X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/agedu/blobdiff_plain/cfe942fb3391ae80e816272d7baa45be30e5e7ec..14601b5d4222f2bee568e03eddf2f949b2a9d126:/TODO

diff --git a/TODO b/TODO
index 0b6efba..6046cec 100644
--- a/TODO
+++ b/TODO
@@ -1,43 +1,27 @@
 TODO list for agedu
 ===================
 
-Before it's non-embarrassingly releasable:
+ - stop trying to calculate an upper bound on the index file size.
+   Instead, just mmap it at initial size + delta, and periodically
+   re-mmap it during index building if it grows too big. If we run
+   out of address space, we'll hear about it eventually; and
+   computing upper bounds given the new optimised index tends to be
+   a factor of five out, which is bad because it'll lead to running
+   out of theoretical address space and erroneously reporting
+   failure long before we run out of it for real.
 
- - more flexible running modes
-    + at least some ability to chain actions within the same run:
-      "agedu -s dirname -w" would seem handy.
-
- - work out what to do about atimes on directories in the absence of
-   the Linux syscall magic
-    * one option is to read them during the scan and reinstate them
-      after each recursion pop. Race-condition prone.
-    * marking them in a distinctive colour in the reports is another
-      option.
-    * a third option is simply to ignore space taken up by
-      directories in the first place; inaccurate but terribly simple.
-    * incidentally, sometimes open(...,O_NOATIME) will fail, and
-      then we have to fall back to ordinary open. Be prepared to do
-      this, which probably means getting rid of the icky macro
-      hackery in du.c and turning it into a more sensible run-time
-      abstraction layer.
-
- - polish the plain-text output to make it look more like du
-    + configurable recursive output depth
-    + show the right bits last
-
- - cross-Unix portability:
-    + use autoconf
-       * configure use of stat64
-       * configure use of /proc/net/tcp
-       * configure use of /dev/random
-       * configure use of Linux syscall magic replacing readdir
-          + later glibcs have fdopendir, hooray! So we can use that
-	    too, if it's available and O_NOATIME is too.
-       * what do we do elsewhere about _GNU_SOURCE?
-
- - man page, licence.
-
-Future possibilities:
+ - we could still be using more of the information coming from
+   autoconf. Our config.h is defining a whole bunch of HAVE_FOOs for
+   particular functions (e.g. HAVE_INET_NTOA, HAVE_MEMCHR,
+   HAVE_FNMATCH). We could usefully supply alternatives for some of
+   these functions (e.g. cannibalise the PuTTY wildcard matcher for
+   use in the absence of fnmatch, switch to vanilla truncate() in
+   the absence of ftruncate); where we don't have alternative code,
+   it would perhaps be polite to throw an error at configure time
+   rather than allowing the subsequent build to fail.
+    + however, I don't see anything here that looks very
+      controversial; IIRC it's all in POSIX, for one thing. So more
+      likely this should simply wait until somebody complains.
 
  - IPv6 support in the HTTP server
     * of course, Linux magic auth can still work in this context; we
@@ -62,20 +46,6 @@ Future possibilities:
       straight to terminfo: generate lines of attribute-interleaved
       text and display them, so we only really need the sequences
       "go here and display stuff", "scroll up", "scroll down".
-    + I think the attribute-interleaved text might be possible to do
-      cunningly, as well: we autodetect a basically VT-style
-      terminal, and add 256-colour sequences on the end. So, for
-      instance, we might set ANSI-yellow foreground, set ANSI-red
-      background, _then_ set both foreground and background to the
-      appropriate xterm 256-colour, and then display some
-      appropriate character which would have given the right blend
-      of the ANSI-16 fore and background colours. Then the same
-      display code should gracefully degrade in the face of a
-      terminal which doesn't support xterm-256.
-       * current best plan is to simulate the xterm-256 shading from
-	 0/5 to 5/5 by doing space, colon and hash in colour A on
-	 colour B background, then hash, colon and space in B on A
-	 background.
     + Infrastructure work before doing any of this would be to split
       html.c into two: one part to prepare an abstract data
       structure describing an HTML-like report (in particular, all
@@ -99,3 +69,17 @@ Future possibilities:
       agedu dump file on standard output. Then one would simply feed
       that over the network connection of one's choice to the rest
       of agedu running on Unix as usual.
+
+ - it might conceivably be useful to support a choice of indexing
+   strategies. The current "continuous index" mechanism' tradeoff of
+   taking O(N log N) space in order to be able to support any age
+   cutoff you like is not going to be ideal for everybody. A second
+   more conventional "discrete index" mechanism which allows the
+   user to specify a number of fixed cutoffs and just indexes each
+   directory on those alone would undoubtedly be a useful thing for
+   large-scale users. This will require considerable thought about
+   how to make the indexers pluggable at both index-generation time
+   and query time.
+    * however, now we have the cut-down version of the continuous
+      index, it might be the case that the space gain is no longer
+      worthwhile.