diff options
| -rw-r--r-- | editors/vi.c | 47 |
1 files changed, 29 insertions, 18 deletions
diff --git a/editors/vi.c b/editors/vi.c index a757359..7b213df 100644 --- a/editors/vi.c +++ b/editors/vi.c @@ -629,12 +629,12 @@ static void edit_file(char *fn) } #endif do_cmd(c); // execute the user command - // + // poll to see if there is input already waiting. if we are // not able to display output fast enough to keep up, skip // the display update until we catch up with input. - if (mysleep(0) == 0) { - // no input pending- so update output + if (!chars_to_parse && mysleep(0) == 0) { + // no input pending - so update output refresh(FALSE); show_status_line(); } @@ -2243,8 +2243,10 @@ static char readit(void) // read (maybe cursor) key from stdin n = chars_to_parse; if (n == 0) { - // If no data, block waiting for input. - n = safe_read(0, readbuffer, 1); + // If no data, block waiting for input + // (can't read more than minimal ESC sequence - + // see "n = 0" below). + n = safe_read(0, readbuffer, 3); if (n <= 0) { error: go_bottom_and_clear_to_eol(); @@ -2264,25 +2266,29 @@ static char readit(void) // read (maybe cursor) key from stdin // If it's an escape sequence, loop through known matches. if (c == 27) { const struct esc_cmds *eindex; + struct pollfd pfd; + pfd.fd = STDIN_FILENO; + pfd.events = POLLIN; for (eindex = esccmds; eindex < esccmds + ARRAY_SIZE(esccmds); eindex++) { - // n - position in seq to read - int i = 0; // position in seq to compare - int cnt = strnlen(eindex->seq, 4); + // n - position in sequence we did not read yet + int i = 0; // position in sequence to compare - // Loop through chars in this sequence. + // Loop through chars in this sequence for (;;) { - // We've matched this escape sequence up to [i-1] + // So far escape sequence matches up to [i-1] if (n <= i) { // Need more chars, read another one if it wouldn't block. // (Note that escape sequences come in as a unit, // so if we would block it's not really an escape sequence.) - struct pollfd pfd; - pfd.fd = 0; - pfd.events = POLLIN; - // Timeout is needed to reconnect escape sequences split - // up by transmission over a serial console. - if (safe_poll(&pfd, 1, 25)) { + + // Timeout is needed to reconnect escape sequences + // split up by transmission over a serial console. + // Even though inter-char delay on 1200 baud is <10ms, + // process scheduling can enlarge it arbitrarily, + // on both send and receive sides. + // Erring on the safe side - 5 timer ticks on 100 HZ. + if (safe_poll(&pfd, 1, 50)) { if (safe_read(0, readbuffer + n, 1) <= 0) goto error; n++; @@ -2296,9 +2302,14 @@ static char readit(void) // read (maybe cursor) key from stdin } if (readbuffer[i] != eindex->seq[i]) break; // try next seq - if (++i == cnt) { // entire seq matched + i++; + if (i == 4 || !eindex->seq[i]) { // entire seq matched c = eindex->val; n = 0; + // n -= i; memmove(...); + // would be more correct, + // but we never read ahead that much, + // and n == i here. goto loop_out; } } @@ -2306,7 +2317,7 @@ static char readit(void) // read (maybe cursor) key from stdin // We did not find matching sequence, it was a bare ESC. // We possibly read and stored more input in readbuffer by now. } -loop_out: + loop_out: chars_to_parse = n; return c; |