1 files changed, 130 insertions, 0 deletions
diff --git a/gitstatus/src/request.cc b/gitstatus/src/request.cc
new file mode 100644
index 00000000..1a81bffb
--- /dev/null
+++ b/gitstatus/src/request.cc
@@ -0,0 +1,130 @@
+// Copyright 2019 Roman Perepelitsa.
+//
+// This file is part of GitStatus.
+//
+// GitStatus is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GitStatus is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GitStatus. If not, see <https://www.gnu.org/licenses/>.
+
+#include "request.h"
+
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/select.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <cstdlib>
+#include <iostream>
+
+#include "check.h"
+#include "logging.h"
+#include "print.h"
+#include "serialization.h"
+
+namespace gitstatus {
+
+namespace {
+
+Request ParseRequest(const std::string& s) {
+  Request res;
+  auto begin = s.begin(), end = s.end(), sep = std::find(begin, end, kFieldSep);
+  VERIFY(sep != end) << "Malformed request: " << s;
+  res.id.assign(begin, sep);
+
+  begin = sep + 1;
+  if (*begin == ':') {
+    res.from_dotgit = true;
+    ++begin;
+  }
+  sep = std::find(begin, end, kFieldSep);
+  res.dir.assign(begin, sep);
+  if (sep == end) return res;
+
+  begin = sep + 1;
+  VERIFY(begin + 1 == end && (*begin == '0' || *begin == '1')) << "Malformed request: " << s;
+  res.diff = *begin == '0';
+  return res;
+}
+
+bool IsLockedFd(int fd) {
+  CHECK(fd >= 0);
+  struct flock flock = {};
+  flock.l_type = F_RDLCK;
+  flock.l_whence = SEEK_SET;
+  CHECK(fcntl(fd, F_GETLK, &flock) != -1) << Errno();
+  return flock.l_type != F_UNLCK;
+}
+
+}  // namespace
+
+std::ostream& operator<<(std::ostream& strm, const Request& req) {
+  strm << Print(req.id) << " for " << Print(req.dir);
+  if (req.from_dotgit) strm << " [from-dotgit]";
+  if (!req.diff) strm << " [no-diff]";
+  return strm;
+}
+
+RequestReader::RequestReader(int fd, int lock_fd, int parent_pid)
+    : fd_(fd), lock_fd_(lock_fd), parent_pid_(parent_pid) {
+  CHECK(fd != lock_fd);
+}
+
+bool RequestReader::ReadRequest(Request& req) {
+  auto eol = std::find(read_.begin(), read_.end(), kMsgSep);
+  if (eol != read_.end()) {
+    std::string msg(read_.begin(), eol);
+    read_.erase(read_.begin(), eol + 1);
+    req = ParseRequest(msg);
+    return true;
+  }
+
+  char buf[256];
+  while (true) {
+    fd_set fds;
+    FD_ZERO(&fds);
+    FD_SET(fd_, &fds);
+    struct timeval timeout = {.tv_sec = 1};
+
+    int n;
+    CHECK((n = select(fd_ + 1, &fds, NULL, NULL, &timeout)) >= 0) << Errno();
+    if (n == 0) {
+      if (lock_fd_ >= 0 && !IsLockedFd(lock_fd_)) {
+        LOG(INFO) << "Lock on fd " << lock_fd_ << " is gone. Exiting.";
+        std::exit(0);
+      }
+      if (parent_pid_ >= 0 && kill(parent_pid_, 0)) {
+        LOG(INFO) << "Unable to send signal 0 to " << parent_pid_ << ". Exiting.";
+        std::exit(0);
+      }
+      req = {};
+      return false;
+    }
+
+    CHECK((n = read(fd_, buf, sizeof(buf))) >= 0) << Errno();
+    if (n == 0) {
+      LOG(INFO) << "EOF. Exiting.";
+      std::exit(0);
+    }
+    read_.insert(read_.end(), buf, buf + n);
+    int eol = std::find(buf, buf + n, kMsgSep) - buf;
+    if (eol != n) {
+      std::string msg(read_.begin(), read_.end() - (n - eol));
+      read_.erase(read_.begin(), read_.begin() + msg.size() + 1);
+      req = ParseRequest(msg);
+      return true;
+    }
+  }
+}
+
+}  // namespace gitstatus