diff options
Diffstat (limited to 'src/piper_proc.cc')
| -rw-r--r-- | src/piper_proc.cc | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/src/piper_proc.cc b/src/piper_proc.cc new file mode 100644 index 0000000..396f175 --- /dev/null +++ b/src/piper_proc.cc @@ -0,0 +1,237 @@ +/** + * Copyright (c) 2007-2012, 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. + * + * @file piper_proc.cc + */ + +#include "piper_proc.hh" + +#include <errno.h> +#include <fcntl.h> +#include <poll.h> +#include <signal.h> +#include <stdio.h> +#include <string.h> +#include <sys/time.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "base/fs_util.hh" +#include "base/lnav_log.hh" +#include "config.h" +#include "line_buffer.hh" + +using namespace std::chrono_literals; + +static const char* STDIN_EOF_MSG = "---- END-OF-STDIN ----"; + +static ssize_t +write_timestamp(int fd, off_t woff) +{ + char time_str[64]; + struct timeval tv; + char ms_str[10]; + + gettimeofday(&tv, nullptr); + strftime(time_str, sizeof(time_str), "%FT%T", localtime(&tv.tv_sec)); + snprintf(ms_str, sizeof(ms_str), ".%03d", (int) (tv.tv_usec / 1000)); + strcat(time_str, ms_str); + strcat(time_str, " "); + return pwrite(fd, time_str, strlen(time_str), woff); +} + +piper_proc::piper_proc(auto_fd pipefd, bool timestamp, auto_fd filefd) + : pp_fd(std::move(filefd)), pp_child(-1) +{ + require(pipefd.get() >= 0); + require(this->pp_fd.get() >= 0); + + log_perror(fcntl(this->pp_fd.get(), F_SETFD, FD_CLOEXEC)); + + this->pp_child = fork(); + switch (this->pp_child) { + case -1: + throw error(errno); + + case 0: { + line_buffer lb; + off_t woff = 0, last_woff = 0; + file_range last_range; + + auto open_res = lnav::filesystem::open_file("/dev/null", O_RDWR); + if (open_res.isErr()) { + fprintf(stderr, + "unable to open /dev/null: %s\n", + open_res.unwrapErr().c_str()); + exit(EXIT_FAILURE); + } + auto nullfd = open_res.unwrap(); + if (pipefd != STDIN_FILENO) { + dup2(nullfd, STDIN_FILENO); + } + dup2(nullfd, STDOUT_FILENO); + for (int fd_to_close = 0; fd_to_close < 1024; fd_to_close++) { + int flags; + + if (fd_to_close == this->pp_fd.get()) { + continue; + } + if ((flags = fcntl(fd_to_close, F_GETFD)) == -1) { + continue; + } + if (flags & FD_CLOEXEC) { + close(fd_to_close); + } + } + log_perror(fcntl(pipefd.get(), F_SETFL, O_NONBLOCK)); + lb.set_fd(pipefd); + do { + static const auto TIMEOUT + = std::chrono::duration_cast<std::chrono::milliseconds>(1s) + .count(); + struct pollfd pfd = {lb.get_fd(), POLLIN, 0}; + + auto poll_rc = poll(&pfd, 1, TIMEOUT); + if (poll_rc == 0) { + // update the timestamp to keep the file alive from any + // cleanup processes + log_perror(futimes(this->pp_fd.get(), nullptr)); + continue; + } + while (true) { + auto load_result = lb.load_next_line(last_range); + + if (load_result.isErr()) { + break; + } + + auto li = load_result.unwrap(); + + if (li.li_partial && !lb.is_pipe_closed()) { + break; + } + + if (li.li_file_range.empty()) { + break; + } + + auto read_result = lb.read_range(li.li_file_range); + + if (read_result.isErr()) { + break; + } + + auto sbr = read_result.unwrap(); + + ssize_t wrc; + + last_woff = woff; + if (timestamp) { + wrc = write_timestamp(this->pp_fd, woff); + if (wrc == -1) { + perror("Unable to write to output file for stdin"); + break; + } + woff += wrc; + } + + /* Need to do pwrite here since the fd is used by the main + * lnav process as well. + */ + wrc = pwrite( + this->pp_fd, sbr.get_data(), sbr.length(), woff); + if (wrc == -1) { + perror("Unable to write to output file for stdin"); + break; + } + woff += wrc; + + last_range = li.li_file_range; + if (li.li_partial + && sbr.get_data()[sbr.length() - 1] != '\n' + && (last_range.next_offset() != lb.get_file_size())) + { + woff = last_woff; + } + } + } while (lb.is_pipe() && !lb.is_pipe_closed()); + + if (timestamp) { + ssize_t wrc; + + wrc = write_timestamp(this->pp_fd, woff); + if (wrc == -1) { + perror("Unable to write to output file for stdin"); + break; + } + woff += wrc; + wrc = pwrite( + this->pp_fd, STDIN_EOF_MSG, strlen(STDIN_EOF_MSG), woff); + if (wrc == -1) { + perror("Unable to write to output file for stdin"); + break; + } + } + } + _exit(0); + break; + + default: + break; + } +} + +bool +piper_proc::has_exited() +{ + if (this->pp_child > 0) { + int rc, status; + + rc = waitpid(this->pp_child, &status, WNOHANG); + if (rc == -1 || rc == 0) { + return false; + } + this->pp_child = -1; + } + + return true; +} + +piper_proc::~piper_proc() +{ + if (this->pp_child > 0) { + int status; + + kill(this->pp_child, SIGTERM); + while (waitpid(this->pp_child, &status, 0) < 0 && (errno == EINTR)) { + ; + } + + this->pp_child = -1; + } +} |