xesite/vendor/gopkg.in/segmentio/analytics-go.v3/config.go

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2018-08-22 03:17:59 +00:00
package analytics
import (
"net/http"
"time"
"github.com/segmentio/backo-go"
"github.com/xtgo/uuid"
)
// Instances of this type carry the different configuration options that may
// be set when instantiating a client.
//
// Each field's zero-value is either meaningful or interpreted as using the
// default value defined by the library.
type Config struct {
// The endpoint to which the client connect and send their messages, set to
// `DefaultEndpoint` by default.
Endpoint string
// The flushing interval of the client. Messages will be sent when they've
// been queued up to the maximum batch size or when the flushing interval
// timer triggers.
Interval time.Duration
// The HTTP transport used by the client, this allows an application to
// redefine how requests are being sent at the HTTP level (for example,
// to change the connection pooling policy).
// If none is specified the client uses `http.DefaultTransport`.
Transport http.RoundTripper
// The logger used by the client to output info or error messages when that
// are generated by background operations.
// If none is specified the client uses a standard logger that outputs to
// `os.Stderr`.
Logger Logger
// The callback object that will be used by the client to notify the
// application when messages sends to the backend API succeeded or failed.
Callback Callback
// The maximum number of messages that will be sent in one API call.
// Messages will be sent when they've been queued up to the maximum batch
// size or when the flushing interval timer triggers.
// Note that the API will still enforce a 500KB limit on each HTTP request
// which is independent from the number of embedded messages.
BatchSize int
// When set to true the client will send more frequent and detailed messages
// to its logger.
Verbose bool
// The default context set on each message sent by the client.
DefaultContext *Context
// The retry policy used by the client to resend requests that have failed.
// The function is called with how many times the operation has been retried
// and is expected to return how long the client should wait before trying
// again.
// If not set the client will fallback to use a default retry policy.
RetryAfter func(int) time.Duration
// A function called by the client to generate unique message identifiers.
// The client uses a UUID generator if none is provided.
// This field is not exported and only exposed internally to let unit tests
// mock the id generation.
uid func() string
// A function called by the client to get the current time, `time.Now` is
// used by default.
// This field is not exported and only exposed internally to let unit tests
// mock the current time.
now func() time.Time
// The maximum number of goroutines that will be spawned by a client to send
// requests to the backend API.
// This field is not exported and only exposed internally to let unit tests
// mock the current time.
maxConcurrentRequests int
}
// This constant sets the default endpoint to which client instances send
// messages if none was explictly set.
const DefaultEndpoint = "https://api.segment.io"
// This constant sets the default flush interval used by client instances if
// none was explicitly set.
const DefaultInterval = 5 * time.Second
// This constant sets the default batch size used by client instances if none
// was explicitly set.
const DefaultBatchSize = 250
// Verifies that fields that don't have zero-values are set to valid values,
// returns an error describing the problem if a field was invalid.
func (c *Config) validate() error {
if c.Interval < 0 {
return ConfigError{
Reason: "negative time intervals are not supported",
Field: "Interval",
Value: c.Interval,
}
}
if c.BatchSize < 0 {
return ConfigError{
Reason: "negative batch sizes are not supported",
Field: "BatchSize",
Value: c.BatchSize,
}
}
return nil
}
// Given a config object as argument the function will set all zero-values to
// their defaults and return the modified object.
func makeConfig(c Config) Config {
if len(c.Endpoint) == 0 {
c.Endpoint = DefaultEndpoint
}
if c.Interval == 0 {
c.Interval = DefaultInterval
}
if c.Transport == nil {
c.Transport = http.DefaultTransport
}
if c.Logger == nil {
c.Logger = newDefaultLogger()
}
if c.BatchSize == 0 {
c.BatchSize = DefaultBatchSize
}
if c.DefaultContext == nil {
c.DefaultContext = &Context{}
}
if c.RetryAfter == nil {
c.RetryAfter = backo.DefaultBacko().Duration
}
if c.uid == nil {
c.uid = uid
}
if c.now == nil {
c.now = time.Now
}
if c.maxConcurrentRequests == 0 {
c.maxConcurrentRequests = 1000
}
// We always overwrite the 'library' field of the default context set on the
// client because we want this information to be accurate.
c.DefaultContext.Library = LibraryInfo{
Name: "analytics-go",
Version: Version,
}
return c
}
// This function returns a string representation of a UUID, it's the default
// function used for generating unique IDs.
func uid() string {
return uuid.NewRandom().String()
}