defaults

README

Defaults

Provide some global default values, supporting Go 1.21+.

Documentation

Overview

Package defaults provides some global default values.

Index

• Variables
• func Exit(code int)
• func ExitContext() context.Context
• func ExitSignals() []os.Signal
• func ExitWait()
• func Fatal(msg string, args ...any)
• func GetCaller(skip int) string
• func GetClientIP(ctx context.Context, req any) netip.Addr
• func GetRequestID(ctx context.Context, req any) string
• func GetStacks(skip int) []string
• func GetStructFieldName(sf reflect.StructField) (name, arg string)
• func HandlePanic(ctx context.Context, r any)
• func Now() time.Time
• func OnExit(f func())
• func OnExitPost(f func())
• func OnInit(f func())
• func OnInitPre(f func())
• func Recover(ctx context.Context)
• func SignalForExit()
• func ToBool(input any) (bool, error)
• func ToDuration(input any) (time.Duration, error)
• func ToFloat64(input any) (float64, error)
• func ToInt64(input any) (int64, error)
• func ToString(input any) (string, error)
• func ToTime(input any) (time.Time, error)
• func ToUint64(input any) (uint64, error)
• func TrimPkgFile(file string) string
• func ValidateStruct(value any) (err error)
• func ValidateWithRule(value any, rule string) (err error)
• type Value
  • func NewValue[T any](initial T) *Value[T]
  • func NewValueWithValidation[T any](initial T, validate func(T) error) *Value[T]
  • func (v *Value[T]) Get() T
  • func (v *Value[T]) Set(new T)
  • func (v *Value[T]) Swap(new T) (old T)
  • func (v *Value[T]) Validate(value T) error

Examples

• TrimPkgFile

Variables

var (
	// ToBoolFunc is used to convert an input to bool.
	ToBoolFunc = NewValueWithValidation(tobool, castValidation[bool]("ToBool"))

	// ToInt64Func is used to convert an input to int64.
	ToInt64Func = NewValueWithValidation(toint64, castValidation[int64]("ToInt64"))

	// ToUint64Func is used to convert an input to uint64.
	ToUint64Func = NewValueWithValidation(touint64, castValidation[uint64]("ToUint64"))

	// ToFloat64Func is used to convert an input to float64.
	ToFloat64Func = NewValueWithValidation(tofloat64, castValidation[float64]("ToFloat64"))

	// ToStringFunc is used to convert an input to string.
	ToStringFunc = NewValueWithValidation(tostring, castValidation[string]("ToString"))

	// ToDurationFunc is used to convert an input to time.Duraiton.
	ToDurationFunc = NewValueWithValidation(toduration, castValidation[time.Duration]("ToDuration"))

	// ToTimeFunc is used to convert an input to time.Time.
	ToTimeFunc = NewValueWithValidation(totime, castValidation[time.Time]("ToTime"))
)

var (
	// ExitFunc is used to exit the program.
	//
	// Default: calling assists.RunExit and os.Exit in turn.
	ExitFunc = NewValueWithValidation(exit, fA1Validation[int]("Exit"))

	// ExitWaitFunc is used to wait until the program exit.
	//
	// Default: assists.WaitExit
	ExitWaitFunc = NewValueWithValidation(assists.WaitExit, fValidation("ExitWait"))

	// ExitContextFunc is used to get the exit context.
	//
	// Default: assists.ExitContext
	ExitContextFunc = NewValueWithValidation(assists.ExitContext, fR1Validation[context.Context]("ExitContext"))

	// ExitSignalsFunc is used to get the signals to let the program exit.
	//
	// For default, on Unix/Linux or Windows, it contains the signals as follow:
	//
	//	os.Interrupt
	//	syscall.SIGTERM
	//	syscall.SIGQUIT
	//	syscall.SIGABRT
	//	syscall.SIGINT
	//
	// On others, it only contains the signal os.Interrupt.
	ExitSignalsFunc = NewValueWithValidation(exitSignalsFunc, fR1Validation[[]os.Signal]("ExitSignals"))
)

var (
	// HeaderXRequestID is used by GetRequestIDFunc to try
	// to get the request id from the http request.
	HeaderXRequestID = "X-Request-Id"

	// GetRequestIDFunc is used to get the unique request session id.
	//
	// For the default implementation, it only supports the types and interfaces:
	//
	// 	*http.Request
	//	interface{ RequestID() string }
	//	interface{ GetRequestID() string }
	//
	// Or, return "".
	GetRequestIDFunc = NewValueWithValidation(getRequestID, fActxAifaceR1[string]("GetRequestID"))
)

var (
	// TrimPkgFileFunc is used to trim the prefix of the package file path.
	TrimPkgFileFunc = NewValueWithValidation(trimPkgFile, fA1R1Validation[string, string]("TrimPkgFile"))

	// GetStacksFunc is used to get the stacks of the function calling.
	GetStacksFunc = NewValueWithValidation(getStacks, fA1R1Validation[int, []string]("GetStacks"))

	GetCallerFunc = NewValueWithValidation(getCaller, fA1R1Validation[int, string]("GetCaller"))
)

var (
	TimeFormat   = NewValueWithValidation(time.RFC3339Nano, validateTimeFormat)
	TimeFormats  = NewValueWithValidation([]string{time.RFC3339Nano, "2006-01-02 15:04:05"}, validateTimeFormats)
	TimeLocation = NewValueWithValidation(time.UTC, validateTimeLocation)
	TimeNowFunc  = NewValueWithValidation(time.Now, validateTimeNow)
)

Pre-define some global variables about time.

var (
	// RuleValidator is used to validate whether a value conforms with the rule.
	//
	// Note: in general, it is used to validate a struct field with the tag rule.
	RuleValidator = NewValue(assists.RuleValidator(nil))

	// StructValidator is used to validate whether a struct value is valid.
	StructValidator = NewValue(assists.StructValidator(nil))
)

var (
	// FatalFunc is used to log the message with the FATAL level,
	// then the program exits.
	//
	// Default: use slog.LevelError+4 as the FATAL level, then exit by Exit(1).
	FatalFunc = NewValueWithValidation(fatal, fA2Validation[string, []any]("Fatal"))
)

var (
	// GetClientIPFunc is used to get the client ip of the request.
	//
	// For the default implementation, it only supports the types or interfaces:
	//
	// 	*http.Request
	// 	interface{ ClientIP() netip.Addr }
	// 	interface{ ClientIP() net.IP }
	// 	interface{ ClientIP() string }
	// 	interface{ RemoteAddr() netip.Addr }
	// 	interface{ RemoteAddr() net.Addr }
	// 	interface{ RemoteAddr() string }
	//
	// Or, return nil.
	GetClientIPFunc = NewValueWithValidation(getClientIP, fActxAifaceR1[netip.Addr]("GetClientIP"))
)

var (
	// HandlePanicFunc is used to handle the panic value returned by recover().
	HandlePanicFunc = NewValueWithValidation(handlePanic, fActxAiface("HandlePanic"))
)

var (
	// StructFieldNameFunc is used to get the obtain the name and arg
	// of the struct field, which needs to return a empty string for
	// the field name, that's "", if the field should be ignored.
	//
	// Example:
	//
	//	StructFieldNameFunc.Set(func(sf reflect.StructField) (name string, arg string) {
	//	    value := sf.Tag.Get("json")
	//	    if index := strings.IndexByte(value, ','); index > -1 {
	//	        arg = strings.TrimSpace(value[index+1:])
	//	        value = strings.TrimSpace(value[:index])
	//	    }
	//
	//	    switch value {
	//	    case "-":
	//	    case "":
	//	        name = sf.Name
	//	    default:
	//	        name = value
	//	    }
	//
	//	    return
	//	})
	//
	StructFieldNameFunc = NewValueWithValidation(assists.StructFieldNameFuncWithTags("json"),
		fA1R2Validation[reflect.StructField, string, string]("StructFieldName"))
)

Functions

func Exit

func Exit(code int)

Exit is the proxy of ExitFunc to call the function to exit the program.

func ExitContext

func ExitContext() context.Context

ExitContext is the proxy of ExitContextFunc to get the exit context.

func ExitSignals

func ExitSignals() []os.Signal

ExitSignals is the proxy of ExitSignalsFunc to call it to get the exit signals.

func ExitWait

func ExitWait()

ExitWait is the proxy of ExitContextFunc to call it to wait until the program exit.

func Fatal

func Fatal(msg string, args ...any)

Fatal is the proxy of FatalFunc to log the message with the FATAL level, then the program exits.

func GetCaller

func GetCaller(skip int) string

func GetClientIP

func GetClientIP(ctx context.Context, req any) netip.Addr

GetClientIP is the proxy of GetClientIPFunc to call the function.

func GetRequestID

func GetRequestID(ctx context.Context, req any) string

GetRequestID is the proxy of GetRequestIDFunc to call the function.

func GetStacks

func GetStacks(skip int) []string

GetStacks is the proxy of GetStacksFunc to call the funciton.

func GetStructFieldName

func GetStructFieldName(sf reflect.StructField) (name, arg string)

GetStructFieldName is the proxy of StructFieldNameFunc to call the function, just like StructFieldNameFunc.Get()(sf).

func HandlePanic

func HandlePanic(ctx context.Context, r any)

HandlePanic is the proxy of HandlePanicFunc to call the funciton.

func Now

func Now() time.Time

Now returns the current time by using TimeNow and TimeLocation.

func OnExit

func OnExit(f func())

OnExit registers the exit function f, which is the proxy of assists.OnExit.

func OnExitPost

func OnExitPost(f func())

OnExitPost registers the post-exit function f, which is the proxy of assists.OnExitPost.

func OnInit

func OnInit(f func())

OnInit registers the init function f, which is the proxy of assists.OnInit.

func OnInitPre

func OnInitPre(f func())

OnInitPre registers the pre-init function f, which is the proxy of assists.OnInitPre.

func Recover

func Recover(ctx context.Context)

Recover is a convenient function to wrap and recover the panic if occurring, then call HandlePanic to handle it.

NOTICE: It must be called after defer, like

defer Recover(context.Background())

func SignalForExit

func SignalForExit()

SignalForExit watches the exit signals and calls the Exit function when any exit signal occurs.

func ToBool

func ToBool(input any) (bool, error)

ToBool is the proxy of ToBoolFunc to convert an input to bool.

func ToDuration

func ToDuration(input any) (time.Duration, error)

ToDuration is the proxy of ToDurationFunc to convert an input to time.Duration.

func ToFloat64

func ToFloat64(input any) (float64, error)

ToFloat64 is the proxy of ToFloat64Func to convert an input to float64.

func ToInt64

func ToInt64(input any) (int64, error)

ToInt64 is the proxy of ToInt64Func to convert an input to int64.

func ToString

func ToString(input any) (string, error)

ToString is the proxy of ToStringFunc to convert an input to string.

func ToTime

func ToTime(input any) (time.Time, error)

ToTime is the proxy of ToTimeFunc to convert an input to time.Time.

func ToUint64

func ToUint64(input any) (uint64, error)

ToUint64 is the proxy of ToUint64Func to convert an input to uint64.

func TrimPkgFile

func TrimPkgFile(file string) string

TrimPkgFile is the proxy of TrimPkgFileFunc to call the funciton.

Example

srcfile := TrimPkgFile("/path/to/src/github.com/xgfone/go-defaults/srcfile.go")
modfile := TrimPkgFile("/path/to/pkg/mod/github.com/xgfone/go-defaults/modfile.go")
origfile := TrimPkgFile("/path/to/github.com/xgfone/go-defaults/modfile.go")

fmt.Println(srcfile)
fmt.Println(modfile)
fmt.Println(origfile)

Output:

github.com/xgfone/go-defaults/srcfile.go
github.com/xgfone/go-defaults/modfile.go
/path/to/github.com/xgfone/go-defaults/modfile.go

func ValidateStruct

func ValidateStruct(value any) (err error)

ValidateStruct uses Validator to validate the struct value if StructValidator is not nil.

func ValidateWithRule

func ValidateWithRule(value any, rule string) (err error)

ValidateWithRule uses RuleValidator to validate a value conforms with the rule if RuleValidator is not nil.

Types

type Value

type Value[T any] struct {
	// contains filtered or unexported fields
}

Value represents a common value.

func NewValue

func NewValue[T any](initial T) *Value[T]

NewValue returns a new Value with the initial value.

func NewValueWithValidation

func NewValueWithValidation[T any](initial T, validate func(T) error) *Value[T]

NewValueWithValidation returns a new Value with the initial value and the validation.

validate may be nil, which is equal to always return nil.

func (*Value[T]) Get

func (v *Value[T]) Get() T

Get returns the inner value.

func (*Value[T]) Set

func (v *Value[T]) Set(new T)

Set sets the value to new.

It will panic if failing to validate the new value.

func (*Value[T]) Swap

func (v *Value[T]) Swap(new T) (old T)

Swap sets the value to new and returns the old value.

It will panic if failing to validate the new value.

func (*Value[T]) Validate

func (v *Value[T]) Validate(value T) error

Validate validate whether the input value is valid.