150 lines · cpp
1//===----------------------------------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++0310 11// <fstream>12 13// streamsize xsputn(const char_type*, streamsize) override;14 15// This isn't a required override by the standard, but most implementations override it, since it allows for16// significantly improved performance in some cases. All of this code is required to work, so this isn't a libc++17// extension18 19#include <algorithm>20#include <cassert>21#include <codecvt>22#include <cstring>23#include <fstream>24#include <locale>25#include <vector>26 27#include "test_macros.h"28 29typedef std::filebuf::pos_type pos_type;30typedef std::filebuf::off_type off_type;31 32void sputn_seekoff(char* buf,33 const size_t buf_size,34 const std::streamsize chunk_size1,35 const off_type offset1,36 const std::streamsize chunk_size2) {37 std::string data{"abcdefghijklmnopqrstuvwxyz"};38 const std::streamsize data_size = static_cast<std::streamsize>(data.size());39 assert(chunk_size1 <= data_size);40 assert(chunk_size2 <= data_size);41 // vector with expected data in the file to be written42 std::size_t result_size = 5 + chunk_size1 + chunk_size2 + 1;43 if (offset1 > 0) {44 result_size += offset1;45 }46 std::vector<char> result(result_size, 0);47 {48 std::filebuf f;49 f.pubsetbuf(buf, buf_size);50 assert(f.open("sputn_seekoff.dat", std::ios_base::out) != 0);51 assert(f.is_open());52 53 assert(f.pubseekoff(off_type(5), std::ios_base::beg) = off_type(5));54 55 std::vector<char> chunk(data.begin() + 5, data.begin() + 5 + chunk_size1);56 std::copy(chunk.begin(), chunk.end(), result.begin() + 5);57 const std::streamsize len1 = f.sputn(chunk.data(), chunk_size1);58 assert(len1 == chunk_size1);59 // check that nothing in the original chunk was modified by sputn()60 assert(std::strncmp(chunk.data(), data.substr(5, len1).c_str(), len1) == 0);61 62 pos_type p1 = f.pubseekoff(offset1, std::ios_base::cur);63 char c;64 if (p1 < 0) {65 p1 = f.pubseekoff(0, std::ios_base::beg);66 assert(p1 == 0);67 c = '^';68 } else {69 assert(p1 == 5 + len1 + offset1);70 if (p1 > data_size) {71 c = '_';72 } else {73 c = data[p1];74 }75 }76 77 result[p1] = c;78 assert(f.sputc(c) == c);79 80 f.pubseekpos(std::ios_base::beg);81 result[0] = 'A';82 assert(f.sputc(toupper(data[0])) == 'A');83 84 pos_type end_pos = f.pubseekoff(off_type(0), std::ios_base::end);85 assert(f.sputc(toupper(data[data_size - 1])) == 'Z');86 result[end_pos] = 'Z';87 88 assert(f.pubseekpos(p1) == p1);89 result[p1] = toupper(c);90 assert(f.sputc(toupper(c)) == toupper(c));91 92 pos_type new_pos = result_size - chunk_size2;93 pos_type p2 = f.pubseekoff(new_pos, std::ios_base::beg);94 assert(p2 == new_pos);95 chunk = std::vector<char>(data.end() - chunk_size2, data.end());96 std::copy(chunk.begin(), chunk.end(), result.begin() + p2);97 const std::streamsize len2 = f.sputn(chunk.data(), chunk_size2);98 assert(len2 == chunk_size2);99 assert(std::strncmp(chunk.data(), data.substr(data_size - chunk_size2, chunk_size2).c_str(), len2) == 0);100 f.close();101 }102 std::filebuf f;103 assert(f.open("sputn_seekoff.dat", std::ios_base::in) != 0);104 assert(f.is_open());105 std::vector<char> check(result.size(), -1);106 const std::size_t len = f.sgetn(check.data(), check.size());107 assert(len == result.size());108 for (size_t i = 0; i < len; ++i) {109 assert(check[i] == result[i]);110 }111}112 113void sputn_not_open() {114 std::vector<char> data(10, 'a');115 std::filebuf f;116 std::streamsize len = f.sputn(data.data(), data.size());117 assert(len == 0);118 assert(std::strncmp(data.data(), "aaaaaaaaaa", 10) == 0);119}120 121#ifndef TEST_HAS_NO_WIDE_CHARACTERS122void sputn_not_open_wchar() {123 std::vector<wchar_t> data(10, L'a');124 std::wfilebuf f;125 std::streamsize len = f.sputn(data.data(), data.size());126 assert(len == 0);127 assert(std::wcsncmp(data.data(), L"aaaaaaaaaa", 10) == 0);128}129#endif130 131int main(int, char**) {132 sputn_not_open();133#ifndef TEST_HAS_NO_WIDE_CHARACTERS134 sputn_not_open_wchar();135#endif136 137 sputn_seekoff(nullptr, 10, 21, -27, 1);138 sputn_seekoff(nullptr, 10, 1, -27, 1);139 sputn_seekoff(nullptr, 10, 10, 14, 12);140 sputn_seekoff(nullptr, 10, 1, -2, 1);141 sputn_seekoff(nullptr, 10, 10, -4, 12);142 sputn_seekoff(nullptr, 10, 11, -12, 3);143 sputn_seekoff(nullptr, 10, 7, 3, 8);144 sputn_seekoff(nullptr, 10, 5, -5, 12);145 sputn_seekoff(nullptr, 10, 1, 1, 1);146 sputn_seekoff(nullptr, 10, 9, 0, 1);147 148 return 0;149}150