TODO list for agedu
===================
- 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.)
- non-ASCII character set support
+ could usefully apply to --title and also to file names
+ how do we determine the input charset? Via locale, presumably.
+ how do we do translation? Importing my charset library is one
heavyweight option; alternatively, does the native C locale
mechanism provide enough functionality to do the job by itself?
+ in HTML, we would need to decide on an _output_ character set,
specify it in a tag, and translate to it from
the input locale
- one option is to make the output charset the same as the
input one, in which case all we need is to identify its name
for the tag
- the other option is to make the output charset UTF-8 always
and translate to that from everything else
- in the web server and CGI modes, it would probably be nicer
to move that tag into a proper HTTP header
+ even in text mode we would want to parse the filenames in some
fashion, due to the unhelpful corner case of Shift-JIS Windows
(in which backslashes in the input string must be classified as
path separators or the second byte of a two-byte character)
- that's really painful, since it will impact string processing
of filenames throughout the code
- so perhaps a better approach would be to do locale processing
of filenames at _scan_ time, and normalise to UTF-8 in both
the index and dump files?
+ involves incrementing the version of the dump-file format
+ then paths given on the command line are translated
quickly to UTF-8 before comparing them against index paths
+ and now the HTML output side becomes easy, though the text
output involves translating back again
+ but what if the filenames aren't intended to be
interpreted in any particular character set (old-style
Unix semantics) or in a consistent one?
- 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.
- run-time configuration in the HTTP server
* I think this probably works by having a configuration form, or
a link pointing to one, somewhere on the report page. If you
want to reconfigure anything, you fill in and submit the form;
the web server receives HTTP GET with parameters and a
referer, adjusts its internal configuration, and returns an
HTTP redirect back to the referring page - which it then
re-renders in accordance with the change.
* All the same options should have their starting states
configurable on the command line too.
- curses-ish equivalent of the web output
+ try using xterm 256-colour mode. Can (n)curses handle that? If
not, try doing it manually.
+ I think my current best idea is to bypass ncurses and go
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".
+ 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
the index lookups, percentage calculation, vector arithmetic
and line sorting), and another part to generate the literal
HTML. Then the former can be reused to produce very similar
reports in coloured plain text.
- 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's 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.