summaryrefslogtreecommitdiffstats
path: root/third_party/python/Jinja2/jinja2/bccache.py
diff options
context:
space:
mode:
Diffstat (limited to 'third_party/python/Jinja2/jinja2/bccache.py')
-rw-r--r--third_party/python/Jinja2/jinja2/bccache.py350
1 files changed, 350 insertions, 0 deletions
diff --git a/third_party/python/Jinja2/jinja2/bccache.py b/third_party/python/Jinja2/jinja2/bccache.py
new file mode 100644
index 0000000000..9c0661030f
--- /dev/null
+++ b/third_party/python/Jinja2/jinja2/bccache.py
@@ -0,0 +1,350 @@
+# -*- coding: utf-8 -*-
+"""The optional bytecode cache system. This is useful if you have very
+complex template situations and the compilation of all those templates
+slows down your application too much.
+
+Situations where this is useful are often forking web applications that
+are initialized on the first request.
+"""
+import errno
+import fnmatch
+import os
+import stat
+import sys
+import tempfile
+from hashlib import sha1
+from os import listdir
+from os import path
+
+from ._compat import BytesIO
+from ._compat import marshal_dump
+from ._compat import marshal_load
+from ._compat import pickle
+from ._compat import text_type
+from .utils import open_if_exists
+
+bc_version = 4
+# Magic bytes to identify Jinja bytecode cache files. Contains the
+# Python major and minor version to avoid loading incompatible bytecode
+# if a project upgrades its Python version.
+bc_magic = (
+ b"j2"
+ + pickle.dumps(bc_version, 2)
+ + pickle.dumps((sys.version_info[0] << 24) | sys.version_info[1], 2)
+)
+
+
+class Bucket(object):
+ """Buckets are used to store the bytecode for one template. It's created
+ and initialized by the bytecode cache and passed to the loading functions.
+
+ The buckets get an internal checksum from the cache assigned and use this
+ to automatically reject outdated cache material. Individual bytecode
+ cache subclasses don't have to care about cache invalidation.
+ """
+
+ def __init__(self, environment, key, checksum):
+ self.environment = environment
+ self.key = key
+ self.checksum = checksum
+ self.reset()
+
+ def reset(self):
+ """Resets the bucket (unloads the bytecode)."""
+ self.code = None
+
+ def load_bytecode(self, f):
+ """Loads bytecode from a file or file like object."""
+ # make sure the magic header is correct
+ magic = f.read(len(bc_magic))
+ if magic != bc_magic:
+ self.reset()
+ return
+ # the source code of the file changed, we need to reload
+ checksum = pickle.load(f)
+ if self.checksum != checksum:
+ self.reset()
+ return
+ # if marshal_load fails then we need to reload
+ try:
+ self.code = marshal_load(f)
+ except (EOFError, ValueError, TypeError):
+ self.reset()
+ return
+
+ def write_bytecode(self, f):
+ """Dump the bytecode into the file or file like object passed."""
+ if self.code is None:
+ raise TypeError("can't write empty bucket")
+ f.write(bc_magic)
+ pickle.dump(self.checksum, f, 2)
+ marshal_dump(self.code, f)
+
+ def bytecode_from_string(self, string):
+ """Load bytecode from a string."""
+ self.load_bytecode(BytesIO(string))
+
+ def bytecode_to_string(self):
+ """Return the bytecode as string."""
+ out = BytesIO()
+ self.write_bytecode(out)
+ return out.getvalue()
+
+
+class BytecodeCache(object):
+ """To implement your own bytecode cache you have to subclass this class
+ and override :meth:`load_bytecode` and :meth:`dump_bytecode`. Both of
+ these methods are passed a :class:`~jinja2.bccache.Bucket`.
+
+ A very basic bytecode cache that saves the bytecode on the file system::
+
+ from os import path
+
+ class MyCache(BytecodeCache):
+
+ def __init__(self, directory):
+ self.directory = directory
+
+ def load_bytecode(self, bucket):
+ filename = path.join(self.directory, bucket.key)
+ if path.exists(filename):
+ with open(filename, 'rb') as f:
+ bucket.load_bytecode(f)
+
+ def dump_bytecode(self, bucket):
+ filename = path.join(self.directory, bucket.key)
+ with open(filename, 'wb') as f:
+ bucket.write_bytecode(f)
+
+ A more advanced version of a filesystem based bytecode cache is part of
+ Jinja.
+ """
+
+ def load_bytecode(self, bucket):
+ """Subclasses have to override this method to load bytecode into a
+ bucket. If they are not able to find code in the cache for the
+ bucket, it must not do anything.
+ """
+ raise NotImplementedError()
+
+ def dump_bytecode(self, bucket):
+ """Subclasses have to override this method to write the bytecode
+ from a bucket back to the cache. If it unable to do so it must not
+ fail silently but raise an exception.
+ """
+ raise NotImplementedError()
+
+ def clear(self):
+ """Clears the cache. This method is not used by Jinja but should be
+ implemented to allow applications to clear the bytecode cache used
+ by a particular environment.
+ """
+
+ def get_cache_key(self, name, filename=None):
+ """Returns the unique hash key for this template name."""
+ hash = sha1(name.encode("utf-8"))
+ if filename is not None:
+ filename = "|" + filename
+ if isinstance(filename, text_type):
+ filename = filename.encode("utf-8")
+ hash.update(filename)
+ return hash.hexdigest()
+
+ def get_source_checksum(self, source):
+ """Returns a checksum for the source."""
+ return sha1(source.encode("utf-8")).hexdigest()
+
+ def get_bucket(self, environment, name, filename, source):
+ """Return a cache bucket for the given template. All arguments are
+ mandatory but filename may be `None`.
+ """
+ key = self.get_cache_key(name, filename)
+ checksum = self.get_source_checksum(source)
+ bucket = Bucket(environment, key, checksum)
+ self.load_bytecode(bucket)
+ return bucket
+
+ def set_bucket(self, bucket):
+ """Put the bucket into the cache."""
+ self.dump_bytecode(bucket)
+
+
+class FileSystemBytecodeCache(BytecodeCache):
+ """A bytecode cache that stores bytecode on the filesystem. It accepts
+ two arguments: The directory where the cache items are stored and a
+ pattern string that is used to build the filename.
+
+ If no directory is specified a default cache directory is selected. On
+ Windows the user's temp directory is used, on UNIX systems a directory
+ is created for the user in the system temp directory.
+
+ The pattern can be used to have multiple separate caches operate on the
+ same directory. The default pattern is ``'__jinja2_%s.cache'``. ``%s``
+ is replaced with the cache key.
+
+ >>> bcc = FileSystemBytecodeCache('/tmp/jinja_cache', '%s.cache')
+
+ This bytecode cache supports clearing of the cache using the clear method.
+ """
+
+ def __init__(self, directory=None, pattern="__jinja2_%s.cache"):
+ if directory is None:
+ directory = self._get_default_cache_dir()
+ self.directory = directory
+ self.pattern = pattern
+
+ def _get_default_cache_dir(self):
+ def _unsafe_dir():
+ raise RuntimeError(
+ "Cannot determine safe temp directory. You "
+ "need to explicitly provide one."
+ )
+
+ tmpdir = tempfile.gettempdir()
+
+ # On windows the temporary directory is used specific unless
+ # explicitly forced otherwise. We can just use that.
+ if os.name == "nt":
+ return tmpdir
+ if not hasattr(os, "getuid"):
+ _unsafe_dir()
+
+ dirname = "_jinja2-cache-%d" % os.getuid()
+ actual_dir = os.path.join(tmpdir, dirname)
+
+ try:
+ os.mkdir(actual_dir, stat.S_IRWXU)
+ except OSError as e:
+ if e.errno != errno.EEXIST:
+ raise
+ try:
+ os.chmod(actual_dir, stat.S_IRWXU)
+ actual_dir_stat = os.lstat(actual_dir)
+ if (
+ actual_dir_stat.st_uid != os.getuid()
+ or not stat.S_ISDIR(actual_dir_stat.st_mode)
+ or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU
+ ):
+ _unsafe_dir()
+ except OSError as e:
+ if e.errno != errno.EEXIST:
+ raise
+
+ actual_dir_stat = os.lstat(actual_dir)
+ if (
+ actual_dir_stat.st_uid != os.getuid()
+ or not stat.S_ISDIR(actual_dir_stat.st_mode)
+ or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU
+ ):
+ _unsafe_dir()
+
+ return actual_dir
+
+ def _get_cache_filename(self, bucket):
+ return path.join(self.directory, self.pattern % bucket.key)
+
+ def load_bytecode(self, bucket):
+ f = open_if_exists(self._get_cache_filename(bucket), "rb")
+ if f is not None:
+ try:
+ bucket.load_bytecode(f)
+ finally:
+ f.close()
+
+ def dump_bytecode(self, bucket):
+ f = open(self._get_cache_filename(bucket), "wb")
+ try:
+ bucket.write_bytecode(f)
+ finally:
+ f.close()
+
+ def clear(self):
+ # imported lazily here because google app-engine doesn't support
+ # write access on the file system and the function does not exist
+ # normally.
+ from os import remove
+
+ files = fnmatch.filter(listdir(self.directory), self.pattern % "*")
+ for filename in files:
+ try:
+ remove(path.join(self.directory, filename))
+ except OSError:
+ pass
+
+
+class MemcachedBytecodeCache(BytecodeCache):
+ """This class implements a bytecode cache that uses a memcache cache for
+ storing the information. It does not enforce a specific memcache library
+ (tummy's memcache or cmemcache) but will accept any class that provides
+ the minimal interface required.
+
+ Libraries compatible with this class:
+
+ - `cachelib <https://github.com/pallets/cachelib>`_
+ - `python-memcached <https://pypi.org/project/python-memcached/>`_
+
+ (Unfortunately the django cache interface is not compatible because it
+ does not support storing binary data, only unicode. You can however pass
+ the underlying cache client to the bytecode cache which is available
+ as `django.core.cache.cache._client`.)
+
+ The minimal interface for the client passed to the constructor is this:
+
+ .. class:: MinimalClientInterface
+
+ .. method:: set(key, value[, timeout])
+
+ Stores the bytecode in the cache. `value` is a string and
+ `timeout` the timeout of the key. If timeout is not provided
+ a default timeout or no timeout should be assumed, if it's
+ provided it's an integer with the number of seconds the cache
+ item should exist.
+
+ .. method:: get(key)
+
+ Returns the value for the cache key. If the item does not
+ exist in the cache the return value must be `None`.
+
+ The other arguments to the constructor are the prefix for all keys that
+ is added before the actual cache key and the timeout for the bytecode in
+ the cache system. We recommend a high (or no) timeout.
+
+ This bytecode cache does not support clearing of used items in the cache.
+ The clear method is a no-operation function.
+
+ .. versionadded:: 2.7
+ Added support for ignoring memcache errors through the
+ `ignore_memcache_errors` parameter.
+ """
+
+ def __init__(
+ self,
+ client,
+ prefix="jinja2/bytecode/",
+ timeout=None,
+ ignore_memcache_errors=True,
+ ):
+ self.client = client
+ self.prefix = prefix
+ self.timeout = timeout
+ self.ignore_memcache_errors = ignore_memcache_errors
+
+ def load_bytecode(self, bucket):
+ try:
+ code = self.client.get(self.prefix + bucket.key)
+ except Exception:
+ if not self.ignore_memcache_errors:
+ raise
+ code = None
+ if code is not None:
+ bucket.bytecode_from_string(code)
+
+ def dump_bytecode(self, bucket):
+ args = (self.prefix + bucket.key, bucket.bytecode_to_string())
+ if self.timeout is not None:
+ args += (self.timeout,)
+ try:
+ self.client.set(*args)
+ except Exception:
+ if not self.ignore_memcache_errors:
+ raise