--[[
Copyright (C) 2014 Brendan Gregg.

This file is part of sysdig.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

--]]

--[[
fileslower.lua - trace file I/O slower than a given threshold.

USAGE: sysdig -c fileslower min_ms
   eg,

   sysdig -c fileslower 10					# show file I/O slower than 10 ms
   sysdig -c fileslower 0					# show all file I/O
   sysdig -c fileslower "1 disable_colors"	# show file I/O slower than 1 ms. w/ no colors
   sysdig -pc -c fileslower 0				# show all file I/O and container output

By default this skips file I/O to /dev. Modify the skip_dev variable in this
chisel to change this behavior.

Note: The file I/O traced is those matched by the sysdig filter:
"evt.is_io=true and fd.type=file".

--]]

-- Chisel description
description = "Trace file I/O slower than a threshold, or all file I/O. This chisel is compatible with containers using the sysdig -pc or -pcontainer argument, otherwise no container information will be shown. (Blue represents a process running within a container, and Green represents a host process)";
short_description = "Trace slow file I/O";
category = "Performance";

skip_dev = true	  -- skip /dev/... files

-- Chisel argument list
args =
{
	{
		name = "min_ms",
		description = "Minimum millisecond threshold for showing file I/O",
		argtype = "int",
		optional = false
	},
	{
		name = "disable_color",
		description = "Set to 'disable_colors' if you want to disable color output",
		argtype = "string",
		optional = true
	},
}

require "common"
terminal = require "ansiterminal"
terminal.enable_color(true)

-- Argument notification callback
function on_set_arg(name, val)

	if name == "disable_color" and val == "disable_color" then
	   terminal.enable_color(false)
	elseif name == "min_ms" then
	   min_ms = parse_numeric_input(val, name)
	end

	return true
end

-- Initialization callback
function on_init()
	-- set the following fields on_event()
	etype = chisel.request_field("evt.type")
	dir = chisel.request_field("evt.dir")
	datetime = chisel.request_field("evt.datetime")
	fname = chisel.request_field("fd.name")
	pname = chisel.request_field("proc.name")
	latency = chisel.request_field("evt.latency")
	fcontainername = chisel.request_field("container.name")
	fcontainerid = chisel.request_field("container.id")

	-- The -pc or -pcontainer options was supplied on the cmd line
	print_container = sysdig.is_print_container_data()

	-- filter for file I/O
	chisel.set_filter("evt.is_io=true and fd.type=file")

	-- The -pc or -pcontainer options was supplied on the cmd line
	if print_container then
		print(string.format("%-23.23s %-20.20s %-20.20s %-12.12s %-8s %-12s %s",
							"evt.datetime",
							"container.id",
							"container.name",
							"proc.name",
							"evt.type",
							"LATENCY(ms)",
							"fd.name"))
		print(string.format("%-23.23s %-20.20s %-20.20s %-12.12s %-8s %-12s %s",
							"-----------------------",
							"------------------------------",
							"------------------------------",
							"------------",
							"--------",
							"------------",
							"-----------------------------------------"))
	else
		print(string.format("%-23.23s %-12.12s %-8s %-12s %s",
							"evt.datetime",
							"proc.name",
							"evt.type",
							"LATENCY(ms)",
							"fd.name"))
		print(string.format("%-23.23s %-12.12s %-8s %-12s %s",
							"-----------------------",
							"------------",
							"--------",
							"------------",
							"-----------------------------------------"))
	end

	return true
end

-- Event callback
function on_event()

	local color = terminal.green

	lat = evt.field(latency) / 1000000
	fn = evt.field(fname)

	if evt.field(dir) == "<" and lat > min_ms then

		 -- filter /dev files if needed
		 if skip_dev == false or string.sub(fn, 0, 5) ~= "/dev/" then

			 -- If this is a container modify the output color
			 if evt.field(fcontainername) ~= "host" then
				 color = terminal.blue
			 end

			 -- The -pc or -pcontainer options was supplied on the cmd line
			 if print_container then
				 print(color .. string.format("%-23.23s %-20.20s %-20.20s %-12.12s %-8s %12d %s",
												evt.field(datetime),
												evt.field(fcontainerid),
												evt.field(fcontainername),
												evt.field(pname),
												evt.field(etype),
												lat,
												fn ))
			 else
				 print(color .. string.format("%-23.23s %-12.12s %-8s %12d %s",
												evt.field(datetime),
												evt.field(pname),
												evt.field(etype),
												lat,
												fn ))
			 end
		 end
	end

	return true
end