fermentord/vendor/github.com/nats-io/nats.go/jsm.go

1775 lines
49 KiB
Go

// Copyright 2021-2023 The NATS Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package nats
import (
"context"
"encoding/json"
"errors"
"fmt"
"strconv"
"strings"
"time"
)
// JetStreamManager manages JetStream Streams and Consumers.
type JetStreamManager interface {
// AddStream creates a stream.
AddStream(cfg *StreamConfig, opts ...JSOpt) (*StreamInfo, error)
// UpdateStream updates a stream.
UpdateStream(cfg *StreamConfig, opts ...JSOpt) (*StreamInfo, error)
// DeleteStream deletes a stream.
DeleteStream(name string, opts ...JSOpt) error
// StreamInfo retrieves information from a stream.
StreamInfo(stream string, opts ...JSOpt) (*StreamInfo, error)
// PurgeStream purges a stream messages.
PurgeStream(name string, opts ...JSOpt) error
// StreamsInfo can be used to retrieve a list of StreamInfo objects.
// DEPRECATED: Use Streams() instead.
StreamsInfo(opts ...JSOpt) <-chan *StreamInfo
// Streams can be used to retrieve a list of StreamInfo objects.
Streams(opts ...JSOpt) <-chan *StreamInfo
// StreamNames is used to retrieve a list of Stream names.
StreamNames(opts ...JSOpt) <-chan string
// GetMsg retrieves a raw stream message stored in JetStream by sequence number.
// Use options nats.DirectGet() or nats.DirectGetNext() to trigger retrieval
// directly from a distributed group of servers (leader and replicas).
// The stream must have been created/updated with the AllowDirect boolean.
GetMsg(name string, seq uint64, opts ...JSOpt) (*RawStreamMsg, error)
// GetLastMsg retrieves the last raw stream message stored in JetStream by subject.
// Use option nats.DirectGet() to trigger retrieval
// directly from a distributed group of servers (leader and replicas).
// The stream must have been created/updated with the AllowDirect boolean.
GetLastMsg(name, subject string, opts ...JSOpt) (*RawStreamMsg, error)
// DeleteMsg deletes a message from a stream. The message is marked as erased, but its value is not overwritten.
DeleteMsg(name string, seq uint64, opts ...JSOpt) error
// SecureDeleteMsg deletes a message from a stream. The deleted message is overwritten with random data
// As a result, this operation is slower than DeleteMsg()
SecureDeleteMsg(name string, seq uint64, opts ...JSOpt) error
// AddConsumer adds a consumer to a stream.
// If the consumer already exists, and the configuration is the same, it
// will return the existing consumer.
// If the consumer already exists, and the configuration is different, it
// will return ErrConsumerNameAlreadyInUse.
AddConsumer(stream string, cfg *ConsumerConfig, opts ...JSOpt) (*ConsumerInfo, error)
// UpdateConsumer updates an existing consumer.
UpdateConsumer(stream string, cfg *ConsumerConfig, opts ...JSOpt) (*ConsumerInfo, error)
// DeleteConsumer deletes a consumer.
DeleteConsumer(stream, consumer string, opts ...JSOpt) error
// ConsumerInfo retrieves information of a consumer from a stream.
ConsumerInfo(stream, name string, opts ...JSOpt) (*ConsumerInfo, error)
// ConsumersInfo is used to retrieve a list of ConsumerInfo objects.
// DEPRECATED: Use Consumers() instead.
ConsumersInfo(stream string, opts ...JSOpt) <-chan *ConsumerInfo
// Consumers is used to retrieve a list of ConsumerInfo objects.
Consumers(stream string, opts ...JSOpt) <-chan *ConsumerInfo
// ConsumerNames is used to retrieve a list of Consumer names.
ConsumerNames(stream string, opts ...JSOpt) <-chan string
// AccountInfo retrieves info about the JetStream usage from an account.
AccountInfo(opts ...JSOpt) (*AccountInfo, error)
// StreamNameBySubject returns a stream matching given subject.
StreamNameBySubject(string, ...JSOpt) (string, error)
}
// StreamConfig will determine the properties for a stream.
// There are sensible defaults for most. If no subjects are
// given the name will be used as the only subject.
type StreamConfig struct {
// Name is the name of the stream. It is required and must be unique
// across the JetStream account.
//
// Name Names cannot contain whitespace, ., *, >, path separators
// (forward or backwards slash), and non-printable characters.
Name string `json:"name"`
// Description is an optional description of the stream.
Description string `json:"description,omitempty"`
// Subjects is a list of subjects that the stream is listening on.
// Wildcards are supported. Subjects cannot be set if the stream is
// created as a mirror.
Subjects []string `json:"subjects,omitempty"`
// Retention defines the message retention policy for the stream.
// Defaults to LimitsPolicy.
Retention RetentionPolicy `json:"retention"`
// MaxConsumers specifies the maximum number of consumers allowed for
// the stream.
MaxConsumers int `json:"max_consumers"`
// MaxMsgs is the maximum number of messages the stream will store.
// After reaching the limit, stream adheres to the discard policy.
// If not set, server default is -1 (unlimited).
MaxMsgs int64 `json:"max_msgs"`
// MaxBytes is the maximum total size of messages the stream will store.
// After reaching the limit, stream adheres to the discard policy.
// If not set, server default is -1 (unlimited).
MaxBytes int64 `json:"max_bytes"`
// Discard defines the policy for handling messages when the stream
// reaches its limits in terms of number of messages or total bytes.
Discard DiscardPolicy `json:"discard"`
// DiscardNewPerSubject is a flag to enable discarding new messages per
// subject when limits are reached. Requires DiscardPolicy to be
// DiscardNew and the MaxMsgsPerSubject to be set.
DiscardNewPerSubject bool `json:"discard_new_per_subject,omitempty"`
// MaxAge is the maximum age of messages that the stream will retain.
MaxAge time.Duration `json:"max_age"`
// MaxMsgsPerSubject is the maximum number of messages per subject that
// the stream will retain.
MaxMsgsPerSubject int64 `json:"max_msgs_per_subject"`
// MaxMsgSize is the maximum size of any single message in the stream.
MaxMsgSize int32 `json:"max_msg_size,omitempty"`
// Storage specifies the type of storage backend used for the stream
// (file or memory).
Storage StorageType `json:"storage"`
// Replicas is the number of stream replicas in clustered JetStream.
// Defaults to 1, maximum is 5.
Replicas int `json:"num_replicas"`
// NoAck is a flag to disable acknowledging messages received by this
// stream.
//
// If set to true, publish methods from the JetStream client will not
// work as expected, since they rely on acknowledgements. Core NATS
// publish methods should be used instead. Note that this will make
// message delivery less reliable.
NoAck bool `json:"no_ack,omitempty"`
// Duplicates is the window within which to track duplicate messages.
// If not set, server default is 2 minutes.
Duplicates time.Duration `json:"duplicate_window,omitempty"`
// Placement is used to declare where the stream should be placed via
// tags and/or an explicit cluster name.
Placement *Placement `json:"placement,omitempty"`
// Mirror defines the configuration for mirroring another stream.
Mirror *StreamSource `json:"mirror,omitempty"`
// Sources is a list of other streams this stream sources messages from.
Sources []*StreamSource `json:"sources,omitempty"`
// Sealed streams do not allow messages to be published or deleted via limits or API,
// sealed streams can not be unsealed via configuration update. Can only
// be set on already created streams via the Update API.
Sealed bool `json:"sealed,omitempty"`
// DenyDelete restricts the ability to delete messages from a stream via
// the API. Defaults to false.
DenyDelete bool `json:"deny_delete,omitempty"`
// DenyPurge restricts the ability to purge messages from a stream via
// the API. Defaults to false.
DenyPurge bool `json:"deny_purge,omitempty"`
// AllowRollup allows the use of the Nats-Rollup header to replace all
// contents of a stream, or subject in a stream, with a single new
// message.
AllowRollup bool `json:"allow_rollup_hdrs,omitempty"`
// Compression specifies the message storage compression algorithm.
// Defaults to NoCompression.
Compression StoreCompression `json:"compression"`
// FirstSeq is the initial sequence number of the first message in the
// stream.
FirstSeq uint64 `json:"first_seq,omitempty"`
// SubjectTransform allows applying a transformation to matching
// messages' subjects.
SubjectTransform *SubjectTransformConfig `json:"subject_transform,omitempty"`
// RePublish allows immediate republishing a message to the configured
// subject after it's stored.
RePublish *RePublish `json:"republish,omitempty"`
// AllowDirect enables direct access to individual messages using direct
// get API. Defaults to false.
AllowDirect bool `json:"allow_direct"`
// MirrorDirect enables direct access to individual messages from the
// origin stream using direct get API. Defaults to false.
MirrorDirect bool `json:"mirror_direct"`
// ConsumerLimits defines limits of certain values that consumers can
// set, defaults for those who don't set these settings
ConsumerLimits StreamConsumerLimits `json:"consumer_limits,omitempty"`
// Metadata is a set of application-defined key-value pairs for
// associating metadata on the stream. This feature requires nats-server
// v2.10.0 or later.
Metadata map[string]string `json:"metadata,omitempty"`
// Template identifies the template that manages the Stream. DEPRECATED:
// This feature is no longer supported.
Template string `json:"template_owner,omitempty"`
}
// SubjectTransformConfig is for applying a subject transform (to matching messages) before doing anything else when a new message is received.
type SubjectTransformConfig struct {
Source string `json:"src,omitempty"`
Destination string `json:"dest"`
}
// RePublish is for republishing messages once committed to a stream. The original
// subject cis remapped from the subject pattern to the destination pattern.
type RePublish struct {
Source string `json:"src,omitempty"`
Destination string `json:"dest"`
HeadersOnly bool `json:"headers_only,omitempty"`
}
// Placement is used to guide placement of streams in clustered JetStream.
type Placement struct {
Cluster string `json:"cluster"`
Tags []string `json:"tags,omitempty"`
}
// StreamSource dictates how streams can source from other streams.
type StreamSource struct {
Name string `json:"name"`
OptStartSeq uint64 `json:"opt_start_seq,omitempty"`
OptStartTime *time.Time `json:"opt_start_time,omitempty"`
FilterSubject string `json:"filter_subject,omitempty"`
SubjectTransforms []SubjectTransformConfig `json:"subject_transforms,omitempty"`
External *ExternalStream `json:"external,omitempty"`
Domain string `json:"-"`
}
// ExternalStream allows you to qualify access to a stream source in another
// account.
type ExternalStream struct {
APIPrefix string `json:"api"`
DeliverPrefix string `json:"deliver,omitempty"`
}
// StreamConsumerLimits are the limits for a consumer on a stream.
// These can be overridden on a per consumer basis.
type StreamConsumerLimits struct {
InactiveThreshold time.Duration `json:"inactive_threshold,omitempty"`
MaxAckPending int `json:"max_ack_pending,omitempty"`
}
// Helper for copying when we do not want to change user's version.
func (ss *StreamSource) copy() *StreamSource {
nss := *ss
// Check pointers
if ss.OptStartTime != nil {
t := *ss.OptStartTime
nss.OptStartTime = &t
}
if ss.External != nil {
ext := *ss.External
nss.External = &ext
}
return &nss
}
// If we have a Domain, convert to the appropriate ext.APIPrefix.
// This will change the stream source, so should be a copy passed in.
func (ss *StreamSource) convertDomain() error {
if ss.Domain == _EMPTY_ {
return nil
}
if ss.External != nil {
// These should be mutually exclusive.
// TODO(dlc) - Make generic?
return errors.New("nats: domain and external are both set")
}
ss.External = &ExternalStream{APIPrefix: fmt.Sprintf(jsExtDomainT, ss.Domain)}
return nil
}
// apiResponse is a standard response from the JetStream JSON API
type apiResponse struct {
Type string `json:"type"`
Error *APIError `json:"error,omitempty"`
}
// apiPaged includes variables used to create paged responses from the JSON API
type apiPaged struct {
Total int `json:"total"`
Offset int `json:"offset"`
Limit int `json:"limit"`
}
// apiPagedRequest includes parameters allowing specific pages to be requested
// from APIs responding with apiPaged.
type apiPagedRequest struct {
Offset int `json:"offset,omitempty"`
}
// AccountInfo contains info about the JetStream usage from the current account.
type AccountInfo struct {
Tier
Domain string `json:"domain"`
API APIStats `json:"api"`
Tiers map[string]Tier `json:"tiers"`
}
type Tier struct {
Memory uint64 `json:"memory"`
Store uint64 `json:"storage"`
ReservedMemory uint64 `json:"reserved_memory"`
ReservedStore uint64 `json:"reserved_storage"`
Streams int `json:"streams"`
Consumers int `json:"consumers"`
Limits AccountLimits `json:"limits"`
}
// APIStats reports on API calls to JetStream for this account.
type APIStats struct {
Total uint64 `json:"total"`
Errors uint64 `json:"errors"`
}
// AccountLimits includes the JetStream limits of the current account.
type AccountLimits struct {
MaxMemory int64 `json:"max_memory"`
MaxStore int64 `json:"max_storage"`
MaxStreams int `json:"max_streams"`
MaxConsumers int `json:"max_consumers"`
MaxAckPending int `json:"max_ack_pending"`
MemoryMaxStreamBytes int64 `json:"memory_max_stream_bytes"`
StoreMaxStreamBytes int64 `json:"storage_max_stream_bytes"`
MaxBytesRequired bool `json:"max_bytes_required"`
}
type accountInfoResponse struct {
apiResponse
AccountInfo
}
// AccountInfo fetches account information from the server, containing details
// about the account associated with this JetStream connection. If account is
// not enabled for JetStream, ErrJetStreamNotEnabledForAccount is returned.
//
// If the server does not have JetStream enabled, ErrJetStreamNotEnabled is
// returned (for a single server setup). For clustered topologies, AccountInfo
// will time out.
func (js *js) AccountInfo(opts ...JSOpt) (*AccountInfo, error) {
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return nil, err
}
if cancel != nil {
defer cancel()
}
resp, err := js.apiRequestWithContext(o.ctx, js.apiSubj(apiAccountInfo), nil)
if err != nil {
// todo maybe nats server should never have no responder on this subject and always respond if they know there is no js to be had
if errors.Is(err, ErrNoResponders) {
err = ErrJetStreamNotEnabled
}
return nil, err
}
var info accountInfoResponse
if err := json.Unmarshal(resp.Data, &info); err != nil {
return nil, err
}
if info.Error != nil {
// Internally checks based on error code instead of description match.
if errors.Is(info.Error, ErrJetStreamNotEnabledForAccount) {
return nil, ErrJetStreamNotEnabledForAccount
}
return nil, info.Error
}
return &info.AccountInfo, nil
}
type createConsumerRequest struct {
Stream string `json:"stream_name"`
Config *ConsumerConfig `json:"config"`
}
type consumerResponse struct {
apiResponse
*ConsumerInfo
}
// AddConsumer adds a consumer to a stream.
// If the consumer already exists, and the configuration is the same, it
// will return the existing consumer.
// If the consumer already exists, and the configuration is different, it
// will return ErrConsumerNameAlreadyInUse.
func (js *js) AddConsumer(stream string, cfg *ConsumerConfig, opts ...JSOpt) (*ConsumerInfo, error) {
if cfg == nil {
cfg = &ConsumerConfig{}
}
consumerName := cfg.Name
if consumerName == _EMPTY_ {
consumerName = cfg.Durable
}
if consumerName != _EMPTY_ {
consInfo, err := js.ConsumerInfo(stream, consumerName, opts...)
if err != nil && !errors.Is(err, ErrConsumerNotFound) && !errors.Is(err, ErrStreamNotFound) {
return nil, err
}
if consInfo != nil {
sameConfig := checkConfig(&consInfo.Config, cfg)
if sameConfig != nil {
return nil, fmt.Errorf("%w: creating consumer %q on stream %q", ErrConsumerNameAlreadyInUse, consumerName, stream)
} else {
return consInfo, nil
}
}
}
return js.upsertConsumer(stream, consumerName, cfg, opts...)
}
func (js *js) UpdateConsumer(stream string, cfg *ConsumerConfig, opts ...JSOpt) (*ConsumerInfo, error) {
if cfg == nil {
return nil, ErrConsumerConfigRequired
}
consumerName := cfg.Name
if consumerName == _EMPTY_ {
consumerName = cfg.Durable
}
if consumerName == _EMPTY_ {
return nil, ErrConsumerNameRequired
}
return js.upsertConsumer(stream, consumerName, cfg, opts...)
}
func (js *js) upsertConsumer(stream, consumerName string, cfg *ConsumerConfig, opts ...JSOpt) (*ConsumerInfo, error) {
if err := checkStreamName(stream); err != nil {
return nil, err
}
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return nil, err
}
if cancel != nil {
defer cancel()
}
req, err := json.Marshal(&createConsumerRequest{Stream: stream, Config: cfg})
if err != nil {
return nil, err
}
var ccSubj string
if consumerName == _EMPTY_ {
// if consumer name is empty (neither Durable nor Name is set), use the legacy ephemeral endpoint
ccSubj = fmt.Sprintf(apiLegacyConsumerCreateT, stream)
} else if err := checkConsumerName(consumerName); err != nil {
return nil, err
} else if js.nc.serverMinVersion(2, 9, 0) {
if cfg.Durable != "" && js.opts.featureFlags.useDurableConsumerCreate {
// if user set the useDurableConsumerCreate flag, use the legacy DURABLE.CREATE endpoint
ccSubj = fmt.Sprintf(apiDurableCreateT, stream, consumerName)
} else if cfg.FilterSubject == _EMPTY_ || cfg.FilterSubject == ">" {
// if filter subject is empty or ">", use the endpoint without filter subject
ccSubj = fmt.Sprintf(apiConsumerCreateT, stream, consumerName)
} else {
// safeguard against passing invalid filter subject in request subject
if cfg.FilterSubject[0] == '.' || cfg.FilterSubject[len(cfg.FilterSubject)-1] == '.' {
return nil, fmt.Errorf("%w: %q", ErrInvalidFilterSubject, cfg.FilterSubject)
}
// if filter subject is not empty, use the endpoint with filter subject
ccSubj = fmt.Sprintf(apiConsumerCreateWithFilterSubjectT, stream, consumerName, cfg.FilterSubject)
}
} else {
if cfg.Durable != "" {
// if Durable is set, use the DURABLE.CREATE endpoint
ccSubj = fmt.Sprintf(apiDurableCreateT, stream, consumerName)
} else {
// if Durable is not set, use the legacy ephemeral endpoint
ccSubj = fmt.Sprintf(apiLegacyConsumerCreateT, stream)
}
}
resp, err := js.apiRequestWithContext(o.ctx, js.apiSubj(ccSubj), req)
if err != nil {
if errors.Is(err, ErrNoResponders) {
err = ErrJetStreamNotEnabled
}
return nil, err
}
var info consumerResponse
err = json.Unmarshal(resp.Data, &info)
if err != nil {
return nil, err
}
if info.Error != nil {
if errors.Is(info.Error, ErrStreamNotFound) {
return nil, ErrStreamNotFound
}
if errors.Is(info.Error, ErrConsumerNotFound) {
return nil, ErrConsumerNotFound
}
return nil, info.Error
}
// check whether multiple filter subjects (if used) are reflected in the returned ConsumerInfo
if len(cfg.FilterSubjects) != 0 && len(info.Config.FilterSubjects) == 0 {
return nil, ErrConsumerMultipleFilterSubjectsNotSupported
}
return info.ConsumerInfo, nil
}
// consumerDeleteResponse is the response for a Consumer delete request.
type consumerDeleteResponse struct {
apiResponse
Success bool `json:"success,omitempty"`
}
func checkStreamName(stream string) error {
if stream == _EMPTY_ {
return ErrStreamNameRequired
}
if strings.ContainsAny(stream, ". ") {
return ErrInvalidStreamName
}
return nil
}
// Check that the consumer name is not empty and is valid (does not contain "." and " ").
// Additional consumer name validation is done in nats-server.
// Returns ErrConsumerNameRequired if consumer name is empty, ErrInvalidConsumerName is invalid, otherwise nil
func checkConsumerName(consumer string) error {
if consumer == _EMPTY_ {
return ErrConsumerNameRequired
}
if strings.ContainsAny(consumer, ". ") {
return ErrInvalidConsumerName
}
return nil
}
// DeleteConsumer deletes a Consumer.
func (js *js) DeleteConsumer(stream, consumer string, opts ...JSOpt) error {
if err := checkStreamName(stream); err != nil {
return err
}
if err := checkConsumerName(consumer); err != nil {
return err
}
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return err
}
if cancel != nil {
defer cancel()
}
dcSubj := js.apiSubj(fmt.Sprintf(apiConsumerDeleteT, stream, consumer))
r, err := js.apiRequestWithContext(o.ctx, dcSubj, nil)
if err != nil {
return err
}
var resp consumerDeleteResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
return err
}
if resp.Error != nil {
if errors.Is(resp.Error, ErrConsumerNotFound) {
return ErrConsumerNotFound
}
return resp.Error
}
return nil
}
// ConsumerInfo returns information about a Consumer.
func (js *js) ConsumerInfo(stream, consumer string, opts ...JSOpt) (*ConsumerInfo, error) {
if err := checkStreamName(stream); err != nil {
return nil, err
}
if err := checkConsumerName(consumer); err != nil {
return nil, err
}
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return nil, err
}
if cancel != nil {
defer cancel()
}
return js.getConsumerInfoContext(o.ctx, stream, consumer)
}
// consumerLister fetches pages of ConsumerInfo objects. This object is not
// safe to use for multiple threads.
type consumerLister struct {
stream string
js *js
err error
offset int
page []*ConsumerInfo
pageInfo *apiPaged
}
// consumersRequest is the type used for Consumers requests.
type consumersRequest struct {
apiPagedRequest
}
// consumerListResponse is the response for a Consumers List request.
type consumerListResponse struct {
apiResponse
apiPaged
Consumers []*ConsumerInfo `json:"consumers"`
}
// Next fetches the next ConsumerInfo page.
func (c *consumerLister) Next() bool {
if c.err != nil {
return false
}
if err := checkStreamName(c.stream); err != nil {
c.err = err
return false
}
if c.pageInfo != nil && c.offset >= c.pageInfo.Total {
return false
}
req, err := json.Marshal(consumersRequest{
apiPagedRequest: apiPagedRequest{Offset: c.offset},
})
if err != nil {
c.err = err
return false
}
var cancel context.CancelFunc
ctx := c.js.opts.ctx
if ctx == nil {
ctx, cancel = context.WithTimeout(context.Background(), c.js.opts.wait)
defer cancel()
}
clSubj := c.js.apiSubj(fmt.Sprintf(apiConsumerListT, c.stream))
r, err := c.js.apiRequestWithContext(ctx, clSubj, req)
if err != nil {
c.err = err
return false
}
var resp consumerListResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
c.err = err
return false
}
if resp.Error != nil {
c.err = resp.Error
return false
}
c.pageInfo = &resp.apiPaged
c.page = resp.Consumers
c.offset += len(c.page)
return true
}
// Page returns the current ConsumerInfo page.
func (c *consumerLister) Page() []*ConsumerInfo {
return c.page
}
// Err returns any errors found while fetching pages.
func (c *consumerLister) Err() error {
return c.err
}
// Consumers is used to retrieve a list of ConsumerInfo objects.
func (jsc *js) Consumers(stream string, opts ...JSOpt) <-chan *ConsumerInfo {
o, cancel, err := getJSContextOpts(jsc.opts, opts...)
if err != nil {
return nil
}
ch := make(chan *ConsumerInfo)
l := &consumerLister{js: &js{nc: jsc.nc, opts: o}, stream: stream}
go func() {
if cancel != nil {
defer cancel()
}
defer close(ch)
for l.Next() {
for _, info := range l.Page() {
select {
case ch <- info:
case <-o.ctx.Done():
return
}
}
}
}()
return ch
}
// ConsumersInfo is used to retrieve a list of ConsumerInfo objects.
// DEPRECATED: Use Consumers() instead.
func (jsc *js) ConsumersInfo(stream string, opts ...JSOpt) <-chan *ConsumerInfo {
return jsc.Consumers(stream, opts...)
}
type consumerNamesLister struct {
stream string
js *js
err error
offset int
page []string
pageInfo *apiPaged
}
// consumerNamesListResponse is the response for a Consumers Names List request.
type consumerNamesListResponse struct {
apiResponse
apiPaged
Consumers []string `json:"consumers"`
}
// Next fetches the next consumer names page.
func (c *consumerNamesLister) Next() bool {
if c.err != nil {
return false
}
if err := checkStreamName(c.stream); err != nil {
c.err = err
return false
}
if c.pageInfo != nil && c.offset >= c.pageInfo.Total {
return false
}
var cancel context.CancelFunc
ctx := c.js.opts.ctx
if ctx == nil {
ctx, cancel = context.WithTimeout(context.Background(), c.js.opts.wait)
defer cancel()
}
req, err := json.Marshal(consumersRequest{
apiPagedRequest: apiPagedRequest{Offset: c.offset},
})
if err != nil {
c.err = err
return false
}
clSubj := c.js.apiSubj(fmt.Sprintf(apiConsumerNamesT, c.stream))
r, err := c.js.apiRequestWithContext(ctx, clSubj, req)
if err != nil {
c.err = err
return false
}
var resp consumerNamesListResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
c.err = err
return false
}
if resp.Error != nil {
c.err = resp.Error
return false
}
c.pageInfo = &resp.apiPaged
c.page = resp.Consumers
c.offset += len(c.page)
return true
}
// Page returns the current ConsumerInfo page.
func (c *consumerNamesLister) Page() []string {
return c.page
}
// Err returns any errors found while fetching pages.
func (c *consumerNamesLister) Err() error {
return c.err
}
// ConsumerNames is used to retrieve a list of Consumer names.
func (jsc *js) ConsumerNames(stream string, opts ...JSOpt) <-chan string {
o, cancel, err := getJSContextOpts(jsc.opts, opts...)
if err != nil {
return nil
}
ch := make(chan string)
l := &consumerNamesLister{stream: stream, js: &js{nc: jsc.nc, opts: o}}
go func() {
if cancel != nil {
defer cancel()
}
defer close(ch)
for l.Next() {
for _, info := range l.Page() {
select {
case ch <- info:
case <-o.ctx.Done():
return
}
}
}
}()
return ch
}
// streamCreateResponse stream creation.
type streamCreateResponse struct {
apiResponse
*StreamInfo
}
func (js *js) AddStream(cfg *StreamConfig, opts ...JSOpt) (*StreamInfo, error) {
if cfg == nil {
return nil, ErrStreamConfigRequired
}
if err := checkStreamName(cfg.Name); err != nil {
return nil, err
}
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return nil, err
}
if cancel != nil {
defer cancel()
}
// In case we need to change anything, copy so we do not change the caller's version.
ncfg := *cfg
// If we have a mirror and an external domain, convert to ext.APIPrefix.
if cfg.Mirror != nil && cfg.Mirror.Domain != _EMPTY_ {
// Copy so we do not change the caller's version.
ncfg.Mirror = ncfg.Mirror.copy()
if err := ncfg.Mirror.convertDomain(); err != nil {
return nil, err
}
}
// Check sources for the same.
if len(ncfg.Sources) > 0 {
ncfg.Sources = append([]*StreamSource(nil), ncfg.Sources...)
for i, ss := range ncfg.Sources {
if ss.Domain != _EMPTY_ {
ncfg.Sources[i] = ss.copy()
if err := ncfg.Sources[i].convertDomain(); err != nil {
return nil, err
}
}
}
}
req, err := json.Marshal(&ncfg)
if err != nil {
return nil, err
}
csSubj := js.apiSubj(fmt.Sprintf(apiStreamCreateT, cfg.Name))
r, err := js.apiRequestWithContext(o.ctx, csSubj, req)
if err != nil {
return nil, err
}
var resp streamCreateResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
return nil, err
}
if resp.Error != nil {
if errors.Is(resp.Error, ErrStreamNameAlreadyInUse) {
return nil, ErrStreamNameAlreadyInUse
}
return nil, resp.Error
}
// check that input subject transform (if used) is reflected in the returned ConsumerInfo
if cfg.SubjectTransform != nil && resp.StreamInfo.Config.SubjectTransform == nil {
return nil, ErrStreamSubjectTransformNotSupported
}
if len(cfg.Sources) != 0 {
if len(cfg.Sources) != len(resp.Config.Sources) {
return nil, ErrStreamSourceNotSupported
}
for i := range cfg.Sources {
if len(cfg.Sources[i].SubjectTransforms) != 0 && len(resp.Sources[i].SubjectTransforms) == 0 {
return nil, ErrStreamSourceMultipleSubjectTransformsNotSupported
}
}
}
return resp.StreamInfo, nil
}
type (
// StreamInfoRequest contains additional option to return
StreamInfoRequest struct {
apiPagedRequest
// DeletedDetails when true includes information about deleted messages
DeletedDetails bool `json:"deleted_details,omitempty"`
// SubjectsFilter when set, returns information on the matched subjects
SubjectsFilter string `json:"subjects_filter,omitempty"`
}
streamInfoResponse = struct {
apiResponse
apiPaged
*StreamInfo
}
)
func (js *js) StreamInfo(stream string, opts ...JSOpt) (*StreamInfo, error) {
if err := checkStreamName(stream); err != nil {
return nil, err
}
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return nil, err
}
if cancel != nil {
defer cancel()
}
var i int
var subjectMessagesMap map[string]uint64
var req []byte
var requestPayload bool
var siOpts StreamInfoRequest
if o.streamInfoOpts != nil {
requestPayload = true
siOpts = *o.streamInfoOpts
}
for {
if requestPayload {
siOpts.Offset = i
if req, err = json.Marshal(&siOpts); err != nil {
return nil, err
}
}
siSubj := js.apiSubj(fmt.Sprintf(apiStreamInfoT, stream))
r, err := js.apiRequestWithContext(o.ctx, siSubj, req)
if err != nil {
return nil, err
}
var resp streamInfoResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
return nil, err
}
if resp.Error != nil {
if errors.Is(resp.Error, ErrStreamNotFound) {
return nil, ErrStreamNotFound
}
return nil, resp.Error
}
var total int
// for backwards compatibility
if resp.Total != 0 {
total = resp.Total
} else {
total = len(resp.State.Subjects)
}
if requestPayload && len(resp.StreamInfo.State.Subjects) > 0 {
if subjectMessagesMap == nil {
subjectMessagesMap = make(map[string]uint64, total)
}
for k, j := range resp.State.Subjects {
subjectMessagesMap[k] = j
i++
}
}
if i >= total {
if requestPayload {
resp.StreamInfo.State.Subjects = subjectMessagesMap
}
return resp.StreamInfo, nil
}
}
}
// StreamInfo shows config and current state for this stream.
type StreamInfo struct {
Config StreamConfig `json:"config"`
Created time.Time `json:"created"`
State StreamState `json:"state"`
Cluster *ClusterInfo `json:"cluster,omitempty"`
Mirror *StreamSourceInfo `json:"mirror,omitempty"`
Sources []*StreamSourceInfo `json:"sources,omitempty"`
Alternates []*StreamAlternate `json:"alternates,omitempty"`
}
// StreamAlternate is an alternate stream represented by a mirror.
type StreamAlternate struct {
Name string `json:"name"`
Domain string `json:"domain,omitempty"`
Cluster string `json:"cluster"`
}
// StreamSourceInfo shows information about an upstream stream source.
type StreamSourceInfo struct {
Name string `json:"name"`
Lag uint64 `json:"lag"`
Active time.Duration `json:"active"`
External *ExternalStream `json:"external"`
Error *APIError `json:"error"`
FilterSubject string `json:"filter_subject,omitempty"`
SubjectTransforms []SubjectTransformConfig `json:"subject_transforms,omitempty"`
}
// StreamState is information about the given stream.
type StreamState struct {
Msgs uint64 `json:"messages"`
Bytes uint64 `json:"bytes"`
FirstSeq uint64 `json:"first_seq"`
FirstTime time.Time `json:"first_ts"`
LastSeq uint64 `json:"last_seq"`
LastTime time.Time `json:"last_ts"`
Consumers int `json:"consumer_count"`
Deleted []uint64 `json:"deleted"`
NumDeleted int `json:"num_deleted"`
NumSubjects uint64 `json:"num_subjects"`
Subjects map[string]uint64 `json:"subjects"`
}
// ClusterInfo shows information about the underlying set of servers
// that make up the stream or consumer.
type ClusterInfo struct {
Name string `json:"name,omitempty"`
Leader string `json:"leader,omitempty"`
Replicas []*PeerInfo `json:"replicas,omitempty"`
}
// PeerInfo shows information about all the peers in the cluster that
// are supporting the stream or consumer.
type PeerInfo struct {
Name string `json:"name"`
Current bool `json:"current"`
Offline bool `json:"offline,omitempty"`
Active time.Duration `json:"active"`
Lag uint64 `json:"lag,omitempty"`
}
// UpdateStream updates a Stream.
func (js *js) UpdateStream(cfg *StreamConfig, opts ...JSOpt) (*StreamInfo, error) {
if cfg == nil {
return nil, ErrStreamConfigRequired
}
if err := checkStreamName(cfg.Name); err != nil {
return nil, err
}
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return nil, err
}
if cancel != nil {
defer cancel()
}
req, err := json.Marshal(cfg)
if err != nil {
return nil, err
}
usSubj := js.apiSubj(fmt.Sprintf(apiStreamUpdateT, cfg.Name))
r, err := js.apiRequestWithContext(o.ctx, usSubj, req)
if err != nil {
return nil, err
}
var resp streamInfoResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
return nil, err
}
if resp.Error != nil {
if errors.Is(resp.Error, ErrStreamNotFound) {
return nil, ErrStreamNotFound
}
return nil, resp.Error
}
// check that input subject transform (if used) is reflected in the returned StreamInfo
if cfg.SubjectTransform != nil && resp.StreamInfo.Config.SubjectTransform == nil {
return nil, ErrStreamSubjectTransformNotSupported
}
if len(cfg.Sources) != 0 {
if len(cfg.Sources) != len(resp.Config.Sources) {
return nil, ErrStreamSourceNotSupported
}
for i := range cfg.Sources {
if len(cfg.Sources[i].SubjectTransforms) != 0 && len(resp.Sources[i].SubjectTransforms) == 0 {
return nil, ErrStreamSourceMultipleSubjectTransformsNotSupported
}
}
}
return resp.StreamInfo, nil
}
// streamDeleteResponse is the response for a Stream delete request.
type streamDeleteResponse struct {
apiResponse
Success bool `json:"success,omitempty"`
}
// DeleteStream deletes a Stream.
func (js *js) DeleteStream(name string, opts ...JSOpt) error {
if err := checkStreamName(name); err != nil {
return err
}
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return err
}
if cancel != nil {
defer cancel()
}
dsSubj := js.apiSubj(fmt.Sprintf(apiStreamDeleteT, name))
r, err := js.apiRequestWithContext(o.ctx, dsSubj, nil)
if err != nil {
return err
}
var resp streamDeleteResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
return err
}
if resp.Error != nil {
if errors.Is(resp.Error, ErrStreamNotFound) {
return ErrStreamNotFound
}
return resp.Error
}
return nil
}
type apiMsgGetRequest struct {
Seq uint64 `json:"seq,omitempty"`
LastFor string `json:"last_by_subj,omitempty"`
NextFor string `json:"next_by_subj,omitempty"`
}
// RawStreamMsg is a raw message stored in JetStream.
type RawStreamMsg struct {
Subject string
Sequence uint64
Header Header
Data []byte
Time time.Time
}
// storedMsg is a raw message stored in JetStream.
type storedMsg struct {
Subject string `json:"subject"`
Sequence uint64 `json:"seq"`
Header []byte `json:"hdrs,omitempty"`
Data []byte `json:"data,omitempty"`
Time time.Time `json:"time"`
}
// apiMsgGetResponse is the response for a Stream get request.
type apiMsgGetResponse struct {
apiResponse
Message *storedMsg `json:"message,omitempty"`
}
// GetLastMsg retrieves the last raw stream message stored in JetStream by subject.
func (js *js) GetLastMsg(name, subject string, opts ...JSOpt) (*RawStreamMsg, error) {
return js.getMsg(name, &apiMsgGetRequest{LastFor: subject}, opts...)
}
// GetMsg retrieves a raw stream message stored in JetStream by sequence number.
func (js *js) GetMsg(name string, seq uint64, opts ...JSOpt) (*RawStreamMsg, error) {
return js.getMsg(name, &apiMsgGetRequest{Seq: seq}, opts...)
}
// Low level getMsg
func (js *js) getMsg(name string, mreq *apiMsgGetRequest, opts ...JSOpt) (*RawStreamMsg, error) {
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return nil, err
}
if cancel != nil {
defer cancel()
}
if err := checkStreamName(name); err != nil {
return nil, err
}
var apiSubj string
if o.directGet && mreq.LastFor != _EMPTY_ {
apiSubj = apiDirectMsgGetLastBySubjectT
dsSubj := js.apiSubj(fmt.Sprintf(apiSubj, name, mreq.LastFor))
r, err := js.apiRequestWithContext(o.ctx, dsSubj, nil)
if err != nil {
return nil, err
}
return convertDirectGetMsgResponseToMsg(name, r)
}
if o.directGet {
apiSubj = apiDirectMsgGetT
mreq.NextFor = o.directNextFor
} else {
apiSubj = apiMsgGetT
}
req, err := json.Marshal(mreq)
if err != nil {
return nil, err
}
dsSubj := js.apiSubj(fmt.Sprintf(apiSubj, name))
r, err := js.apiRequestWithContext(o.ctx, dsSubj, req)
if err != nil {
return nil, err
}
if o.directGet {
return convertDirectGetMsgResponseToMsg(name, r)
}
var resp apiMsgGetResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
return nil, err
}
if resp.Error != nil {
if errors.Is(resp.Error, ErrMsgNotFound) {
return nil, ErrMsgNotFound
}
if errors.Is(resp.Error, ErrStreamNotFound) {
return nil, ErrStreamNotFound
}
return nil, resp.Error
}
msg := resp.Message
var hdr Header
if len(msg.Header) > 0 {
hdr, err = DecodeHeadersMsg(msg.Header)
if err != nil {
return nil, err
}
}
return &RawStreamMsg{
Subject: msg.Subject,
Sequence: msg.Sequence,
Header: hdr,
Data: msg.Data,
Time: msg.Time,
}, nil
}
func convertDirectGetMsgResponseToMsg(name string, r *Msg) (*RawStreamMsg, error) {
// Check for 404/408. We would get a no-payload message and a "Status" header
if len(r.Data) == 0 {
val := r.Header.Get(statusHdr)
if val != _EMPTY_ {
switch val {
case noMessagesSts:
return nil, ErrMsgNotFound
default:
desc := r.Header.Get(descrHdr)
if desc == _EMPTY_ {
desc = "unable to get message"
}
return nil, fmt.Errorf("nats: %s", desc)
}
}
}
// Check for headers that give us the required information to
// reconstruct the message.
if len(r.Header) == 0 {
return nil, fmt.Errorf("nats: response should have headers")
}
stream := r.Header.Get(JSStream)
if stream == _EMPTY_ {
return nil, fmt.Errorf("nats: missing stream header")
}
// Mirrors can now answer direct gets, so removing check for name equality.
// TODO(dlc) - We could have server also have a header with origin and check that?
seqStr := r.Header.Get(JSSequence)
if seqStr == _EMPTY_ {
return nil, fmt.Errorf("nats: missing sequence header")
}
seq, err := strconv.ParseUint(seqStr, 10, 64)
if err != nil {
return nil, fmt.Errorf("nats: invalid sequence header '%s': %v", seqStr, err)
}
timeStr := r.Header.Get(JSTimeStamp)
if timeStr == _EMPTY_ {
return nil, fmt.Errorf("nats: missing timestamp header")
}
// Temporary code: the server in main branch is sending with format
// "2006-01-02 15:04:05.999999999 +0000 UTC", but will be changed
// to use format RFC3339Nano. Because of server test deps/cycle,
// support both until the server PR lands.
tm, err := time.Parse(time.RFC3339Nano, timeStr)
if err != nil {
tm, err = time.Parse("2006-01-02 15:04:05.999999999 +0000 UTC", timeStr)
if err != nil {
return nil, fmt.Errorf("nats: invalid timestamp header '%s': %v", timeStr, err)
}
}
subj := r.Header.Get(JSSubject)
if subj == _EMPTY_ {
return nil, fmt.Errorf("nats: missing subject header")
}
return &RawStreamMsg{
Subject: subj,
Sequence: seq,
Header: r.Header,
Data: r.Data,
Time: tm,
}, nil
}
type msgDeleteRequest struct {
Seq uint64 `json:"seq"`
NoErase bool `json:"no_erase,omitempty"`
}
// msgDeleteResponse is the response for a Stream delete request.
type msgDeleteResponse struct {
apiResponse
Success bool `json:"success,omitempty"`
}
// DeleteMsg deletes a message from a stream.
// The message is marked as erased, but not overwritten
func (js *js) DeleteMsg(name string, seq uint64, opts ...JSOpt) error {
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return err
}
if cancel != nil {
defer cancel()
}
return js.deleteMsg(o.ctx, name, &msgDeleteRequest{Seq: seq, NoErase: true})
}
// SecureDeleteMsg deletes a message from a stream. The deleted message is overwritten with random data
// As a result, this operation is slower than DeleteMsg()
func (js *js) SecureDeleteMsg(name string, seq uint64, opts ...JSOpt) error {
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return err
}
if cancel != nil {
defer cancel()
}
return js.deleteMsg(o.ctx, name, &msgDeleteRequest{Seq: seq})
}
func (js *js) deleteMsg(ctx context.Context, stream string, req *msgDeleteRequest) error {
if err := checkStreamName(stream); err != nil {
return err
}
reqJSON, err := json.Marshal(req)
if err != nil {
return err
}
dsSubj := js.apiSubj(fmt.Sprintf(apiMsgDeleteT, stream))
r, err := js.apiRequestWithContext(ctx, dsSubj, reqJSON)
if err != nil {
return err
}
var resp msgDeleteResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
return err
}
if resp.Error != nil {
return resp.Error
}
return nil
}
// StreamPurgeRequest is optional request information to the purge API.
type StreamPurgeRequest struct {
// Purge up to but not including sequence.
Sequence uint64 `json:"seq,omitempty"`
// Subject to match against messages for the purge command.
Subject string `json:"filter,omitempty"`
// Number of messages to keep.
Keep uint64 `json:"keep,omitempty"`
}
type streamPurgeResponse struct {
apiResponse
Success bool `json:"success,omitempty"`
Purged uint64 `json:"purged"`
}
// PurgeStream purges messages on a Stream.
func (js *js) PurgeStream(stream string, opts ...JSOpt) error {
if err := checkStreamName(stream); err != nil {
return err
}
var req *StreamPurgeRequest
var ok bool
for _, opt := range opts {
// For PurgeStream, only request body opt is relevant
if req, ok = opt.(*StreamPurgeRequest); ok {
break
}
}
return js.purgeStream(stream, req)
}
func (js *js) purgeStream(stream string, req *StreamPurgeRequest, opts ...JSOpt) error {
o, cancel, err := getJSContextOpts(js.opts, opts...)
if err != nil {
return err
}
if cancel != nil {
defer cancel()
}
var b []byte
if req != nil {
if b, err = json.Marshal(req); err != nil {
return err
}
}
psSubj := js.apiSubj(fmt.Sprintf(apiStreamPurgeT, stream))
r, err := js.apiRequestWithContext(o.ctx, psSubj, b)
if err != nil {
return err
}
var resp streamPurgeResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
return err
}
if resp.Error != nil {
if errors.Is(resp.Error, ErrBadRequest) {
return fmt.Errorf("%w: %s", ErrBadRequest, "invalid purge request body")
}
return resp.Error
}
return nil
}
// streamLister fetches pages of StreamInfo objects. This object is not safe
// to use for multiple threads.
type streamLister struct {
js *js
page []*StreamInfo
err error
offset int
pageInfo *apiPaged
}
// streamListResponse list of detailed stream information.
// A nil request is valid and means all streams.
type streamListResponse struct {
apiResponse
apiPaged
Streams []*StreamInfo `json:"streams"`
}
// streamNamesRequest is used for Stream Name requests.
type streamNamesRequest struct {
apiPagedRequest
// These are filters that can be applied to the list.
Subject string `json:"subject,omitempty"`
}
// Next fetches the next StreamInfo page.
func (s *streamLister) Next() bool {
if s.err != nil {
return false
}
if s.pageInfo != nil && s.offset >= s.pageInfo.Total {
return false
}
req, err := json.Marshal(streamNamesRequest{
apiPagedRequest: apiPagedRequest{Offset: s.offset},
Subject: s.js.opts.streamListSubject,
})
if err != nil {
s.err = err
return false
}
var cancel context.CancelFunc
ctx := s.js.opts.ctx
if ctx == nil {
ctx, cancel = context.WithTimeout(context.Background(), s.js.opts.wait)
defer cancel()
}
slSubj := s.js.apiSubj(apiStreamListT)
r, err := s.js.apiRequestWithContext(ctx, slSubj, req)
if err != nil {
s.err = err
return false
}
var resp streamListResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
s.err = err
return false
}
if resp.Error != nil {
s.err = resp.Error
return false
}
s.pageInfo = &resp.apiPaged
s.page = resp.Streams
s.offset += len(s.page)
return true
}
// Page returns the current StreamInfo page.
func (s *streamLister) Page() []*StreamInfo {
return s.page
}
// Err returns any errors found while fetching pages.
func (s *streamLister) Err() error {
return s.err
}
// Streams can be used to retrieve a list of StreamInfo objects.
func (jsc *js) Streams(opts ...JSOpt) <-chan *StreamInfo {
o, cancel, err := getJSContextOpts(jsc.opts, opts...)
if err != nil {
return nil
}
ch := make(chan *StreamInfo)
l := &streamLister{js: &js{nc: jsc.nc, opts: o}}
go func() {
if cancel != nil {
defer cancel()
}
defer close(ch)
for l.Next() {
for _, info := range l.Page() {
select {
case ch <- info:
case <-o.ctx.Done():
return
}
}
}
}()
return ch
}
// StreamsInfo can be used to retrieve a list of StreamInfo objects.
// DEPRECATED: Use Streams() instead.
func (jsc *js) StreamsInfo(opts ...JSOpt) <-chan *StreamInfo {
return jsc.Streams(opts...)
}
type streamNamesLister struct {
js *js
err error
offset int
page []string
pageInfo *apiPaged
}
// Next fetches the next stream names page.
func (l *streamNamesLister) Next() bool {
if l.err != nil {
return false
}
if l.pageInfo != nil && l.offset >= l.pageInfo.Total {
return false
}
var cancel context.CancelFunc
ctx := l.js.opts.ctx
if ctx == nil {
ctx, cancel = context.WithTimeout(context.Background(), l.js.opts.wait)
defer cancel()
}
req, err := json.Marshal(streamNamesRequest{
apiPagedRequest: apiPagedRequest{Offset: l.offset},
Subject: l.js.opts.streamListSubject,
})
if err != nil {
l.err = err
return false
}
r, err := l.js.apiRequestWithContext(ctx, l.js.apiSubj(apiStreams), req)
if err != nil {
l.err = err
return false
}
var resp streamNamesResponse
if err := json.Unmarshal(r.Data, &resp); err != nil {
l.err = err
return false
}
if resp.Error != nil {
l.err = resp.Error
return false
}
l.pageInfo = &resp.apiPaged
l.page = resp.Streams
l.offset += len(l.page)
return true
}
// Page returns the current ConsumerInfo page.
func (l *streamNamesLister) Page() []string {
return l.page
}
// Err returns any errors found while fetching pages.
func (l *streamNamesLister) Err() error {
return l.err
}
// StreamNames is used to retrieve a list of Stream names.
func (jsc *js) StreamNames(opts ...JSOpt) <-chan string {
o, cancel, err := getJSContextOpts(jsc.opts, opts...)
if err != nil {
return nil
}
ch := make(chan string)
l := &streamNamesLister{js: &js{nc: jsc.nc, opts: o}}
go func() {
if cancel != nil {
defer cancel()
}
defer close(ch)
for l.Next() {
for _, info := range l.Page() {
select {
case ch <- info:
case <-o.ctx.Done():
return
}
}
}
}()
return ch
}
// StreamNameBySubject returns a stream name that matches the subject.
func (jsc *js) StreamNameBySubject(subj string, opts ...JSOpt) (string, error) {
o, cancel, err := getJSContextOpts(jsc.opts, opts...)
if err != nil {
return "", err
}
if cancel != nil {
defer cancel()
}
var slr streamNamesResponse
req := &streamRequest{subj}
j, err := json.Marshal(req)
if err != nil {
return _EMPTY_, err
}
resp, err := jsc.apiRequestWithContext(o.ctx, jsc.apiSubj(apiStreams), j)
if err != nil {
if errors.Is(err, ErrNoResponders) {
err = ErrJetStreamNotEnabled
}
return _EMPTY_, err
}
if err := json.Unmarshal(resp.Data, &slr); err != nil {
return _EMPTY_, err
}
if slr.Error != nil || len(slr.Streams) != 1 {
return _EMPTY_, ErrNoMatchingStream
}
return slr.Streams[0], nil
}
func getJSContextOpts(defs *jsOpts, opts ...JSOpt) (*jsOpts, context.CancelFunc, error) {
var o jsOpts
for _, opt := range opts {
if err := opt.configureJSContext(&o); err != nil {
return nil, nil, err
}
}
// Check for option collisions. Right now just timeout and context.
if o.ctx != nil && o.wait != 0 {
return nil, nil, ErrContextAndTimeout
}
if o.wait == 0 && o.ctx == nil {
o.wait = defs.wait
}
var cancel context.CancelFunc
if o.ctx == nil && o.wait > 0 {
o.ctx, cancel = context.WithTimeout(context.Background(), o.wait)
}
if o.pre == _EMPTY_ {
o.pre = defs.pre
}
return &o, cancel, nil
}