2016-01-12 16:26:00

1 files changed, 107 insertions, 0 deletions

diff --git a/tex/context/base/mkiv/l-md5.lua b/tex/context/base/mkiv/l-md5.lua
new file mode 100644
index 000000000..00272c873
--- /dev/null
+++ b/tex/context/base/mkiv/l-md5.lua
@@ -0,0 +1,107 @@
+if not modules then modules = { } end modules ['l-md5'] = {
+    version   = 1.001,
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+-- This also provides file checksums and checkers.
+
+if not md5 then
+    md5 = optionalrequire("md5")
+end
+
+if not md5 then
+    md5 = {
+        sum     = function(str) print("error: md5 is not loaded (sum     ignored)") return str end,
+        sumhexa = function(str) print("error: md5 is not loaded (sumhexa ignored)") return str end,
+    }
+end
+
+local md5, file = md5, file
+local gsub = string.gsub
+
+-- local gsub, format, byte = string.gsub, string.format, string.byte
+--
+-- local function convert(str,fmt)
+--     return (gsub(md5sum(str),".",function(chr) return format(fmt,byte(chr)) end))
+-- end
+--
+-- if not md5.HEX then function md5.HEX(str) return convert(str,"%02X") end end
+-- if not md5.hex then function md5.hex(str) return convert(str,"%02x") end end
+-- if not md5.dec then function md5.dec(str) return convert(str,"%03i") end end
+
+do
+
+    local patterns = lpeg and lpeg.patterns
+
+    if patterns then
+
+        local bytestoHEX = patterns.bytestoHEX
+        local bytestohex = patterns.bytestohex
+        local bytestodec = patterns.bytestodec
+
+        local lpegmatch = lpeg.match
+        local md5sum    = md5.sum
+
+        if not md5.HEX then function md5.HEX(str) if str then return lpegmatch(bytestoHEX,md5sum(str)) end end end
+        if not md5.hex then function md5.hex(str) if str then return lpegmatch(bytestohex,md5sum(str)) end end end
+        if not md5.dec then function md5.dec(str) if str then return lpegmatch(bytestodec,md5sum(str)) end end end
+
+    end
+
+end
+
+function file.needsupdating(oldname,newname,threshold) -- size modification access change
+    local oldtime = lfs.attributes(oldname,"modification")
+    if oldtime then
+        local newtime = lfs.attributes(newname,"modification")
+        if not newtime then
+            return true -- no new file, so no updating needed
+        elseif newtime >= oldtime then
+            return false -- new file definitely needs updating
+        elseif oldtime - newtime < (threshold or 1) then
+            return false -- new file is probably still okay
+        else
+            return true -- new file has to be updated
+        end
+    else
+        return false -- no old file, so no updating needed
+    end
+end
+
+file.needs_updating = file.needsupdating
+
+function file.syncmtimes(oldname,newname)
+    local oldtime = lfs.attributes(oldname,"modification")
+    if oldtime and lfs.isfile(newname) then
+        lfs.touch(newname,oldtime,oldtime)
+    end
+end
+
+function file.checksum(name)
+    if md5 then
+        local data = io.loaddata(name)
+        if data then
+            return md5.HEX(data)
+        end
+    end
+    return nil
+end
+
+function file.loadchecksum(name)
+    if md5 then
+        local data = io.loaddata(name .. ".md5")
+        return data and (gsub(data,"%s",""))
+    end
+    return nil
+end
+
+function file.savechecksum(name,checksum)
+    if not checksum then checksum = file.checksum(name) end
+    if checksum then
+        io.savedata(name .. ".md5",checksum)
+        return checksum
+    end
+    return nil
+end