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author | Joey Hess <joeyh@joeyh.name> | 2017-06-26 12:15:27 -0400 |
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committer | Joey Hess <joeyh@joeyh.name> | 2017-06-26 12:15:55 -0400 |
commit | 63f9aba33b45e5bab688ffaa5e4182801c152828 (patch) | |
tree | 1f4e16640503b27bbd0f33241cbe1cb2c4a4eb89 /Utility/DataUnits.hs | |
parent | c799b05deae723690bfac5e867f7985e8f800d0d (diff) | |
download | git-repair-63f9aba33b45e5bab688ffaa5e4182801c152828.tar.gz |
merge from git-annex
Removes dependency on MissingH, adding a dependency on split instead.
This commit was sponsored by Brock Spratlen on Patreon.
Diffstat (limited to 'Utility/DataUnits.hs')
-rw-r--r-- | Utility/DataUnits.hs | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/Utility/DataUnits.hs b/Utility/DataUnits.hs new file mode 100644 index 0000000..a6c9ffc --- /dev/null +++ b/Utility/DataUnits.hs @@ -0,0 +1,166 @@ +{- data size display and parsing + - + - Copyright 2011 Joey Hess <id@joeyh.name> + - + - License: BSD-2-clause + - + - + - And now a rant: + - + - In the beginning, we had powers of two, and they were good. + - + - Disk drive manufacturers noticed that some powers of two were + - sorta close to some powers of ten, and that rounding down to the nearest + - power of ten allowed them to advertise their drives were bigger. This + - was sorta annoying. + - + - Then drives got big. Really, really big. This was good. + - + - Except that the small rounding error perpretrated by the drive + - manufacturers suffered the fate of a small error, and became a large + - error. This was bad. + - + - So, a committee was formed. And it arrived at a committee-like decision, + - which satisfied noone, confused everyone, and made the world an uglier + - place. As with all committees, this was meh. + - + - And the drive manufacturers happily continued selling drives that are + - increasingly smaller than you'd expect, if you don't count on your + - fingers. But that are increasingly too big for anyone to much notice. + - This caused me to need git-annex. + - + - Thus, I use units here that I loathe. Because if I didn't, people would + - be confused that their drives seem the wrong size, and other people would + - complain at me for not being standards compliant. And we call this + - progress? + -} + +module Utility.DataUnits ( + dataUnits, + storageUnits, + memoryUnits, + bandwidthUnits, + oldSchoolUnits, + Unit(..), + ByteSize, + + roughSize, + roughSize', + compareSizes, + readSize +) where + +import Data.List +import Data.Char + +import Utility.HumanNumber + +type ByteSize = Integer +type Name = String +type Abbrev = String +data Unit = Unit ByteSize Abbrev Name + deriving (Ord, Show, Eq) + +dataUnits :: [Unit] +dataUnits = storageUnits ++ memoryUnits + +{- Storage units are (stupidly) powers of ten. -} +storageUnits :: [Unit] +storageUnits = + [ Unit (p 8) "YB" "yottabyte" + , Unit (p 7) "ZB" "zettabyte" + , Unit (p 6) "EB" "exabyte" + , Unit (p 5) "PB" "petabyte" + , Unit (p 4) "TB" "terabyte" + , Unit (p 3) "GB" "gigabyte" + , Unit (p 2) "MB" "megabyte" + , Unit (p 1) "kB" "kilobyte" -- weird capitalization thanks to committe + , Unit (p 0) "B" "byte" + ] + where + p :: Integer -> Integer + p n = 1000^n + +{- Memory units are (stupidly named) powers of 2. -} +memoryUnits :: [Unit] +memoryUnits = + [ Unit (p 8) "YiB" "yobibyte" + , Unit (p 7) "ZiB" "zebibyte" + , Unit (p 6) "EiB" "exbibyte" + , Unit (p 5) "PiB" "pebibyte" + , Unit (p 4) "TiB" "tebibyte" + , Unit (p 3) "GiB" "gibibyte" + , Unit (p 2) "MiB" "mebibyte" + , Unit (p 1) "KiB" "kibibyte" + , Unit (p 0) "B" "byte" + ] + where + p :: Integer -> Integer + p n = 2^(n*10) + +{- Bandwidth units are only measured in bits if you're some crazy telco. -} +bandwidthUnits :: [Unit] +bandwidthUnits = error "stop trying to rip people off" + +{- Do you yearn for the days when men were men and megabytes were megabytes? -} +oldSchoolUnits :: [Unit] +oldSchoolUnits = zipWith (curry mingle) storageUnits memoryUnits + where + mingle (Unit _ a n, Unit s' _ _) = Unit s' a n + +{- approximate display of a particular number of bytes -} +roughSize :: [Unit] -> Bool -> ByteSize -> String +roughSize units short i = roughSize' units short 2 i + +roughSize' :: [Unit] -> Bool -> Int -> ByteSize -> String +roughSize' units short precision i + | i < 0 = '-' : findUnit units' (negate i) + | otherwise = findUnit units' i + where + units' = sortBy (flip compare) units -- largest first + + findUnit (u@(Unit s _ _):us) i' + | i' >= s = showUnit i' u + | otherwise = findUnit us i' + findUnit [] i' = showUnit i' (last units') -- bytes + + showUnit x (Unit size abbrev name) = s ++ " " ++ unit + where + v = (fromInteger x :: Double) / fromInteger size + s = showImprecise precision v + unit + | short = abbrev + | s == "1" = name + | otherwise = name ++ "s" + +{- displays comparison of two sizes -} +compareSizes :: [Unit] -> Bool -> ByteSize -> ByteSize -> String +compareSizes units abbrev old new + | old > new = roughSize units abbrev (old - new) ++ " smaller" + | old < new = roughSize units abbrev (new - old) ++ " larger" + | otherwise = "same" + +{- Parses strings like "10 kilobytes" or "0.5tb". -} +readSize :: [Unit] -> String -> Maybe ByteSize +readSize units input + | null parsednum || null parsedunit = Nothing + | otherwise = Just $ round $ number * fromIntegral multiplier + where + (number, rest) = head parsednum + multiplier = head parsedunit + unitname = takeWhile isAlpha $ dropWhile isSpace rest + + parsednum = reads input :: [(Double, String)] + parsedunit = lookupUnit units unitname + + lookupUnit _ [] = [1] -- no unit given, assume bytes + lookupUnit [] _ = [] + lookupUnit (Unit s a n:us) v + | a ~~ v || n ~~ v = [s] + | plural n ~~ v || a ~~ byteabbrev v = [s] + | otherwise = lookupUnit us v + + a ~~ b = map toLower a == map toLower b + + plural n = n ++ "s" + byteabbrev a = a ++ "b" |