bin/autotest_utils.py

"""Convenience functions for use by tests or whomever.
"""

import os,os.path,shutil,urllib,sys,signal,commands,pickle
from error import *
import re

def grep(pattern, file):
	"""This is mainly to fix the return code inversion from grep"""
	return not system('grep "' + pattern + '" "' + file + '"')
	
	
def difflist(list1, list2):
	"""returns items in list2 that are not in list1"""
	diff = [];
	for x in list2:
		if x not in list1:
			diff.append(x)
	return diff


def cat_file_to_cmd(file, command):
	"""equivalent to 'cat file | command' but knows to use zcat or bzcat if appropriate"""
	if not os.path.isfile(file):
		raise NameError, 'invalid file %s to cat to command %s' % file, command
	if file.endswith('.bz2'):
		system('bzcat ' + file + ' | ' + command)
	elif (file.endswith('.gz') or file.endswith('.tgz')):
		system('zcat ' + file + ' | ' + command)
	else:
		system('cat ' + file + ' | ' + command)


def extract_tarball_to_dir(tarball, dir):
	"""
	Extract a tarball to a specified directory name instead of whatever 
	the top level of a tarball is - useful for versioned directory names, etc
	"""
	if os.path.exists(dir):
		raise NameError, 'target %s already exists' % dir
	pwd = os.getcwd()
	os.chdir(os.path.dirname(os.path.abspath(dir)))
	newdir = extract_tarball(tarball)
	os.rename(newdir, dir)
	os.chdir(pwd)


def extract_tarball(tarball):
	"""Returns the first found newly created directory by the tarball extraction"""
	oldlist = os.listdir('.')
	cat_file_to_cmd(tarball, 'tar xf -')
	newlist = os.listdir('.')
	newfiles = difflist(oldlist, newlist)   # what is new dir ?
	new_dir = None
	for newfile in newfiles:
		if (os.path.isdir(newfile)):
			return newfile
	raise NameError, "extracting tarball produced no dir"


def update_version(srcdir, new_version, install):
	"""Make sure srcdir is version new_version

	If not, delete it and install() the new version
	"""
	versionfile = srcdir + '/.version'
	if os.path.exists(srcdir):
		if os.path.exists(versionfile):
			old_version = pickle.load(open(versionfile, 'r'))
			if (old_version != new_version):
				system('rm -rf ' + srcdir)
		else:
			system('rm -rf ' + srcdir)
	if not os.path.exists(srcdir):
		install()
		if os.path.exists(srcdir):
			pickle.dump(new_version, open(versionfile, 'w'))
                

def is_url(path):
	"""true if path is a url
	"""
	# should cope with other url types here, but we only handle http and ftp
	if (path.startswith('http://')) or (path.startswith('ftp://')):
		return 1
	return 0


def get_file(src, dest):
	"""get a file, either from url or local"""
	if (src == dest):      # no-op here allows clean overrides in tests
		return
	if (is_url(src)):
		print 'PWD: ' + os.getcwd()
		print 'Fetching \n\t', src, '\n\t->', dest
		try:
			urllib.urlretrieve(src, dest)
		except IOError:
			sys.stderr.write("Unable to retrieve %s (to %s)\n" % (src, dest))
			sys.exit(1)
		return dest
	shutil.copyfile(src, dest)
	return dest


def unmap_url(srcdir, src, destdir = '.'):
	if is_url(src):
		dest = destdir + '/' + os.path.basename(src)
		get_file(src, dest)
		return dest
	else:
		return srcdir + '/' + src


def basename(path):
	i = path.rfind('/');
	return path[i+1:]


def force_copy(src, dest):
	"""Replace dest with a new copy of src, even if it exists"""
	if os.path.isfile(dest):
		os.remove(dest)
	return shutil.copyfile(src, dest)


def file_contains_pattern(file, pattern):
	"""Return true if file contains the specified egrep pattern"""
	if not os.path.isfile(file):
		raise NameError, 'file %s does not exist' % file
	return not system('egrep -q ' + pattern + ' ' + file, ignorestatus = 1)


def list_grep(list, pattern):
	"""True if any item in list matches the specified pattern."""
	compiled = re.compile(pattern)
	for line in list:
		match = compiled.search(line)
		if (match):
			return 1
	return 0


def get_vmlinux():
	"""Return the full path to vmlinux

	Ahem. This is crap. Pray harder. Bad Martin.
	"""
	vmlinux = '/boot/vmlinux'
	if not os.path.isfile(vmlinux):
		raise NameError, 'Cannot find vmlinux'
	return vmlinux


def get_systemmap():
	"""Return the full path to System.map

	Ahem. This is crap. Pray harder. Bad Martin.
	"""
	map = '/boot/System.map'
	if not os.path.isfile(map):
		raise NameError, 'Cannot find System.map'
	return map


def get_modules_dir():
	"""Return the modules dir for the running kernel version"""
	kernel_version = system_output('uname -r')
	return '/lib/modules/%s/kernel' % kernel_version


def get_cpu_arch():
	"""Work out which CPU architecture we're running on"""
	f = open('/proc/cpuinfo', 'r')
	cpuinfo = f.readlines()
	f.close()
	if list_grep(cpuinfo, '^cpu.*(RS64|POWER3|Broadband Engine)'):
		return 'power'
	elif list_grep(cpuinfo, '^cpu.*POWER4'):
		return 'power4'
	elif list_grep(cpuinfo, '^cpu.*POWER5'):
		return 'power5'
	elif list_grep(cpuinfo, '^cpu.*POWER6'):
		return 'power6'
	elif list_grep(cpuinfo, '^cpu.*PPC970'):
		return 'power970'
	elif list_grep(cpuinfo, 'Opteron'):
		return 'x86_64'
	elif list_grep(cpuinfo, 'GenuineIntel') and list_grep(cpuinfo, '48 bits virtual'):
		return 'x86_64'
	else:
		return 'i386'


def get_kernel_arch():
	"""Work out the current kernel architecture (as a kernel arch)"""
	arch = os.popen('uname -m').read().rstrip()
	if ((arch == 'i586') or (arch == 'i686')):
		return 'i386'
	else:
		return arch


def kernelexpand(kernel):
	# if not (kernel.startswith('http://') or kernel.startswith('ftp://') or os.path.isfile(kernel)):
	if kernel.find('/'):
		w, r = os.popen2('./kernelexpand ' + kernel)

		kernel = r.readline().strip()
		r.close()
		w.close()
	return kernel


def count_cpus():
	"""number of CPUs in the local machine according to /proc/cpuinfo"""
	f = file('/proc/cpuinfo', 'r')
	cpus = 0
	for line in f.readlines():
		if line.startswith('processor'):
			cpus += 1
	return cpus

def system(cmd, ignorestatus = 0):
	"""os.system replacement

	We have our own definition of system here, as the stock os.system doesn't
	correctly handle sigpipe 
	(ie things like "yes | head" will hang because yes doesn't get the SIGPIPE).
 
	Also the stock os.system didn't raise errors based on exit status, this 
	version does unless you explicitly specify ignorestatus=1
	"""
	signal.signal(signal.SIGPIPE, signal.SIG_DFL)
	try:
		status = os.system(cmd)
	finally:
		signal.signal(signal.SIGPIPE, signal.SIG_IGN)

	if ((status != 0) and not ignorestatus):
		raise CmdError(cmd, status)
	return status


def system_output(command, ignorestatus = 0):
	"""Run command and return its output

	ignorestatus
		whether to raise a CmdError if command has a nonzero exit status
	"""
	(result, data) = commands.getstatusoutput(command)
	if ((result != 0) and not ignorestatus):
		raise CmdError, 'command failed: ' + command
	return data


def where_art_thy_filehandles():
	"""Dump the current list of filehandles"""
	os.system("ls -l /proc/%d/fd >> /dev/tty" % os.getpid())


def print_to_tty(string):
	"""Output string straight to the tty"""
	os.system("echo " + string + " >> /dev/tty")


def dump_object(object):
	"""Dump an object's attributes and methods

	kind of like dir()
	"""
	for item in object.__dict__.iteritems():
		print item
		try:
			(key,value) = item
			dump_object(value)
		except:
			continue


def environ(env_key):
	"""return the requested environment variable, or '' if unset"""
	if (os.environ.has_key(env_key)):
		return os.environ(env_key)
	else:
		return ''


def prepend_path(newpath, oldpath):
	"""prepend newpath to oldpath"""
	if (oldpath):
		return newpath + ':' + oldpath
	else:
		return newpath


def append_path(oldpath, newpath):
	"""append newpath to oldpath"""
	if (oldpath):
		return oldpath + ':' + newpath
	else:
		return newpath


class fd_stack:
	"""a stack of fd redirects

	Redirects cause existing fd's to be pushed on the stack; restore()
	causes the current set of redirects to be popped, restoring the previous
	filehandle destinations.

	Note that we need to redirect both the sys.stdout type descriptor
	(which print, etc use) and the low level OS numbered descriptor
	which os.system() etc use.
	"""

	def __init__(self, fd, filehandle):
		self.fd = fd				# eg 1
		self.filehandle = filehandle		# eg sys.stdout
		self.stack = [(fd, filehandle)]


	def redirect(self, filename):
		"""Redirect output to the specified file

		Overwrites the previous contents, if any.	
		"""
		fdcopy = os.dup(self.fd)
		self.stack.append( (fdcopy, self.filehandle) )
		# self.filehandle = file(filename, 'w')
		if (os.path.isfile(filename)):
			newfd = os.open(filename, os.O_WRONLY)
		else:
			newfd = os.open(filename, os.O_WRONLY | os.O_CREAT)
		os.dup2(newfd, self.fd)
		os.close(newfd)
		self.filehandle = os.fdopen(self.fd, 'w')


	def tee_redirect(self, filename):
		"""Tee output to the specified file

		Overwrites the previous contents, if any.	
		"""
		print_to_tty("tee_redirect to " + filename)
		where_art_thy_filehandles()
		fdcopy = os.dup(self.fd)
		self.stack.append( (fdcopy, self.filehandle) )
		r, w = os.pipe()
		pid = os.fork()
		if pid:			# parent
			os.close(r)
			os.dup2(w, self.fd)
			os.close(w)
		else:			# child
			os.close(w)
			os.dup2(r, 0)
			os.dup2(2, 1)
			os.execlp('tee', 'tee', filename)
		self.filehandle = os.fdopen(self.fd, 'w')
		where_art_thy_filehandles()
		print_to_tty("done tee_redirect to " + filename)

	
	def restore(self):
		"""unredirect one level"""
		# print_to_tty("ENTERING RESTORE %d" % self.fd)
		# where_art_thy_filehandles()
		(old_fd, old_filehandle) = self.stack.pop()
		# print_to_tty("old_fd %d" % old_fd)
		# print_to_tty("self.fd %d" % self.fd)
		self.filehandle.close()   # seems to close old_fd as well.
		# where_art_thy_filehandles()
		os.dup2(old_fd, self.fd)
		# print_to_tty("CLOSING FD %d" % old_fd)
		os.close(old_fd)
		# where_art_thy_filehandles()
		self.filehandle = old_filehandle
		# where_art_thy_filehandles()
		# print_to_tty("EXIT RESTORE %d" % self.fd)