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#pragma once
#include <util/system/types.h>
#include <util/system/yassert.h>
#include <cstddef>
namespace NYsonPull {
//! \brief A non-owning buffer model.
//!
//! Represents a \p pos pointer moving between \p begin and \p end.
template <typename T>
class buffer {
T* begin_ = nullptr;
T* pos_ = nullptr;
T* end_ = nullptr;
public:
T* begin() const noexcept {
return begin_;
}
T* pos() const noexcept {
return pos_;
}
T* end() const noexcept {
return end_;
}
//! \brief Amount of data after current position.
size_t available() const noexcept {
return end_ - pos_;
}
//! \brief Amount of data before current position.
size_t used() const noexcept {
return pos_ - begin_;
}
//! \brief Move current position \p nbytes forward.
void advance(size_t nbytes) noexcept {
Y_ASSERT(pos_ + nbytes <= end_);
pos_ += nbytes;
}
//! \brief Reset buffer pointers.
void reset(T* new_begin, T* new_end, T* new_pos) {
begin_ = new_begin;
pos_ = new_pos;
end_ = new_end;
}
//! \brief Reset buffer to beginning
void reset(T* new_begin, T* new_end) {
reset(new_begin, new_end, new_begin);
}
};
class output_buffer: public buffer<ui8> {
public:
//! \brief An output buffer is empty when there is no data written to it.
bool is_empty() const noexcept {
return pos() == begin();
}
//! \brief An output buffer is full when there is no space to write more data to it.
bool is_full() const noexcept {
return pos() == end();
}
};
class input_buffer: public buffer<const ui8> {
public:
//! An input stream is empty when there is no data to read in it.
bool is_empty() const noexcept {
return pos() == end();
}
};
}
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