diff options
Diffstat (limited to 'libbutl/fdstream.cxx')
| -rw-r--r-- | libbutl/fdstream.cxx | 164 |
1 files changed, 142 insertions, 22 deletions
diff --git a/libbutl/fdstream.cxx b/libbutl/fdstream.cxx index 03c007c..07cb9f2 100644 --- a/libbutl/fdstream.cxx +++ b/libbutl/fdstream.cxx @@ -17,6 +17,10 @@ #else # include <libbutl/win32-utility.hxx> +# ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING +# define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0x04 +# endif + # include <io.h> // _close(), _read(), _write(), _setmode(), _sopen(), // _lseek(), _dup(), _pipe(), _chsize_s, // _get_osfhandle() @@ -34,6 +38,7 @@ # include <wchar.h> // wcsncmp(), wcsstr() +# include <thread> // this_thread::yield() # include <algorithm> // count() #endif @@ -41,7 +46,8 @@ #include <new> // bad_alloc #include <limits> // numeric_limits #include <cassert> -#include <cstring> // memcpy(), memmove() +#include <cstring> // memcpy(), memmove(), memchr(), strcmp() +#include <cstdlib> // getenv() #include <iostream> // cin, cout #include <exception> // uncaught_exception[s]() #include <stdexcept> // invalid_argument @@ -353,14 +359,6 @@ namespace butl return save () ? 0 : -1; } -#ifdef _WIN32 - static inline int - write (int fd, const void* buf, size_t n) - { - return _write (fd, buf, static_cast<unsigned int> (n)); - } -#endif - bool fdstreambuf:: save () { @@ -372,7 +370,7 @@ namespace butl // descriptor opened for read-only access (while -1 with errno EBADF is // expected). This is in contrast with VC's _write() and POSIX's write(). // - auto m (write (fd_.get (), buf_, n)); + auto m (fdwrite (fd_.get (), buf_, n)); if (m == -1) throw_generic_ios_failure (errno); @@ -487,7 +485,7 @@ namespace butl // Flush the buffer. // size_t wn (bn + an); - int r (wn > 0 ? write (fd_.get (), buf_, wn) : 0); + streamsize r (wn > 0 ? fdwrite (fd_.get (), buf_, wn) : 0); if (r == -1) throw_generic_ios_failure (errno); @@ -530,7 +528,7 @@ namespace butl // The data tail doesn't fit the buffer so write it to the file. // - r = write (fd_.get (), s, n); + r = fdwrite (fd_.get (), s, n); if (r == -1) throw_generic_ios_failure (errno); @@ -846,7 +844,7 @@ namespace butl } ifdstream& - getline (ifdstream& is, string& s, char delim) + getline (ifdstream& is, string& l, char delim) { ifdstream::iostate eb (is.exceptions ()); assert (eb & ifdstream::badbit); @@ -863,7 +861,7 @@ namespace butl if (eb != ifdstream::badbit) is.exceptions (ifdstream::badbit); - std::getline (is, s, delim); + std::getline (is, l, delim); // Throw if any of the newly set bits are present in the exception mask. // @@ -876,6 +874,58 @@ namespace butl return is; } + bool + getline_non_blocking (ifdstream& is, string& l, char delim) + { + assert (!is.blocking () && (is.exceptions () & ifdstream::badbit) != 0); + + fdstreambuf& sb (*static_cast<fdstreambuf*> (is.rdbuf ())); + + // Read until blocked (0), EOF (-1) or encounter the delimiter. + // + // Note that here we reasonably assume that any failure in in_avail() + // will lead to badbit and thus an exception (see showmanyc()). + // + streamsize s; + while ((s = sb.in_avail ()) > 0) + { + const char* p (sb.gptr ()); + size_t n (sb.egptr () - p); + + const char* e (static_cast<const char*> (memchr (p, delim, n))); + if (e != nullptr) + n = e - p; + + l.append (p, n); + + // Note: consume the delimiter if found. + // + sb.gbump (static_cast<int> (n + (e != nullptr ? 1 : 0))); + + if (e != nullptr) + break; + } + + // Here s can be: + // + // -1 -- EOF. + // 0 -- blocked before encountering delimiter/EOF. + // >0 -- encountered the delimiter. + // + if (s == -1) + { + is.setstate (ifdstream::eofbit); + + // If we couldn't extract anything, not even the delimiter, then this is + // a failure per the getline() interface. + // + if (l.empty ()) + is.setstate (ifdstream::failbit); + } + + return s != 0; + } + // ofdstream // ofdstream:: @@ -1120,12 +1170,12 @@ namespace butl // open it results in EINVAL POSIX error, ERROR_USER_MAPPED_FILE system // error. So we retry those as well. // - for (size_t i (0); i < 21; ++i) + for (size_t i (0); i < 41; ++i) { - // Sleep 100 milliseconds before the open retry. + // Sleep 50 milliseconds before the open retry. // if (i != 0) - Sleep (100); + Sleep (50); fd = pass_perm ? _sopen (f, of, _SH_DENYNO, pf) @@ -1394,6 +1444,16 @@ namespace butl throw_generic_ios_failure (errno); } + bool + fdterm_color (int, bool) + { + const char* t (std::getenv ("TERM")); + + // This test was lifted from GCC (Emacs shell sets TERM=dumb). + // + return t != nullptr && strcmp (t, "dumb") != 0; + } + static pair<size_t, size_t> fdselect (fdselect_set& read, fdselect_set& write, @@ -1412,6 +1472,8 @@ namespace butl for (fdselect_state& s: from) { + s.ready = false; + if (s.fd == nullfd) continue; @@ -1419,7 +1481,6 @@ namespace butl throw invalid_argument ("invalid file descriptor"); FD_SET (s.fd, &to); - s.ready = false; if (max_fd < s.fd) max_fd = s.fd; @@ -1526,6 +1587,12 @@ namespace butl return read (fd, buf, n); } + streamsize + fdwrite (int fd, const void* buf, size_t n) + { + return write (fd, buf, n); + } + #else auto_fd @@ -1806,6 +1873,9 @@ namespace butl bool fdterm (int fd) { + // @@ Both GCC and Clang simply call GetConsoleMode() for this check. I + // wonder why we don't do the same? See also fdterm_color() below. + // We don't need to close it (see fd_to_handle()). // HANDLE h (fd_to_handle (fd)); @@ -1891,6 +1961,42 @@ namespace butl return false; } + bool + fdterm_color (int fd, bool enable) + { + // We don't need to close it (see fd_to_handle()). + // + HANDLE h (fd_to_handle (fd)); + + // See GH issue #312 for background on this logic. + // + DWORD m; + if (!GetConsoleMode (h, &m)) + throw_system_ios_failure (GetLastError ()); + + // Some terminals (e.g. Windows Terminal) enable VT processing by default. + // + if ((m & ENABLE_VIRTUAL_TERMINAL_PROCESSING) != 0) + return true; + + if (enable) + { + // If SetConsoleMode() fails, assume VT processing is unsupported (it + // is only supported from a certain build of Windows 10). + // + // Note that Wine pretends to support this but doesn't handle the escape + // sequences. See https://bugs.winehq.org/show_bug.cgi?id=49780. + // + if (SetConsoleMode (h, + (m | + ENABLE_PROCESSED_OUTPUT | + ENABLE_VIRTUAL_TERMINAL_PROCESSING))) + return true; + } + + return false; + } + static pair<size_t, size_t> fdselect (fdselect_set& read, fdselect_set& write, @@ -1907,13 +2013,14 @@ namespace butl for (fdselect_state& s: read) { + s.ready = false; + if (s.fd == nullfd) continue; if (s.fd < 0) throw invalid_argument ("invalid file descriptor"); - s.ready = false; ++n; } @@ -1934,7 +2041,7 @@ namespace butl // size_t r (0); - while (true) + for (size_t i (0);; ++i) { for (fdselect_state& s: read) { @@ -2007,7 +2114,11 @@ namespace butl if (r != 0) break; - DWORD t (50); + // Use exponential backoff but not too aggressive and with 25ms max. + // + DWORD t ( + static_cast<DWORD> (i <= 1000 ? 0 : + i >= 1000 + 100 ? 25 : 1 + ((i - 1000) / 4))); if (timeout) { @@ -2024,7 +2135,10 @@ namespace butl break; } - Sleep (t); + if (t == 0) + this_thread::yield (); + else + Sleep (t); } return make_pair (r, 0); @@ -2067,6 +2181,12 @@ namespace butl return r; } + streamsize + fdwrite (int fd, const void* buf, size_t n) + { + return _write (fd, buf, static_cast<unsigned int> (n)); + } + #endif pair<size_t, size_t> |