X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=README;h=fe94477c205b04410784eaed3775c6867851ba28;hb=a001f12e6aaf4ea0b068028a95c188af1f7925e9;hp=db2222ededb298583937ed792d695578debe370a;hpb=f15fe27971bcf37a06bb9542ea1907f11444515a;p=goredo.git diff --git a/README b/README index db2222e..fe94477 100644 --- a/README +++ b/README @@ -31,42 +31,43 @@ NOTES *goredo-notes* * .do's arguments are relative paths * .do search goes up to / by default, but can be limited with either REDO_TOP_DIR environment variable, or by having .redo/top file in it -* executable .do is run as is -* shebangless .do is run with /bin/sh -e[x] +* target's completion messages are written after they finish +* executable .do is run as is, non-executable is run with /bin/sh -e[x] +* tracing (-x) can be done only for non-executable .do FEATURES *goredo-features* -* explicit check that stdout and $3 are not written simultaneously -* explicit check (similar to apenwarr/redo's one) that generated target - was not modified "externally" outside the redo, preventing its - overwriting, but continuing the build +* explicit useful and convenient checks from apenwarr/redo: + * check that $1 was not touched during .do execution + * check that stdout and $3 are not written simultaneously + * check that generated target was not modified "externally" outside + the redo, preventing its overwriting, but continuing the build * targets, dependency information and their directories are explicitly synced (can be disabled, should work faster) -* file's change is detected by comparing its ctime and, if it differs, - its BLAKE2b hash. Hash checking is done to prevent false positives - (can be disabled, will work faster) +* file's change is detected by comparing its ctime and BLAKE2b hash * files creation is umask-friendly (unlike mkstemp() used in redo-c) +* parallel build with jobs limit, optionally in infinite mode * coloured messages (can be disabled) * verbose debug messages, including out-of-date determination, PIDs, - lock acquirings/releases -* parallel build with jobs limit, optionally in infinite mode -* optional display of each target's execution time + lock and jobserver acquirings/releases +* displaying of each target's execution time * each target's stderr can be displayed with the PID +* optional statusline with currently running/waiting/done jobs * target's stderr can be stored on the disk with TAI64N timestamp - prefixes for each line (you can use tai64nlocal utility from - daemontools (http://cr.yp.to/daemontools/tai64nlocal.html) to convert - them to local time). Captures can be viewed any time later - + prefixes for each line. To convert them to localtime you can use either + tai64nlocal utility from daemontools (http://cr.yp.to/daemontools.html) + or make a symlink, to use built-in slower decoder: > + $ ln -s goredo tai64nlocal +< COMMANDS *goredo-commands* * redo-ifchange, redo-ifcreate, redo-always (useful with redo-stamp) * redo -- same as redo-ifchange, but forcefully and *sequentially* run specified targets * redo-log -- display TAI64N timestamped last stderr of the target -* redo-stamp -- record stamp dependency and consider it non out-of-date - if stamp equals to the previous one -* redo-cleanup -- removes either temporary, or log files, or - everything related to goredo +* redo-stamp -- record stamp dependency. Nothing more, just dummy +* redo-cleanup -- removes either temporary, log files, or everything + related to goredo * redo-whichdo -- .do search paths for specified target (similar to apenwarr/redo): > $ redo-whichdo x/y/a.b.o @@ -82,7 +83,57 @@ COMMANDS *goredo-commands* default.do ../default.b.o.do ../default.o.do +* redo-dot -- dependency DOT graph generator. For example to visualize + your dependencies with GraphViz: > + $ redo target [...] # to assure that .redo is filled up + $ redo-dot target [...] > whatever.dot + $ dot -Tpng whatever.dot > whatever.png # possibly add -Gsplines=ortho < +FAQ *goredo-faq* + + Hashing and stamping~ + +All targets are checksummed if their ctime differs from the previous +ones. apenwarr/redo gives many reasons why every time checksumming is +bad, but in my opinion in practice all of his reasons do not apply. + +* Aggregate targets and willing to be out-of-date ones just must not + produce empty output files. apenwarr/*, redo-c and goredo + implementations consider non existing file as an out-of-date target +* If you really wish to produce an empty target file, just: touch $3 + +DJB's proposal with both stdout and $3 gives that ability to control +your desired behaviour. Those who does not capture stdout -- failed. +Those who creates an empty file if no stdout was written -- failed. + +redo is a tool for helping people. Literally all targets can be safely +"redo-stamp < $3"-ed, reducing false positive out-of-dates. Of course, +with the correct working with stdout/$3 and placing necessary results in +$3, instead of just silently feeding them in redo-stamp. + +redo implementations are already automatically records -ifchange on .do +files and -ifcreate on non-existing .do files. So why they can not +record redo-stamp the same way implicitly? No, Zen of Python does not +applicable there, because -ifchange/-ifcreate contradict it already. + +Modern cryptographic hash algorithms and CPUs are so fast, that even all +read and writes to or from hard drive arrays can be easily checksummed +and transparently compressed, as ZFS with LZ4 and Skein/BLAKE[23] +algorithms demonstrate us. + +goredo includes redo-stamp, that really records the stamp in the .dep +file, but it does not play any role later. It is stayed just for +compatibility. + + Removed .do can lead to permanent errors of its non existence~ + +That is true, because dependency on it was recorded previously. Is it +safe to assume that .do-less target now is an ordinary source-file? I +have no confidence in such behaviour. So it is user's decision how to +deal with it, probably it was just his inaccuracy mistake. If you really +want to get rid of that dependency knowledge for foo/bar target, then +just remove foo/.redo/bar.dep. + STATE *goredo-state* Dependency and build state is kept inside .redo subdirectory in each