src/developer/shell/josh/lib/qjs_util.h

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef SRC_DEVELOPER_SHELL_JOSH_LIB_QJS_UTIL_H_
#define SRC_DEVELOPER_SHELL_JOSH_LIB_QJS_UTIL_H_

#include "third_party/quickjs/quickjs.h"

// This is one of those terrific grab-bag utilities files that everyone loves.

namespace shell {

// A unique_ptr-alike for C strings generated by quickjs from JS strings.
class CStringHolder {
 public:
  explicit CStringHolder(JSContext* ctx) : ctx_(ctx), val_(nullptr) {}
  CStringHolder(JSContext* ctx, const JSValueConst& val)
      : ctx_(ctx), val_(JS_ToCString(ctx, val)) {}
  ~CStringHolder() {
    if (val_) {
      JS_FreeCString(ctx_, val_);
    }
  }

  const char* reset(const JSValueConst& val) {
    if (val_) {
      JS_FreeCString(ctx_, val_);
    }
    val_ = JS_ToCString(ctx_, val);
    return val_;
  }
  const char* get() { return val_; }

 private:
  JSContext* ctx_;
  const char* val_;
};

}  // namespace shell

#endif  // SRC_DEVELOPER_SHELL_JOSH_LIB_QJS_UTIL_H_