Refactor pipe reader/writer

This commit is contained in:
Maxime Coste 2021-03-04 20:59:15 +11:00
parent da80a8cf6a
commit f6c8ebc4d0

View File

@ -165,6 +165,49 @@ Vector<String> generate_env(StringView cmdline, const Context& context, const Sh
return env; return env;
} }
FDWatcher make_pipe_reader(Pipe& pipe, String& contents)
{
return {pipe.read_fd(), FdEvents::Read,
[&contents, &pipe](FDWatcher& watcher, FdEvents, EventMode) {
char buffer[1024];
while (fd_readable(pipe.read_fd()))
{
size_t size = ::read(pipe.read_fd(), buffer, sizeof(buffer));
if (size <= 0)
{
pipe.close_read_fd();
watcher.disable();
return;
}
contents += StringView{buffer, buffer+size};
}
}};
}
FDWatcher make_pipe_writer(Pipe& pipe, StringView contents)
{
int flags = fcntl(pipe.write_fd(), F_GETFL, 0);
fcntl(pipe.write_fd(), F_SETFL, flags | O_NONBLOCK);
return {pipe.write_fd(), FdEvents::Write,
[contents, &pipe](FDWatcher& watcher, FdEvents, EventMode) mutable {
while (fd_writable(pipe.write_fd()))
{
ssize_t size = ::write(pipe.write_fd(), contents.begin(),
(size_t)contents.length());
if (size > 0)
contents = contents.substr(ByteCount{(int)size});
if (size == -1 and (errno == EAGAIN or errno == EWOULDBLOCK))
return;
if (size < 0 or contents.empty())
{
pipe.close_write_fd();
watcher.disable();
return;
}
}
}};
}
} }
std::pair<String, int> ShellManager::eval( std::pair<String, int> ShellManager::eval(
@ -213,58 +256,10 @@ std::pair<String, int> ShellManager::eval(
auto wait_time = Clock::now(); auto wait_time = Clock::now();
struct PipeReader : FDWatcher
{
PipeReader(Pipe& pipe, String& contents)
: FDWatcher(pipe.read_fd(), FdEvents::Read,
[&contents, &pipe](FDWatcher& watcher, FdEvents, EventMode) {
char buffer[1024];
while (fd_readable(pipe.read_fd()))
{
size_t size = ::read(pipe.read_fd(), buffer, 1024);
if (size <= 0)
{
pipe.close_read_fd();
watcher.disable();
return;
}
contents += StringView{buffer, buffer+size};
}
})
{}
};
struct PipeWriter : FDWatcher
{
PipeWriter(Pipe& pipe, StringView contents)
: FDWatcher(pipe.write_fd(), FdEvents::Write,
[contents, &pipe](FDWatcher& watcher, FdEvents, EventMode) mutable {
while (fd_writable(pipe.write_fd()))
{
ssize_t size = ::write(pipe.write_fd(), contents.begin(),
(size_t)contents.length());
if (size > 0)
contents = contents.substr(ByteCount{(int)size});
if (size == -1 and (errno == EAGAIN or errno == EWOULDBLOCK))
return;
if (size < 0 or contents.empty())
{
pipe.close_write_fd();
watcher.disable();
return;
}
}
})
{
int flags = fcntl(pipe.write_fd(), F_GETFL, 0);
fcntl(pipe.write_fd(), F_SETFL, flags | O_NONBLOCK);
}
};
String stdout_contents, stderr_contents; String stdout_contents, stderr_contents;
PipeReader stdout_reader{child_stdout, stdout_contents}; auto stdout_reader = make_pipe_reader(child_stdout, stdout_contents);
PipeReader stderr_reader{child_stderr, stderr_contents}; auto stderr_reader = make_pipe_reader(child_stderr, stderr_contents);
PipeWriter stdin_writer{child_stdin, input}; auto stdin_writer = make_pipe_writer(child_stdin, input);
// block SIGCHLD to make sure we wont receive it before // block SIGCHLD to make sure we wont receive it before
// our call to pselect, that will end up blocking indefinitly. // our call to pselect, that will end up blocking indefinitly.