text: #!/usr/bin/env python
  # encoding: utf-8
  # Thomas Nagy, 2005-2010 (ita)
  
  """
  Node: filesystem structure, contains lists of nodes
  
  #. Each file/folder is represented by exactly one node.
  
  #. Some potential class properties are stored on :py:class:`waflib.Build.BuildContext` : nodes to depend on, etc.
     Unused class members can increase the `.wafpickle` file size sensibly.
  
  #. Node objects should never be created directly, use
     the methods :py:func:`Node.make_node` or :py:func:`Node.find_node`
  
  #. The methods :py:func:`Node.find_resource`, :py:func:`Node.find_dir` :py:func:`Node.find_or_declare` should be
     used when a build context is present
  
  #. Each instance of :py:class:`waflib.Context.Context` has a unique :py:class:`Node` subclass.
     (:py:class:`waflib.Node.Nod3`, see the :py:class:`waflib.Context.Context` initializer). A reference to the context owning a node is held as self.ctx
  """
  
  import os, re, sys, shutil
  from waflib import Utils, Errors
  
  exclude_regs = '''
  **/*~
  **/#*#
  **/.#*
  **/%*%
  **/._*
  **/CVS
  **/CVS/**
  **/.cvsignore
  **/SCCS
  **/SCCS/**
  **/vssver.scc
  **/.svn
  **/.svn/**
  **/BitKeeper
  **/.git
  **/.git/**
  **/.gitignore
  **/.bzr
  **/.bzrignore
  **/.bzr/**
  **/.hg
  **/.hg/**
  **/_MTN
  **/_MTN/**
  **/.arch-ids
  **/{arch}
  **/_darcs
  **/_darcs/**
  **/.intlcache
  **/.DS_Store'''
  """
  Ant patterns for files and folders to exclude while doing the
  recursive traversal in :py:meth:`waflib.Node.Node.ant_glob`
  """
  
  def split_path(path):
  	"""
  	Split a path by os.sep (This is not os.path.split)
  
  	:param path: path to split
  	:type path: string
  	:rtype: list of string
  	:return: the path, split
  	"""
  	return path.split('/')
  
  def split_path_cygwin(path):
  	if path.startswith('//'):
  		ret = path.split('/')[2:]
  		ret[0] = '/' + ret[0]
  		return ret
  	return path.split('/')
  
  re_sp = re.compile('[/\\\\]')
  def split_path_win32(path):
  	if path.startswith('\\\\'):
  		ret = re.split(re_sp, path)[2:]
  		ret[0] = '\\' + ret[0]
  		return ret
  	return re.split(re_sp, path)
  
  if sys.platform == 'cygwin':
  	split_path = split_path_cygwin
  elif Utils.is_win32:
  	split_path = split_path_win32
  
  class Node(object):
  	"""
  	This class is organized in two parts
  
  	* The basic methods meant for filesystem access (compute paths, create folders, etc)
  	* The methods bound to a :py:class:`waflib.Build.BuildContext` (require ``bld.srcnode`` and ``bld.bldnode``)
  
  	The Node objects are not thread safe in any way.
  	"""
  
  	__slots__ = ('name', 'sig', 'children', 'parent', 'cache_abspath', 'cache_isdir', 'cache_sig')
  	def __init__(self, name, parent):
  		self.name = name
  		self.parent = parent
  
  		if parent:
  			if name in parent.children:
  				raise Errors.WafError('node %s exists in the parent files %r already' % (name, parent))
  			parent.children[name] = self
  
  	def __setstate__(self, data):
  		"Deserializes from data"
  		self.name = data[0]
  		self.parent = data[1]
  		if data[2] is not None:
  			self.children = data[2]
  		if data[3] is not None:
  			self.sig = data[3]
  
  	def __getstate__(self):
  		"Serialize the node info"
  		return (self.name, self.parent, getattr(self, 'children', None), getattr(self, 'sig', None))
  
  	def __str__(self):
  		"String representation (name), for debugging purposes"
  		return self.name
  
  	def __repr__(self):
  		"String representation (abspath), for debugging purposes"
  		return self.abspath()
  
  	def __hash__(self):
  		"Node hash, used for storage in dicts. This hash is not persistent."
  		return id(self)
  
  	def __eq__(self, node):
  		"Node comparison, based on the IDs"
  		return id(self) == id(node)
  
  	def __copy__(self):
  		"Implemented to prevent nodes from being copied (raises an exception)"
  		raise Errors.WafError('nodes are not supposed to be copied')
  
  	def read(self, flags='r', encoding='ISO8859-1'):
  		"""
  		Return the contents of the file represented by this node::
  
  			def build(bld):
  				bld.path.find_node('wscript').read()
  
  		:type  fname: string
  		:param fname: Path to file
  		:type  m: string
  		:param m: Open mode
  		:rtype: string
  		:return: File contents
  		"""
  		return Utils.readf(self.abspath(), flags, encoding)
  
  	def write(self, data, flags='w', encoding='ISO8859-1'):
  		"""
  		Write some text to the physical file represented by this node::
  
  			def build(bld):
  				bld.path.make_node('foo.txt').write('Hello, world!')
  
  		:type  data: string
  		:param data: data to write
  		:type  flags: string
  		:param flags: Write mode
  		"""
  		Utils.writef(self.abspath(), data, flags, encoding)
  
  	def chmod(self, val):
  		"""
  		Change file/dir permissions::
  
  			def build(bld):
  				bld.path.chmod(493) # 0755
  		"""
  		os.chmod(self.abspath(), val)
  
  	def delete(self):
  		"""Delete the file/folders, and remove this node from the tree. It becomes invalid after that"""
  		try:
  			if hasattr(self, 'children'):
  				shutil.rmtree(self.abspath())
  			else:
  				os.remove(self.abspath())
  		except OSError:
  			pass
  		self.evict()
  
  	def evict(self):
  		"""Internal - called when a node is removed"""
  		del self.parent.children[self.name]
  
  	def suffix(self):
  		"""Return the file extension"""
  		k = max(0, self.name.rfind('.'))
  		return self.name[k:]
  
  	def height(self):
  		"""Depth in the folder hierarchy from the filesystem root or from all the file drives"""
  		d = self
  		val = -1
  		while d:
  			d = d.parent
  			val += 1
  		return val
  
  	def listdir(self):
  		"""List the folder contents"""
  		lst = Utils.listdir(self.abspath())
  		lst.sort()
  		return lst
  
  	def mkdir(self):
  		"""
  		Create a folder represented by this node, creating intermediate nodes as needed
  		An exception will be raised only when the folder cannot possibly exist there
  		"""
  		if getattr(self, 'cache_isdir', None):
  			return
  
  		try:
  			self.parent.mkdir()
  		except OSError:
  			pass
  
  		if self.name:
  			try:
  				os.makedirs(self.abspath())
  			except OSError:
  				pass
  
  			if not os.path.isdir(self.abspath()):
  				raise Errors.WafError('Could not create the directory %s' % self.abspath())
  
  			try:
  				self.children
  			except AttributeError:
  				self.children = {}
  
  		self.cache_isdir = True
  
  	def find_node(self, lst):
  		"""
  		Find a node on the file system (files or folders), create intermediate nodes as needed
  
  		:param lst: path
  		:type lst: string or list of string
  		"""
  
  		if isinstance(lst, str):
  			lst = [x for x in split_path(lst) if x and x != '.']
  
  		cur = self
  		for x in lst:
  			if x == '..':
  				cur = cur.parent or cur
  				continue
  
  			try:
  				ch = cur.children
  			except AttributeError:
  				cur.children = {}
  			else:
  				try:
  					cur = cur.children[x]
  					continue
  				except KeyError:
  					pass
  
  			# optimistic: create the node first then look if it was correct to do so
  			cur = self.__class__(x, cur)
  			try:
  				os.stat(cur.abspath())
  			except OSError:
  				cur.evict()
  				return None
  
  		ret = cur
  
  		try:
  			os.stat(ret.abspath())
  		except OSError:
  			ret.evict()
  			return None
  
  		try:
  			while not getattr(cur.parent, 'cache_isdir', None):
  				cur = cur.parent
  				cur.cache_isdir = True
  		except AttributeError:
  			pass
  
  		return ret
  
  	def make_node(self, lst):
  		"""
  		Find or create a node without looking on the filesystem
  
  		:param lst: path
  		:type lst: string or list of string
  		"""
  		if isinstance(lst, str):
  			lst = [x for x in split_path(lst) if x and x != '.']
  
  		cur = self
  		for x in lst:
  			if x == '..':
  				cur = cur.parent or cur
  				continue
  
  			if getattr(cur, 'children', {}):
  				if x in cur.children:
  					cur = cur.children[x]
  					continue
  			else:
  				cur.children = {}
  			cur = self.__class__(x, cur)
  		return cur
  
  	def search_node(self, lst):
  		"""
  		Search for a node without looking on the filesystem
  
  		:param lst: path
  		:type lst: string or list of string
  		"""
  		if isinstance(lst, str):
  			lst = [x for x in split_path(lst) if x and x != '.']
  
  		cur = self
  		for x in lst:
  			if x == '..':
  				cur = cur.parent or cur
  			else:
  				try:
  					cur = cur.children[x]
  				except (AttributeError, KeyError):
  					return None
  		return cur
  
  	def path_from(self, node):
  		"""
  		Path of this node seen from the other::
  
  			def build(bld):
  				n1 = bld.path.find_node('foo/bar/xyz.txt')
  				n2 = bld.path.find_node('foo/stuff/')
  				n1.path_from(n2) # '../bar/xyz.txt'
  
  		:param node: path to use as a reference
  		:type node: :py:class:`waflib.Node.Node`
  		"""
  
  		c1 = self
  		c2 = node
  
  		c1h = c1.height()
  		c2h = c2.height()
  
  		lst = []
  		up = 0
  
  		while c1h > c2h:
  			lst.append(c1.name)
  			c1 = c1.parent
  			c1h -= 1
  
  		while c2h > c1h:
  			up += 1
  			c2 = c2.parent
  			c2h -= 1
  
  		while id(c1) != id(c2):
  			lst.append(c1.name)
  			up += 1
  
  			c1 = c1.parent
  			c2 = c2.parent
  
  		for i in range(up):
  			lst.append('..')
  		lst.reverse()
  		return os.sep.join(lst) or '.'
  
  	def abspath(self):
  		"""
  		Absolute path. A cache is kept in the context as ``cache_node_abspath``
  		"""
  		try:
  			return self.cache_abspath
  		except AttributeError:
  			pass
  		# think twice before touching this (performance + complexity + correctness)
  
  		if os.sep == '/':
  			if not self.parent:
  				val = os.sep
  			elif not self.parent.name:
  				val = os.sep + self.name
  			else:
  				val = self.parent.abspath() + os.sep + self.name
  		else:
  			if not self.parent:
  				val = ''
  			elif not self.parent.name:
  				val = self.name + os.sep
  			else:
  				val = self.parent.abspath().rstrip(os.sep) + os.sep + self.name
  
  		self.cache_abspath = val
  		return val
  
  	def is_child_of(self, node):
  		"""
  		Does this node belong to the subtree node?::
  
  			def build(bld):
  				node = bld.path.find_node('wscript')
  				node.is_child_of(bld.path) # True
  
  		:param node: path to use as a reference
  		:type node: :py:class:`waflib.Node.Node`
  		"""
  		p = self
  		diff = self.height() - node.height()
  		while diff > 0:
  			diff -= 1
  			p = p.parent
  		return id(p) == id(node)
  
  	def ant_iter(self, accept=None, maxdepth=25, pats=[], dir=False, src=True, remove=True):
  		"""
  		Semi-private and recursive method used by ant_glob.
  
  		:param accept: function used for accepting/rejecting a node, returns the patterns that can be still accepted in recursion
  		:type accept: function
  		:param maxdepth: maximum depth in the filesystem (25)
  		:type maxdepth: int
  		:param pats: list of patterns to accept and list of patterns to exclude
  		:type pats: tuple
  		:param dir: return folders too (False by default)
  		:type dir: bool
  		:param src: return files (True by default)
  		:type src: bool
  		:param remove: remove files/folders that do not exist (True by default)
  		:type remove: bool
  		"""
  		dircont = self.listdir()
  		dircont.sort()
  
  		try:
  			lst = set(self.children.keys())
  		except AttributeError:
  			self.children = {}
  		else:
  			if remove:
  				for x in lst - set(dircont):
  					self.children[x].evict()
  
  		for name in dircont:
  			npats = accept(name, pats)
  			if npats and npats[0]:
  				accepted = [] in npats[0]
  
  				node = self.make_node([name])
  
  				isdir = os.path.isdir(node.abspath())
  				if accepted:
  					if isdir:
  						if dir:
  							yield node
  					else:
  						if src:
  							yield node
  
  				if getattr(node, 'cache_isdir', None) or isdir:
  					node.cache_isdir = True
  					if maxdepth:
  						for k in node.ant_iter(accept=accept, maxdepth=maxdepth - 1, pats=npats, dir=dir, src=src, remove=remove):
  							yield k
  		raise StopIteration
  
  	def ant_glob(self, *k, **kw):
  		"""
  		This method is used for finding files across folders. It behaves like ant patterns:
  
  		* ``**/*`` find all files recursively
  		* ``**/*.class`` find all files ending by .class
  		* ``..`` find files having two dot characters
  
  		For example::
  
  			def configure(cfg):
  				cfg.path.ant_glob('**/*.cpp') # find all .cpp files
  				cfg.root.ant_glob('etc/*.txt') # using the filesystem root can be slow
  				cfg.path.ant_glob('*.cpp', excl=['*.c'], src=True, dir=False)
  
  		For more information see http://ant.apache.org/manual/dirtasks.html
  
  		The nodes that correspond to files and folders that do not exist will be removed. To prevent this
  		behaviour, pass 'remove=False'
  
  		:param incl: ant patterns or list of patterns to include
  		:type incl: string or list of strings
  		:param excl: ant patterns or list of patterns to exclude
  		:type excl: string or list of strings
  		:param dir: return folders too (False by default)
  		:type dir: bool
  		:param src: return files (True by default)
  		:type src: bool
  		:param remove: remove files/folders that do not exist (True by default)
  		:type remove: bool
  		:param maxdepth: maximum depth of recursion
  		:type maxdepth: int
  		:param ignorecase: ignore case while matching (False by default)
  		:type ignorecase: bool
  		"""
  
  		src = kw.get('src', True)
  		dir = kw.get('dir', False)
  
  		excl = kw.get('excl', exclude_regs)
  		incl = k and k[0] or kw.get('incl', '**')
  		reflags = kw.get('ignorecase', 0) and re.I
  
  		def to_pat(s):
  			lst = Utils.to_list(s)
  			ret = []
  			for x in lst:
  				x = x.replace('\\', '/').replace('//', '/')
  				if x.endswith('/'):
  					x += '**'
  				lst2 = x.split('/')
  				accu = []
  				for k in lst2:
  					if k == '**':
  						accu.append(k)
  					else:
  						k = k.replace('.', '[.]').replace('*','.*').replace('?', '.').replace('+', '\\+')
  						k = '^%s$' % k
  						try:
  							#print "pattern", k
  							accu.append(re.compile(k, flags=reflags))
  						except Exception as e:
  							raise Errors.WafError("Invalid pattern: %s" % k, e)
  				ret.append(accu)
  			return ret
  
  		def filtre(name, nn):
  			ret = []
  			for lst in nn:
  				if not lst:
  					pass
  				elif lst[0] == '**':
  					ret.append(lst)
  					if len(lst) > 1:
  						if lst[1].match(name):
  							ret.append(lst[2:])
  					else:
  						ret.append([])
  				elif lst[0].match(name):
  					ret.append(lst[1:])
  			return ret
  
  		def accept(name, pats):
  			nacc = filtre(name, pats[0])
  			nrej = filtre(name, pats[1])
  			if [] in nrej:
  				nacc = []
  			return [nacc, nrej]
  
  		ret = [x for x in self.ant_iter(accept=accept, pats=[to_pat(incl), to_pat(excl)], maxdepth=kw.get('maxdepth', 25), dir=dir, src=src, remove=kw.get('remove', True))]
  		if kw.get('flat', False):
  			return ' '.join([x.path_from(self) for x in ret])
  
  		return ret
  
  	# --------------------------------------------------------------------------------
  	# the following methods require the source/build folders (bld.srcnode/bld.bldnode)
  	# using a subclass is a possibility, but is that really necessary?
  	# --------------------------------------------------------------------------------
  
  	def is_src(self):
  		"""
  		True if the node is below the source directory
  		note: !is_src does not imply is_bld()
  
  		:rtype: bool
  		"""
  		cur = self
  		x = id(self.ctx.srcnode)
  		y = id(self.ctx.bldnode)
  		while cur.parent:
  			if id(cur) == y:
  				return False
  			if id(cur) == x:
  				return True
  			cur = cur.parent
  		return False
  
  	def is_bld(self):
  		"""
  		True if the node is below the build directory
  		note: !is_bld does not imply is_src
  
  		:rtype: bool
  		"""
  		cur = self
  		y = id(self.ctx.bldnode)
  		while cur.parent:
  			if id(cur) == y:
  				return True
  			cur = cur.parent
  		return False
  
  	def get_src(self):
  		"""
  		Return the equivalent src node (or self if not possible)
  
  		:rtype: :py:class:`waflib.Node.Node`
  		"""
  		cur = self
  		x = id(self.ctx.srcnode)
  		y = id(self.ctx.bldnode)
  		lst = []
  		while cur.parent:
  			if id(cur) == y:
  				lst.reverse()
  				return self.ctx.srcnode.make_node(lst)
  			if id(cur) == x:
  				return self
  			lst.append(cur.name)
  			cur = cur.parent
  		return self
  
  	def get_bld(self):
  		"""
  		Return the equivalent bld node (or self if not possible)
  
  		:rtype: :py:class:`waflib.Node.Node`
  		"""
  		cur = self
  		x = id(self.ctx.srcnode)
  		y = id(self.ctx.bldnode)
  		lst = []
  		while cur.parent:
  			if id(cur) == y:
  				return self
  			if id(cur) == x:
  				lst.reverse()
  				return self.ctx.bldnode.make_node(lst)
  			lst.append(cur.name)
  			cur = cur.parent
  		# the file is external to the current project, make a fake root in the current build directory
  		lst.reverse()
  		if lst and Utils.is_win32 and len(lst[0]) == 2 and lst[0].endswith(':'):
  			lst[0] = lst[0][0]
  		return self.ctx.bldnode.make_node(['__root__'] + lst)
  
  	def find_resource(self, lst):
  		"""
  		Try to find a declared build node or a source file
  
  		:param lst: path
  		:type lst: string or list of string
  		"""
  		if isinstance(lst, str):
  			lst = [x for x in split_path(lst) if x and x != '.']
  
  		node = self.get_bld().search_node(lst)
  		if not node:
  			self = self.get_src()
  			node = self.find_node(lst)
  		if node:
  			if os.path.isdir(node.abspath()):
  				return None
  		return node
  
  	def find_or_declare(self, lst):
  		"""
  		if 'self' is in build directory, try to return an existing node
  		if no node is found, go to the source directory
  		try to find an existing node in the source directory
  		if no node is found, create it in the build directory
  
  		:param lst: path
  		:type lst: string or list of string
  		"""
  		if isinstance(lst, str):
  			lst = [x for x in split_path(lst) if x and x != '.']
  
  		node = self.get_bld().search_node(lst)
  		if node:
  			if not os.path.isfile(node.abspath()):
  				node.sig = None
  				node.parent.mkdir()
  			return node
  		self = self.get_src()
  		node = self.find_node(lst)
  		if node:
  			if not os.path.isfile(node.abspath()):
  				node.sig = None
  				node.parent.mkdir()
  			return node
  		node = self.get_bld().make_node(lst)
  		node.parent.mkdir()
  		return node
  
  	def find_dir(self, lst):
  		"""
  		Search for a folder in the filesystem
  
  		:param lst: path
  		:type lst: string or list of string
  		"""
  		if isinstance(lst, str):
  			lst = [x for x in split_path(lst) if x and x != '.']
  
  		node = self.find_node(lst)
  		try:
  			if not os.path.isdir(node.abspath()):
  				return None
  		except (OSError, AttributeError):
  			# the node might be None, and raise an AttributeError
  			return None
  		return node
  
  	# helpers for building things
  	def change_ext(self, ext, ext_in=None):
  		"""
  		:return: A build node of the same path, but with a different extension
  		:rtype: :py:class:`waflib.Node.Node`
  		"""
  		name = self.name
  		if ext_in is None:
  			k = name.rfind('.')
  			if k >= 0:
  				name = name[:k] + ext
  			else:
  				name = name + ext
  		else:
  			name = name[:- len(ext_in)] + ext
  
  		return self.parent.find_or_declare([name])
  
  	def nice_path(self, env=None):
  		"""
  		Return the path seen from the launch directory.
  		Can be used for opening files easily (copy-paste in the console).
  		"""
  		return self.path_from(self.ctx.launch_node())
  
  	def bldpath(self):
  		"Path seen from the build directory default/src/foo.cpp"
  		return self.path_from(self.ctx.bldnode)
  
  	def srcpath(self):
  		"Path seen from the source directory ../src/foo.cpp"
  		return self.path_from(self.ctx.srcnode)
  
  	def relpath(self):
  		"If a file in the build directory, bldpath, else srcpath"
  		cur = self
  		x = id(self.ctx.bldnode)
  		while cur.parent:
  			if id(cur) == x:
  				return self.bldpath()
  			cur = cur.parent
  		return self.srcpath()
  
  	def bld_dir(self):
  		"Build path without the file name"
  		return self.parent.bldpath()
  
  	def bld_base(self):
  		"Build path without the extension: src/dir/foo(.cpp)"
  		s = os.path.splitext(self.name)[0]
  		return self.bld_dir() + os.sep + s
  
  	def get_bld_sig(self):
  		"""
  		Node signature, assuming the file is in the build directory
  		"""
  		try:
  			return self.cache_sig
  		except AttributeError:
  			pass
  
  		if not self.is_bld() or self.ctx.bldnode is self.ctx.srcnode:
  			self.sig = Utils.h_file(self.abspath())
  		self.cache_sig = ret = self.sig
  		return ret
  
  
  	# TODO Waf 1.8
  	search = search_node
  
  pickle_lock = Utils.threading.Lock()
  """Lock mandatory for thread-safe node serialization"""
  
  class Nod3(Node):
  	"""Mandatory subclass for thread-safe node serialization"""
  	pass # do not remove
  
  
  