APPROVE COMMIT NOTE: This patch has been committed # HG changeset patch # User Aidan Kehoe <kehoea(a)parhasard.net&gt; # Date 1492621216 -3600 # Wed Apr 19 18:00:16 2017 +0100 # Node ID 513b2ed98e3ea153c0e65bce5a93994c48d10b42 # Parent 74b4d4c11264e149d03d748b9c34f253a69801bf Sync API of #'generate-new-buffer-name with GNU. Thank you GNU! src/ChangeLog addition: 2017-04-19 Aidan Kehoe <kehoea(a)parhasard.net&gt; * buffer.c: * buffer.c (get_buffer): Vbuffer_alist is an internal list, no need to GCPRO and call Fassoc. * buffer.c (Fgenerate_new_buffer_name): Update this to match GNU's current API; if NAME starts with a space, generate the candidate new buffer names using get_random(), start with suffixes of <2> rather than <1>. Don't make new Lisp strings or call get_buffer() in the loop. Copy string extent info to the new buffer name if NAME has extent info. man/ChangeLog addition: 2017-04-19 Aidan Kehoe <kehoea(a)parhasard.net&gt; * lispref/buffers.texi (Buffer Names): Update documentation on #'generate-new-buffer-name to reflect changes made to it today. diff -r 74b4d4c11264 -r 513b2ed98e3e man/ChangeLog --- a/man/ChangeLog Sun Mar 19 23:27:07 2017 +0000 +++ b/man/ChangeLog Wed Apr 19 18:00:16 2017 +0100 ＠＠ -1,3 +1,9 ＠＠ +2017-04-19 Aidan Kehoe <kehoea(a)parhasard.net&gt; + + * lispref/buffers.texi (Buffer Names): + Update documentation on #'generate-new-buffer-name to reflect + changes made to it today. + 2017-03-09 Aidan Kehoe <kehoea(a)parhasard.net&gt; * widget.texi (Introduction): diff -r 74b4d4c11264 -r 513b2ed98e3e man/lispref/buffers.texi --- a/man/lispref/buffers.texi Sun Mar 19 23:27:07 2017 +0000 +++ b/man/lispref/buffers.texi Wed Apr 19 18:00:16 2017 +0100 ＠＠ -293,10 +293,13 ＠＠ This function returns a name that would be unique for a new buffer---but does not create the buffer. It starts with ＠var{starting-name}, and produces a name not currently in use for any buffer by appending a -number inside of ＠samp{<＠dots{}>}. +number inside of ＠samp{<＠dots{}>}. The numbers appended start at 2, or +at a random value if ＠var{starting-name} begins with the space +character, which indicates that a buffer is not visible to users. -If ＠var{ignore} is given, it specifies a name that is okay to use (if it -is in the sequence to be tried), even if a buffer with that name exists. +If ＠var{ignore} is given, it should be a string. This means to consider +＠var{ignore} as an acceptable buffer name, even if a buffer of that name +already exists. See the related function ＠code{generate-new-buffer} in ＠ref{Creating Buffers}. diff -r 74b4d4c11264 -r 513b2ed98e3e src/ChangeLog --- a/src/ChangeLog Sun Mar 19 23:27:07 2017 +0000 +++ b/src/ChangeLog Wed Apr 19 18:00:16 2017 +0100 ＠＠ -1,3 +1,17 ＠＠ +2017-04-19 Aidan Kehoe <kehoea(a)parhasard.net&gt; + + * buffer.c: + * buffer.c (get_buffer): + Vbuffer_alist is an internal list, no need to GCPRO and call + Fassoc. + * buffer.c (Fgenerate_new_buffer_name): + Update this to match GNU's current API; if NAME starts with a + space, generate the candidate new buffer names using get_random(), + start with suffixes of <2> rather than <1>. + Don't make new Lisp strings or call get_buffer() in the loop. + Copy string extent info to the new buffer name if NAME has extent + info. + 2017-03-19 Aidan Kehoe <kehoea(a)parhasard.net&gt; * gc.c (GC_CONS_THRESHOLD): diff -r 74b4d4c11264 -r 513b2ed98e3e src/buffer.c --- a/src/buffer.c Sun Mar 19 23:27:07 2017 +0000 +++ b/src/buffer.c Wed Apr 19 18:00:16 2017 +0100 ＠＠ -395,13 +395,11 ＠＠ else { Lisp_Object buf; - struct gcpro gcpro1; CHECK_STRING (name); name = LISP_GETTEXT (name); - GCPRO1 (name); - buf = Fcdr (Fassoc (name, Vbuffer_alist)); - UNGCPRO; + buf = Fcdr (assoc_no_quit (name, Vbuffer_alist)); + if (NILP (buf) && error_if_deleted_or_does_not_exist) nsberror (name); return buf; ＠＠ -770,43 +768,98 ＠＠ Return a string that is the name of no existing buffer based on NAME. If there is no live buffer named NAME, then return NAME. Otherwise modify name by appending `<NUMBER>', incrementing NUMBER -until an unused name is found, and then return that name. -Optional second argument IGNORE specifies a name that is okay to use -\(if it is in the sequence to be tried) -even if a buffer with that name exists. +\(starting at 2) until an unused name is found, and then return that name. + +Optional second argument IGNORE specifies a name that is okay to use (if it +is in the sequence to be tried) even if a buffer with that name exists. + +If NAME begins with a space (i.e., a buffer that is not normally +visible to users), then if buffer NAME already exists a random number +is first appended to NAME, to speed up finding a non-existent buffer. */ (name, ignore)) { - REGISTER Lisp_Object gentemp, tem; - int count; - Ibyte number[10]; + Ibyte *candidate; + Bytecount csize, clen, ignore_length = -1; + EMACS_INT count; CHECK_STRING (name); - name = LISP_GETTEXT (name); #ifdef I18N3 /* #### Doc string should indicate that the buffer name will get translated. */ #endif - - tem = Fget_buffer (name); - if (NILP (tem)) - return name; - - count = 1; + name = LISP_GETTEXT (name); + + if (!NILP (ignore)) + { + CHECK_STRING (ignore); + ignore_length = XSTRING_LENGTH (ignore); + + if (ignore_length == XSTRING_LENGTH (name) + && !qxememcmp (XSTRING_DATA (name), XSTRING_DATA (ignore), + ignore_length)) + { + return name; + } + } + + if (NILP (Fget_buffer (name))) /* XEmacs; don't #'string-equal on nil, see + above for the IGNORE handling. */ + { + return name; + } + + csize = XSTRING_LENGTH (name) + DECIMAL_PRINT_SIZE (EMACS_INT) + + sizeof ("<>"); + candidate = alloca_ibytes (csize); + + count = itext_ichar_eql (XSTRING_DATA (name), ' ') ? get_random () : 2; while (1) { - qxesprintf (number, "<%d>", ++count); - gentemp = concat2 (name, build_istring (number)); - if (!NILP (ignore)) + /* XEmacs; GNU worry about the performance of this function, and then + allocate a full new Lisp string on the heap for every iteration of + the loop, and call a full Fget_buffer, too. If the performance of + #'generate-new-buffer-name really matters--and I've seen no real + evidence that is the case--the approach below with snprintf() and + ALIST_LOOP_3() is better. */ + clen = emacs_snprintf (candidate, csize, "%s<%ld>", XSTRING_DATA (name), + ++count); + if (clen == ignore_length && + !qxememcmp (candidate, XSTRING_DATA (ignore), clen)) { - tem = Fstring_equal (gentemp, ignore); - if (!NILP (tem)) - return gentemp; + return ignore; } - tem = Fget_buffer (gentemp); - if (NILP (tem)) - return gentemp; + else + { + Boolint seen = 0; + ALIST_LOOP_3 (bufname, bufobj, Vbuffer_alist) + { + if (XSTRING_LENGTH (bufname) == clen + && !qxememcmp (candidate, XSTRING_DATA (bufname), clen)) + { + seen = 1; + break; + } + } + + USED (bufobj); /* Silence warning for this. */ + + if (!seen) + { + Lisp_Object result = make_string (candidate, clen); + + if (string_extent_info (name) != NULL) + { + /* Despite what other code thinks, stretch_string_extents() + doesn't call Lisp, this is OK from the GC perspective. */ + stretch_string_extents (result, name, 0, 0, + XSTRING_LENGTH (name), clen); + } + + return result; + } + } } } -- ‘As I sat looking up at the Guinness ad, I could never figure out / How your man stayed up on the surfboard after forty pints of stout’ (C. Moore)