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Diffstat (limited to 'src/base/fs_util.cc')
| -rw-r--r-- | src/base/fs_util.cc | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/src/base/fs_util.cc b/src/base/fs_util.cc new file mode 100644 index 0000000..f72aaa6 --- /dev/null +++ b/src/base/fs_util.cc @@ -0,0 +1,183 @@ +/** + * Copyright (c) 2022, Timothy Stack + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of Timothy Stack nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "fs_util.hh" + +#include "config.h" +#include "fmt/format.h" +#include "itertools.hh" +#include "opt_util.hh" + +namespace lnav { +namespace filesystem { + +Result<auto_fd, std::string> +create_file(const ghc::filesystem::path& path, int flags, mode_t mode) +{ + auto fd = openp(path, flags | O_CREAT, mode); + + if (fd == -1) { + return Err(fmt::format(FMT_STRING("Failed to open: {} -- {}"), + path.string(), + strerror(errno))); + } + + return Ok(auto_fd(fd)); +} + +Result<auto_fd, std::string> +open_file(const ghc::filesystem::path& path, int flags) +{ + auto fd = openp(path, flags); + + if (fd == -1) { + return Err(fmt::format(FMT_STRING("Failed to open: {} -- {}"), + path.string(), + strerror(errno))); + } + + return Ok(auto_fd(fd)); +} + +Result<std::pair<ghc::filesystem::path, auto_fd>, std::string> +open_temp_file(const ghc::filesystem::path& pattern) +{ + auto pattern_str = pattern.string(); + char pattern_copy[pattern_str.size() + 1]; + int fd; + + strcpy(pattern_copy, pattern_str.c_str()); + if ((fd = mkstemp(pattern_copy)) == -1) { + return Err( + fmt::format(FMT_STRING("unable to create temporary file: {} -- {}"), + pattern.string(), + strerror(errno))); + } + + return Ok(std::make_pair(ghc::filesystem::path(pattern_copy), auto_fd(fd))); +} + +Result<std::string, std::string> +read_file(const ghc::filesystem::path& path) +{ + try { + ghc::filesystem::ifstream file_stream(path); + + if (!file_stream) { + return Err(std::string(strerror(errno))); + } + + std::string retval; + retval.assign((std::istreambuf_iterator<char>(file_stream)), + std::istreambuf_iterator<char>()); + return Ok(retval); + } catch (const std::exception& e) { + return Err(std::string(e.what())); + } +} + +Result<void, std::string> +write_file(const ghc::filesystem::path& path, const string_fragment& content) +{ + auto tmp_pattern = path; + tmp_pattern += ".XXXXXX"; + + auto tmp_pair = TRY(open_temp_file(tmp_pattern)); + auto bytes_written + = write(tmp_pair.second.get(), content.data(), content.length()); + if (bytes_written < 0) { + return Err( + fmt::format(FMT_STRING("unable to write to temporary file {}: {}"), + tmp_pair.first.string(), + strerror(errno))); + } + if (bytes_written != content.length()) { + return Err(fmt::format(FMT_STRING("short write to file {}: {} < {}"), + tmp_pair.first.string(), + bytes_written, + content.length())); + } + std::error_code ec; + ghc::filesystem::rename(tmp_pair.first, path, ec); + if (ec) { + return Err( + fmt::format(FMT_STRING("unable to move temporary file {}: {}"), + tmp_pair.first.string(), + ec.message())); + } + + return Ok(); +} + +std::string +build_path(const std::vector<ghc::filesystem::path>& paths) +{ + return paths + | lnav::itertools::map([](const auto& path) { return path.string(); }) + | lnav::itertools::append(getenv_opt("PATH").value_or("")) + | lnav::itertools::filter_out(&std::string::empty) + | lnav::itertools::fold( + [](const auto& elem, auto& accum) { + if (!accum.empty()) { + accum.push_back(':'); + } + return accum.append(elem); + }, + std::string()); +} + +Result<struct stat, std::string> +stat_file(const ghc::filesystem::path& path) +{ + struct stat retval; + + if (statp(path, &retval) == 0) { + return Ok(retval); + } + + return Err(fmt::format(FMT_STRING("failed to find file: {} -- {}"), + path.string(), + strerror(errno))); +} + +file_lock::file_lock(const ghc::filesystem::path& archive_path) +{ + auto lock_path = archive_path; + + lock_path += ".lck"; + auto open_res + = lnav::filesystem::create_file(lock_path, O_RDWR | O_CLOEXEC, 0600); + if (open_res.isErr()) { + throw std::runtime_error(open_res.unwrapErr()); + } + this->lh_fd = open_res.unwrap(); +} + +} // namespace filesystem +} // namespace lnav |