# BSD Licensed, Copyright (c) 2006-2010 TileCache Contributors
from TileCache.Cache import Cache
import sys, os, time, warnings
[docs]class Disk (Cache):
def __init__ (self, base = None, umask = '002', **kwargs):
Cache.__init__(self, **kwargs)
self.basedir = base
self.umask = int(umask, 0)
if sys.platform.startswith("java"):
from java.io import File
self.file_module = File
self.platform = "jython"
else:
self.platform = "cpython"
if not self.access(base, 'read'):
self.makedirs(base)
[docs] def makedirs(self, path, hide_dir_exists=True):
if hasattr(os, "umask"):
old_umask = os.umask(self.umask)
try:
os.makedirs(path)
except OSError, E:
# os.makedirs can suffer a race condition because it doesn't check
# that the directory doesn't exist at each step, nor does it
# catch errors. This lets 'directory exists' errors pass through,
# since they mean that as far as we're concerned, os.makedirs
# has 'worked'
if E.errno != 17 or not hide_dir_exists:
raise E
if hasattr(os, "umask"):
os.umask(old_umask)
[docs] def access(self, path, type='read'):
if self.platform == "jython":
if type == "read":
return self.file_module(path).canRead()
else:
return self.file_module(path).canWrite()
else:
if type =="read":
return os.access(path, os.R_OK)
else:
return os.access(path, os.W_OK)
[docs] def getKey (self, tile):
components = ( self.basedir,
tile.layer.name,
"%02d" % tile.z,
"%03d" % int(tile.x / 1000000),
"%03d" % (int(tile.x / 1000) % 1000),
"%03d" % (int(tile.x) % 1000),
"%03d" % int(tile.y / 1000000),
"%03d" % (int(tile.y / 1000) % 1000),
"%03d.%s" % (int(tile.y) % 1000, tile.layer.extension)
)
filename = os.path.join( *components )
return filename
[docs] def get (self, tile):
filename = self.getKey(tile)
if self.access(filename, 'read'):
if self.sendfile:
return filename
else:
tile.data = file(filename, "rb").read()
return tile.data
else:
return None
[docs] def set (self, tile, data):
if self.readonly: return data
filename = self.getKey(tile)
dirname = os.path.dirname(filename)
if not self.access(dirname, 'write'):
self.makedirs(dirname)
tmpfile = filename + ".%d.tmp" % os.getpid()
if hasattr(os, "umask"):
old_umask = os.umask(self.umask)
output = file(tmpfile, "wb")
output.write(data)
output.close()
if hasattr(os, "umask"):
os.umask( old_umask );
try:
os.rename(tmpfile, filename)
except OSError:
os.unlink(filename)
os.rename(tmpfile, filename)
tile.data = data
return data
[docs] def delete (self, tile):
filename = self.getKey(tile)
if self.access(filename, 'read'):
os.unlink(filename)
[docs] def attemptLock (self, tile):
name = self.getLockName(tile)
try:
self.makedirs(name, hide_dir_exists=False)
return True
except OSError:
pass
try:
st = os.stat(name)
if st.st_ctime + self.stale < time.time():
warnings.warn("removing stale lock %s" % name)
# remove stale lock
self.unlock(tile)
self.makedirs(name)
return True
except OSError:
pass
return False
[docs] def unlock (self, tile):
name = self.getLockName(tile)
try:
os.rmdir(name)
except OSError, E:
print >>sys.stderr, "unlock %s failed: %s" % (name, str(E))