Initial QSfera import

Server/vendor/github.com/open-policy-agent/opa/v1/util/decoding/context.go

@@ -0,0 +1,31 @@
+package decoding
+
+import "context"
+
+type requestContextKey string
+
+// Note(philipc): We can add functions later to add the max request body length
+// to contexts, if we ever need to.
+const (
+	reqCtxKeyMaxLen     = requestContextKey("server-decoding-plugin-context-max-length")
+	reqCtxKeyGzipMaxLen = requestContextKey("server-decoding-plugin-context-gzip-max-length")
+)
+
+func AddServerDecodingMaxLen(ctx context.Context, maxLen int64) context.Context {
+	return context.WithValue(ctx, reqCtxKeyMaxLen, maxLen)
+}
+
+func AddServerDecodingGzipMaxLen(ctx context.Context, maxLen int64) context.Context {
+	return context.WithValue(ctx, reqCtxKeyGzipMaxLen, maxLen)
+}
+
+// Used for enforcing max body content limits when dealing with chunked requests.
+func GetServerDecodingMaxLen(ctx context.Context) (int64, bool) {
+	maxLength, ok := ctx.Value(reqCtxKeyMaxLen).(int64)
+	return maxLength, ok
+}
+
+func GetServerDecodingGzipMaxLen(ctx context.Context) (int64, bool) {
+	gzipMaxLength, ok := ctx.Value(reqCtxKeyGzipMaxLen).(int64)
+	return gzipMaxLength, ok
+}