1//===-- lib/Parser/char-buffer.cpp ----------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "flang/Parser/char-buffer.h"
10#include "flang/Common/idioms.h"
11#include <algorithm>
12#include <cstddef>
13#include <cstring>
14
15namespace Fortran::parser {
16
17char *CharBuffer::FreeSpace(std::size_t &n) {
18 int offset{LastBlockOffset()};
19 if (blocks_.empty()) {
20 blocks_.emplace_front();
21 lastBlockEmpty_ = true;
22 } else if (offset == 0 && !lastBlockEmpty_) {
23 blocks_.emplace_back();
24 lastBlockEmpty_ = true;
25 }
26 n = Block::capacity - offset;
27 return blocks_.back().data + offset;
28}
29
30void CharBuffer::Claim(std::size_t n) {
31 if (n > 0) {
32 bytes_ += n;
33 lastBlockEmpty_ = false;
34 }
35}
36
37std::size_t CharBuffer::Put(const char *data, std::size_t n) {
38 std::size_t chunk;
39 for (std::size_t at{0}; at < n; at += chunk) {
40 char *to{FreeSpace(chunk)};
41 chunk = std::min(n - at, chunk);
42 Claim(chunk);
43 std::memcpy(to, data + at, chunk);
44 }
45 return bytes_ - n;
46}
47
48std::size_t CharBuffer::Put(const std::string &str) {
49 return Put(str.data(), str.size());
50}
51
52std::string CharBuffer::Marshal() const {
53 std::string result;
54 std::size_t bytes{bytes_};
55 result.reserve(bytes);
56 for (const Block &block : blocks_) {
57 std::size_t chunk{std::min(bytes, Block::capacity)};
58 for (std::size_t j{0}; j < chunk; ++j) {
59 result += block.data[j];
60 }
61 bytes -= chunk;
62 }
63 result.shrink_to_fit();
64 CHECK(result.size() == bytes_);
65 return result;
66}
67} // namespace Fortran::parser
68

source code of flang/lib/Parser/char-buffer.cpp