add l-gzip

1 files changed, 54 insertions, 0 deletions

diff --git a/lualibs-gzip.lua b/lualibs-gzip.lua
new file mode 100644
index 0000000..5100e47
--- /dev/null
+++ b/lualibs-gzip.lua
@@ -0,0 +1,54 @@
+if not modules then modules = { } end modules ['l-gzip'] = {
+    version   = 1.001,
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+if not gzip then
+
+    -- no fallback yet
+
+    return
+
+end
+
+local suffix, suffixes = file.suffix, file.suffixes
+
+function gzip.load(filename)
+    local f = io.open(filename,"rb")
+    if not f then
+        -- invalid file
+    elseif suffix(filename) == "gz" then
+        f:close()
+        local g = gzip.open(filename,"rb")
+        if g then
+            local str = g:read("*all")
+            g:close()
+            return str
+        end
+    else
+        local str = f:read("*all")
+        f:close()
+        return str
+    end
+end
+
+function gzip.save(filename,data)
+    if suffix(filename) ~= "gz" then
+        filename = filename .. ".gz"
+    end
+    local f = io.open(filename,"wb")
+    if f then
+        local s = zlib.compress(data or "",9,nil,15+16)
+        f:write(s)
+        f:close()
+        return #s
+    end
+end
+
+function gzip.suffix(filename)
+    local suffix, extra = suffixes(filename)
+    local gzipped = extra == "gz"
+    return suffix, gzipped
+end