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"""list based, symlink aware fs listdir caching implementation"""
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import os,stat,weakref
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def norm_path(mypath):
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newpath = os.path.normpath(mypath)
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if len(mypath) > 1:
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if newpath[:2] == "//":
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newpath=newpath.replace("//","/")
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return newpath
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def abs_link(sym):
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# note this doesn't parse every single entry. that's up to you.
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l=os.readlink(sym)
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if l[0] != '/':
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l = os.path.dirname(sym)+"/"+l
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return norm_path(l)
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class node:
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"""class representing a directory"""
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__slots__=["dir_node_name","dir_node_ref","dirs","files","others","sdirs","sfiles","mtime"]
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# instances = 0
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def __init__(self):#,dirs=[],others=[],files=[],mtime=-1):
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self.dir_node_ref=[]
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self.dir_node_name=[]
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self.dirs=[]
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self.files=[]
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self.others=[]
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self.sdirs=[]
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self.sfiles=[]
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self.mtime=-1
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# def __del__(self):
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# print "del'ing a node"
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# del self.dir_node_n
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# del self.sdirs
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# del self.sfiles
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# del self.dirs
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# del self.files
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# del self.others
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# del self.mtime
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def get_node(self,nnode):
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"""retrieve directory node if exists"""
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try:
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x=self.dir_node_name.index(nnode)
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return self.dir_node_ref[x]
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except (ReferenceError,ValueError),e :
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# print "ref exception",e
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return None
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def add_node(self,nnode,ref_node=None,symlink=False):
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self.dir_node_name.append(nnode)
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if ref_node:
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if symlink:
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self.dir_node_ref.append(weakref.proxy(ref_node))
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else:
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self.dir_node_ref.append(ref_node)
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else:
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self.dir_node_ref.append(node())
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return self.dir_node_ref[-1]
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def del_node(self,nnode):
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try:
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x=self.dir_node_name.index(nnode)
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del self.dir_node_name[x]
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del self.dir_node_ref[x]
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except Exception,e:
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print "warning, dcache was asked to delete a non_existant node: lacks node %s" % nnode
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print "e=",e
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def rec_del_node(self):
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while len(self.dir_node_n):
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self.dir_node_name[0].rec_del_node()
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del self.dir_node_name[0][0]
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del self.dir_node_ref[0]
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class dcache:
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def __init__(self):
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self.cache=node()
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def _get_dir_ent(self, mypath,symlink=False):
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p=mypath.split("/")
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if not p[0]:
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p = p[1:]
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if not p[-1]:
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p = p[0:-1]
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fullpath=''
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c = self.cache
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if not len(p):
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return self.cache
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while len(p):
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fullpath += '/' + p[0]
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g=c.get_node(p[0])
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if not g:
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st=os.lstat(fullpath)
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if stat.S_ISLNK(st.st_mode):
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# yippee
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fullpath=abs_link(fullpath)
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# print "hijacking %s to %s" % (p[0], fullpath)
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g=self._get_dir_ent(fullpath)
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g=c.add_node(p[0],ref_node=self._get_dir_ent(fullpath))
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elif stat.S_ISDIR(st.st_mode):
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g=c.add_node(p[0])
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else:
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raise Exception("%s is not a dir!" % fullpath)
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c=g
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p.pop(0)
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if symlink:
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c["actpath"]=fullpath
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return c
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def cacheddir(self, mypath):
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mypath=norm_path(mypath)
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if mypath=="/":
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ent=self.cache
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else:
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ent = self._get_dir_ent(mypath)
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# print "nodes mtime=",ent.mtime
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listing_needed = (ent.mtime == -1)
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mtime = os.stat(mypath).st_mtime
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if not listing_needed:
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# print "nost listing needed"
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if mtime != ent.mtime:
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print "mtime flipped it"
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self._invalidate_dir_node(ent)
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listing_needed = True
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# print "ent = ",ent,"listing_needed=",listing_needed
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if listing_needed:
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ent.mtime=mtime
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# print "set nodes mtime to",ent.mtime,"from",mtime
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l = os.listdir(mypath)
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for x in l:
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try:
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ps=os.lstat(mypath+"/"+x).st_mode
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if stat.S_ISREG(ps):
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ent.files.append(x)
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elif stat.S_ISDIR(ps):
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ent.dirs.append(x)
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elif stat.S_ISLNK(ps):
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ps=os.stat(mypath+"/"+x).st_mode
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if stat.S_ISDIR(ps):
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ent.sdirs.append(x)
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else:
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ent.sfiles.append(x)
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else:
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ent.others.append(x)
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except:
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ent.others.append(x)
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return list(ent.dirs + ent.sdirs + ent.files + ent.sfiles + ent.others),\
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[1 for x in ent.dirs]+[3 for x in ent.sdirs]+ \
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[0 for x in ent.files]+ [2 for x in ent.sfiles]+[4 for x in ent.others]
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