This library is compatible with Go 1.8+
Please refer to CHANGELOG.md if you encounter breaking changes.
- Motivation
- Collection Utilities
- Converter && Conversion Utilities
- Struct Utilities
- Function Utilities
- Time Utilities
- Storage API
- Macro
- ServiceRouter
- Decoder and Encoder
- Logger
- BatchLimiter
- License
- Credits and Acknowledgements
This library was developed as part of Datastore Connectivity and Testibility libraries: (Assertly, Datastore testing, End to end testing) as a way to share utilities, and other abstractions that may be useful in other projects.
Example
slice := []string{"a", "z", "c"}
iterator := toolbox.NewSliceIterator(slice)
value := ""
for iterator.HasNext() {
iterator.Next(&value)
...
}The following methods work on any slice type.
ProcessSlice
Example
var aSlice interface{}
toolbox.ProcessSlice(aSlice, func(item interface{}) bool {
...
return true //to continue to next element return true
})
ProcessSliceWithIndex
Example:
var aSlice interface{}
toolbox.ProcessSlice(aSlice, func(index int, item interface{}) bool {
...
return true //to continue to next element return true
})
IndexSlice
Example:
type Foo struct{
id int
name string
}
var aSlice = []Foo{ Foo{1, "A"}, Foo{2, "B"} }
var indexedMap = make(map[int]Foo)
toolbox.IndexSlice(aSlice, indexedMap, func(foo Foo) int {
return foo.id
})
CopySliceElements
Example:
source := []interface{}{
"abc", "def", "cyz",
}
var target = make([]string, 0)
toolbox.CopySliceElements(source, &target)
FilterSliceElements
Example:
source := []interface{}{
"abc", "def", "cyz","adc",
}
var target = make([]string, 0)
toolbox.FilterSliceElements(source, func(item string) bool {
return strings.HasPrefix(item, "a") //this matches any elements starting with a
}, &target)HasSliceAnyElements
Example:
source := []interface{}{
"abc", "def", "cyz","adc",
}
toolbox.HasSliceAnyElements(source, "cyz")SliceToMap
Example:
var source = []Foo{ Foo{1, "A"}, Foo{2, "B"} }
var target = make(map[int]string)
toolbox.MakeMapFromSlice(source, target, func(foo Foo) int {
return foo.id
},
func(foo Foo) string {
return foo.name
})
TransformSlice
Example:
type Product struct{ vendor, name string }
products := []Product{
Product{"Vendor1", "Product1"},
Product{"Vendor2", "Product2"},
Product{"Vendor1", "Product3"},
Product{"Vendor1", "Product4"},
}
var vendors=make([]string, 0)
toolbox.TransformSlice(products, &vendors, func(product Product) string {
return product.vendor
})ProcessMap
The following methods work on any map type.
Example:
var aMap interface{}
toolbox.ProcessMap(aMap, func(key, value interface{}) bool {
...
return true //to continue to next element return true
})CopyMapEntries
Example:
type Foo struct{id int;name string}
source := map[interface{}]interface{} {
1: Foo{1, "A"},
2: Foo{2, "B"},
}
var target = make(map[int]Foo)
toolbox.CopyMapEntries(source, target)MapKeysToSlice
Example:
aMap := map[string]int {
"abc":1,
"efg":2,
}
var keys = make([]string, 0)
toolbox.MapKeysToSlice(aMap, &keys)GroupSliceElements
Example:
type Product struct{vendor,name string}
products := []Product{
Product{"Vendor1", "Product1"},
Product{"Vendor2", "Product2"},
Product{"Vendor1", "Product3"},
Product{"Vendor1", "Product4"},
}
productsByVendor := make(map[string][]Product)
toolbox.GroupSliceElements(products, productsByVendor, func(product Product) string {
return product.vendor
})SliceToMultimap
type Product struct {
vendor, name string
productId int
}
products := []Product{
Product{"Vendor1", "Product1", 1},
Product{"Vendor2", "Product2", 2},
Product{"Vendor1", "Product3", 3},
Product{"Vendor1", "Product4", 4},
}
productsByVendor := make(map[string][]int)
toolbox.SliceToMultimap(products, productsByVendor, func(product Product) string {
return product.vendor
},
func(product Product) int {
return product.productId
})DateFormatToLayout
Java date format style to go date layout conversion.
dateLaout := toolbox.DateFormatToLayout("yyyy-MM-dd hh:mm:ss z")
timeValue, err := time.Parse(dateLaout, "2016-02-22 12:32:01 UTC")Storage API provides unified way of accessing local or remote storage system.
Example
import (
"github.com/viant/toolbox/storage"
_ "github.com/viant/toolbox/storage/gs"
)
destinationURL := "gs://myBucket/set1/content.gz"
destinationCredentialFile = "gs-secret.json"
storageService, err := storage.NewServiceForURL(destinationURL, destinationCredentialFile)This ServiceRouter provides simple WebService Endpoint abstractin and RESET Client utilities.
Take as example of a ReverseService defined as follow
type ReverseService interface {
Reverse(values []int) []int
}
type reverseService struct{}
func (r *reverseService) Reverse(values []int) []int {
var result = make([]int, 0)
for i := len(values) - 1; i >= 0; i-- {
result = append(result, values[i])
}
return result
}In order to define Endpoint for this service, define a server, a router with the service routes;
type Server struct {
service ReverseService
port string
}
func (s *Server) Start() {
router := toolbox.NewServiceRouter(
toolbox.ServiceRouting{
HTTPMethod: "GET",
URI: "/v1/reverse/{ids}",
Handler: s.service.Reverse,
Parameters: []string{"ids"},
},
toolbox.ServiceRouting{
HTTPMethod: "POST",
URI: "/v1/reverse/",
Handler: s.service.Reverse,
Parameters: []string{"ids"},
})
http.HandleFunc("/v1/", func(writer http.ResponseWriter, reader *http.Request) {
err := router.Route(writer, reader)
if err != nil {
response.WriteHeader(http.StatusInternalServerError)
}
})
fmt.Printf("Started test server on port %v\n", port)
log.Fatal(http.ListenAndServe(":"+port, nil))
}
ServiceRouting parameters define handler parameters that can be extracted from URI, QueryString, or from Post Body (json payload) In addition two special parameter names are supported: @httpRequest, @httpResponseWriter to pass in request, and response object respectively.
The REST client utility invoking our reverse service may look as follow
var result = make([]int, 0)
err := toolbox.RouteToService("get", "http://127.0.0.1:8082/v1/reverse/1,7,3", nil, &result)
//...
err := toolbox.RouteToService("post", "http://127.0.0.1:8082/v1/reverse/", []int{1, 7, 3}, &result)By default a service router uses reflection to call the matched routes handler, it is possible to avoid reflection overhead by providing the custom handler invoker.
var ReverseInvoker = func(serviceRouting *toolbox.ServiceRouting, request *http.Request, response http.ResponseWriter, uriParameters map[string]interface{}) error {
var function = serviceRouting.Handler.(func(values []int) []int)
idsParam := uriParameters["ids"]
ids := idsParam.([]string)
values := make([]int, 0)
for _, item := range ids {
values = append(values, toolbox.AsInt(item))
}
var result = function(values)
err := toolbox.WriteServiceRoutingResponse(response, request, serviceRouting, result)
if err != nil {
return err
}
return nil
}
//...
router := toolbox.NewServiceRouter(
toolbox.ServiceRouting{
HTTPMethod: "GET",
URI: "/v1/reverse/{ids}",
Handler: s.service.Reverse,
Parameters: []string{"ids"},
HandlerInvoker: ReverseInvoker,
})
//...
This library defines DecoderFactory interface to delegate decoder creation, This library comes with standard JSON and UnMarshaler (protobuf) factory implementation.
Example
factory :=toolbox.NewJsonDecoderFactory()
....
decoder := factory.Create(reader)
foo := &Foo{}
err = decoder.Decode(foo)
marshalerFactory := toolbox.NewUnMarshalerDecoderFactory()
decoder := marshalerFactory.Create(reader)
foo := &Foo{}
err = decoder.Decode(foo)This library defines EncoderFactory interface to delegate encoder creation, This library comes with standard JSON and Marshaler (protobuf) factory implementation.
Example
factory :=toolbox.NewJsonEncoderFactory()
....
buffer := new(bytes.Buffer)
decoder := factory.Create(buffer)
err = decoder.Encode(foo)
marshalerFactory := toolbox.NewMarshalerEncoderFactory()
decoder := marshalerFactory.Create(buffer)
err = decoder.Encode(foo)This library provides a file logger implementation that optimizes writes. Log messages are queues until max queue size or flush frequency are met. On top of that Ctrl-C also forces immediate log messages flush to disk.
File template support java style time format to manage rotation on the file name level.
logger, err := toolbox.NewFileLogger(toolbox.FileLoggerConfig{
LogType: "test",
FileTemplate: "/tmp/test[yyyyMMdd-hhmm].log",
QueueFlashCount: 250,
MaxQueueSize: 500,
FlushFrequencyInMs: 2000,
MaxIddleTimeInSec: 1,
}, toolbox.FileLoggerConfig{
LogType: "transaction",
FileTemplate: "/tmp/transaction[yyyyMMdd-hhmm].log",
QueueFlashCount: 250,
MaxQueueSize: 500,
FlushFrequencyInMs:2000,
MaxIddleTimeInSec: 1,
},
)
logger.Log(&toolbox.LogMessage{
MessageType: "test",
Message: message
})
logger.Log(&toolbox.LogMessage{
MessageType: "transaction",
Message: message
})This library provides a batch limiter, that enables controling number of active go routines.
var tasks []*Task
var batchSize = 4
limiter:= toolbox.NewBatchLimiter(batchSize, len(tasks))
for i, _ := range tasks {
go func(task *Task) {
limiter.Acquire()
defer limiter.Done()
task.Run();
}(tasks[i])
}
limiter.Wait()The source code is made available under the terms of the Apache License, Version 2, as stated in the file LICENSE.
Individual files may be made available under their own specific license, all compatible with Apache License, Version 2. Please see individual files for details.
Library Author: Adrian Witas
Contributors: