| 1 | from __future__ import with_statement |
| 2 | import threading, time, pickle, random, os |
| 3 | import cookie, env |
| 4 | |
| 5 | __all__ = ["db", "get"] |
| 6 | |
| 7 | def hexencode(str): |
| 8 | ret = "" |
| 9 | for byte in str: |
| 10 | ret += "%02X" % (ord(byte),) |
| 11 | return ret |
| 12 | |
| 13 | def gennonce(length): |
| 14 | nonce = "" |
| 15 | for i in xrange(length): |
| 16 | nonce += chr(random.randint(0, 255)) |
| 17 | return nonce |
| 18 | |
| 19 | class session(object): |
| 20 | def __init__(self, lock, expire = 86400 * 7): |
| 21 | self.id = hexencode(gennonce(16)) |
| 22 | self.dict = {} |
| 23 | self.lock = lock |
| 24 | self.ctime = self.atime = self.mtime = int(time.time()) |
| 25 | self.expire = expire |
| 26 | self.dctl = set() |
| 27 | self.dirtyp = False |
| 28 | |
| 29 | def dirty(self): |
| 30 | for d in self.dctl: |
| 31 | if d.sessdirty(): |
| 32 | return True |
| 33 | return self.dirtyp |
| 34 | |
| 35 | def frozen(self): |
| 36 | for d in self.dctl: |
| 37 | d.sessfrozen() |
| 38 | self.dirtyp = False |
| 39 | |
| 40 | def __getitem__(self, key): |
| 41 | return self.dict[key] |
| 42 | |
| 43 | def get(self, key, default = None): |
| 44 | return self.dict.get(key, default) |
| 45 | |
| 46 | def __setitem__(self, key, value): |
| 47 | self.dict[key] = value |
| 48 | if hasattr(value, "sessdirty"): |
| 49 | self.dctl.add(value) |
| 50 | else: |
| 51 | self.dirtyp = True |
| 52 | |
| 53 | def __delitem__(self, key): |
| 54 | old = self.dict.pop(key) |
| 55 | if old in self.dctl: |
| 56 | self.dctl.remove(old) |
| 57 | self.dirtyp = True |
| 58 | |
| 59 | def __contains__(self, key): |
| 60 | return key in self.dict |
| 61 | |
| 62 | def __getstate__(self): |
| 63 | ret = [] |
| 64 | for k, v in self.__dict__.items(): |
| 65 | if k == "lock": continue |
| 66 | ret.append((k, v)) |
| 67 | return ret |
| 68 | |
| 69 | def __setstate__(self, st): |
| 70 | for k, v in st: |
| 71 | self.__dict__[k] = v |
| 72 | # The proper lock is set by the thawer |
| 73 | |
| 74 | def __repr__(self): |
| 75 | return "<session %s>" % self.id |
| 76 | |
| 77 | class db(object): |
| 78 | def __init__(self, backdb = None, cookiename = "wrwsess", path = "/"): |
| 79 | self.live = {} |
| 80 | self.cookiename = cookiename |
| 81 | self.path = path |
| 82 | self.lock = threading.Lock() |
| 83 | self.cthread = None |
| 84 | self.freezetime = 3600 |
| 85 | self.backdb = backdb |
| 86 | |
| 87 | def clean(self): |
| 88 | now = int(time.time()) |
| 89 | with self.lock: |
| 90 | clist = self.live.keys() |
| 91 | for sessid in clist: |
| 92 | with self.lock: |
| 93 | try: |
| 94 | entry = self.live[sessid] |
| 95 | except KeyError: |
| 96 | continue |
| 97 | with entry[0]: |
| 98 | rm = False |
| 99 | if entry[1] == "retired": |
| 100 | pass |
| 101 | elif entry[1] is None: |
| 102 | pass |
| 103 | else: |
| 104 | sess = entry[1] |
| 105 | if sess.atime + self.freezetime < now: |
| 106 | try: |
| 107 | if sess.dirty(): |
| 108 | self.freeze(sess) |
| 109 | except: |
| 110 | if sess.atime + sess.expire < now: |
| 111 | rm = True |
| 112 | else: |
| 113 | rm = True |
| 114 | if rm: |
| 115 | entry[1] = "retired" |
| 116 | with self.lock: |
| 117 | del self.live[sessid] |
| 118 | |
| 119 | def cleanloop(self): |
| 120 | try: |
| 121 | while True: |
| 122 | time.sleep(300) |
| 123 | self.clean() |
| 124 | if len(self.live) == 0: |
| 125 | break |
| 126 | finally: |
| 127 | with self.lock: |
| 128 | self.cthread = None |
| 129 | |
| 130 | def _fetch(self, sessid): |
| 131 | while True: |
| 132 | now = int(time.time()) |
| 133 | with self.lock: |
| 134 | if sessid in self.live: |
| 135 | entry = self.live[sessid] |
| 136 | else: |
| 137 | entry = self.live[sessid] = [threading.RLock(), None] |
| 138 | with entry[0]: |
| 139 | if isinstance(entry[1], session): |
| 140 | entry[1].atime = now |
| 141 | return entry[1] |
| 142 | elif entry[1] == "retired": |
| 143 | continue |
| 144 | elif entry[1] is None: |
| 145 | try: |
| 146 | thawed = self.thaw(sessid) |
| 147 | if thawed.atime + thawed.expire < now: |
| 148 | raise KeyError() |
| 149 | thawed.lock = entry[0] |
| 150 | thawed.atime = now |
| 151 | entry[1] = thawed |
| 152 | return thawed |
| 153 | finally: |
| 154 | if entry[1] is None: |
| 155 | entry[1] = "retired" |
| 156 | with self.lock: |
| 157 | del self.live[sessid] |
| 158 | else: |
| 159 | raise Exception("Illegal session entry: " + repr(entry[1])) |
| 160 | |
| 161 | def checkclean(self): |
| 162 | with self.lock: |
| 163 | if self.cthread is None: |
| 164 | self.cthread = threading.Thread(target = self.cleanloop) |
| 165 | self.cthread.setDaemon(True) |
| 166 | self.cthread.start() |
| 167 | |
| 168 | def mksession(self, req): |
| 169 | return session(threading.RLock()) |
| 170 | |
| 171 | def mkcookie(self, req, sess): |
| 172 | cookie.add(req, self.cookiename, sess.id, |
| 173 | path=self.path, |
| 174 | expires=cookie.cdate(time.time() + sess.expire)) |
| 175 | |
| 176 | def fetch(self, req): |
| 177 | now = int(time.time()) |
| 178 | sessid = cookie.get(req, self.cookiename) |
| 179 | new = False |
| 180 | try: |
| 181 | if sessid is None: |
| 182 | raise KeyError() |
| 183 | sess = self._fetch(sessid) |
| 184 | except KeyError: |
| 185 | sess = self.mksession(req) |
| 186 | new = True |
| 187 | |
| 188 | def ckfreeze(req): |
| 189 | if sess.dirty(): |
| 190 | if new: |
| 191 | self.mkcookie(req, sess) |
| 192 | with self.lock: |
| 193 | self.live[sess.id] = [sess.lock, sess] |
| 194 | try: |
| 195 | self.freeze(sess) |
| 196 | except: |
| 197 | pass |
| 198 | self.checkclean() |
| 199 | req.oncommit(ckfreeze) |
| 200 | return sess |
| 201 | |
| 202 | def thaw(self, sessid): |
| 203 | if self.backdb is None: |
| 204 | raise KeyError() |
| 205 | data = self.backdb[sessid] |
| 206 | try: |
| 207 | return pickle.loads(data) |
| 208 | except Exception, e: |
| 209 | raise KeyError() |
| 210 | |
| 211 | def freeze(self, sess): |
| 212 | if self.backdb is None: |
| 213 | raise TypeError() |
| 214 | with sess.lock: |
| 215 | data = pickle.dumps(sess, -1) |
| 216 | self.backdb[sess.id] = data |
| 217 | sess.frozen() |
| 218 | |
| 219 | def get(self, req): |
| 220 | return req.item(self.fetch) |
| 221 | |
| 222 | class dirback(object): |
| 223 | def __init__(self, path): |
| 224 | self.path = path |
| 225 | |
| 226 | def __getitem__(self, key): |
| 227 | try: |
| 228 | with open(os.path.join(self.path, key)) as inf: |
| 229 | return inf.read() |
| 230 | except IOError: |
| 231 | raise KeyError(key) |
| 232 | |
| 233 | def __setitem__(self, key, value): |
| 234 | if not os.path.exists(self.path): |
| 235 | os.makedirs(self.path) |
| 236 | with open(os.path.join(self.path, key), "w") as out: |
| 237 | out.write(value) |
| 238 | |
| 239 | default = env.var(db(backdb = dirback(os.path.join("/tmp", "wrwsess-" + str(os.getuid()))))) |
| 240 | |
| 241 | def get(req): |
| 242 | return default.val.get(req) |