+# ------------------------------------------------------------------------------
+have_lz4=no
+AC_ARG_ENABLE(lz4, AS_HELP_STRING([--enable-lz4], [Enable optional LZ4 support]))
+AS_IF([test "x$enable_lz4" == "xyes"], [
+ AC_CHECK_HEADERS(lz4.h,
+ [AC_DEFINE(HAVE_LZ4, 1, [Define in LZ4 is available]) have_lz4=yes],
+ [AC_MSG_ERROR([*** LZ4 support requested but headers not found])])
+])
+AM_CONDITIONAL(HAVE_LZ4, [test "$have_lz4" = "yes"])
+
+AM_CONDITIONAL(HAVE_COMPRESSION, [test "$have_xz" = "yes" -o "$have_lz4" = "yes"])
+