87 lines
1.7 KiB
C++
87 lines
1.7 KiB
C++
// SPDX-License-Identifier: BSD-2-Clause
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// author: Max Kellermann <max.kellermann@gmail.com>
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#pragma once
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#include "util/DynamicFifoBuffer.hxx"
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#include <cstddef>
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#include <span>
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class Reader;
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class BufferedReader {
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static constexpr std::size_t MAX_SIZE = 512 * 1024;
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Reader &reader;
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DynamicFifoBuffer<std::byte> buffer;
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bool eof = false;
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unsigned line_number = 0;
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public:
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explicit BufferedReader(Reader &_reader) noexcept
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:reader(_reader), buffer(16384) {}
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/**
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* Reset the internal state. Should be called after rewinding
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* the underlying #Reader.
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*/
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void Reset() noexcept {
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buffer.Clear();
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eof = false;
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line_number = 0;
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}
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bool Fill(bool need_more);
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[[gnu::pure]]
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std::span<std::byte> Read() const noexcept {
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return std::as_writable_bytes(buffer.Read());
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}
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/**
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* Read a buffer of exactly the given size (without consuming
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* it). Throws std::runtime_error if not enough data is
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* available.
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*/
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void *ReadFull(std::size_t size);
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void Consume(std::size_t n) noexcept {
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buffer.Consume(n);
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}
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/**
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* Read (and consume) data from the input buffer into the
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* given buffer. Does not attempt to refill the buffer.
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*/
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std::size_t ReadFromBuffer(std::span<std::byte> dest) noexcept;
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/**
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* Read data into the given buffer and consume it from our
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* buffer. Throw an exception if the request cannot be
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* forfilled.
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*/
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void ReadFull(std::span<std::byte> dest);
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template<typename T>
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void ReadFullT(T &dest) {
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ReadFull(std::as_writable_bytes(std::span{&dest, 1}));
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}
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template<typename T>
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T ReadFullT() {
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T dest;
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ReadFullT<T>(dest);
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return dest;
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}
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char *ReadLine();
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unsigned GetLineNumber() const noexcept {
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return line_number;
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}
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};
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