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author | Eric Wong <e@80x24.org> | 2016-12-26 23:04:57 +0000 |
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committer | Eric Wong <e@80x24.org> | 2016-12-26 23:10:53 +0000 |
commit | efd81f4f6be4e91225aa893787d4ede84b46ed5e (patch) | |
tree | b0bccd43e292a08c538794b5ee85d289eeb1e538 /lib | |
parent | 53c3abbbb222e3ab84c565498b8461009a3059c0 (diff) | |
download | dtas-efd81f4f6be4e91225aa893787d4ede84b46ed5e.tar.gz |
We often waste cycles rerunning commands we don't need to run frequently. Introduce a short term cache for these.
Diffstat (limited to 'lib')
-rw-r--r-- | lib/dtas/mcache.rb | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/lib/dtas/mcache.rb b/lib/dtas/mcache.rb new file mode 100644 index 0000000..b638a23 --- /dev/null +++ b/lib/dtas/mcache.rb @@ -0,0 +1,31 @@ +# Copyright (C) 2016 all contributors <dtas-all@nongnu.org> +# License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt> +# frozen_string_literal: true +# encoding: binary +require_relative '../dtas' + +class DTAS::Mcache + def initialize(shift = 8, ttl = 60) + @mask = (1 << shift) - 1 + @ttl = ttl + @tbl = [] + end + + def lookup(infile) + bucket = infile.hash & @mask + if cur = @tbl[bucket] + if cur[:infile] == infile && (DTAS.now - cur[:btime]) < @ttl + return cur + end + end + return unless block_given? + @tbl[bucket] = begin + cur = cur ? cur.clear : {} + if ret = yield(infile, cur) + ret[:infile] = infile.frozen? ? infile : infile.dup.freeze + ret[:btime] = DTAS.now + end + ret + end + end +end |