| //===-- include/flang/Parser/char-buffer.h ----------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef FORTRAN_PARSER_CHAR_BUFFER_H_ |
| #define FORTRAN_PARSER_CHAR_BUFFER_H_ |
| |
| // Defines a simple expandable buffer suitable for efficiently accumulating |
| // a stream of bytes. |
| |
| #include <cstddef> |
| #include <list> |
| #include <string> |
| #include <utility> |
| #include <vector> |
| |
| namespace Fortran::parser { |
| |
| class CharBuffer { |
| public: |
| CharBuffer() {} |
| CharBuffer(CharBuffer &&that) |
| : blocks_(std::move(that.blocks_)), bytes_{that.bytes_}, |
| lastBlockEmpty_{that.lastBlockEmpty_} { |
| that.clear(); |
| } |
| CharBuffer &operator=(CharBuffer &&that) { |
| blocks_ = std::move(that.blocks_); |
| bytes_ = that.bytes_; |
| lastBlockEmpty_ = that.lastBlockEmpty_; |
| that.clear(); |
| return *this; |
| } |
| |
| bool empty() const { return bytes_ == 0; } |
| std::size_t bytes() const { return bytes_; } |
| |
| void clear() { |
| blocks_.clear(); |
| bytes_ = 0; |
| lastBlockEmpty_ = false; |
| } |
| |
| char *FreeSpace(std::size_t &); |
| void Claim(std::size_t); |
| |
| // The return value is the byte offset of the new data, |
| // i.e. the value of size() before the call. |
| std::size_t Put(const char *data, std::size_t n); |
| std::size_t Put(const std::string &); |
| std::size_t Put(char x) { return Put(&x, 1); } |
| |
| std::string Marshal() const; |
| |
| private: |
| struct Block { |
| static constexpr std::size_t capacity{1 << 20}; |
| char data[capacity]; |
| }; |
| |
| int LastBlockOffset() const { return bytes_ % Block::capacity; } |
| std::list<Block> blocks_; |
| std::size_t bytes_{0}; |
| bool lastBlockEmpty_{false}; |
| }; |
| } // namespace Fortran::parser |
| #endif // FORTRAN_PARSER_CHAR_BUFFER_H_ |