s3 cache client-side support

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/aws/aws-sdk-go-v2/service/internal/presigned-url/context.go

@@ -0,0 +1,48 @@
+package presignedurl
+
+import (
+	"context"
+
+	"github.com/aws/smithy-go/middleware"
+)
+
+// WithIsPresigning adds the isPresigning sentinel value to a context to signal
+// that the middleware stack is using the presign flow.
+//
+// Scoped to stack values. Use github.com/aws/smithy-go/middleware#ClearStackValues
+// to clear all stack values.
+func WithIsPresigning(ctx context.Context) context.Context {
+	return middleware.WithStackValue(ctx, isPresigningKey{}, true)
+}
+
+// GetIsPresigning returns if the context contains the isPresigning sentinel
+// value for presigning flows.
+//
+// Scoped to stack values. Use github.com/aws/smithy-go/middleware#ClearStackValues
+// to clear all stack values.
+func GetIsPresigning(ctx context.Context) bool {
+	v, _ := middleware.GetStackValue(ctx, isPresigningKey{}).(bool)
+	return v
+}
+
+type isPresigningKey struct{}
+
+// AddAsIsPresigingMiddleware adds a middleware to the head of the stack that
+// will update the stack's context to be flagged as being invoked for the
+// purpose of presigning.
+func AddAsIsPresigingMiddleware(stack *middleware.Stack) error {
+	return stack.Initialize.Add(asIsPresigningMiddleware{}, middleware.Before)
+}
+
+type asIsPresigningMiddleware struct{}
+
+func (asIsPresigningMiddleware) ID() string { return "AsIsPresigningMiddleware" }
+
+func (asIsPresigningMiddleware) HandleInitialize(
+	ctx context.Context, in middleware.InitializeInput, next middleware.InitializeHandler,
+) (
+	out middleware.InitializeOutput, metadata middleware.Metadata, err error,
+) {
+	ctx = WithIsPresigning(ctx)
+	return next.HandleInitialize(ctx, in)
+}