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author | Paul Eggert <eggert@cs.ucla.edu> | 2013-02-11 15:37:18 -0800 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2013-02-11 15:37:18 -0800 |
commit | a84b7c5334e232913111b840f2283d0138a6f5fb (patch) | |
tree | 8ee4e55f7059d1eb918fb5966cd81ee3f84153bc /src/search.c | |
parent | 71d4202f204ea5fad93eb34406f0ef671630f271 (diff) | |
download | emacs-a84b7c5334e232913111b840f2283d0138a6f5fb.tar.gz |
Tune by using memchr and memrchr.
* .bzrignore: Add string.h.
* admin/merge-gnulib (GNULIB_MODULES): Add memrchr.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib/memrchr.c, lib/string.in.h, m4/memrchr.m4, m4/string_h.m4:
New files, from gnulib.
* src/doc.c (Fsnarf_documentation):
* src/fileio.c (Fsubstitute_in_file_name):
* src/search.c (find_newline, scan_newline):
* src/xdisp.c (pos_visible_p, display_count_lines):
Use memchr and memrchr rather than scanning byte-by-byte.
* src/search.c (find_newline): Rename from scan_buffer.
Omit first arg TARGET, as it's always '\n'. All callers changed.
Diffstat (limited to 'src/search.c')
-rw-r--r-- | src/search.c | 172 |
1 files changed, 81 insertions, 91 deletions
diff --git a/src/search.c b/src/search.c index c4ccf6c257b..c25d2441018 100644 --- a/src/search.c +++ b/src/search.c @@ -619,7 +619,7 @@ newline_cache_on_off (struct buffer *buf) } -/* Search for COUNT instances of the character TARGET between START and END. +/* Search for COUNT newlines between START and END. If COUNT is positive, search forwards; END must be >= START. If COUNT is negative, search backwards for the -COUNTth instance; @@ -634,14 +634,14 @@ newline_cache_on_off (struct buffer *buf) this is not the same as the usual convention for Emacs motion commands. If we don't find COUNT instances before reaching END, set *SHORTAGE - to the number of TARGETs left unfound, and return END. + to the number of newlines left unfound, and return END. If ALLOW_QUIT, set immediate_quit. That's good to do except when inside redisplay. */ ptrdiff_t -scan_buffer (int target, ptrdiff_t start, ptrdiff_t end, - ptrdiff_t count, ptrdiff_t *shortage, bool allow_quit) +find_newline (ptrdiff_t start, ptrdiff_t end, + ptrdiff_t count, ptrdiff_t *shortage, bool allow_quit) { struct region_cache *newline_cache; ptrdiff_t end_byte = -1; @@ -656,7 +656,7 @@ scan_buffer (int target, ptrdiff_t start, ptrdiff_t end, else { direction = -1; - if (!end) + if (!end) end = BEGV, end_byte = BEGV_BYTE; } if (end_byte == -1) @@ -684,7 +684,7 @@ scan_buffer (int target, ptrdiff_t start, ptrdiff_t end, /* If we're looking for a newline, consult the newline cache to see where we can avoid some scanning. */ - if (target == '\n' && newline_cache) + if (newline_cache) { ptrdiff_t next_change; immediate_quit = 0; @@ -723,32 +723,32 @@ scan_buffer (int target, ptrdiff_t start, ptrdiff_t end, while (cursor < ceiling_addr) { - unsigned char *scan_start = cursor; - /* The dumb loop. */ - while (*cursor != target && ++cursor < ceiling_addr) - ; + unsigned char *nl = memchr (cursor, '\n', ceiling_addr - cursor); /* If we're looking for newlines, cache the fact that the region from start to cursor is free of them. */ - if (target == '\n' && newline_cache) - know_region_cache (current_buffer, newline_cache, - BYTE_TO_CHAR (start_byte + scan_start - base), - BYTE_TO_CHAR (start_byte + cursor - base)); - - /* Did we find the target character? */ - if (cursor < ceiling_addr) - { - if (--count == 0) - { - immediate_quit = 0; - return BYTE_TO_CHAR (start_byte + cursor - base + 1); - } - cursor++; - } + if (newline_cache) + { + unsigned char *low = cursor; + unsigned char *lim = nl ? nl : ceiling_addr; + know_region_cache (current_buffer, newline_cache, + BYTE_TO_CHAR (low - base + start_byte), + BYTE_TO_CHAR (lim - base + start_byte)); + } + + if (! nl) + break; + + if (--count == 0) + { + immediate_quit = 0; + return BYTE_TO_CHAR (nl + 1 - base + start_byte); + } + cursor = nl + 1; } - start = BYTE_TO_CHAR (start_byte + cursor - base); + start = BYTE_TO_CHAR (ceiling_addr - base + start_byte); } } else @@ -760,7 +760,7 @@ scan_buffer (int target, ptrdiff_t start, ptrdiff_t end, ptrdiff_t tem; /* Consult the newline cache, if appropriate. */ - if (target == '\n' && newline_cache) + if (newline_cache) { ptrdiff_t next_change; immediate_quit = 0; @@ -794,31 +794,32 @@ scan_buffer (int target, ptrdiff_t start, ptrdiff_t end, while (cursor >= ceiling_addr) { - unsigned char *scan_start = cursor; - - while (*cursor != target && --cursor >= ceiling_addr) - ; + unsigned char *nl = memrchr (ceiling_addr, '\n', + cursor + 1 - ceiling_addr); /* If we're looking for newlines, cache the fact that the region from after the cursor to start is free of them. */ - if (target == '\n' && newline_cache) - know_region_cache (current_buffer, newline_cache, - BYTE_TO_CHAR (start_byte + cursor - base), - BYTE_TO_CHAR (start_byte + scan_start - base)); - - /* Did we find the target character? */ - if (cursor >= ceiling_addr) - { - if (++count >= 0) - { - immediate_quit = 0; - return BYTE_TO_CHAR (start_byte + cursor - base); - } - cursor--; - } + if (newline_cache) + { + unsigned char *low = nl ? nl : ceiling_addr - 1; + unsigned char *lim = cursor; + know_region_cache (current_buffer, newline_cache, + BYTE_TO_CHAR (low - base + start_byte), + BYTE_TO_CHAR (lim - base + start_byte)); + } + + if (! nl) + break; + + if (++count >= 0) + { + immediate_quit = 0; + return BYTE_TO_CHAR (nl - base + start_byte); + } + cursor = nl - 1; } - start = BYTE_TO_CHAR (start_byte + cursor - base); + start = BYTE_TO_CHAR (ceiling_addr - 1 - base + start_byte); } } @@ -828,8 +829,7 @@ scan_buffer (int target, ptrdiff_t start, ptrdiff_t end, return start; } -/* Search for COUNT instances of a line boundary, which means either a - newline or (if selective display enabled) a carriage return. +/* Search for COUNT instances of a line boundary. Start at START. If COUNT is negative, search backwards. We report the resulting position by calling TEMP_SET_PT_BOTH. @@ -860,9 +860,6 @@ scan_newline (ptrdiff_t start, ptrdiff_t start_byte, bool old_immediate_quit = immediate_quit; - /* The code that follows is like scan_buffer - but checks for either newline or carriage return. */ - if (allow_quit) immediate_quit++; @@ -874,29 +871,25 @@ scan_newline (ptrdiff_t start, ptrdiff_t start_byte, ceiling = min (limit_byte - 1, ceiling); ceiling_addr = BYTE_POS_ADDR (ceiling) + 1; base = (cursor = BYTE_POS_ADDR (start_byte)); - while (1) - { - while (*cursor != '\n' && ++cursor != ceiling_addr) - ; - if (cursor != ceiling_addr) + do + { + unsigned char *nl = memchr (cursor, '\n', ceiling_addr - cursor); + if (! nl) + break; + if (--count == 0) { - if (--count == 0) - { - immediate_quit = old_immediate_quit; - start_byte = start_byte + cursor - base + 1; - start = BYTE_TO_CHAR (start_byte); - TEMP_SET_PT_BOTH (start, start_byte); - return 0; - } - else - if (++cursor == ceiling_addr) - break; + immediate_quit = old_immediate_quit; + start_byte += nl - base + 1; + start = BYTE_TO_CHAR (start_byte); + TEMP_SET_PT_BOTH (start, start_byte); + return 0; } - else - break; + cursor = nl + 1; } - start_byte += cursor - base; + while (cursor < ceiling_addr); + + start_byte += ceiling_addr - base; } } else @@ -905,31 +898,28 @@ scan_newline (ptrdiff_t start, ptrdiff_t start_byte, { ceiling = BUFFER_FLOOR_OF (start_byte - 1); ceiling = max (limit_byte, ceiling); - ceiling_addr = BYTE_POS_ADDR (ceiling) - 1; + ceiling_addr = BYTE_POS_ADDR (ceiling); base = (cursor = BYTE_POS_ADDR (start_byte - 1) + 1); while (1) { - while (--cursor != ceiling_addr && *cursor != '\n') - ; + unsigned char *nl = memrchr (ceiling_addr, '\n', + cursor - ceiling_addr); + if (! nl) + break; - if (cursor != ceiling_addr) + if (++count == 0) { - if (++count == 0) - { - immediate_quit = old_immediate_quit; - /* Return the position AFTER the match we found. */ - start_byte = start_byte + cursor - base + 1; - start = BYTE_TO_CHAR (start_byte); - TEMP_SET_PT_BOTH (start, start_byte); - return 0; - } + immediate_quit = old_immediate_quit; + /* Return the position AFTER the match we found. */ + start_byte += nl - base + 1; + start = BYTE_TO_CHAR (start_byte); + TEMP_SET_PT_BOTH (start, start_byte); + return 0; } - else - break; + + cursor = nl; } - /* Here we add 1 to compensate for the last decrement - of CURSOR, which took it past the valid range. */ - start_byte += cursor - base + 1; + start_byte += ceiling_addr - base; } } @@ -942,7 +932,7 @@ scan_newline (ptrdiff_t start, ptrdiff_t start_byte, ptrdiff_t find_next_newline_no_quit (ptrdiff_t from, ptrdiff_t cnt) { - return scan_buffer ('\n', from, 0, cnt, (ptrdiff_t *) 0, 0); + return find_newline (from, 0, cnt, (ptrdiff_t *) 0, 0); } /* Like find_next_newline, but returns position before the newline, @@ -953,7 +943,7 @@ ptrdiff_t find_before_next_newline (ptrdiff_t from, ptrdiff_t to, ptrdiff_t cnt) { ptrdiff_t shortage; - ptrdiff_t pos = scan_buffer ('\n', from, to, cnt, &shortage, 1); + ptrdiff_t pos = find_newline (from, to, cnt, &shortage, 1); if (shortage == 0) pos--; |