ffi/hashoir: new module for hashing memory

Using xxHash's 64bits variant of XXH3.

Author: benoit-pierre

ffi/hashoir.lua

@@ -0,0 +1,41 @@
+local ffi = require("ffi")
+require "ffi/xxhash_h"
+
+local xxhash = ffi.loadlib("xxhash", "0")
+
+local Hashoir = {}
+
+function Hashoir:new()
+    local o = {}
+    setmetatable(o, self)
+    self.__index = self
+    o.hs = ffi.gc(xxhash.XXH3_createState(), xxhash.XXH3_freeState)
+    assert(o.hs ~= nil)
+    xxhash.XXH3_64bits_reset(o.hs)
+    return o
+end
+
+function Hashoir:free()
+    xxhash.XXH3_freeState(ffi.gc(self.hs, nil))
+    self.hs = nil
+end
+
+function Hashoir:reset()
+    xxhash.XXH3_64bits_reset(self.hs)
+    return self
+end
+
+function Hashoir:update(ptr, len)
+    xxhash.XXH3_64bits_update(self.hs, ptr, len)
+    return self
+end
+
+function Hashoir:digest()
+    return xxhash.XXH3_64bits_digest(self.hs)
+end
+
+function Hashoir:hexdigest()
+    return string.format("%016x", xxhash.XXH3_64bits_digest(self.hs))
+end
+
+return Hashoir