X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/agedu/blobdiff_plain/1e8d78b987550c351f47b204d3c9649cc1872e45..acaf12ce5eade22797c4bcf3530e3bb4e929e261:/TODO diff --git a/TODO b/TODO index 9b93ca2..f8c723d 100644 --- a/TODO +++ b/TODO @@ -1,71 +1,23 @@ TODO list for agedu =================== -Before it's non-embarrassingly releasable: - - - more flexible running modes - + combined scan+dump mode which doesn't even generate an index - file (nearly indistinguishable from find(1)) - + load mode which reads a dump from standard input and builds - the index (need to nail down a perfectly general dump format) - + 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 - - - figure out what to do about scans starting in the root directory - + Currently we end up with a double leading slash on the - pathnames, which is ugly, and we also get a zero-length href - in between those slashes which means the web interface doesn't - let you click back up to the top level at all. - + One big problem here is that a lot of the code assumes that - you can find the extent of a pathname by searching for "foo" - and "foo^A", trusting that anything inside the directory will - begin "foo/". So I'd need to consistently fix this everywhere - so that a trailing slash is disregarded while doing it, but - not actually removed. - + The text output gets it all wrong. - + The HTML output is fiddly even at the design stage: where - would I _ideally_ put the link to click on to get back to /? - It's unclear! - - - 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? - - - prepare a little in advance for a potential future Windows port: - + store the separator character in the index file when writing - it, and be prepared to cope on reading if it isn't a slash - + store literal byte sizes in all the size fields, instead of - Unixoid 512-byte sectors - - - man page, licence. - -Future directions: + - 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 + merely have to be prepared to open one of /proc/net/tcp or + /proc/net/tcp6 as appropriate. - run-time configuration in the HTTP server * I think this probably works by having a configuration form, or @@ -85,20 +37,6 @@ Future directions: 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 @@ -109,9 +47,34 @@ Future directions: - http://msdn.microsoft.com/en-us/library/ms724290.aspx suggest modern Windowses support atime-equivalents, so a Windows port is - possible in principle. 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. + 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. + * Disk scan procedure: the FindFirstFile / FindNextFile + functions to scan a directory automatically return the file + times along with the filenames, so there's no need to stat + them later. Would want to fiddle the shape of the + abstraction layer to reflect this. + + 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. + + - 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.