Fredrik GustafssonI've been playing a bit with lua. It's an embedded scripting language with strong c integration. It's small and fast.
The interesting feature would be to run C-functions direct inside lua. I suppose that would increase speed even more, at the same time as we have the convinence of a interpreted language. Lua is smaller and faster (well as always, it depends on what you're doing) than python and ruby. Perl is a really pain for the windows folks (I've heard).
A correct implementation for lua support would be to start a lua-interpreter from inside git.c (or somewhere) and load the lua code for a specific command. That would make us independent of any target installation of lua (althought the git binary would increase with the lua library around 300 kb).
However I did a quick test using lua as a replacement for sh (without direct calls to c-functions) and the result is impressive. (However this is the wrong way of using lua, shell scripting is not something lua is good at).
I did some runs on a project with 52 submodules (or 53 if you count the ones in .gitmodules). These results are pretty typical: iveqy@kolya:~/projects/eracle_core$ time /home/iveqy/projects/git/git-submodule.lua > /dev/null
real 0m1.665s user 0m0.276s sys 0m0.452s iveqy@kolya:~/projects/eracle_core$ time git submodule > /dev/null
real 0m3.413s user 0m0.476s sys 0m1.224s
For me, that speedup does matter.
NOTICE!!! This code is experimental. It does have some known bugs, it does have some style issues. A state of the art complete implementation would contain a few more tests/jumps and less concat (which is extremely expensive in lua) and less git-invokation.
Signed-off-by: Fredrik Gustafsson <iveqy@iveqy.com> --- git-submodule.lua | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100755 git-submodule.lua
diff --git a/git-submodule.lua b/git-submodule.lua new file mode 100755 index 0000000..14f71e6 --- /dev/null +++ b/git-submodule.lua @@ -0,0 +1,104 @@ +#!/usr/bin/lua + +function run_cmd(cmd) + local f = io.popen(cmd, 'r'); + local out = f:read('*a'); + f:close() + return out +end + +function fwrite(fmt, ...) + return io.write(string.format(fmt, ...)) +end + +function read_gitmodules() + local inf = assert(io.open('.gitmodules', 'r')) + local config = inf:read("*all") + gitmodules = {} + for sm in string.gmatch(config, '%[[^]]*%][^%[]*') do + local thismod = {} + local name = string.match(sm, '%[%s-submodule%s-"(.+)"%s-%]') + thismod["name"] = name + local path = '' + for k, v in string.gmatch(sm, '\n%s*([^=^%s]*)%s*=%s*([^\n]*)') do + if k == 'path' then + path = v + else + thismod[k] = v + end + end + if path == '' then + fwrite("No path found for %s in .gitmodules\n", name) + os.exit(1) + end + gitmodules[path] = thismod + end + + return gitmodules +end + +function module_list() + local lsfiles = 'git ls-files --stage --error-unmatch -z || echo "#unmatched"' + local out = run_cmd(lsfiles) + local unmerged = '' + local subs = read_gitmodules() + + for row in string.gmatch(out, '.-\0') do + if row == '#unmatched' then + os.exit(1) + end + + local mode, sha1, stage, path = string.match(row, '(%d+)%s([0-9a-f]+)%s(.)%s(.*)\0') + if mode == '160000' then + if stage == '0' then + subs[path]["sha1"] = sha1 + subs[path]["stage"] = stage + else + if unmerged ~= path then + local null_sha1 = '0000000000000000000000000000000000000000' + subs[path]["sha1"] = null_sha1 + subs[path]["stage"] = 'U' + end + unmerged = path + end + end + end + return subs +end + +function get_name_rev(path, sha1) + if sha1 == nil then sha1="" end + local cmd = "cd \"" .. path .. "\" && (git describe " .. sha1 .. + " 2>/dev/null || git describe --tags " .. sha1 .. + " 2>/dev/null || git describe --contains " .. sha1 .. + " 2>/dev/null || git describe --all --always " .. sha1 .. + " 2>/dev/null) " + return string.gsub(run_cmd(cmd), '\n', '') +end + +function cmd_status() + subs = module_list() + for smpath in pairs(subs) do + if (subs[smpath].sha1) then + if subs[smpath].stage == 'U' then + subs[smpath]["revname"] = get_name_rev(smpath, subs[smpath].sha1) + fwrite("U%s %s (%s)", subs[smpath].sha1, smpath, subs[smpath].revname) + elseif run_cmd("test -z " .. subs[smpath].url .. " || ! test -d " .. smpath .."/.git -o -f " .. smpath .. "/.git || echo '0' ") ~= '0\n' then + subs[smpath]["revname"] = get_name_rev(smpath, subs[smpath].sha1) + fwrite("-%s %s (%s)\n", subs[smpath].sha1, smpath, subs[smpath].revname) + elseif run_cmd("git diff-files --ignore-submodules=dirty --quiet -- " .. smpath .. " || echo '0'") ~= '0\n' then + p = run_cmd("git diff-files --ignore-submodules=dirty --quiet -- " .. smpath .. " || echo '0'") + subs[smpath]["revname"] = get_name_rev(smpath, subs[smpath].sha1) + fwrite(" %s %s (%s)\n", subs[smpath].sha1, smpath, subs[smpath].revname) + else + subs[smpath].sha1 = string.gsub(run_cmd('cd ' .. smpath .. ' && git rev-parse --verify HEAD'), "\n", "") + subs[smpath]["revname"] = get_name_rev(smpath, subs[smpath].sha1) + fwrite("+%s %s (%s)\n", subs[smpath].sha1, smpath, subs[smpath].revname) + end + end + end +end + +if arg[1] == nil or arg[1] == 'status' then + cmd_status() +end
-- 1.8.3.1.381.g2ab719e.dirty
