library/cpp/yson_pull/detail/input/stream.h


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#pragma once 
 
#include <library/cpp/yson_pull/detail/macros.h>
 
#include <library/cpp/yson_pull/input.h>
 
#include <util/stream/buffered.h> 
#include <util/stream/file.h> 
#include <util/stream/zerocopy.h> 
#include <util/system/file.h> 
 
namespace NYsonPull { 
    namespace NDetail { 
        namespace NInput { 
            class TStreamBase: public NYsonPull::NInput::IStream { 
            protected: 
                result DoFillBufferFrom(IZeroCopyInput& input) {
                    void* ptr = nullptr; 
                    size_t size = input.Next(&ptr); 
                    if (Y_UNLIKELY(size == 0)) { 
                        return result::at_end; 
                    } 
                    buffer().reset(static_cast<ui8*>(ptr), static_cast<ui8*>(ptr) + size); 
                    return result::have_more_data; 
                } 
            }; 
 
            class TZeroCopy: public TStreamBase { 
                IZeroCopyInput* Input;
 
            public: 
                explicit TZeroCopy(IZeroCopyInput* input)
                    : Input(input) 
                { 
                } 
 
            protected: 
                result do_fill_buffer() override { 
                    return DoFillBufferFrom(*Input); 
                } 
            }; 
 
            template <typename TBuffered>
            class TOwned: public TStreamBase { 
                TBuffered Input; 
 
            public: 
                template <typename... Args>
                explicit TOwned(Args&&... args) 
                    : Input(std::forward<Args>(args)...) 
                { 
                } 
 
            protected: 
                result do_fill_buffer() override { 
                    return DoFillBufferFrom(Input); 
                } 
            }; 
 
            class TFHandle: public TOwned<TFileInput> {
            public: 
                TFHandle(int fd, size_t buffer_size) 
                    : TOwned<TFileInput>(Duplicate(fd), buffer_size)
                { 
                } 
            }; 
        } 
    }     // namespace NDetail
}