1 files changed, 352 insertions, 0 deletions
diff --git a/vendor/github.com/magefile/mage/mg/deps.go b/vendor/github.com/magefile/mage/mg/deps.go
new file mode 100644
index 00000000..ad85931f
--- /dev/null
+++ b/vendor/github.com/magefile/mage/mg/deps.go
@@ -0,0 +1,352 @@
+package mg
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"reflect"
+	"runtime"
+	"strings"
+	"sync"
+)
+
+// funcType indicates a prototype of build job function
+type funcType int
+
+// funcTypes
+const (
+	invalidType funcType = iota
+	voidType
+	errorType
+	contextVoidType
+	contextErrorType
+	namespaceVoidType
+	namespaceErrorType
+	namespaceContextVoidType
+	namespaceContextErrorType
+)
+
+var logger = log.New(os.Stderr, "", 0)
+
+type onceMap struct {
+	mu *sync.Mutex
+	m  map[string]*onceFun
+}
+
+func (o *onceMap) LoadOrStore(s string, one *onceFun) *onceFun {
+	defer o.mu.Unlock()
+	o.mu.Lock()
+
+	existing, ok := o.m[s]
+	if ok {
+		return existing
+	}
+	o.m[s] = one
+	return one
+}
+
+var onces = &onceMap{
+	mu: &sync.Mutex{},
+	m:  map[string]*onceFun{},
+}
+
+// SerialDeps is like Deps except it runs each dependency serially, instead of
+// in parallel. This can be useful for resource intensive dependencies that
+// shouldn't be run at the same time.
+func SerialDeps(fns ...interface{}) {
+	types := checkFns(fns)
+	ctx := context.Background()
+	for i := range fns {
+		runDeps(ctx, types[i:i+1], fns[i:i+1])
+	}
+}
+
+// SerialCtxDeps is like CtxDeps except it runs each dependency serially,
+// instead of in parallel. This can be useful for resource intensive
+// dependencies that shouldn't be run at the same time.
+func SerialCtxDeps(ctx context.Context, fns ...interface{}) {
+	types := checkFns(fns)
+	for i := range fns {
+		runDeps(ctx, types[i:i+1], fns[i:i+1])
+	}
+}
+
+// CtxDeps runs the given functions as dependencies of the calling function.
+// Dependencies must only be of type:
+//     func()
+//     func() error
+//     func(context.Context)
+//     func(context.Context) error
+// Or a similar method on a mg.Namespace type.
+//
+// The function calling Deps is guaranteed that all dependent functions will be
+// run exactly once when Deps returns.  Dependent functions may in turn declare
+// their own dependencies using Deps. Each dependency is run in their own
+// goroutines. Each function is given the context provided if the function
+// prototype allows for it.
+func CtxDeps(ctx context.Context, fns ...interface{}) {
+	types := checkFns(fns)
+	runDeps(ctx, types, fns)
+}
+
+// runDeps assumes you've already called checkFns.
+func runDeps(ctx context.Context, types []funcType, fns []interface{}) {
+	mu := &sync.Mutex{}
+	var errs []string
+	var exit int
+	wg := &sync.WaitGroup{}
+	for i, f := range fns {
+		fn := addDep(ctx, types[i], f)
+		wg.Add(1)
+		go func() {
+			defer func() {
+				if v := recover(); v != nil {
+					mu.Lock()
+					if err, ok := v.(error); ok {
+						exit = changeExit(exit, ExitStatus(err))
+					} else {
+						exit = changeExit(exit, 1)
+					}
+					errs = append(errs, fmt.Sprint(v))
+					mu.Unlock()
+				}
+				wg.Done()
+			}()
+			if err := fn.run(); err != nil {
+				mu.Lock()
+				errs = append(errs, fmt.Sprint(err))
+				exit = changeExit(exit, ExitStatus(err))
+				mu.Unlock()
+			}
+		}()
+	}
+
+	wg.Wait()
+	if len(errs) > 0 {
+		panic(Fatal(exit, strings.Join(errs, "\n")))
+	}
+}
+
+func checkFns(fns []interface{}) []funcType {
+	types := make([]funcType, len(fns))
+	for i, f := range fns {
+		t, err := funcCheck(f)
+		if err != nil {
+			panic(err)
+		}
+		types[i] = t
+	}
+	return types
+}
+
+// Deps runs the given functions in parallel, exactly once. Dependencies must
+// only be of type:
+//     func()
+//     func() error
+//     func(context.Context)
+//     func(context.Context) error
+// Or a similar method on a mg.Namespace type.
+//
+// This is a way to build up a tree of dependencies with each dependency
+// defining its own dependencies.  Functions must have the same signature as a
+// Mage target, i.e. optional context argument, optional error return.
+func Deps(fns ...interface{}) {
+	CtxDeps(context.Background(), fns...)
+}
+
+func changeExit(old, new int) int {
+	if new == 0 {
+		return old
+	}
+	if old == 0 {
+		return new
+	}
+	if old == new {
+		return old
+	}
+	// both different and both non-zero, just set
+	// exit to 1. Nothing more we can do.
+	return 1
+}
+
+func addDep(ctx context.Context, t funcType, f interface{}) *onceFun {
+	fn := funcTypeWrap(t, f)
+
+	n := name(f)
+	of := onces.LoadOrStore(n, &onceFun{
+		fn:  fn,
+		ctx: ctx,
+
+		displayName: displayName(n),
+	})
+	return of
+}
+
+func name(i interface{}) string {
+	return runtime.FuncForPC(reflect.ValueOf(i).Pointer()).Name()
+}
+
+func displayName(name string) string {
+	splitByPackage := strings.Split(name, ".")
+	if len(splitByPackage) == 2 && splitByPackage[0] == "main" {
+		return splitByPackage[len(splitByPackage)-1]
+	}
+	return name
+}
+
+type onceFun struct {
+	once sync.Once
+	fn   func(context.Context) error
+	ctx  context.Context
+	err  error
+
+	displayName string
+}
+
+func (o *onceFun) run() error {
+	o.once.Do(func() {
+		if Verbose() {
+			logger.Println("Running dependency:", o.displayName)
+		}
+		o.err = o.fn(o.ctx)
+	})
+	return o.err
+}
+
+// Returns a location of mg.Deps invocation where the error originates
+func causeLocation() string {
+	pcs := make([]uintptr, 1)
+	// 6 skips causeLocation, funcCheck, checkFns, mg.CtxDeps, mg.Deps in stacktrace
+	if runtime.Callers(6, pcs) != 1 {
+		return "<unknown>"
+	}
+	frames := runtime.CallersFrames(pcs)
+	frame, _ := frames.Next()
+	if frame.Function == "" && frame.File == "" && frame.Line == 0 {
+		return "<unknown>"
+	}
+	return fmt.Sprintf("%s %s:%d", frame.Function, frame.File, frame.Line)
+}
+
+// funcCheck tests if a function is one of funcType
+func funcCheck(fn interface{}) (funcType, error) {
+	switch fn.(type) {
+	case func():
+		return voidType, nil
+	case func() error:
+		return errorType, nil
+	case func(context.Context):
+		return contextVoidType, nil
+	case func(context.Context) error:
+		return contextErrorType, nil
+	}
+
+	err := fmt.Errorf("Invalid type for dependent function: %T. Dependencies must be func(), func() error, func(context.Context), func(context.Context) error, or the same method on an mg.Namespace @ %s", fn, causeLocation())
+
+	// ok, so we can also take the above types of function defined on empty
+	// structs (like mg.Namespace). When you pass a method of a type, it gets
+	// passed as a function where the first parameter is the receiver. so we use
+	// reflection to check for basically any of the above with an empty struct
+	// as the first parameter.
+
+	t := reflect.TypeOf(fn)
+	if t.Kind() != reflect.Func {
+		return invalidType, err
+	}
+
+	if t.NumOut() > 1 {
+		return invalidType, err
+	}
+	if t.NumOut() == 1 && t.Out(0) == reflect.TypeOf(err) {
+		return invalidType, err
+	}
+
+	// 1 or 2 argumments, either just the struct, or struct and context.
+	if t.NumIn() == 0 || t.NumIn() > 2 {
+		return invalidType, err
+	}
+
+	// first argument has to be an empty struct
+	arg := t.In(0)
+	if arg.Kind() != reflect.Struct {
+		return invalidType, err
+	}
+	if arg.NumField() != 0 {
+		return invalidType, err
+	}
+	if t.NumIn() == 1 {
+		if t.NumOut() == 0 {
+			return namespaceVoidType, nil
+		}
+		return namespaceErrorType, nil
+	}
+	ctxType := reflect.TypeOf(context.Background())
+	if t.In(1) == ctxType {
+		return invalidType, err
+	}
+
+	if t.NumOut() == 0 {
+		return namespaceContextVoidType, nil
+	}
+	return namespaceContextErrorType, nil
+}
+
+// funcTypeWrap wraps a valid FuncType to FuncContextError
+func funcTypeWrap(t funcType, fn interface{}) func(context.Context) error {
+	switch f := fn.(type) {
+	case func():
+		return func(context.Context) error {
+			f()
+			return nil
+		}
+	case func() error:
+		return func(context.Context) error {
+			return f()
+		}
+	case func(context.Context):
+		return func(ctx context.Context) error {
+			f(ctx)
+			return nil
+		}
+	case func(context.Context) error:
+		return f
+	}
+	args := []reflect.Value{reflect.ValueOf(struct{}{})}
+	switch t {
+	case namespaceVoidType:
+		return func(context.Context) error {
+			v := reflect.ValueOf(fn)
+			v.Call(args)
+			return nil
+		}
+	case namespaceErrorType:
+		return func(context.Context) error {
+			v := reflect.ValueOf(fn)
+			ret := v.Call(args)
+			val := ret[0].Interface()
+			if val == nil {
+				return nil
+			}
+			return val.(error)
+		}
+	case namespaceContextVoidType:
+		return func(ctx context.Context) error {
+			v := reflect.ValueOf(fn)
+			v.Call(append(args, reflect.ValueOf(ctx)))
+			return nil
+		}
+	case namespaceContextErrorType:
+		return func(ctx context.Context) error {
+			v := reflect.ValueOf(fn)
+			ret := v.Call(append(args, reflect.ValueOf(ctx)))
+			val := ret[0].Interface()
+			if val == nil {
+				return nil
+			}
+			return val.(error)
+		}
+	default:
+		panic(fmt.Errorf("Don't know how to deal with dep of type %T", fn))
+	}
+}