#! /usr/bin/env python

"""
You will need either bzip2 or gzip, and a local waf copy
(unset the variable WAFDIR if set)

Using more than 100000 tasks may eat your memory
"""

top = '.'
out = 'build'

TEMPLATE = """
#! /usr/bin/gnuplot -persist
# output file, compression type, input file
set terminal png
set output "%s"
set ylabel "Amount of files created"
set xlabel "File size in kB"
set title "Compressed tar file distribution (%s)"
plot '%s' using 1:2 with lines lt 3 title ""
"""

import random, bz2, os, threading
lock = threading.Lock()

def options(opt):
	opt.add_option('--num', action='store', type='int', default=200, help='amount of compressed files to create')

# values for storing the min and max
gzip  = [10000000, 0]
bzip2 = [10000000, 0]
xz    = [10000000, 0]

def try_compress(self):
	global mi, ma

	frompath = self.generator.frompath

	uid = id(threading.current_thread())
	filename = frompath.abspath() + os.sep + 'test%d.bin' % uid

	self.files = self.generator.files[:]
	random.shuffle(self.files)

	if self.generator.kind == 'bzip2':
		store = bzip2
		cmd = 'cjf'
		ext = 'bz2'
	elif self.generator.kind == 'xz':
		store = xz
		cmd = 'cJf'
		ext = 'xz'
	else:
		store = gzip
		cmd = 'czf'
		ext = 'gz'

	self.generator.bld.exec_command('tar %s  %s  %s' % (cmd, filename, ' '.join(self.files)), cwd=frompath.abspath())

	siz = os.stat(filename).st_size
	if siz == 0:
		return -1

	try:
		lock.acquire()
		self.outputs[0].write('%d\n' % siz, 'a')

		if siz < store[0]:
			store[0] = siz
			os.rename(filename, self.generator.bld.bldnode.abspath() + os.sep + 'min%d.tar.%s' % (siz, ext))
		elif siz > store[1]:
			store[1] = siz
			os.rename(filename, self.generator.bld.bldnode.abspath() + os.sep + 'max%d.tar.%s' % (siz, ext))
		else:
			os.unlink(filename)
	finally:
		lock.release()

def count_result(self):
	txt = self.inputs[0].read().strip()
	lst = txt.split()
	lst = [int(x) for x in lst if x]
	mi = min(lst)
	ma = max(lst)

	dc = {}
	for x in lst:
		try:
			dc[x] += 1
		except KeyError:
			dc[x] = 1

	nlst = ['%d %d' % (x, dc.get(x, 0)) for x in range(mi, ma+1)]
	self.outputs[0].write('\n'.join(nlst))

def write_template(self):
	t = self.generator.triplet
	self.outputs[0].write(TEMPLATE % (t[0].abspath(), t[1], t[2].abspath()))

def configure(conf):
	conf.find_program('gzip', mandatory=False)
	conf.find_program('bzip2', mandatory=False)
	if not conf.env.GZIP and not conf.env.BZIP2:
		conf.fatal('Either gzip or bzip2 is necessary for this')

	# xz is a gzip-like, lzma-based compression tool
	conf.find_program('xz', mandatory=False)

	conf.find_program('gnuplot', var='GNUPLOT')

def build(bld):
	wafdir_lst = bld.srcnode.ant_glob('.waf-1.6*', dir=True)
	if not wafdir_lst:
		bld.fatal('Missing local Waf directory')
	node = wafdir_lst[0]
	rels = [x.path_from(node) for x in node.ant_glob('**/*.py')]

	KINDS = []
	if bld.env.BZIP2:
		KINDS.append('bzip2')
	if bld.env.GZIP:
		KINDS.append('gzip')
	if bld.env.XZ:
		KINDS.append('xz')

	for kind in KINDS:
		p = bld.bldnode

		ini  = p.make_node('size_%s_1.txt' % kind)  # list of file sizes
		dist = p.make_node('size_%s_2.txt' % kind)  # distribution file (count the results)
		plot = p.make_node('size_%s_3.plot' % kind) # script file created for gnuplot
		png  = p.make_node('size_%s_4.png' % kind)  # picture created

		for x in range(bld.options.num):
			# the same target cannot have the signature of all the tasks that update it
			# so the tasks will be executed each time
			bld(rule=try_compress, target=ini, always=True, kind=kind, frompath=node, files=rels)

		# for the same reason, count_result will be executed each time
		bld(rule=count_result, target=dist, source=ini, always=True, update_outputs=True)
		bld(rule=write_template, target=plot, triplet=[png, kind, dist], always=True)
		bld(rule='${GNUPLOT} < ${SRC[1].abspath()}', target=png, source=[dist, plot])