to integrate with gocql:

  • journey is a migration tool with Cassandra support.
  • negronicql is gocql middleware for Negroni.
  • cqlr adds the ability to auto-bind a CQL iterator to a struct or to bind a struct to an INSERT statement.
  • cqlc generates gocql compliant code from your Cassandra schema so that you can write type safe CQL statements in Go with a natural query syntax.
  • gocassa provides query building, adds data binding, and provides easy-to-use "recipe" tables for common query use-cases.
  • gocqltable is a wrapper around gocql that aims to simplify common operations.
  • gockle provides simple, mockable interfaces that wrap gocql types
  • scylladb is a fast Apache Cassandra-compatible NoSQL database

Other Projects

  • gocqldriver is the predecessor of gocql based on Go's database/sql package. This project isn't maintained anymore, because Cassandra wasn't a good fit for the traditional database/sql API. Use this package instead.

SEO

For some reason, when you Google golang cassandra, this project doesn't feature very highly in the result list. But if you Google go cassandra, then we're a bit higher up the list. So this is note to try to convince Google that golang is an alias for Go.

License

Copyright (c) 2012-2016 The gocql Authors. All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

Documentation

Overview

Package gocql implements a fast and robust Cassandra driver for the Go programming language.

Copyright (c) 2012 The gocql Authors. All rights reserved. Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. This file will be the future home for more policies

The uuid package can be used to generate and parse universally unique identifiers, a standardized format in the form of a 128 bit number.

http://tools.ietf.org/html/rfc4122

Index

Constants

View Source 
const (
	NodeUp nodeState = iota
	NodeDown
)
View Source 
const (
	DEFAULT_KEY_ALIAS    = "key"
	DEFAULT_COLUMN_ALIAS = "column"
	DEFAULT_VALUE_ALIAS  = "value"
)

default alias values

View Source 
const (
	REVERSED_TYPE   = "org.apache.cassandra.db.marshal.ReversedType"
	COMPOSITE_TYPE  = "org.apache.cassandra.db.marshal.CompositeType"
	COLLECTION_TYPE = "org.apache.cassandra.db.marshal.ColumnToCollectionType"
	LIST_TYPE       = "org.apache.cassandra.db.marshal.ListType"
	SET_TYPE        = "org.apache.cassandra.db.marshal.SetType"
	MAP_TYPE        = "org.apache.cassandra.db.marshal.MapType"
)
View Source 
const (
	VariantNCSCompat = 0
	VariantIETF      = 2
	VariantMicrosoft = 6
	VariantFuture    = 7
)
View Source 
const BatchSizeMaximum = 65535

BatchSizeMaximum is the maximum number of statements a batch operation can have. This limit is set by cassandra and could change in the future.

Variables

View Source 
var (
	ErrNoHosts              = errors.New("no hosts provided")
	ErrNoConnectionsStarted = errors.New("no connections were made when creating the session")
	ErrHostQueryFailed      = errors.New("unable to populate Hosts")
)
View Source 
var (
	ErrQueryArgLength    = errors.New("gocql: query argument length mismatch")
	ErrTimeoutNoResponse = errors.New("gocql: no response received from cassandra within timeout period")
	ErrTooManyTimeouts   = errors.New("gocql: too many query timeouts on the connection")
	ErrConnectionClosed  = errors.New("gocql: connection closed waiting for response")
	ErrNoStreams         = errors.New("gocql: no streams available on connection")
)
View Source 
var (
	ErrNotFound             = errors.New("not found")
	ErrUnavailable          = errors.New("unavailable")
	ErrUnsupported          = errors.New("feature not supported")
	ErrTooManyStmts         = errors.New("too many statements")
	ErrUseStmt              = errors.New("use statements aren't supported. Please see https://github.com/gocql/gocql for explanation.")
	ErrSessionClosed        = errors.New("session has been closed")
	ErrNoConnections        = errors.New("gocql: no hosts available in the pool")
	ErrNoKeyspace           = errors.New("no keyspace provided")
	ErrKeyspaceDoesNotExist = errors.New("keyspace does not exist")
	ErrNoMetadata           = errors.New("no metadata available")
)
View Source 
var (
	ErrFrameTooBig = errors.New("frame length is bigger than the maximum allowed")
)
View Source 
var (
	ErrorUDTUnavailable = errors.New("UDT are not available on protocols less than 3, please update config")
)
View Source 
var TimeoutLimit int64 = 10

If not zero, how many timeouts we will allow to occur before the connection is closed and restarted. This is to prevent a single query timeout from killing a connection which may be serving more queries just fine. Default is 10, should not be changed concurrently with queries.

View Source 
var UnsetValue = unsetColumn{}

Functions

func JoinHostPort 

func JoinHostPort(addr string, port int) string

JoinHostPort is a utility to return a address string that can be used gocql.Conn to form a connection with a host.

func Marshal 

func Marshal(info TypeInfo, value interface{}) ([]byte, error)

Marshal returns the CQL encoding of the value for the Cassandra internal type described by the info parameter.

func NewErrProtocol 

func NewErrProtocol(format string, args ...interface{}) error

func TupleColumnName 

func TupleColumnName(c string, n int) string

TupeColumnName will return the column name of a tuple value in a column named c at index n. It should be used if a specific element within a tuple is needed to be extracted from a map returned from SliceMap or MapScan.

func Unmarshal 

func Unmarshal(info TypeInfo, data []byte, value interface{}) error

Unmarshal parses the CQL encoded data based on the info parameter that describes the Cassandra internal data type and stores the result in the value pointed by value.

Types

type AddressTranslator 

type AddressTranslator interface {
	// Translate will translate the provided address and/or port to another
	// address and/or port. If no translation is possible, Translate will return the
	// address and port provided to it.
	Translate(addr net.IP, port int) (net.IP, int)
}

AddressTranslator provides a way to translate node addresses (and ports) that are discovered or received as a node event. This can be useful in an ec2 environment, for instance, to translate public IPs to private IPs.

func IdentityTranslator 

func IdentityTranslator() AddressTranslator

IdentityTranslator will do nothing but return what it was provided. It is essentially a no-op.

type AddressTranslatorFunc 

type AddressTranslatorFunc func(addr net.IP, port int) (net.IP, int)

func (AddressTranslatorFunc) Translate 

func (fn AddressTranslatorFunc) Translate(addr net.IP, port int) (net.IP, int)

type Authenticator 

type Authenticator interface {
	Challenge(req []byte) (resp []byte, auth Authenticator, err error)
	Success(data []byte) error
}

type Batch 

type Batch struct {
	Type    BatchType
	Entries []BatchEntry
	Cons    Consistency
	// contains filtered or unexported fields
}

func NewBatch 

func NewBatch(typ BatchType) *Batch

NewBatch creates a new batch operation without defaults from the cluster

func (*Batch) Attempts 

func (b *Batch) Attempts() int

Attempts returns the number of attempts made to execute the batch.

func (*Batch) Bind 

func (b *Batch) Bind(stmt string, bind func(q *QueryInfo) ([]interface{}, error))

Bind adds the query to the batch operation and correlates it with a binding callback that will be invoked when the batch is executed. The binding callback allows the application to define which query argument values will be marshalled as part of the batch execution.

func (*Batch) DefaultTimestamp 

func (b *Batch) DefaultTimestamp(enable bool) *Batch

DefaultTimestamp will enable the with default timestamp flag on the query. If enable, this will replace the server side assigned timestamp as default timestamp. Note that a timestamp in the query itself will still override this timestamp. This is entirely optional.

Only available on protocol >= 3

func (*Batch) GetConsistency 

func (b *Batch) GetConsistency() Consistency

GetConsistency returns the currently configured consistency level for the batch operation.

func (*Batch) GetRoutingKey 

func (b *Batch) GetRoutingKey() ([]byte, error)

func (*Batch) Latency 

func (b *Batch) Latency() int64

Latency returns the average number of nanoseconds to execute a single attempt of the batch.

func (*Batch) Query 

func (b *Batch) Query(stmt string, args ...interface{})

Query adds the query to the batch operation

func (*Batch) RetryPolicy 

func (b *Batch) RetryPolicy(r RetryPolicy) *Batch

RetryPolicy sets the retry policy to use when executing the batch operation

func (*Batch) SerialConsistency 

func (b *Batch) SerialConsistency(cons SerialConsistency) *Batch

SerialConsistency sets the consistency level for the serial phase of conditional updates. That consistency can only be either SERIAL or LOCAL_SERIAL and if not present, it defaults to SERIAL. This option will be ignored for anything else that a conditional update/insert.

Only available for protocol 3 and above

func (*Batch) Size 

func (b *Batch) Size() int

Size returns the number of batch statements to be executed by the batch operation.

func (*Batch) WithContext 

func (b *Batch) WithContext(ctx context.Context) *Batch

WithContext will set the context to use during a query, it will be used to timeout when waiting for responses from Cassandra.

func (*Batch) WithTimestamp 

func (b *Batch) WithTimestamp(timestamp int64) *Batch

WithTimestamp will enable the with default timestamp flag on the query like DefaultTimestamp does. But also allows to define value for timestamp. It works the same way as USING TIMESTAMP in the query itself, but should not break prepared query optimization

Only available on protocol >= 3

type BatchEntry 

type BatchEntry struct {
	Stmt string
	Args []interface{}
	// contains filtered or unexported fields
}

type BatchType 

type BatchType byte
const (
	LoggedBatch   BatchType = 0
	UnloggedBatch BatchType = 1
	CounterBatch  BatchType = 2
)

type ClusterConfig 

type ClusterConfig struct {
	// addresses for the initial connections. It is recommended to use the value set in
	// the Cassandra config for broadcast_address or listen_address, an IP address not
	// a domain name. This is because events from Cassandra will use the configured IP
	// address, which is used to index connected hosts. If the domain name specified
	// resolves to more than 1 IP address then the driver may connect multiple times to
	// the same host, and will not mark the node being down or up from events.
	Hosts      []string
	CQLVersion string // CQL version (default: 3.0.0)

	// ProtoVersion sets the version of the native protocol to use, this will
	// enable features in the driver for specific protocol versions, generally this
	// should be set to a known version (2,3,4) for the cluster being connected to.
	//
	// If it is 0 or unset (the default) then the driver will attempt to discover the
	// highest supported protocol for the cluster. In clusters with nodes of different
	// versions the protocol selected is not defined (ie, it can be any of the supported in the cluster)
	ProtoVersion      int
	Timeout           time.Duration     // connection timeout (default: 600ms)
	ConnectTimeout    time.Duration     // initial connection timeout, used during initial dial to server (default: 600ms)
	Port              int               // port (default: 9042)
	Keyspace          string            // initial keyspace (optional)
	NumConns          int               // number of connections per host (default: 2)
	Consistency       Consistency       // default consistency level (default: Quorum)
	Compressor        Compressor        // compression algorithm (default: nil)
	Authenticator     Authenticator     // authenticator (default: nil)
	RetryPolicy       RetryPolicy       // Default retry policy to use for queries (default: 0)
	SocketKeepalive   time.Duration     // The keepalive period to use, enabled if > 0 (default: 0)
	MaxPreparedStmts  int               // Sets the maximum cache size for prepared statements globally for gocql (default: 1000)
	MaxRoutingKeyInfo int               // Sets the maximum cache size for query info about statements for each session (default: 1000)
	PageSize          int               // Default page size to use for created sessions (default: 5000)
	SerialConsistency SerialConsistency // Sets the consistency for the serial part of queries, values can be either SERIAL or LOCAL_SERIAL (default: unset)
	SslOpts           *SslOptions
	DefaultTimestamp  bool // Sends a client side timestamp for all requests which overrides the timestamp at which it arrives at the server. (default: true, only enabled for protocol 3 and above)
	// PoolConfig configures the underlying connection pool, allowing the
	// configuration of host selection and connection selection policies.
	PoolConfig PoolConfig

	// If not zero, gocql attempt to reconnect known DOWN nodes in every ReconnectInterval.
	ReconnectInterval time.Duration

	// The maximum amount of time to wait for schema agreement in a cluster after
	// receiving a schema change frame. (deault: 60s)
	MaxWaitSchemaAgreement time.Duration

	// HostFilter will filter all incoming events for host, any which don't pass
	// the filter will be ignored. If set will take precedence over any options set
	// via Discovery
	HostFilter HostFilter

	// AddressTranslator will translate addresses found on peer discovery and/or
	// node change events.
	AddressTranslator AddressTranslator

	// If IgnorePeerAddr is true and the address in system.peers does not match
	// the supplied host by either initial hosts or discovered via events then the
	// host will be replaced with the supplied address.
	//
	// For example if an event comes in with host=10.0.0.1 but when looking up that
	// address in system.local or system.peers returns 127.0.0.1, the peer will be
	// set to 10.0.0.1 which is what will be used to connect to.
	IgnorePeerAddr bool

	// If DisableInitialHostLookup then the driver will not attempt to get host info
	// from the system.peers table, this will mean that the driver will connect to
	// hosts supplied and will not attempt to lookup the hosts information, this will
	// mean that data_centre, rack and token information will not be available and as
	// such host filtering and token aware query routing will not be available.
	DisableInitialHostLookup bool

	// Configure events the driver will register for
	Events struct {
		// disable registering for status events (node up/down)
		DisableNodeStatusEvents bool
		// disable registering for topology events (node added/removed/moved)
		DisableTopologyEvents bool
		// disable registering for schema events (keyspace/table/function removed/created/updated)
		DisableSchemaEvents bool
	}

	// DisableSkipMetadata will override the internal result metadata cache so that the driver does not
	// send skip_metadata for queries, this means that the result will always contain
	// the metadata to parse the rows and will not reuse the metadata from the prepared
	// statement.
	//
	// See https://issues.apache.org/jira/browse/CASSANDRA-10786
	DisableSkipMetadata bool
	// contains filtered or unexported fields
}

ClusterConfig is a struct to configure the default cluster implementation of gocql. It has a variety of attributes that can be used to modify the behavior to fit the most common use cases. Applications that require a different setup must implement their own cluster.

func NewCluster 

func NewCluster(hosts ...string) *ClusterConfig

NewCluster generates a new config for the default cluster implementation.

The supplied hosts are used to initially connect to the cluster then the rest of the ring will be automatically discovered. It is recommended to use the value set in the Cassandra config for broadcast_address or listen_address, an IP address not a domain name. This is because events from Cassandra will use the configured IP address, which is used to index connected hosts. If the domain name specified resolves to more than 1 IP address then the driver may connect multiple times to the same host, and will not mark the node being down or up from events.

func (*ClusterConfig) CreateSession 

func (cfg *ClusterConfig) CreateSession() (*Session, error)

CreateSession initializes the cluster based on this config and returns a session object that can be used to interact with the database.

type CollectionType 

type CollectionType struct {
	NativeType
	Key  TypeInfo // only used for TypeMap
	Elem TypeInfo // only used for TypeMap, TypeList and TypeSet
}

func (CollectionType) New 

func (t CollectionType) New() interface{}

func (CollectionType) String 

func (c CollectionType) String() string

type ColumnIndexMetadata 

type ColumnIndexMetadata struct {
	Name    string
	Type    string
	Options map[string]interface{}
}

type ColumnInfo 

type ColumnInfo struct {
	Keyspace string
	Table    string
	Name     string
	TypeInfo TypeInfo
}

func (ColumnInfo) String 

func (c ColumnInfo) String() string

type ColumnKind 

type ColumnKind int
const (
	ColumnUnkownKind ColumnKind = iota
	ColumnPartitionKey
	ColumnClusteringKey
	ColumnRegular
	ColumnCompact
	ColumnStatic
)

func (ColumnKind) String 

func (c ColumnKind) String() string

func (*ColumnKind) UnmarshalCQL 

func (c *ColumnKind) UnmarshalCQL(typ TypeInfo, p []byte) error

type ColumnMetadata 

type ColumnMetadata struct {
	Keyspace        string
	Table           string
	Name            string
	ComponentIndex  int
	Kind            ColumnKind
	Validator       string
	Type            TypeInfo
	ClusteringOrder string
	Order           ColumnOrder
	Index           ColumnIndexMetadata
}

schema metadata for a column

type ColumnOrder 

type ColumnOrder bool

the ordering of the column with regard to its comparator 

const (
	ASC  ColumnOrder = false
	DESC             = true
)

type Compressor 

type Compressor interface {
	Name() string
	Encode(data []byte) ([]byte, error)
	Decode(data []byte) ([]byte, error)
}

type Conn 

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

Conn is a single connection to a Cassandra node. It can be used to execute queries, but users are usually advised to use a more reliable, higher level API.

func Connect 

func Connect(host *HostInfo, cfg *ConnConfig, errorHandler ConnErrorHandler, session *Session) (*Conn, error)

Connect establishes a connection to a Cassandra node.

func (*Conn) Address 

func (c *Conn) Address() string

func (*Conn) AvailableStreams 

func (c *Conn) AvailableStreams() int

func (*Conn) Close 

func (c *Conn) Close()

func (*Conn) Closed 

func (c *Conn) Closed() bool

func (*Conn) Pick 

func (c *Conn) Pick(qry *Query) *Conn

func (*Conn) Read 

func (c *Conn) Read(p []byte) (n int, err error)

func (*Conn) UseKeyspace 

func (c *Conn) UseKeyspace(keyspace string) error

func (*Conn) Write 

func (c *Conn) Write(p []byte) (int, error)

type ConnConfig 

type ConnConfig struct {
	ProtoVersion   int
	CQLVersion     string
	Timeout        time.Duration
	ConnectTimeout time.Duration
	Compressor     Compressor
	Authenticator  Authenticator
	Keepalive      time.Duration
	// contains filtered or unexported fields
}

type ConnErrorHandler 

type ConnErrorHandler interface {
	HandleError(conn *Conn, err error, closed bool)
}

type Consistency 

type Consistency uint16
const (
	Any         Consistency = 0x00
	One         Consistency = 0x01
	Two         Consistency = 0x02
	Three       Consistency = 0x03
	Quorum      Consistency = 0x04
	All         Consistency = 0x05
	LocalQuorum Consistency = 0x06
	EachQuorum  Consistency = 0x07
	LocalOne    Consistency = 0x0A
)

func ParseConsistency 

func ParseConsistency(s string) Consistency

func ParseConsistencyWrapper 

func ParseConsistencyWrapper(s string) (consistency Consistency, err error)

ParseConsistencyWrapper wraps gocql.ParseConsistency to provide an err return instead of a panic

func (Consistency) String 

func (c Consistency) String() string

type ErrProtocol 

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

type Error 

type Error struct {
	Code    int
	Message string
}

func (Error) Error 

func (e Error) Error() string

type ExecutableQuery 

type ExecutableQuery interface {
	GetRoutingKey() ([]byte, error)
	RetryableQuery
	// contains filtered or unexported methods
}

type ExponentialBackoffRetryPolicy 

type ExponentialBackoffRetryPolicy struct {
	NumRetries int
	Min, Max   time.Duration
}

ExponentialBackoffRetryPolicy sleeps between attempts

func (*ExponentialBackoffRetryPolicy) Attempt 

func (e *ExponentialBackoffRetryPolicy) Attempt(q RetryableQuery) bool

type HostFilter 

type HostFilter interface {
	// Called when a new host is discovered, returning true will cause the host
	// to be added to the pools.
	Accept(host *HostInfo) bool
}

HostFilter interface is used when a host is discovered via server sent events.

func AcceptAllFilter 

func AcceptAllFilter() HostFilter

AcceptAllFilter will accept all hosts

func DataCentreHostFilter 

func DataCentreHostFilter(dataCentre string) HostFilter

DataCentreHostFilter filters all hosts such that they are in the same data centre as the supplied data centre.

func DenyAllFilter 

func DenyAllFilter() HostFilter

func WhiteListHostFilter 

func WhiteListHostFilter(hosts ...string) HostFilter

WhiteListHostFilter filters incoming hosts by checking that their address is in the initial hosts whitelist.

type HostFilterFunc 

type HostFilterFunc func(host *HostInfo) bool

HostFilterFunc converts a func(host HostInfo) bool into a HostFilter

func (HostFilterFunc) Accept 

func (fn HostFilterFunc) Accept(host *HostInfo) bool

type HostInfo 

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

func (*HostInfo) BroadcastAddress 

func (h *HostInfo) BroadcastAddress() net.IP

func (*HostInfo) ClusterName 

func (h *HostInfo) ClusterName() string

func (*HostInfo) ConnectAddress 

func (h *HostInfo) ConnectAddress() net.IP

Returns the address that should be used to connect to the host. If you wish to override this, use an AddressTranslator or use a HostFilter to SetConnectAddress()

func (*HostInfo) DSEVersion 

func (h *HostInfo) DSEVersion() string

func (*HostInfo) DataCenter 

func (h *HostInfo) DataCenter() string

func (*HostInfo) Equal 

func (h *HostInfo) Equal(host *HostInfo) bool

func (*HostInfo) Graph 

func (h *HostInfo) Graph() bool

func (*HostInfo) HostID 

func (h *HostInfo) HostID() string

func (*HostInfo) IsUp 

func (h *HostInfo) IsUp() bool

func (*HostInfo) ListenAddress 

func (h *HostInfo) ListenAddress() net.IP

func (*HostInfo) Partitioner 

func (h *HostInfo) Partitioner() string

func (*HostInfo) Peer 

func (h *HostInfo) Peer() net.IP

func (*HostInfo) Port 

func (h *HostInfo) Port() int

func (*HostInfo) PreferredIP 

func (h *HostInfo) PreferredIP() net.IP

func (*HostInfo) RPCAddress 

func (h *HostInfo) RPCAddress() net.IP

func (*HostInfo) Rack 

func (h *HostInfo) Rack() string

func (*HostInfo) SetConnectAddress 

func (h *HostInfo) SetConnectAddress(address net.IP) *HostInfo

func (*HostInfo) State 

func (h *HostInfo) State() nodeState

func (*HostInfo) String 

func (h *HostInfo) String() string

func (*HostInfo) Tokens 

func (h *HostInfo) Tokens() []string

func (*HostInfo) Version 

func (h *HostInfo) Version() cassVersion

func (*HostInfo) WorkLoad 

func (h *HostInfo) WorkLoad() string

type HostSelectionPolicy 

type HostSelectionPolicy interface {
	HostStateNotifier
	SetPartitioner
	//Pick returns an iteration function over selected hosts
	Pick(ExecutableQuery) NextHost
}

HostSelectionPolicy is an interface for selecting the most appropriate host to execute a given query.

func DCAwareRoundRobinPolicy 

func DCAwareRoundRobinPolicy(localDC string) HostSelectionPolicy

DCAwareRoundRobinPolicy is a host selection policies which will priorities and return hosts which are in the local datacentre before returning hosts in all other datercentres

func HostPoolHostPolicy 

func HostPoolHostPolicy(hp hostpool.HostPool) HostSelectionPolicy

HostPoolHostPolicy is a host policy which uses the bitly/go-hostpool library to distribute queries between hosts and prevent sending queries to unresponsive hosts. When creating the host pool that is passed to the policy use an empty slice of hosts as the hostpool will be populated later by gocql. See below for examples of usage: 

// Create host selection policy using a simple host pool
cluster.PoolConfig.HostSelectionPolicy = HostPoolHostPolicy(hostpool.New(nil))

// Create host selection policy using an epsilon greedy pool
cluster.PoolConfig.HostSelectionPolicy = HostPoolHostPolicy(
    hostpool.NewEpsilonGreedy(nil, 0, &hostpool.LinearEpsilonValueCalculator{}),
)

func RoundRobinHostPolicy 

func RoundRobinHostPolicy() HostSelectionPolicy

RoundRobinHostPolicy is a round-robin load balancing policy, where each host is tried sequentially for each query.

func TokenAwareHostPolicy 

func TokenAwareHostPolicy(fallback HostSelectionPolicy) HostSelectionPolicy

TokenAwareHostPolicy is a token aware host selection policy, where hosts are selected based on the partition key, so queries are sent to the host which owns the partition. Fallback is used when routing information is not available.

type HostStateNotifier 

type HostStateNotifier interface {
	AddHost(host *HostInfo)
	RemoveHost(host *HostInfo)
	HostUp(host *HostInfo)
	HostDown(host *HostInfo)
}

type Iter 

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

Iter represents an iterator that can be used to iterate over all rows that were returned by a query. The iterator might send additional queries to the database during the iteration if paging was enabled.

func (*Iter) Close 

func (iter *Iter) Close() error

Close closes the iterator and returns any errors that happened during the query or the iteration.

func (*Iter) Columns 

func (iter *Iter) Columns() []ColumnInfo

Columns returns the name and type of the selected columns.

func (*Iter) GetCustomPayload 

func (iter *Iter) GetCustomPayload() map[string][]byte

GetCustomPayload returns any parsed custom payload results if given in the response from Cassandra. Note that the result is not a copy.

This additional feature of CQL Protocol v4 allows additional results and query information to be returned by custom QueryHandlers running in your C* cluster. See https://datastax.github.io/java-driver/manual/custom_payloads/

func (*Iter) Host 

func (iter *Iter) Host() *HostInfo

Host returns the host which the query was sent to.

func (*Iter) MapScan 

func (iter *Iter) MapScan(m map[string]interface{}) bool

MapScan takes a map[string]interface{} and populates it with a row that is returned from cassandra.

Each call to MapScan() must be called with a new map object. During the call to MapScan() any pointers in the existing map are replaced with non pointer types before the call returns 

iter := session.Query(`SELECT * FROM mytable`).Iter()
for {
	// New map each iteration
	row = make(map[string]interface{})
	if !iter.MapScan(row) {
		break
	}
	// Do things with row
	if fullname, ok := row["fullname"]; ok {
		fmt.Printf("Full Name: %s\n", fullname)
	}
}

You can also pass pointers in the map before each call 

var fullName FullName // Implements gocql.Unmarshaler and gocql.Marshaler interfaces
var address net.IP
var age int
iter := session.Query(`SELECT * FROM scan_map_table`).Iter()
for {
	// New map each iteration
	row := map[string]interface{}{
		"fullname": &fullName,
		"age":      &age,
		"address":  &address,
	}
	if !iter.MapScan(row) {
		break
	}
	fmt.Printf("First: %s Age: %d Address: %q\n", fullName.FirstName, age, address)
}

func (*Iter) NumRows 

func (iter *Iter) NumRows() int

NumRows returns the number of rows in this pagination, it will update when new pages are fetched, it is not the value of the total number of rows this iter will return unless there is only a single page returned.

func (*Iter) PageState 

func (iter *Iter) PageState() []byte

PageState return the current paging state for a query which can be used for subsequent quries to resume paging this point.

func (*Iter) RowData 

func (iter *Iter) RowData() (RowData, error)

func (*Iter) Scan 

func (iter *Iter) Scan(dest ...interface{}) bool

Scan consumes the next row of the iterator and copies the columns of the current row into the values pointed at by dest. Use nil as a dest value to skip the corresponding column. Scan might send additional queries to the database to retrieve the next set of rows if paging was enabled.

Scan returns true if the row was successfully unmarshaled or false if the end of the result set was reached or if an error occurred. Close should be called afterwards to retrieve any potential errors.

func (*Iter) Scanner 

func (iter *Iter) Scanner() Scanner

Scanner returns a row Scanner which provides an interface to scan rows in a manner which is similar to database/sql. The iter should NOT be used again after calling this method.

func (*Iter) SliceMap 

func (iter *Iter) SliceMap() ([]map[string]interface{}, error)

SliceMap is a helper function to make the API easier to use returns the data from the query in the form of []map[string]interface{}

func (*Iter) Warnings 

func (iter *Iter) Warnings() []string

Warnings returns any warnings generated if given in the response from Cassandra.

This is only available starting with CQL Protocol v4.

func (*Iter) WillSwitchPage 

func (iter *Iter) WillSwitchPage() bool

WillSwitchPage detects if iterator reached end of current page and the next page is available.

type KeyspaceMetadata 

type KeyspaceMetadata struct {
	Name            string
	DurableWrites   bool
	StrategyClass   string
	StrategyOptions map[string]interface{}
	Tables          map[string]*TableMetadata
}

schema metadata for a keyspace

type MarshalError 

type MarshalError string

func (MarshalError) Error 

func (m MarshalError) Error() string

type Marshaler 

type Marshaler interface {
	MarshalCQL(info TypeInfo) ([]byte, error)
}

Marshaler is the interface implemented by objects that can marshal themselves into values understood by Cassandra.

type NativeType 

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

func NewNativeType 

func NewNativeType(proto byte, typ Type, custom string) NativeType

func (NativeType) Custom 

func (s NativeType) Custom() string

func (NativeType) New 

func (t NativeType) New() interface{}

func (NativeType) String 

func (s NativeType) String() string

func (NativeType) Type 

func (s NativeType) Type() Type

func (NativeType) Version 

func (s NativeType) Version() byte

type NextHost 

type NextHost func() SelectedHost

NextHost is an iteration function over picked hosts

type Node 

type Node interface {
	Pick(qry *Query) *Conn
	Close()
}

type PasswordAuthenticator 

type PasswordAuthenticator struct {
	Username string
	Password string
}

func (PasswordAuthenticator) Challenge 

func (p PasswordAuthenticator) Challenge(req []byte) ([]byte, Authenticator, error)

func (PasswordAuthenticator) Success 

func (p PasswordAuthenticator) Success(data []byte) error

type PoolConfig 

type PoolConfig struct {
	// HostSelectionPolicy sets the policy for selecting which host to use for a
	// given query (default: RoundRobinHostPolicy())
	HostSelectionPolicy HostSelectionPolicy
}

PoolConfig configures the connection pool used by the driver, it defaults to using a round-robin host selection policy and a round-robin connection selection policy for each host.

type Query 

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

Query represents a CQL statement that can be executed.

func (*Query) Attempts 

func (q *Query) Attempts() int

Attempts returns the number of times the query was executed.

func (*Query) Bind 

func (q *Query) Bind(v ...interface{}) *Query

Bind sets query arguments of query. This can also be used to rebind new query arguments to an existing query instance.

func (*Query) Consistency 

func (q *Query) Consistency(c Consistency) *Query

Consistency sets the consistency level for this query. If no consistency level have been set, the default consistency level of the cluster is used.

func (*Query) DefaultTimestamp 

func (q *Query) DefaultTimestamp(enable bool) *Query

DefaultTimestamp will enable the with default timestamp flag on the query. If enable, this will replace the server side assigned timestamp as default timestamp. Note that a timestamp in the query itself will still override this timestamp. This is entirely optional.

Only available on protocol >= 3

func (*Query) Exec 

func (q *Query) Exec() error

Exec executes the query without returning any rows.

func (*Query) GetConsistency 

func (q *Query) GetConsistency() Consistency

GetConsistency returns the currently configured consistency level for the query.

func (*Query) GetRoutingKey 

func (q *Query) GetRoutingKey() ([]byte, error)

GetRoutingKey gets the routing key to use for routing this query. If a routing key has not been explicitly set, then the routing key will be constructed if possible using the keyspace's schema and the query info for this query statement. If the routing key cannot be determined then nil will be returned with no error. On any error condition, an error description will be returned.

func (*Query) Iter 

func (q *Query) Iter() *Iter

Iter executes the query and returns an iterator capable of iterating over all results.

func (*Query) Latency 

func (q *Query) Latency() int64

Latency returns the average amount of nanoseconds per attempt of the query.

func (*Query) MapScan 

func (q *Query) MapScan(m map[string]interface{}) error

MapScan executes the query, copies the columns of the first selected row into the map pointed at by m and discards the rest. If no rows were selected, ErrNotFound is returned.

func (*Query) MapScanCAS 

func (q *Query) MapScanCAS(dest map[string]interface{}) (applied bool, err error)

MapScanCAS executes a lightweight transaction (i.e. an UPDATE or INSERT statement containing an IF clause). If the transaction fails because the existing values did not match, the previous values will be stored in dest map.

As for INSERT .. IF NOT EXISTS, previous values will be returned as if SELECT * FROM. So using ScanCAS with INSERT is inherently prone to column mismatching. MapScanCAS is added to capture them safely.

func (*Query) NoSkipMetadata 

func (q *Query) NoSkipMetadata() *Query

NoSkipMetadata will override the internal result metadata cache so that the driver does not send skip_metadata for queries, this means that the result will always contain the metadata to parse the rows and will not reuse the metadata from the prepared staement. This should only be used to work around cassandra bugs, such as when using CAS operations which do not end in Cas.

See https://issues.apache.org/jira/browse/CASSANDRA-11099 https://github.com/gocql/gocql/issues/612

func (*Query) PageSize 

func (q *Query) PageSize(n int) *Query

PageSize will tell the iterator to fetch the result in pages of size n. This is useful for iterating over large result sets, but setting the page size too low might decrease the performance. This feature is only available in Cassandra 2 and onwards.

func (*Query) PageState 

func (q *Query) PageState(state []byte) *Query

PageState sets the paging state for the query to resume paging from a specific point in time. Setting this will disable to query paging for this query, and must be used for all subsequent pages.

func (*Query) Prefetch 

func (q *Query) Prefetch(p float64) *Query

SetPrefetch sets the default threshold for pre-fetching new pages. If there are only p*pageSize rows remaining, the next page will be requested automatically.

func (*Query) Release 

func (q *Query) Release()

Release releases a query back into a pool of queries. Released Queries cannot be reused.

Example: 

qry := session.Query("SELECT * FROM my_table")
qry.Exec()
qry.Release()

func (*Query) RetryPolicy 

func (q *Query) RetryPolicy(r RetryPolicy) *Query

RetryPolicy sets the policy to use when retrying the query.

func (*Query) RoutingKey 

func (q *Query) RoutingKey(routingKey []byte) *Query

RoutingKey sets the routing key to use when a token aware connection pool is used to optimize the routing of this query.

func (*Query) Scan 

func (q *Query) Scan(dest ...interface{}) error

Scan executes the query, copies the columns of the first selected row into the values pointed at by dest and discards the rest. If no rows were selected, ErrNotFound is returned.

func (*Query) ScanCAS 

func (q *Query) ScanCAS(dest ...interface{}) (applied bool, err error)

ScanCAS executes a lightweight transaction (i.e. an UPDATE or INSERT statement containing an IF clause). If the transaction fails because the existing values did not match, the previous values will be stored in dest.

func (*Query) SerialConsistency 

func (q *Query) SerialConsistency(cons SerialConsistency) *Query

SerialConsistency sets the consistency level for the serial phase of conditional updates. That consistency can only be either SERIAL or LOCAL_SERIAL and if not present, it defaults to SERIAL. This option will be ignored for anything else that a conditional update/insert.

func (Query) String 

func (q Query) String() string

String implements the stringer interface.

func (*Query) Trace 

func (q *Query) Trace(trace Tracer) *Query

Trace enables tracing of this query. Look at the documentation of the Tracer interface to learn more about tracing.

func (*Query) WithContext 

func (q *Query) WithContext(ctx context.Context) *Query

WithContext will set the context to use during a query, it will be used to timeout when waiting for responses from Cassandra.

func (*Query) WithTimestamp 

func (q *Query) WithTimestamp(timestamp int64) *Query

WithTimestamp will enable the with default timestamp flag on the query like DefaultTimestamp does. But also allows to define value for timestamp. It works the same way as USING TIMESTAMP in the query itself, but should not break prepared query optimization

Only available on protocol >= 3

type QueryInfo 

type QueryInfo struct {
	Id          []byte
	Args        []ColumnInfo
	Rval        []ColumnInfo
	PKeyColumns []int
}

type RequestErrAlreadyExists 

type RequestErrAlreadyExists struct {
	Keyspace string
	Table    string
	// contains filtered or unexported fields
}

func (RequestErrAlreadyExists) Code 

func (e RequestErrAlreadyExists) Code() int

func (RequestErrAlreadyExists) Error 

func (e RequestErrAlreadyExists) Error() string

func (RequestErrAlreadyExists) Message 

func (e RequestErrAlreadyExists) Message() string

func (RequestErrAlreadyExists) String 

func (e RequestErrAlreadyExists) String() string

type RequestErrFunctionFailure 

type RequestErrFunctionFailure struct {
	Keyspace string
	Function string
	ArgTypes []string
	// contains filtered or unexported fields
}

func (RequestErrFunctionFailure) Code 

func (e RequestErrFunctionFailure) Code() int

func (RequestErrFunctionFailure) Error 

func (e RequestErrFunctionFailure) Error() string

func (RequestErrFunctionFailure) Message 

func (e RequestErrFunctionFailure) Message() string

func (RequestErrFunctionFailure) String 

func (e RequestErrFunctionFailure) String() string

type RequestErrReadFailure 

type RequestErrReadFailure struct {
	Consistency Consistency
	Received    int
	BlockFor    int
	NumFailures int
	DataPresent bool
	// contains filtered or unexported fields
}

func (RequestErrReadFailure) Code 

func (e RequestErrReadFailure) Code() int

func (RequestErrReadFailure) Error 

func (e RequestErrReadFailure) Error() string

func (RequestErrReadFailure) Message 

func (e RequestErrReadFailure) Message() string

func (RequestErrReadFailure) String 

func (e RequestErrReadFailure) String() string

type RequestErrReadTimeout 

type RequestErrReadTimeout struct {
	Consistency Consistency
	Received    int
	BlockFor    int
	DataPresent byte
	// contains filtered or unexported fields
}

func (RequestErrReadTimeout) Code 

func (e RequestErrReadTimeout) Code() int

func (RequestErrReadTimeout) Error 

func (e RequestErrReadTimeout) Error() string

func (RequestErrReadTimeout) Message 

func (e RequestErrReadTimeout) Message() string

func (RequestErrReadTimeout) String 

func (e RequestErrReadTimeout) String() string

type RequestErrUnavailable 

type RequestErrUnavailable struct {
	Consistency Consistency
	Required    int
	Alive       int
	// contains filtered or unexported fields
}

func (RequestErrUnavailable) Code 

func (e RequestErrUnavailable) Code() int

func (RequestErrUnavailable) Error 

func (e RequestErrUnavailable) Error() string

func (RequestErrUnavailable) Message 

func (e RequestErrUnavailable) Message() string

func (*RequestErrUnavailable) String 

func (e *RequestErrUnavailable) String() string

type RequestErrUnprepared 

type RequestErrUnprepared struct {
	StatementId []byte
	// contains filtered or unexported fields
}

func (RequestErrUnprepared) Code 

func (e RequestErrUnprepared) Code() int

func (RequestErrUnprepared) Error 

func (e RequestErrUnprepared) Error() string

func (RequestErrUnprepared) Message 

func (e RequestErrUnprepared) Message() string

func (RequestErrUnprepared) String 

func (e RequestErrUnprepared) String() string

type RequestErrWriteFailure 

type RequestErrWriteFailure struct {
	Consistency Consistency
	Received    int
	BlockFor    int
	NumFailures int
	WriteType   string
	// contains filtered or unexported fields
}

func (RequestErrWriteFailure) Code 

func (e RequestErrWriteFailure) Code() int

func (RequestErrWriteFailure) Error 

func (e RequestErrWriteFailure) Error() string

func (RequestErrWriteFailure) Message 

func (e RequestErrWriteFailure) Message() string

func (RequestErrWriteFailure) String 

func (e RequestErrWriteFailure) String() string

type RequestErrWriteTimeout 

type RequestErrWriteTimeout struct {
	Consistency Consistency
	Received    int
	BlockFor    int
	WriteType   string
	// contains filtered or unexported fields
}

func (RequestErrWriteTimeout) Code 

func (e RequestErrWriteTimeout) Code() int

func (RequestErrWriteTimeout) Error 

func (e RequestErrWriteTimeout) Error() string

func (RequestErrWriteTimeout) Message 

func (e RequestErrWriteTimeout) Message() string

func (RequestErrWriteTimeout) String 

func (e RequestErrWriteTimeout) String() string

type RequestError 

type RequestError interface {
	Code() int
	Message() string
	Error() string
}

type RetryPolicy 

type RetryPolicy interface {
	Attempt(RetryableQuery) bool
}

RetryPolicy interface is used by gocql to determine if a query can be attempted again after a retryable error has been received. The interface allows gocql users to implement their own logic to determine if a query can be attempted again.

See SimpleRetryPolicy as an example of implementing and using a RetryPolicy interface.

type RetryableQuery 

type RetryableQuery interface {
	Attempts() int
	GetConsistency() Consistency
}

RetryableQuery is an interface that represents a query or batch statement that exposes the correct functions for the retry policy logic to evaluate correctly.

type RoundRobin 

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

func NewRoundRobin 

func NewRoundRobin() *RoundRobin

func (*RoundRobin) AddNode 

func (r *RoundRobin) AddNode(node Node)

func (*RoundRobin) Close 

func (r *RoundRobin) Close()

func (*RoundRobin) Pick 

func (r *RoundRobin) Pick(qry *Query) *Conn

func (*RoundRobin) RemoveNode 

func (r *RoundRobin) RemoveNode(node Node)

func (*RoundRobin) Size 

func (r *RoundRobin) Size() int

type RowData 

type RowData struct {
	Columns []string
	Values  []interface{}
}

type Scanner 

type Scanner interface {
	Next() bool
	Scan(...interface{}) error
	Err() error
}

type SelectedHost 

type SelectedHost interface {
	Info() *HostInfo
	Mark(error)
}

SelectedHost is an interface returned when picking a host from a host selection policy.

type SerialConsistency 

type SerialConsistency uint16
const (
	Serial      SerialConsistency = 0x08
	LocalSerial SerialConsistency = 0x09
)

func (SerialConsistency) String 

func (s SerialConsistency) String() string

type Session 

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

Session is the interface used by users to interact with the database.

It's safe for concurrent use by multiple goroutines and a typical usage scenario is to have one global session object to interact with the whole Cassandra cluster.

This type extends the Node interface by adding a convinient query builder and automatically sets a default consistency level on all operations that do not have a consistency level set.

func NewSession 

func NewSession(cfg ClusterConfig) (*Session, error)

NewSession wraps an existing Node.

func (*Session) Bind 

func (s *Session) Bind(stmt string, b func(q *QueryInfo) ([]interface{}, error)) *Query

Bind generates a new query object based on the query statement passed in. The query is automatically prepared if it has not previously been executed. The binding callback allows the application to define which query argument values will be marshalled as part of the query execution. During execution, the meta data of the prepared query will be routed to the binding callback, which is responsible for producing the query argument values.

func (*Session) Close 

func (s *Session) Close()

Close closes all connections. The session is unusable after this operation.

func (*Session) Closed 

func (s *Session) Closed() bool

func (*Session) ExecuteBatch 

func (s *Session) ExecuteBatch(batch *Batch) error

ExecuteBatch executes a batch operation and returns nil if successful otherwise an error is returned describing the failure.

func (*Session) ExecuteBatchCAS 

func (s *Session) ExecuteBatchCAS(batch *Batch, dest ...interface{}) (applied bool, iter *Iter, err error)

ExecuteBatchCAS executes a batch operation and returns true if successful and an iterator (to scan aditional rows if more than one conditional statement) was sent. Further scans on the interator must also remember to include the applied boolean as the first argument to *Iter.Scan

func (*Session) KeyspaceMetadata 

func (s *Session) KeyspaceMetadata(keyspace string) (*KeyspaceMetadata, error)

KeyspaceMetadata returns the schema metadata for the keyspace specified. Returns an error if the keyspace does not exist.

func (*Session) MapExecuteBatchCAS 

func (s *Session) MapExecuteBatchCAS(batch *Batch, dest map[string]interface{}) (applied bool, iter *Iter, err error)

MapExecuteBatchCAS executes a batch operation much like ExecuteBatchCAS, however it accepts a map rather than a list of arguments for the initial scan.

func (*Session) NewBatch 

func (s *Session) NewBatch(typ BatchType) *Batch

NewBatch creates a new batch operation using defaults defined in the cluster

func (*Session) Query 

func (s *Session) Query(stmt string, values ...interface{}) *Query

Query generates a new query object for interacting with the database. Further details of the query may be tweaked using the resulting query value before the query is executed. Query is automatically prepared if it has not previously been executed.

func (*Session) SetConsistency 

func (s *Session) SetConsistency(cons Consistency)

SetConsistency sets the default consistency level for this session. This setting can also be changed on a per-query basis and the default value is Quorum.

func (*Session) SetPageSize 

func (s *Session) SetPageSize(n int)

SetPageSize sets the default page size for this session. A value <= 0 will disable paging. This setting can also be changed on a per-query basis.

func (*Session) SetPrefetch 

func (s *Session) SetPrefetch(p float64)

SetPrefetch sets the default threshold for pre-fetching new pages. If there are only p*pageSize rows remaining, the next page will be requested automatically. This value can also be changed on a per-query basis and the default value is 0.25.

func (*Session) SetTrace 

func (s *Session) SetTrace(trace Tracer)

SetTrace sets the default tracer for this session. This setting can also be changed on a per-query basis.

type SetHosts 

type SetHosts interface {
	SetHosts(hosts []*HostInfo)
}

interface to implement to receive the host information

type SetPartitioner 

type SetPartitioner interface {
	SetPartitioner(partitioner string)
}

interface to implement to receive the partitioner value

type SimpleRetryPolicy 

type SimpleRetryPolicy struct {
	NumRetries int //Number of times to retry a query
}

SimpleRetryPolicy has simple logic for attempting a query a fixed number of times.

See below for examples of usage: 

//Assign to the cluster
cluster.RetryPolicy = &gocql.SimpleRetryPolicy{NumRetries: 3}

//Assign to a query
query.RetryPolicy(&gocql.SimpleRetryPolicy{NumRetries: 1})

func (*SimpleRetryPolicy) Attempt 

func (s *SimpleRetryPolicy) Attempt(q RetryableQuery) bool

Attempt tells gocql to attempt the query again based on query.Attempts being less than the NumRetries defined in the policy.

type SnappyCompressor 

type SnappyCompressor struct{}

SnappyCompressor implements the Compressor interface and can be used to compress incoming and outgoing frames. The snappy compression algorithm aims for very high speeds and reasonable compression.

func (SnappyCompressor) Decode 

func (s SnappyCompressor) Decode(data []byte) ([]byte, error)

func (SnappyCompressor) Encode 

func (s SnappyCompressor) Encode(data []byte) ([]byte, error)

func (SnappyCompressor) Name 

func (s SnappyCompressor) Name() string

type SslOptions 

type SslOptions struct {
	*tls.Config

	// CertPath and KeyPath are optional depending on server
	// config, but both fields must be omitted to avoid using a
	// client certificate
	CertPath string
	KeyPath  string
	CaPath   string //optional depending on server config
	// If you want to verify the hostname and server cert (like a wildcard for cass cluster) then you should turn this on
	// This option is basically the inverse of InSecureSkipVerify
	// See InSecureSkipVerify in http://golang.org/pkg/crypto/tls/ for more info
	EnableHostVerification bool
}

type StdLogger 

type StdLogger interface {
	Print(v ...interface{})
	Printf(format string, v ...interface{})
	Println(v ...interface{})
}
var Logger StdLogger = &defaultLogger{}

type TableMetadata 

type TableMetadata struct {
	Keyspace          string
	Name              string
	KeyValidator      string
	Comparator        string
	DefaultValidator  string
	KeyAliases        []string
	ColumnAliases     []string
	ValueAlias        string
	PartitionKey      []*ColumnMetadata
	ClusteringColumns []*ColumnMetadata
	Columns           map[string]*ColumnMetadata
	OrderedColumns    []string
}

schema metadata for a table (a.k.a. column family)

type Tracer 

type Tracer interface {
	Trace(traceId []byte)
}

Tracer is the interface implemented by query tracers. Tracers have the ability to obtain a detailed event log of all events that happened during the execution of a query from Cassandra. Gathering this information might be essential for debugging and optimizing queries, but this feature should not be used on production systems with very high load.

func NewTraceWriter 

func NewTraceWriter(session *Session, w io.Writer) Tracer

NewTraceWriter returns a simple Tracer implementation that outputs the event log in a textual format.

type TupleTypeInfo 

type TupleTypeInfo struct {
	NativeType
	Elems []TypeInfo
}

func (TupleTypeInfo) New 

func (t TupleTypeInfo) New() interface{}

type Type 

type Type int

String returns a human readable name for the Cassandra datatype described by t. Type is the identifier of a Cassandra internal datatype. 

const (
	TypeCustom    Type = 0x0000
	TypeAscii     Type = 0x0001
	TypeBigInt    Type = 0x0002
	TypeBlob      Type = 0x0003
	TypeBoolean   Type = 0x0004
	TypeCounter   Type = 0x0005
	TypeDecimal   Type = 0x0006
	TypeDouble    Type = 0x0007
	TypeFloat     Type = 0x0008
	TypeInt       Type = 0x0009
	TypeText      Type = 0x000A
	TypeTimestamp Type = 0x000B
	TypeUUID      Type = 0x000C
	TypeVarchar   Type = 0x000D
	TypeVarint    Type = 0x000E
	TypeTimeUUID  Type = 0x000F
	TypeInet      Type = 0x0010
	TypeDate      Type = 0x0011
	TypeTime      Type = 0x0012
	TypeSmallInt  Type = 0x0013
	TypeTinyInt   Type = 0x0014
	TypeList      Type = 0x0020
	TypeMap       Type = 0x0021
	TypeSet       Type = 0x0022
	TypeUDT       Type = 0x0030
	TypeTuple     Type = 0x0031
)

func (Type) String 

func (t Type) String() string

String returns the name of the identifier.

type TypeInfo 

type TypeInfo interface {
	Type() Type
	Version() byte
	Custom() string

	// New creates a pointer to an empty version of whatever type
	// is referenced by the TypeInfo receiver
	New() interface{}
}

TypeInfo describes a Cassandra specific data type.

type UDTField 

type UDTField struct {
	Name string
	Type TypeInfo
}

type UDTMarshaler 

type UDTMarshaler interface {
	// MarshalUDT will be called for each field in the the UDT returned by Cassandra,
	// the implementor should marshal the type to return by for example calling
	// Marshal.
	MarshalUDT(name string, info TypeInfo) ([]byte, error)
}

UDTMarshaler is an interface which should be implemented by users wishing to handle encoding UDT types to sent to Cassandra. Note: due to current implentations methods defined for this interface must be value receivers not pointer receivers.

type UDTTypeInfo 

type UDTTypeInfo struct {
	NativeType
	KeySpace string
	Name     string
	Elements []UDTField
}

func (UDTTypeInfo) New 

func (u UDTTypeInfo) New() interface{}

func (UDTTypeInfo) String 

func (u UDTTypeInfo) String() string

type UDTUnmarshaler 

type UDTUnmarshaler interface {
	// UnmarshalUDT will be called for each field in the UDT return by Cassandra,
	// the implementor should unmarshal the data into the value of their chosing,
	// for example by calling Unmarshal.
	UnmarshalUDT(name string, info TypeInfo, data []byte) error
}

UDTUnmarshaler should be implemented by users wanting to implement custom UDT unmarshaling.

type UUID 

type UUID [16]byte

func ParseUUID 

func ParseUUID(input string) (UUID, error)

ParseUUID parses a 32 digit hexadecimal number (that might contain hypens) representing an UUID.

func RandomUUID 

func RandomUUID() (UUID, error)

RandomUUID generates a totally random UUID (version 4) as described in RFC 4122.

func TimeUUID 

func TimeUUID() UUID

TimeUUID generates a new time based UUID (version 1) using the current time as the timestamp.

func UUIDFromBytes 

func UUIDFromBytes(input []byte) (UUID, error)

UUIDFromBytes converts a raw byte slice to an UUID.

func UUIDFromTime 

func UUIDFromTime(aTime time.Time) UUID

UUIDFromTime generates a new time based UUID (version 1) as described in RFC 4122. This UUID contains the MAC address of the node that generated the UUID, the given timestamp and a sequence number.

func (UUID) Bytes 

func (u UUID) Bytes() []byte

Bytes returns the raw byte slice for this UUID. A UUID is always 128 bits (16 bytes) long.

func (UUID) MarshalJSON 

func (u UUID) MarshalJSON() ([]byte, error)

Marshaling for JSON

func (UUID) MarshalText 

func (u UUID) MarshalText() ([]byte, error)

func (UUID) Node 

func (u UUID) Node() []byte

Node extracts the MAC address of the node who generated this UUID. It will return nil if the UUID is not a time based UUID (version 1).

func (UUID) String 

func (u UUID) String() string

String returns the UUID in it's canonical form, a 32 digit hexadecimal number in the form of xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.

func (UUID) Time 

func (u UUID) Time() time.Time

Time is like Timestamp, except that it returns a time.Time.

func (UUID) Timestamp 

func (u UUID) Timestamp() int64

Timestamp extracts the timestamp information from a time based UUID (version 1).

func (*UUID) UnmarshalJSON 

func (u *UUID) UnmarshalJSON(data []byte) error

Unmarshaling for JSON

func (*UUID) UnmarshalText 

func (u *UUID) UnmarshalText(text []byte) (err error)

func (UUID) Variant 

func (u UUID) Variant() int

Variant returns the variant of this UUID. This package will only generate UUIDs in the IETF variant.

func (UUID) Version 

func (u UUID) Version() int

Version extracts the version of this UUID variant. The RFC 4122 describes five kinds of UUIDs.

type UnmarshalError 

type UnmarshalError string

func (UnmarshalError) Error 

func (m UnmarshalError) Error() string

type Unmarshaler 

type Unmarshaler interface {
	UnmarshalCQL(info TypeInfo, data []byte) error
}

Unmarshaler is the interface implemented by objects that can unmarshal a Cassandra specific description of themselves.

Source Files

View all Source files

Directories

Path Synopsis
internal
lru
Package lru implements an LRU cache.
 Package lru implements an LRU cache.
murmur
streams

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