X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/agedu/blobdiff_plain/e6fde1f73e5a102d808e0b2dc7f3367b7054dc5b..a8a4d6d837f5029124d26483e4b3a390de69823e:/TODO

diff --git a/TODO b/TODO
index 2f5c2d3..df84d4a 100644
--- a/TODO
+++ b/TODO
@@ -1,15 +1,31 @@
 TODO list for agedu
 ===================
 
-Before it's non-embarrassingly releasable:
+ - flexibility in the HTML report output mode: expose the internal
+   mechanism for configuring the output filenames, and allow the
+   user to request individual files with hyperlinks as if the other
+   files existed. (In particular, functionality of this kind would
+   enable other modes of use like the built-in --cgi mode, without
+   me having to anticipate them in detail.)
 
- - now we have a configure framework, actually use it to:
-    * configure use of stat64
-    * 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.
+ - add the option (and perhaps even make it default) to address HTML
+   subpages by pathname rather than by index number. More than just
+   cosmetic: it means that in a scenario where agedu --cgi is always
+   running but the index file is updated by cron, subsidiary
+   pathnames will remain valid across a change.
 
-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
@@ -42,18 +58,42 @@ Future possibilities:
       HTML. Then the former can be reused to produce very similar
       reports in coloured plain text.
 
- - http://msdn.microsoft.com/en-us/library/ms724290.aspx suggest
-   modern Windowses support atime-equivalents, so a Windows port is
-   possible in principle.
-    + For a full Windows port, would need to modify the current
-      structure a lot, to abstract away (at least) memory-mapping of
-      files, details of disk scan procedure, networking for httpd.
-      Unclear what the right UI would be on Windows, too;
-      command-line exactly as now might be considered just a
-      _little_ unfriendly. Or perhaps not.
-    + Alternatively, a much easier approach would be to write a
-      Windows version of just the --scan-dump mode, which does a
-      filesystem scan via the Windows API and generates a valid
-      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.
+ - abstracting away all the Unix calls so as to enable a full
+   Windows port. We can already do the difficult bit on Windows
+   (scanning the filesystem and retrieving atime-analogues).
+   Everything else is just coding - albeit quite a _lot_ of coding,
+   since the Unix assumptions are woven quite tightly into the
+   current code.
+    + If nothing else, it's unclear what the user interface properly
+      ought to be in a Windows port of agedu. A command-line job
+      exactly like the Unix version might be useful to some people,
+      but would certainly be strange and confusing to others.
+
+ - 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, the space saving is less compelling.
+
+ - A user requested what's essentially a VFS layer: given multiple
+   index files and a map of how they fit into an overall namespace,
+   we should be able to construct the right answers for any query
+   about the resulting aggregated hierarchy by doing at most
+   O(number of indexes * normal number of queries) work.
+
+ - Support for filtering the scan by ownership and permissions. The
+   index data structure can't handle this, so we can't build a
+   single index file admitting multiple subset views; but a user
+   suggested that the scan phase could record information about
+   ownership and permissions in the dump file, and then the indexing
+   phase could filter down to a particular sub-view - which would at
+   least allow the construction of various subset indices from one
+   dump file, without having to redo the full disk scan which is the
+   most time-consuming part of all.