Re: Bug#749969: history no longer syncs immediately, INC_APPEND_HISTORY broken

[Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx>]

On Sat, 31 May 2014 20:22:11 +0100
Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx> wrote:
> On Sat, 31 May 2014 11:21:59 +0200
> Frank Terbeck <ft@xxxxxxxxxxxxxxxxxxx> wrote:
> > I think to enable both ways to be possible, there should be two options:
> > INC_APPEND_HISTORY that enables the original behaviour and (if the name
> > is agreeable) DELAY_INC_APPEND_HISTORY, that amends the behaviour of the
> > original option in the way that is reflected by the current behaviour.
> 
> The issue is that, without rewriting the history, either the time taken
> for the command is wrong (that was the old case) or the command isn't
> written out to the history until it's finished (that's the current
> position).  Writing the history to get the best of both worlds probably
> isn't beyond the bounds of 21st century science, but it's beyond my
> understanding of the history code at the moment.  So at the moment
> having two options looks like the only way to allow you to achieve any
> one of the effects.  I think the new behaviour could be
> INC_APPEND_HISTORY_TIME which puts it next to the original one and
> indicates why it exists.
> 
> I haven't looked, but I don't think this ought to be too difficult ---
> there are still some reasons why you might have to deal with history at
> the original place anyway, so it should be possible to add an option
> test at that point as well as one at the later point.

I think this works, but it's getting pretty silly.

diff --git a/Doc/Zsh/options.yo b/Doc/Zsh/options.yo
index 349946d..7e46048 100644
--- a/Doc/Zsh/options.yo
+++ b/Doc/Zsh/options.yo
@@ -971,6 +971,19 @@ The file will still be periodically re-written to trim it when the
 number of lines grows 20% beyond the value specified by
 tt($SAVEHIST) (see also the HIST_SAVE_BY_COPY option).
 )
+pindex(INC_APPEND_HISTORY_TIME)
+pindex(NO_INC_APPEND_HISTORY_TIME)
+pindex(INCAPPENDHISTORYTIME)
+pindex(NOINCAPPENDHISTORYTIME)
+cindex(history, incremental appending to a file with time)
+item(tt(INC_APPEND_HISTORY_TIME))(
+This option is a variant of tt(INC_APPEND_HISTORY) in which, where
+possible, the history entry is written out to the file after the
+command is finished, so that the time taken by the command is recorded
+correctly in the history file in tt(EXTENDED_HISTORY) format.  This
+means that the history entry will not be available immediately from
+other instances of the shell that are using the same history file.
+)
 pindex(SHARE_HISTORY)
 pindex(NO_SHARE_HISTORY)
 pindex(SHAREHISTORY)
diff --git a/Src/hist.c b/Src/hist.c
index 1182994..64f88f5 100644
--- a/Src/hist.c
+++ b/Src/hist.c
@@ -935,9 +935,11 @@ hbegin(int dohist)
 
     hf = getsparam("HISTFILE");
     /*
-     * For INCAPPENDHISTORY, when interactive, save the history here
+     * For INCAPPENDHISTORYTIME, when interactive, save the history here
      * as it gives a better estimate of the times of commands.
      *
+     * If INCAPPENDHISTORY is also set we've already done it.
+     *
      * If SHAREHISTORY is also set continue to do so in the
      * standard place, because that's safer about reading and
      * rewriting history atomically.
@@ -950,7 +952,8 @@ hbegin(int dohist)
      * so that (correctly) nothing happens here.  But it shows
      * I thought about it.
      */
-    if (isset(INCAPPENDHISTORY) && !isset(SHAREHISTORY) &&
+    if (isset(INCAPPENDHISTORYTIME) && !isset(SHAREHISTORY) &&
+	!isset(INCAPPENDHISTORY) &&
 	!(histactive & HA_NOINC) && !strin && histsave_stack_pos == 0)
 	savehistfile(hf, 0, HFILE_USE_OPTIONS | HFILE_FAST);
 }
@@ -1378,7 +1381,8 @@ hend(Eprog prog)
      * For normal INCAPPENDHISTORY case and reasoning, see hbegin().
      */
     if (isset(SHAREHISTORY) ? histfileIsLocked() :
-	(isset(INCAPPENDHISTORY) && histsave_stack_pos != 0))
+	(isset(INCAPPENDHISTORY) || (isset(INCAPPENDHISTORYTIME) &&
+				     histsave_stack_pos != 0)))
 	savehistfile(hf, 0, HFILE_USE_OPTIONS | HFILE_FAST);
     unlockhistfile(hf); /* It's OK to call this even if we aren't locked */
     /*
@@ -2542,7 +2546,7 @@ savehistfile(char *fn, int err, int writeflags)
     }
     if (writeflags & HFILE_USE_OPTIONS) {
 	if (isset(APPENDHISTORY) || isset(INCAPPENDHISTORY)
-	 || isset(SHAREHISTORY))
+	 || isset(INCAPPENDHISTORYTIME) || isset(SHAREHISTORY))
 	    writeflags |= HFILE_APPEND | HFILE_SKIPOLD;
 	else
 	    histfile_linect = 0;
@@ -2578,7 +2582,7 @@ savehistfile(char *fn, int err, int writeflags)
 		tmpfile = NULL;
 		if (err) {
 		    if (isset(APPENDHISTORY) || isset(INCAPPENDHISTORY)
-		     || isset(SHAREHISTORY))
+		     || isset(INCAPPENDHISTORYTIME) || isset(SHAREHISTORY))
 			zerr("rewriting %s would change its ownership -- skipped", fn);
 		    else
 			zerr("rewriting %s would change its ownership -- history not saved", fn);
diff --git a/Src/options.c b/Src/options.c
index e83dc58..2163bff 100644
--- a/Src/options.c
+++ b/Src/options.c
@@ -165,6 +165,7 @@ static struct optname optns[] = {
 {{NULL, "ignoreclosebraces",  OPT_EMULATE},		 IGNORECLOSEBRACES},
 {{NULL, "ignoreeof",	      0},			 IGNOREEOF},
 {{NULL, "incappendhistory",   0},			 INCAPPENDHISTORY},
+{{NULL, "incappendhistorytime",   0},			 INCAPPENDHISTORYTIME},
 {{NULL, "interactive",	      OPT_SPECIAL},		 INTERACTIVE},
 {{NULL, "interactivecomments",OPT_BOURNE},		 INTERACTIVECOMMENTS},
 {{NULL, "ksharrays",	      OPT_EMULATE|OPT_BOURNE},	 KSHARRAYS},
diff --git a/Src/zsh.h b/Src/zsh.h
index 620883b..05d582c 100644
--- a/Src/zsh.h
+++ b/Src/zsh.h
@@ -2115,6 +2115,7 @@ enum {
     IGNORECLOSEBRACES,
     IGNOREEOF,
     INCAPPENDHISTORY,
+    INCAPPENDHISTORYTIME,
     INTERACTIVE,
     INTERACTIVECOMMENTS,
     KSHARRAYS,

-- 
Peter Stephenson <p.w.stephenson@xxxxxxxxxxxx>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/