| // 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. |
| |
| #pragma once |
| |
| #include <algorithm> |
| |
| #include <fbl/unique_ptr.h> |
| #include <fuchsia/mem/c/fidl.h> |
| #include <lib/zx/vmo.h> |
| |
| namespace paver { |
| |
| class VmoReader { |
| public: |
| VmoReader(const fuchsia_mem_Buffer& buffer) |
| : vmo_(buffer.vmo), size_(buffer.size) {} |
| |
| zx_status_t Read(void* buf, size_t buf_size, size_t* size_actual) { |
| if (offset_ >= size_) { |
| return ZX_ERR_OUT_OF_RANGE; |
| } |
| const auto size = std::min(size_ - offset_, buf_size); |
| auto status = vmo_.read(buf, offset_, size); |
| if (status != ZX_OK) { |
| return status; |
| } |
| offset_ += size; |
| *size_actual = size; |
| return ZX_OK; |
| } |
| |
| private: |
| zx::vmo vmo_; |
| size_t size_; |
| zx_off_t offset_ = 0; |
| }; |
| |
| } // namespace paver |