Win32: Thread-safe windows console output
[gitweb.git] / compat / winansi.c
index bec6713b746e2006c34ca21c91ea6e7d633a54f2..fcdd6dc1b394bc71fa71435534f260d3338548a1 100644 (file)
@@ -4,18 +4,13 @@
 
 #undef NOGDI
 #include "../git-compat-util.h"
-#include <malloc.h>
 #include <wingdi.h>
 #include <winreg.h>
 
 /*
  Functions to be wrapped:
 */
-#undef printf
-#undef fprintf
-#undef fputs
-#undef vfprintf
-/* TODO: write */
+#undef isatty
 
 /*
  ANSI codes used by git: m, K
@@ -28,7 +23,10 @@ static HANDLE console;
 static WORD plain_attr;
 static WORD attr;
 static int negative;
-static FILE *last_stream = NULL;
+static int non_ascii_used = 0;
+static HANDLE hthread, hread, hwrite;
+static HANDLE hwrite1 = INVALID_HANDLE_VALUE, hwrite2 = INVALID_HANDLE_VALUE;
+static HANDLE hconsole1, hconsole2;
 
 #ifdef __MINGW32__
 typedef struct _CONSOLE_FONT_INFOEX {
@@ -44,27 +42,19 @@ typedef struct _CONSOLE_FONT_INFOEX {
 typedef BOOL (WINAPI *PGETCURRENTCONSOLEFONTEX)(HANDLE, BOOL,
                PCONSOLE_FONT_INFOEX);
 
-static void print_font_warning(void)
+static void warn_if_raster_font(void)
 {
-       warning("Your console font probably doesn\'t support Unicode. If "
-               "you experience strange characters in the output, consider "
-               "switching to a TrueType font such as Lucida Console!");
-}
-
-static void check_truetype_font(void)
-{
-       static int truetype_font_checked;
        DWORD fontFamily = 0;
        PGETCURRENTCONSOLEFONTEX pGetCurrentConsoleFontEx;
 
-       /* don't do this twice */
-       if (truetype_font_checked)
+       /* don't bother if output was ascii only */
+       if (!non_ascii_used)
                return;
-       truetype_font_checked = 1;
 
        /* GetCurrentConsoleFontEx is available since Vista */
        pGetCurrentConsoleFontEx = (PGETCURRENTCONSOLEFONTEX) GetProcAddress(
-                       GetModuleHandle("kernel32.dll"), "GetCurrentConsoleFontEx");
+                       GetModuleHandle("kernel32.dll"),
+                       "GetCurrentConsoleFontEx");
        if (pGetCurrentConsoleFontEx) {
                CONSOLE_FONT_INFOEX cfi;
                cfi.cbSize = sizeof(cfi);
@@ -73,8 +63,8 @@ static void check_truetype_font(void)
        } else {
                /* pre-Vista: check default console font in registry */
                HKEY hkey;
-               if (ERROR_SUCCESS == RegOpenKeyExA(HKEY_CURRENT_USER, "Console", 0,
-                               KEY_READ, &hkey)) {
+               if (ERROR_SUCCESS == RegOpenKeyExA(HKEY_CURRENT_USER, "Console",
+                               0, KEY_READ, &hkey)) {
                        DWORD size = sizeof(fontFamily);
                        RegQueryValueExA(hkey, "FontFamily", NULL, NULL,
                                        (LPVOID) &fontFamily, &size);
@@ -82,61 +72,64 @@ static void check_truetype_font(void)
                }
        }
 
-       if (!(fontFamily & TMPF_TRUETYPE))
-               atexit(print_font_warning);
+       if (!(fontFamily & TMPF_TRUETYPE)) {
+               const wchar_t *msg = L"\nWarning: Your console font probably "
+                       L"doesn\'t support Unicode. If you experience strange "
+                       L"characters in the output, consider switching to a "
+                       L"TrueType font such as Consolas!\n";
+               DWORD dummy;
+               WriteConsoleW(console, msg, wcslen(msg), &dummy, NULL);
+       }
 }
 
-static int is_console(FILE *stream)
+static int is_console(int fd)
 {
        CONSOLE_SCREEN_BUFFER_INFO sbi;
        HANDLE hcon;
 
        static int initialized = 0;
 
-       /* use cached value if stream hasn't changed */
-       if (stream == last_stream)
-               return console != NULL;
-
-       last_stream = stream;
-       console = NULL;
-
-       /* get OS handle of the stream */
-       hcon = (HANDLE) _get_osfhandle(_fileno(stream));
+       /* get OS handle of the file descriptor */
+       hcon = (HANDLE) _get_osfhandle(fd);
        if (hcon == INVALID_HANDLE_VALUE)
                return 0;
 
+       /* check if its a device (i.e. console, printer, serial port) */
+       if (GetFileType(hcon) != FILE_TYPE_CHAR)
+               return 0;
+
        /* check if its a handle to a console output screen buffer */
        if (!GetConsoleScreenBufferInfo(hcon, &sbi))
                return 0;
 
+       /* initialize attributes */
        if (!initialized) {
                attr = plain_attr = sbi.wAttributes;
                negative = 0;
                initialized = 1;
        }
 
-       console = hcon;
        return 1;
 }
 
-static int write_console(const char *str, size_t len)
+#define BUFFER_SIZE 4096
+#define MAX_PARAMS 16
+
+static void write_console(unsigned char *str, size_t len)
 {
-       /* convert utf-8 to utf-16, write directly to console */
-       int wlen = MultiByteToWideChar(CP_UTF8, 0, str, len, NULL, 0);
-       wchar_t *wbuf = (wchar_t *) alloca(wlen * sizeof(wchar_t));
-       MultiByteToWideChar(CP_UTF8, 0, str, len, wbuf, wlen);
+       /* only called from console_thread, so a static buffer will do */
+       static wchar_t wbuf[2 * BUFFER_SIZE + 1];
+       DWORD dummy;
 
-       WriteConsoleW(console, wbuf, wlen, NULL, NULL);
+       /* convert utf-8 to utf-16 */
+       int wlen = xutftowcsn(wbuf, (char*) str, ARRAY_SIZE(wbuf), len);
 
-       /*
-        * if non-ascii characters are printed, check that the current console
-        * font supports this
-        */
-       if (wlen != len)
-               check_truetype_font();
+       /* write directly to console */
+       WriteConsoleW(console, wbuf, wlen, &dummy, NULL);
 
-       /* return original (utf-8 encoded) length */
-       return len;
+       /* remember if non-ascii characters are printed */
+       if (wlen != len)
+               non_ascii_used = 1;
 }
 
 #define FOREGROUND_ALL (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE)
@@ -182,18 +175,13 @@ static void erase_in_line(void)
                &dummy);
 }
 
-
-static const char *set_attr(const char *str)
+static void set_attr(char func, const int *params, int paramlen)
 {
-       const char *func;
-       size_t len = strspn(str, "0123456789;");
-       func = str + len;
-
-       switch (*func) {
+       int i;
+       switch (func) {
        case 'm':
-               do {
-                       long val = strtol(str, (char **)&str, 10);
-                       switch (val) {
+               for (i = 0; i < paramlen; i++) {
+                       switch (params[i]) {
                        case 0: /* reset */
                                attr = plain_attr;
                                negative = 0;
@@ -316,9 +304,7 @@ static const char *set_attr(const char *str)
                                /* Unsupported code */
                                break;
                        }
-                       str++;
-               } while (*(str-1) == ';');
-
+               }
                set_console_attr();
                break;
        case 'K':
@@ -328,112 +314,251 @@ static const char *set_attr(const char *str)
                /* Unsupported code */
                break;
        }
-
-       return func + 1;
 }
 
-static int ansi_emulate(const char *str, FILE *stream)
-{
-       int rv = 0;
-       const char *pos = str;
+enum {
+       TEXT = 0, ESCAPE = 033, BRACKET = '['
+};
 
-       fflush(stream);
+static DWORD WINAPI console_thread(LPVOID unused)
+{
+       unsigned char buffer[BUFFER_SIZE];
+       DWORD bytes;
+       int start, end = 0, c, parampos = 0, state = TEXT;
+       int params[MAX_PARAMS];
+
+       while (1) {
+               /* read next chunk of bytes from the pipe */
+               if (!ReadFile(hread, buffer + end, BUFFER_SIZE - end, &bytes,
+                               NULL)) {
+                       /* exit if pipe has been closed or disconnected */
+                       if (GetLastError() == ERROR_PIPE_NOT_CONNECTED ||
+                                       GetLastError() == ERROR_BROKEN_PIPE)
+                               break;
+                       /* ignore other errors */
+                       continue;
+               }
 
-       while (*pos) {
-               pos = strstr(str, "\033[");
-               if (pos) {
-                       size_t len = pos - str;
+               /* scan the bytes and handle ANSI control codes */
+               bytes += end;
+               start = end = 0;
+               while (end < bytes) {
+                       c = buffer[end++];
+                       switch (state) {
+                       case TEXT:
+                               if (c == ESCAPE) {
+                                       /* print text seen so far */
+                                       if (end - 1 > start)
+                                               write_console(buffer + start,
+                                                       end - 1 - start);
+
+                                       /* then start parsing escape sequence */
+                                       start = end - 1;
+                                       memset(params, 0, sizeof(params));
+                                       parampos = 0;
+                                       state = ESCAPE;
+                               }
+                               break;
+
+                       case ESCAPE:
+                               /* continue if "\033[", otherwise bail out */
+                               state = (c == BRACKET) ? BRACKET : TEXT;
+                               break;
+
+                       case BRACKET:
+                               /* parse [0-9;]* into array of parameters */
+                               if (c >= '0' && c <= '9') {
+                                       params[parampos] *= 10;
+                                       params[parampos] += c - '0';
+                               } else if (c == ';') {
+                                       /*
+                                        * next parameter, bail out if out of
+                                        * bounds
+                                        */
+                                       parampos++;
+                                       if (parampos >= MAX_PARAMS)
+                                               state = TEXT;
+                               } else {
+                                       /*
+                                        * end of escape sequence, change
+                                        * console attributes
+                                        */
+                                       set_attr(c, params, parampos + 1);
+                                       start = end;
+                                       state = TEXT;
+                               }
+                               break;
+                       }
+               }
 
-                       if (len) {
-                               size_t out_len = write_console(str, len);
-                               rv += out_len;
-                               if (out_len < len)
-                                       return rv;
+               /* print remaining text unless parsing an escape sequence */
+               if (state == TEXT && end > start) {
+                       /* check for incomplete UTF-8 sequences and fix end */
+                       if (buffer[end - 1] >= 0x80) {
+                               if (buffer[end -1] >= 0xc0)
+                                       end--;
+                               else if (end - 1 > start &&
+                                               buffer[end - 2] >= 0xe0)
+                                       end -= 2;
+                               else if (end - 2 > start &&
+                                               buffer[end - 3] >= 0xf0)
+                                       end -= 3;
                        }
 
-                       str = pos + 2;
-                       rv += 2;
+                       /* print remaining complete UTF-8 sequences */
+                       if (end > start)
+                               write_console(buffer + start, end - start);
 
-                       pos = set_attr(str);
-                       rv += pos - str;
-                       str = pos;
+                       /* move remaining bytes to the front */
+                       if (end < bytes)
+                               memmove(buffer, buffer + end, bytes - end);
+                       end = bytes - end;
                } else {
-                       size_t len = strlen(str);
-                       rv += write_console(str, len);
-                       return rv;
+                       /* all data has been consumed, mark buffer empty */
+                       end = 0;
                }
        }
-       return rv;
-}
-
-int winansi_fputs(const char *str, FILE *stream)
-{
-       int rv;
-
-       if (!is_console(stream))
-               return fputs(str, stream);
 
-       rv = ansi_emulate(str, stream);
+       /* check if the console font supports unicode */
+       warn_if_raster_font();
 
-       if (rv >= 0)
-               return 0;
-       else
-               return EOF;
+       CloseHandle(hread);
+       return 0;
 }
 
-int winansi_vfprintf(FILE *stream, const char *format, va_list list)
+static void winansi_exit(void)
 {
-       int len, rv;
-       char small_buf[256];
-       char *buf = small_buf;
-       va_list cp;
-
-       if (!is_console(stream))
-               goto abort;
+       /* flush all streams */
+       _flushall();
+
+       /* signal console thread to exit */
+       FlushFileBuffers(hwrite);
+       DisconnectNamedPipe(hwrite);
+
+       /* wait for console thread to copy remaining data */
+       WaitForSingleObject(hthread, INFINITE);
+
+       /* cleanup handles... */
+       if (hwrite1 != INVALID_HANDLE_VALUE)
+               CloseHandle(hwrite1);
+       if (hwrite2 != INVALID_HANDLE_VALUE)
+               CloseHandle(hwrite2);
+       CloseHandle(hwrite);
+       CloseHandle(hthread);
+}
 
-       va_copy(cp, list);
-       len = vsnprintf(small_buf, sizeof(small_buf), format, cp);
-       va_end(cp);
+static void die_lasterr(const char *fmt, ...)
+{
+       va_list params;
+       va_start(params, fmt);
+       errno = err_win_to_posix(GetLastError());
+       die_errno(fmt, params);
+       va_end(params);
+}
 
-       if (len > sizeof(small_buf) - 1) {
-               buf = malloc(len + 1);
-               if (!buf)
-                       goto abort;
+static HANDLE duplicate_handle(HANDLE hnd)
+{
+       HANDLE hresult, hproc = GetCurrentProcess();
+       if (!DuplicateHandle(hproc, hnd, hproc, &hresult, 0, TRUE,
+                       DUPLICATE_SAME_ACCESS))
+               die_lasterr("DuplicateHandle(%li) failed", (long) hnd);
+       return hresult;
+}
 
-               len = vsnprintf(buf, len + 1, format, list);
-       }
+static HANDLE redirect_console(FILE *stream, HANDLE *phcon, int new_fd)
+{
+       /* get original console handle */
+       int fd = _fileno(stream);
+       HANDLE hcon = (HANDLE) _get_osfhandle(fd);
+       if (hcon == INVALID_HANDLE_VALUE)
+               die_errno("_get_osfhandle(%i) failed", fd);
 
-       rv = ansi_emulate(buf, stream);
+       /* save a copy to phcon and console (used by the background thread) */
+       console = *phcon = duplicate_handle(hcon);
 
-       if (buf != small_buf)
-               free(buf);
-       return rv;
+       /* duplicate new_fd over fd (closes fd and associated handle (hcon)) */
+       if (_dup2(new_fd, fd))
+               die_errno("_dup2(%i, %i) failed", new_fd, fd);
 
-abort:
-       rv = vfprintf(stream, format, list);
-       return rv;
+       /* no buffering, or stdout / stderr will be out of sync */
+       setbuf(stream, NULL);
+       return (HANDLE) _get_osfhandle(fd);
 }
 
-int winansi_fprintf(FILE *stream, const char *format, ...)
+void winansi_init(void)
 {
-       va_list list;
-       int rv;
+       int con1, con2, hwrite_fd;
+       char name[32];
 
-       va_start(list, format);
-       rv = winansi_vfprintf(stream, format, list);
-       va_end(list);
+       /* check if either stdout or stderr is a console output screen buffer */
+       con1 = is_console(1);
+       con2 = is_console(2);
+       if (!con1 && !con2)
+               return;
 
-       return rv;
+       /* create a named pipe to communicate with the console thread */
+       sprintf(name, "\\\\.\\pipe\\winansi%lu", GetCurrentProcessId());
+       hwrite = CreateNamedPipe(name, PIPE_ACCESS_OUTBOUND,
+               PIPE_TYPE_BYTE | PIPE_WAIT, 1, BUFFER_SIZE, 0, 0, NULL);
+       if (hwrite == INVALID_HANDLE_VALUE)
+               die_lasterr("CreateNamedPipe failed");
+
+       hread = CreateFile(name, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
+       if (hread == INVALID_HANDLE_VALUE)
+               die_lasterr("CreateFile for named pipe failed");
+
+       /* start console spool thread on the pipe's read end */
+       hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
+       if (hthread == INVALID_HANDLE_VALUE)
+               die_lasterr("CreateThread(console_thread) failed");
+
+       /* schedule cleanup routine */
+       if (atexit(winansi_exit))
+               die_errno("atexit(winansi_exit) failed");
+
+       /* create a file descriptor for the write end of the pipe */
+       hwrite_fd = _open_osfhandle((long) duplicate_handle(hwrite), _O_BINARY);
+       if (hwrite_fd == -1)
+               die_errno("_open_osfhandle(%li) failed", (long) hwrite);
+
+       /* redirect stdout / stderr to the pipe */
+       if (con1)
+               hwrite1 = redirect_console(stdout, &hconsole1, hwrite_fd);
+       if (con2)
+               hwrite2 = redirect_console(stderr, &hconsole2, hwrite_fd);
+
+       /* close pipe file descriptor (also closes the duped hwrite) */
+       close(hwrite_fd);
 }
 
-int winansi_printf(const char *format, ...)
+static int is_same_handle(HANDLE hnd, int fd)
 {
-       va_list list;
-       int rv;
+       return hnd != INVALID_HANDLE_VALUE && hnd == (HANDLE) _get_osfhandle(fd);
+}
 
-       va_start(list, format);
-       rv = winansi_vfprintf(stdout, format, list);
-       va_end(list);
+/*
+ * Return true if stdout / stderr is a pipe redirecting to the console.
+ */
+int winansi_isatty(int fd)
+{
+       if (fd == 1 && is_same_handle(hwrite1, 1))
+               return 1;
+       else if (fd == 2 && is_same_handle(hwrite2, 2))
+               return 1;
+       else
+               return isatty(fd);
+}
 
-       return rv;
+/*
+ * Returns the real console handle if stdout / stderr is a pipe redirecting
+ * to the console. Allows spawn / exec to pass the console to the next process.
+ */
+HANDLE winansi_get_osfhandle(int fd)
+{
+       if (fd == 1 && is_same_handle(hwrite1, 1))
+               return hconsole1;
+       else if (fd == 2 && is_same_handle(hwrite2, 2))
+               return hconsole2;
+       else
+               return (HANDLE) _get_osfhandle(fd);
 }