1 files changed, 123 insertions, 0 deletions
diff --git a/include/dnsjit/filter/timing.lua b/include/dnsjit/filter/timing.lua
new file mode 100644
index 0000000..cab9574
--- /dev/null
+++ b/include/dnsjit/filter/timing.lua
@@ -0,0 +1,123 @@
+-- Copyright (c) 2018-2021, OARC, Inc.
+-- All rights reserved.
+--
+-- This file is part of dnsjit.
+--
+-- dnsjit is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- dnsjit is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with dnsjit.  If not, see <http://www.gnu.org/licenses/>.
+
+-- dnsjit.filter.timing
+-- Filter to pass objects to the next receiver based on timing between packets
+--   local filter = require("dnsjit.filter.timing").new()
+--   ...
+--   filter:receiver(...)
+--
+-- Filter to manipulate processing so it simulates the actual timing when
+-- packets arrived or to delay processing.
+module(...,package.seeall)
+
+require("dnsjit.filter.timing_h")
+local ffi = require("ffi")
+local C = ffi.C
+
+local Timing = {}
+
+-- Create a new Timing filter.
+function Timing.new()
+    local self = {
+        _receiver = nil,
+        obj = C.filter_timing_new(),
+    }
+    ffi.gc(self.obj, C.filter_timing_free)
+    return setmetatable(self, { __index = Timing })
+end
+
+-- Return the Log object to control logging of this instance or module.
+function Timing:log()
+    if self == nil then
+        return C.filter_timing_log()
+    end
+    return self.obj._log
+end
+
+-- Set the timing mode to keep the timing between packets.
+function Timing:keep()
+    self.obj.mode = "TIMING_MODE_KEEP"
+end
+
+-- Set the timing mode to increase the timing between packets by the given
+-- number of nanoseconds.
+function Timing:increase(ns)
+    self.obj.mode = "TIMING_MODE_INCREASE"
+    self.obj.inc = ns
+end
+
+-- Set the timing mode to reduce the timing between packets by the given
+-- number of nanoseconds.
+function Timing:reduce(ns)
+    self.obj.mode = "TIMING_MODE_REDUCE"
+    self.obj.red = ns
+end
+
+-- Set the timing mode to multiply the timing between packets by the given
+-- factor (float/double).
+function Timing:multiply(factor)
+    self.obj.mode = "TIMING_MODE_MULTIPLY"
+    self.obj.mul = factor
+end
+
+-- Set the timing mode to a fixed number of nanoseconds between packets.
+function Timing:fixed(ns)
+    self.obj.mode = "TIMING_MODE_FIXED"
+    self.obj.fixed = ns
+end
+
+-- Set the timing mode to simulate the timing of packets in realtime.
+-- Packets are processed in batches of given size (default 128) before
+-- adjusting time. Aborts if real time drifts ahead more than given
+-- number of seconds (default 1.0s).
+function Timing:realtime(drift, batch_size)
+    self.obj.mode = "TIMING_MODE_REALTIME"
+    if drift == nil then
+        drift = 1
+    end
+    if batch_size == nil then
+        batch_size = 128
+    end
+    self.obj.rt_batch = batch_size
+    self.obj.rt_drift = math.floor(drift * 1000000000)
+end
+
+-- Return the C functions and context for receiving objects.
+function Timing:receive()
+    return C.filter_timing_receiver(), self.obj
+end
+
+-- Set the receiver to pass objects to.
+function Timing:receiver(o)
+    self.obj.recv, self.obj.ctx = o:receive()
+    self._receiver = o
+end
+
+-- Return the C functions and context for producing objects.
+function Timing:produce()
+    return C.filter_timing_producer(self.obj), self.obj
+end
+
+-- Set the producer to get objects from.
+function Timing:producer(o)
+    self.obj.prod, self.obj.prod_ctx = o:produce()
+    self._producer = o
+end
+
+return Timing