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lineedit: allocate matchBuf only temporarily: saves MAX_LINELEN bytes

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function                                             old     new   delta
input_tab                                           1027    1041     +14
build_match_prefix                                   590     562     -28
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 14/-28)            Total: -14 bytes

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
This commit is contained in:
Denys Vlasenko 2010-09-03 14:09:24 +02:00
parent ba0e103a66
commit 76939e7b72
1 changed files with 48 additions and 45 deletions
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93
libbb/lineedit.c
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@ -150,11 +150,6 @@ struct lineedit_statics {
#if ENABLE_FEATURE_EDITING_ASK_TERMINAL
smallint sent_ESC_br6n;
#endif
/* Formerly these were big buffers on stack: */
#if ENABLE_FEATURE_TAB_COMPLETION
char input_tab__matchBuf[MAX_LINELEN];
#endif
};
/* See lineedit_ptr_hack.c */
@ -810,17 +805,17 @@ static NOINLINE unsigned complete_cmd_dir_file(const char *command, int type)
}
/* build_match_prefix:
* On entry, matchBuf contains everything up to cursor at the moment <tab>
* On entry, match_buf contains everything up to cursor at the moment <tab>
* was pressed. This function looks at it, figures out what part of it
* constitutes the command/file/directory prefix to use for completion,
* and rewrites matchBuf to contain only that part.
* and rewrites match_buf to contain only that part.
*/
#define dbg_bmp 0
/* Helpers: */
/* QUOT is used on elements of int_buf[], which are bytes,
* not Unicode chars. Therefore it works correctly even in Unicode mode.
*/
#define QUOT (UCHAR_MAX+1)
#define dbg_bmp 0
static void remove_chunk(int16_t *int_buf, int beg, int end)
{
/* beg must be <= end */
@ -837,25 +832,29 @@ static void remove_chunk(int16_t *int_buf, int beg, int end)
bb_putchar('\n');
}
}
static NOINLINE int build_match_prefix(char *matchBuf)
/* Caller ensures that match_buf points to a malloced buffer
* big enough to hold strlen(match_buf)*2 + 2
*/
static NOINLINE int build_match_prefix(char *match_buf)
{
int i, j;
int command_mode;
int16_t *int_buf;
int16_t *int_buf = (int16_t*)match_buf;
if (dbg_bmp) printf("\n%s\n", matchBuf);
if (dbg_bmp) printf("\n%s\n", match_buf);
int_buf = xmalloc(sizeof(int_buf[0]) * (strlen(matchBuf) + 1));
i = 0;
while ((int_buf[i] = (unsigned char)matchBuf[i]) != '\0')
i++;
/* Copy in reverse order, since they overlap */
i = strlen(match_buf);
do {
int_buf[i] = (unsigned char)match_buf[i];
i--;
} while (i >= 0);
/* Mark every \c as "quoted c" */
for (i = j = 0; matchBuf[i]; i++, j++) {
if (matchBuf[i] == '\\') {
remove_chunk(int_buf, j, j + 1);
int_buf[j] |= QUOT;
i++;
for (i = 0; int_buf[i]; i++) {
if (int_buf[i] == '\\') {
remove_chunk(int_buf, i, i + 1);
int_buf[i] |= QUOT;
}
}
/* Quote-mark "chars" and 'chars', drop delimiters */
@ -964,13 +963,12 @@ static NOINLINE int build_match_prefix(char *matchBuf)
}
}
/* Store only match prefix */
/* Convert back to string of _chars_ */
i = 0;
while ((matchBuf[i] = int_buf[i]) != '\0')
while ((match_buf[i] = int_buf[i]) != '\0')
i++;
free(int_buf);
if (dbg_bmp) printf("final matchBuf:'%s'\n", matchBuf);
if (dbg_bmp) printf("final match_buf:'%s'\n", match_buf);
return command_mode;
}
@ -1037,9 +1035,8 @@ static char *add_quote_for_spec_chars(char *found)
static NOINLINE void input_tab(smallint *lastWasTab)
{
char *chosen_match;
char *match_buf;
size_t len_found;
/* char matchBuf[MAX_LINELEN]; */
#define matchBuf (S.input_tab__matchBuf)
/* Length of string used for matching */
unsigned match_pfx_len = match_pfx_len;
int find_type;
@ -1065,21 +1062,26 @@ static NOINLINE void input_tab(smallint *lastWasTab)
}
*lastWasTab = 1;
chosen_match = NULL;
/* Make a local copy of the string --
* up to the position of the cursor */
/* Make a local copy of the string up to the position of the cursor.
* build_match_prefix will expand it into int16_t's, need to allocate
* twice as much as the string_len+1.
* (we then also (ab)use this extra space later - see (**))
*/
match_buf = xmalloc(MAX_LINELEN * sizeof(int16_t));
#if !ENABLE_UNICODE_SUPPORT
save_string(matchBuf, cursor + 1);
save_string(match_buf, cursor + 1); /* +1 for NUL */
#else
{
CHAR_T wc = command_ps[cursor];
command_ps[cursor] = BB_NUL;
save_string(matchBuf, MAX_LINELEN);
save_string(match_buf, MAX_LINELEN);
command_ps[cursor] = wc;
cursor_mb = strlen(matchBuf);
cursor_mb = strlen(match_buf);
}
#endif
find_type = build_match_prefix(matchBuf);
find_type = build_match_prefix(match_buf);
/* Free up any memory already allocated */
free_tab_completion_data();
@ -1088,12 +1090,12 @@ static NOINLINE void input_tab(smallint *lastWasTab)
/* If the word starts with `~' and there is no slash in the word,
* then try completing this word as a username. */
if (state->flags & USERNAME_COMPLETION)
if (matchBuf[0] == '~' && strchr(matchBuf, '/') == NULL)
match_pfx_len = complete_username(matchBuf);
if (match_buf[0] == '~' && strchr(match_buf, '/') == NULL)
match_pfx_len = complete_username(match_buf);
#endif
/* Try to match a command in $PATH, or a directory, or a file */
if (!matches)
match_pfx_len = complete_cmd_dir_file(matchBuf, find_type);
match_pfx_len = complete_cmd_dir_file(match_buf, find_type);
/* Remove duplicates */
if (matches) {
unsigned i;
@ -1117,7 +1119,7 @@ static NOINLINE void input_tab(smallint *lastWasTab)
char *cp;
beep();
if (!matches)
return; /* no matches at all */
goto ret; /* no matches at all */
/* Find common prefix */
chosen_match = xstrdup(matches[0]);
for (cp = chosen_match; *cp; cp++) {
@ -1130,8 +1132,7 @@ static NOINLINE void input_tab(smallint *lastWasTab)
}
stop:
if (cp == chosen_match) { /* have unique prefix? */
free(chosen_match); /* no */
return;
goto ret; /* no */
}
*cp = '\0';
cp = add_quote_for_spec_chars(chosen_match);
@ -1158,9 +1159,9 @@ static NOINLINE void input_tab(smallint *lastWasTab)
if ((int)(len_found - match_pfx_len + command_len) < S.maxsize) {
int pos;
/* save tail */
strcpy(matchBuf, &command_ps[cursor]);
strcpy(match_buf, &command_ps[cursor]);
/* add match and tail */
sprintf(&command_ps[cursor], "%s%s", chosen_match + match_pfx_len, matchBuf);
sprintf(&command_ps[cursor], "%s%s", chosen_match + match_pfx_len, match_buf);
command_len = strlen(command_ps);
/* new pos */
pos = cursor + len_found - match_pfx_len;
@ -1169,19 +1170,20 @@ static NOINLINE void input_tab(smallint *lastWasTab)
}
#else
{
char command[MAX_LINELEN];
int len = save_string(command, sizeof(command));
/* Use 2nd half of match_buf as scratch space - see (**) */
char *command = match_buf + MAX_LINELEN;
int len = save_string(command, MAX_LINELEN);
/* Have space to place the match? */
/* cursor_mb + (len_found - match_pfx_len) + (len - cursor_mb) */
if ((int)(len_found - match_pfx_len + len) < MAX_LINELEN) {
int pos;
/* save tail */
strcpy(matchBuf, &command[cursor_mb]);
strcpy(match_buf, &command[cursor_mb]);
/* where do we want to have cursor after all? */
strcpy(&command[cursor_mb], chosen_match + match_pfx_len);
len = load_string(command, S.maxsize);
/* add match and tail */
sprintf(&command[cursor_mb], "%s%s", chosen_match + match_pfx_len, matchBuf);
sprintf(&command[cursor_mb], "%s%s", chosen_match + match_pfx_len, match_buf);
command_len = load_string(command, S.maxsize);
/* write out the matched command */
/* paranoia: load_string can return 0 on conv error,
@ -1191,8 +1193,9 @@ static NOINLINE void input_tab(smallint *lastWasTab)
}
}
#endif
ret:
free(chosen_match);
#undef matchBuf
free(match_buf);
}
#endif /* FEATURE_TAB_COMPLETION */