From 5f6aaf39cff31f5f679fe07449a9e363dd474216 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sat, 25 Oct 2008 23:27:29 +0000 Subject: less: reuse former vi's key reading code. Improve SIGWINCH handling. function old new delta less_main 2056 2097 +41 getch_nowait 248 273 +25 read_key 310 321 +11 static.esccmds 61 69 +8 count_lines 72 74 +2 less_gets 166 142 -24 less_getch 172 43 -129 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 6/5 up/down: 91/-170) Total: -79 bytes text data bss dec hex filename --- miscutils/less.c | 137 +++++++++++++++++++++---------------------------------- 1 file changed, 53 insertions(+), 84 deletions(-) (limited to 'miscutils') diff --git a/miscutils/less.c b/miscutils/less.c index f367b0ebc..d9ada619a 100644 --- a/miscutils/less.c +++ b/miscutils/less.c @@ -36,34 +36,9 @@ /* The escape code to clear to end of line */ #define CLEAR_2_EOL "\033[K" -/* These are the escape sequences corresponding to special keys */ enum { - REAL_KEY_UP = 'A', - REAL_KEY_DOWN = 'B', - REAL_KEY_RIGHT = 'C', - REAL_KEY_LEFT = 'D', - REAL_PAGE_UP = '5', - REAL_PAGE_DOWN = '6', - REAL_KEY_HOME = '7', // vt100? linux vt? or what? - REAL_KEY_END = '8', - REAL_KEY_HOME_ALT = '1', // ESC [1~ (vt100? linux vt? or what?) - REAL_KEY_END_ALT = '4', // ESC [4~ - REAL_KEY_HOME_XTERM = 'H', - REAL_KEY_END_XTERM = 'F', - -/* These are the special codes assigned by this program to the special keys */ - KEY_UP = 20, - KEY_DOWN = 21, - KEY_RIGHT = 22, - KEY_LEFT = 23, - PAGE_UP = 24, - PAGE_DOWN = 25, - KEY_HOME = 26, - KEY_END = 27, - /* Absolute max of lines eaten */ MAXLINES = CONFIG_FEATURE_LESS_MAXLINES, - /* This many "after the end" lines we will show (at max) */ TILDES = 1, }; @@ -133,6 +108,8 @@ struct globals { #define max_displayed_line (G.max_displayed_line) #define width (G.width ) #define winch_counter (G.winch_counter ) +/* This one is 100% not cached by compiler on read access */ +#define WINCH_COUNTER (*(volatile unsigned *)&winch_counter) #define eof_error (G.eof_error ) #define readpos (G.readpos ) #define readeof (G.readeof ) @@ -824,9 +801,10 @@ static void reinitialize(void) buffer_fill_and_print(); } -static ssize_t getch_nowait(char* input, int sz) +static ssize_t getch_nowait(void) { - ssize_t rd; + char input[KEYCODE_BUFFER_SIZE]; + int rd; struct pollfd pfd[2]; pfd[0].fd = STDIN_FILENO; @@ -842,34 +820,39 @@ static ssize_t getch_nowait(char* input, int sz) * (switch fd into O_NONBLOCK'ed mode to avoid it) */ rd = 1; - if (max_fline <= cur_fline + max_displayed_line - && eof_error > 0 /* did NOT reach eof yet */ + /* Are we interested in stdin? */ +//TODO: reuse code for determining this + if (!(option_mask32 & FLAG_S) + ? !(max_fline > cur_fline + max_displayed_line) + : !(max_fline >= cur_fline + && max_lineno > LINENO(flines[cur_fline]) + max_displayed_line) ) { - /* We are interested in stdin */ - rd = 0; + if (eof_error > 0) /* did NOT reach eof yet */ + rd = 0; /* yes, we are interested in stdin */ } - /* position cursor if line input is done */ + /* Position cursor if line input is done */ if (less_gets_pos >= 0) move_cursor(max_displayed_line + 2, less_gets_pos + 1); fflush(stdout); #if ENABLE_FEATURE_LESS_WINCH while (1) { int r; + /* NB: SIGWINCH interrupts poll() */ r = poll(pfd + rd, 2 - rd, -1); - if (/*r < 0 && errno == EINTR &&*/ winch_counter) { - input[0] = '\\'; /* anything which has no defined function */ - return 1; - } + if (/*r < 0 && errno == EINTR &&*/ winch_counter) + return '\\'; /* anything which has no defined function */ if (r) break; } #else safe_poll(pfd + rd, 2 - rd, -1); #endif - input[0] = '\0'; - rd = safe_read(kbd_fd, input, sz); /* NB: kbd_fd is in O_NONBLOCK mode */ - if (rd < 0 && errno == EAGAIN) { - /* No keyboard input -> we have input on stdin! */ + /* We have kbd_fd in O_NONBLOCK mode, read inside read_key() + * would not block even if there is no input available */ + rd = read_key(kbd_fd, NULL, input); + if (rd == -1 && errno == EAGAIN) { + /* No keyboard input available. Since poll() did return, + * we should have input on stdin */ read_lines(); buffer_fill_and_print(); goto again; @@ -883,51 +866,29 @@ static ssize_t getch_nowait(char* input, int sz) * special return codes. Note that this function works best with raw input. */ static int less_getch(int pos) { - unsigned char input[16]; - unsigned i; + int i; again: less_gets_pos = pos; - memset(input, 0, sizeof(input)); - getch_nowait((char *)input, sizeof(input)); + i = getch_nowait(); less_gets_pos = -1; - /* Detect escape sequences (i.e. arrow keys) and handle - * them accordingly */ - if (input[0] == '\033' && input[1] == '[') { - i = input[2] - REAL_KEY_UP; - if (i < 4) - return 20 + i; - i = input[2] - REAL_PAGE_UP; - if (i < 4) - return 24 + i; - if (input[2] == REAL_KEY_HOME_XTERM) - return KEY_HOME; - if (input[2] == REAL_KEY_HOME_ALT) - return KEY_HOME; - if (input[2] == REAL_KEY_END_XTERM) - return KEY_END; - if (input[2] == REAL_KEY_END_ALT) - return KEY_END; - return 0; - } - /* Reject almost all control chars */ - i = input[0]; - if (i < ' ' && i != 0x0d && i != 8) + /* Discard Ctrl-something chars */ + if (i >= 0 && i < ' ' && i != 0x0d && i != 8) goto again; return i; } static char* less_gets(int sz) { - char c; + int c; unsigned i = 0; char *result = xzalloc(1); while (1) { c = '\0'; less_gets_pos = sz + i; - getch_nowait(&c, 1); + c = getch_nowait(); if (c == 0x0d) { result[i] = '\0'; less_gets_pos = -1; @@ -939,7 +900,7 @@ static char* less_gets(int sz) printf("\x8 \x8"); i--; } - if (c < ' ') + if (c < ' ') /* filters out KEYCODE_xxx too (<0) */ continue; if (i >= width - sz - 1) continue; /* len limit */ @@ -1151,8 +1112,8 @@ static void number_process(int first_digit) { unsigned i; int num; + int keypress; char num_input[sizeof(int)*4]; /* more than enough */ - char keypress; num_input[0] = first_digit; @@ -1163,15 +1124,14 @@ static void number_process(int first_digit) /* Receive input until a letter is given */ i = 1; while (i < sizeof(num_input)-1) { - num_input[i] = less_getch(i + 1); - if (!num_input[i] || !isdigit(num_input[i])) + keypress = less_getch(i + 1); + if ((unsigned)keypress > 255 || !isdigit(num_input[i])) break; - bb_putchar(num_input[i]); + num_input[i] = keypress; + bb_putchar(keypress); i++; } - /* Take the final letter out of the digits string */ - keypress = num_input[i]; num_input[i] = '\0'; num = bb_strtou(num_input, NULL, 10); /* on format error, num == -1 */ @@ -1182,10 +1142,10 @@ static void number_process(int first_digit) /* We now know the number and the letter entered, so we process them */ switch (keypress) { - case KEY_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015': + case KEYCODE_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015': buffer_down(num); break; - case KEY_UP: case 'b': case 'w': case 'y': case 'u': + case KEYCODE_UP: case 'b': case 'w': case 'y': case 'u': buffer_up(num); break; case 'g': case '<': case 'G': case '>': @@ -1413,16 +1373,16 @@ static void match_left_bracket(char bracket) static void keypress_process(int keypress) { switch (keypress) { - case KEY_DOWN: case 'e': case 'j': case 0x0d: + case KEYCODE_DOWN: case 'e': case 'j': case 0x0d: buffer_down(1); break; - case KEY_UP: case 'y': case 'k': + case KEYCODE_UP: case 'y': case 'k': buffer_up(1); break; - case PAGE_DOWN: case ' ': case 'z': case 'f': + case KEYCODE_PAGEDOWN: case ' ': case 'z': case 'f': buffer_down(max_displayed_line + 1); break; - case PAGE_UP: case 'w': case 'b': + case KEYCODE_PAGEUP: case 'w': case 'b': buffer_up(max_displayed_line + 1); break; case 'd': @@ -1431,10 +1391,10 @@ static void keypress_process(int keypress) case 'u': buffer_up((max_displayed_line + 1) / 2); break; - case KEY_HOME: case 'g': case 'p': case '<': case '%': + case KEYCODE_HOME: case 'g': case 'p': case '<': case '%': buffer_line(0); break; - case KEY_END: case 'G': case '>': + case KEYCODE_END: case 'G': case '>': cur_fline = MAXLINES; read_lines(); buffer_line(cur_fline); @@ -1586,7 +1546,8 @@ int less_main(int argc, char **argv) reinitialize(); while (1) { #if ENABLE_FEATURE_LESS_WINCH - if (winch_counter) { + while (WINCH_COUNTER) { + again: winch_counter--; get_terminal_width_height(kbd_fd, &width, &max_displayed_line); /* 20: two tabstops + 4 */ @@ -1597,8 +1558,16 @@ int less_main(int argc, char **argv) max_displayed_line -= 2; free(buffer); buffer = xmalloc((max_displayed_line+1) * sizeof(char *)); + /* Avoid re-wrap and/or redraw if we already know + * we need to do it again. These ops are expensive */ + if (WINCH_COUNTER) + goto again; re_wrap(); + if (WINCH_COUNTER) + goto again; buffer_fill_and_print(); + /* This took some time. Loop back and check, + * were there another SIGWINCH? */ } #endif keypress = less_getch(-1); /* -1: do not position cursor */ -- cgit v1.2.3