1 #
2 # Copyright (c) 2001 Bizar Software Pty Ltd (http://www.bizarsoftware.com.au/)
3 # This module is free software, and you may redistribute it and/or modify
4 # under the same terms as Python, so long as this copyright message and
5 # disclaimer are retained in their original form.
6 #
7 # IN NO EVENT SHALL BIZAR SOFTWARE PTY LTD BE LIABLE TO ANY PARTY FOR
8 # DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
9 # OUT OF THE USE OF THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE
10 # POSSIBILITY OF SUCH DAMAGE.
11 #
12 # BIZAR SOFTWARE PTY LTD SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
13 # BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
14 # FOR A PARTICULAR PURPOSE. THE CODE PROVIDED HEREUNDER IS ON AN "AS IS"
15 # BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
16 # SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
17 #
18 # $Id: hyperdb.py,v 1.88 2003-09-04 00:47:01 richard Exp $
20 """
21 Hyperdatabase implementation, especially field types.
22 """
24 # standard python modules
25 import sys, os, time, re
27 # roundup modules
28 import date, password
30 # configure up the DEBUG and TRACE captures
31 class Sink:
32 def write(self, content):
33 pass
34 DEBUG = os.environ.get('HYPERDBDEBUG', '')
35 if DEBUG and __debug__:
36 if DEBUG == 'stdout':
37 DEBUG = sys.stdout
38 else:
39 DEBUG = open(DEBUG, 'a')
40 else:
41 DEBUG = Sink()
42 TRACE = os.environ.get('HYPERDBTRACE', '')
43 if TRACE and __debug__:
44 if TRACE == 'stdout':
45 TRACE = sys.stdout
46 else:
47 TRACE = open(TRACE, 'w')
48 else:
49 TRACE = Sink()
50 def traceMark():
51 print >>TRACE, '**MARK', time.ctime()
52 del Sink
54 #
55 # Types
56 #
57 class String:
58 """An object designating a String property."""
59 def __init__(self, indexme='no'):
60 self.indexme = indexme == 'yes'
61 def __repr__(self):
62 ' more useful for dumps '
63 return '<%s>'%self.__class__
65 class Password:
66 """An object designating a Password property."""
67 def __repr__(self):
68 ' more useful for dumps '
69 return '<%s>'%self.__class__
71 class Date:
72 """An object designating a Date property."""
73 def __repr__(self):
74 ' more useful for dumps '
75 return '<%s>'%self.__class__
77 class Interval:
78 """An object designating an Interval property."""
79 def __repr__(self):
80 ' more useful for dumps '
81 return '<%s>'%self.__class__
83 class Link:
84 """An object designating a Link property that links to a
85 node in a specified class."""
86 def __init__(self, classname, do_journal='yes'):
87 ''' Default is to not journal link and unlink events
88 '''
89 self.classname = classname
90 self.do_journal = do_journal == 'yes'
91 def __repr__(self):
92 ' more useful for dumps '
93 return '<%s to "%s">'%(self.__class__, self.classname)
95 class Multilink:
96 """An object designating a Multilink property that links
97 to nodes in a specified class.
99 "classname" indicates the class to link to
101 "do_journal" indicates whether the linked-to nodes should have
102 'link' and 'unlink' events placed in their journal
103 """
104 def __init__(self, classname, do_journal='yes'):
105 ''' Default is to not journal link and unlink events
106 '''
107 self.classname = classname
108 self.do_journal = do_journal == 'yes'
109 def __repr__(self):
110 ' more useful for dumps '
111 return '<%s to "%s">'%(self.__class__, self.classname)
113 class Boolean:
114 """An object designating a boolean property"""
115 def __repr__(self):
116 'more useful for dumps'
117 return '<%s>' % self.__class__
119 class Number:
120 """An object designating a numeric property"""
121 def __repr__(self):
122 'more useful for dumps'
123 return '<%s>' % self.__class__
124 #
125 # Support for splitting designators
126 #
127 class DesignatorError(ValueError):
128 pass
129 def splitDesignator(designator, dre=re.compile(r'([^\d]+)(\d+)')):
130 ''' Take a foo123 and return ('foo', 123)
131 '''
132 m = dre.match(designator)
133 if m is None:
134 raise DesignatorError, '"%s" not a node designator'%designator
135 return m.group(1), m.group(2)
137 #
138 # the base Database class
139 #
140 class DatabaseError(ValueError):
141 '''Error to be raised when there is some problem in the database code
142 '''
143 pass
144 class Database:
145 '''A database for storing records containing flexible data types.
147 This class defines a hyperdatabase storage layer, which the Classes use to
148 store their data.
151 Transactions
152 ------------
153 The Database should support transactions through the commit() and
154 rollback() methods. All other Database methods should be transaction-aware,
155 using data from the current transaction before looking up the database.
157 An implementation must provide an override for the get() method so that the
158 in-database value is returned in preference to the in-transaction value.
159 This is necessary to determine if any values have changed during a
160 transaction.
163 Implementation
164 --------------
166 All methods except __repr__ and getnode must be implemented by a
167 concrete backend Class.
169 '''
171 # flag to set on retired entries
172 RETIRED_FLAG = '__hyperdb_retired'
174 def __init__(self, config, journaltag=None):
175 """Open a hyperdatabase given a specifier to some storage.
177 The 'storagelocator' is obtained from config.DATABASE.
178 The meaning of 'storagelocator' depends on the particular
179 implementation of the hyperdatabase. It could be a file name,
180 a directory path, a socket descriptor for a connection to a
181 database over the network, etc.
183 The 'journaltag' is a token that will be attached to the journal
184 entries for any edits done on the database. If 'journaltag' is
185 None, the database is opened in read-only mode: the Class.create(),
186 Class.set(), and Class.retire() methods are disabled.
187 """
188 raise NotImplementedError
190 def post_init(self):
191 """Called once the schema initialisation has finished."""
192 raise NotImplementedError
194 def __getattr__(self, classname):
195 """A convenient way of calling self.getclass(classname)."""
196 raise NotImplementedError
198 def addclass(self, cl):
199 '''Add a Class to the hyperdatabase.
200 '''
201 raise NotImplementedError
203 def getclasses(self):
204 """Return a list of the names of all existing classes."""
205 raise NotImplementedError
207 def getclass(self, classname):
208 """Get the Class object representing a particular class.
210 If 'classname' is not a valid class name, a KeyError is raised.
211 """
212 raise NotImplementedError
214 def clear(self):
215 '''Delete all database contents.
216 '''
217 raise NotImplementedError
219 def getclassdb(self, classname, mode='r'):
220 '''Obtain a connection to the class db that will be used for
221 multiple actions.
222 '''
223 raise NotImplementedError
225 def addnode(self, classname, nodeid, node):
226 '''Add the specified node to its class's db.
227 '''
228 raise NotImplementedError
230 def serialise(self, classname, node):
231 '''Copy the node contents, converting non-marshallable data into
232 marshallable data.
233 '''
234 return node
236 def setnode(self, classname, nodeid, node):
237 '''Change the specified node.
238 '''
239 raise NotImplementedError
241 def unserialise(self, classname, node):
242 '''Decode the marshalled node data
243 '''
244 return node
246 def getnode(self, classname, nodeid, db=None, cache=1):
247 '''Get a node from the database.
249 'cache' exists for backwards compatibility, and is not used.
250 '''
251 raise NotImplementedError
253 def hasnode(self, classname, nodeid, db=None):
254 '''Determine if the database has a given node.
255 '''
256 raise NotImplementedError
258 def countnodes(self, classname, db=None):
259 '''Count the number of nodes that exist for a particular Class.
260 '''
261 raise NotImplementedError
263 def getnodeids(self, classname, db=None):
264 '''Retrieve all the ids of the nodes for a particular Class.
265 '''
266 raise NotImplementedError
268 def storefile(self, classname, nodeid, property, content):
269 '''Store the content of the file in the database.
271 The property may be None, in which case the filename does not
272 indicate which property is being saved.
273 '''
274 raise NotImplementedError
276 def getfile(self, classname, nodeid, property):
277 '''Store the content of the file in the database.
278 '''
279 raise NotImplementedError
281 def addjournal(self, classname, nodeid, action, params):
282 ''' Journal the Action
283 'action' may be:
285 'create' or 'set' -- 'params' is a dictionary of property values
286 'link' or 'unlink' -- 'params' is (classname, nodeid, propname)
287 'retire' -- 'params' is None
288 '''
289 raise NotImplementedError
291 def getjournal(self, classname, nodeid):
292 ''' get the journal for id
293 '''
294 raise NotImplementedError
296 def pack(self, pack_before):
297 ''' pack the database
298 '''
299 raise NotImplementedError
301 def commit(self):
302 ''' Commit the current transactions.
304 Save all data changed since the database was opened or since the
305 last commit() or rollback().
306 '''
307 raise NotImplementedError
309 def rollback(self):
310 ''' Reverse all actions from the current transaction.
312 Undo all the changes made since the database was opened or the last
313 commit() or rollback() was performed.
314 '''
315 raise NotImplementedError
317 #
318 # The base Class class
319 #
320 class Class:
321 """ The handle to a particular class of nodes in a hyperdatabase.
323 All methods except __repr__ and getnode must be implemented by a
324 concrete backend Class.
325 """
327 def __init__(self, db, classname, **properties):
328 """Create a new class with a given name and property specification.
330 'classname' must not collide with the name of an existing class,
331 or a ValueError is raised. The keyword arguments in 'properties'
332 must map names to property objects, or a TypeError is raised.
333 """
334 raise NotImplementedError
336 def __repr__(self):
337 '''Slightly more useful representation
338 '''
339 return '<hyperdb.Class "%s">'%self.classname
341 # Editing nodes:
343 def create(self, **propvalues):
344 """Create a new node of this class and return its id.
346 The keyword arguments in 'propvalues' map property names to values.
348 The values of arguments must be acceptable for the types of their
349 corresponding properties or a TypeError is raised.
351 If this class has a key property, it must be present and its value
352 must not collide with other key strings or a ValueError is raised.
354 Any other properties on this class that are missing from the
355 'propvalues' dictionary are set to None.
357 If an id in a link or multilink property does not refer to a valid
358 node, an IndexError is raised.
359 """
360 raise NotImplementedError
362 _marker = []
363 def get(self, nodeid, propname, default=_marker, cache=1):
364 """Get the value of a property on an existing node of this class.
366 'nodeid' must be the id of an existing node of this class or an
367 IndexError is raised. 'propname' must be the name of a property
368 of this class or a KeyError is raised.
370 'cache' exists for backwards compatibility, and is not used.
371 """
372 raise NotImplementedError
374 def getnode(self, nodeid, cache=1):
375 ''' Return a convenience wrapper for the node.
377 'nodeid' must be the id of an existing node of this class or an
378 IndexError is raised.
380 'cache' exists for backwards compatibility, and is not used.
381 '''
382 return Node(self, nodeid)
384 def set(self, nodeid, **propvalues):
385 """Modify a property on an existing node of this class.
387 'nodeid' must be the id of an existing node of this class or an
388 IndexError is raised.
390 Each key in 'propvalues' must be the name of a property of this
391 class or a KeyError is raised.
393 All values in 'propvalues' must be acceptable types for their
394 corresponding properties or a TypeError is raised.
396 If the value of the key property is set, it must not collide with
397 other key strings or a ValueError is raised.
399 If the value of a Link or Multilink property contains an invalid
400 node id, a ValueError is raised.
401 """
402 raise NotImplementedError
404 def retire(self, nodeid):
405 """Retire a node.
407 The properties on the node remain available from the get() method,
408 and the node's id is never reused.
410 Retired nodes are not returned by the find(), list(), or lookup()
411 methods, and other nodes may reuse the values of their key properties.
412 """
413 raise NotImplementedError
415 def restore(self, nodeid):
416 '''Restpre a retired node.
418 Make node available for all operations like it was before retirement.
419 '''
420 raise NotImplementedError
422 def is_retired(self, nodeid):
423 '''Return true if the node is rerired
424 '''
425 raise NotImplementedError
427 def destroy(self, nodeid):
428 """Destroy a node.
430 WARNING: this method should never be used except in extremely rare
431 situations where there could never be links to the node being
432 deleted
433 WARNING: use retire() instead
434 WARNING: the properties of this node will not be available ever again
435 WARNING: really, use retire() instead
437 Well, I think that's enough warnings. This method exists mostly to
438 support the session storage of the cgi interface.
440 The node is completely removed from the hyperdb, including all journal
441 entries. It will no longer be available, and will generally break code
442 if there are any references to the node.
443 """
445 def history(self, nodeid):
446 """Retrieve the journal of edits on a particular node.
448 'nodeid' must be the id of an existing node of this class or an
449 IndexError is raised.
451 The returned list contains tuples of the form
453 (date, tag, action, params)
455 'date' is a Timestamp object specifying the time of the change and
456 'tag' is the journaltag specified when the database was opened.
457 """
458 raise NotImplementedError
460 # Locating nodes:
461 def hasnode(self, nodeid):
462 '''Determine if the given nodeid actually exists
463 '''
464 raise NotImplementedError
466 def setkey(self, propname):
467 """Select a String property of this class to be the key property.
469 'propname' must be the name of a String property of this class or
470 None, or a TypeError is raised. The values of the key property on
471 all existing nodes must be unique or a ValueError is raised.
472 """
473 raise NotImplementedError
475 def getkey(self):
476 """Return the name of the key property for this class or None."""
477 raise NotImplementedError
479 def labelprop(self, default_to_id=0):
480 ''' Return the property name for a label for the given node.
482 This method attempts to generate a consistent label for the node.
483 It tries the following in order:
484 1. key property
485 2. "name" property
486 3. "title" property
487 4. first property from the sorted property name list
488 '''
489 raise NotImplementedError
491 def lookup(self, keyvalue):
492 """Locate a particular node by its key property and return its id.
494 If this class has no key property, a TypeError is raised. If the
495 'keyvalue' matches one of the values for the key property among
496 the nodes in this class, the matching node's id is returned;
497 otherwise a KeyError is raised.
498 """
499 raise NotImplementedError
501 def find(self, **propspec):
502 """Get the ids of nodes in this class which link to the given nodes.
504 'propspec' consists of keyword args propname={nodeid:1,}
505 'propname' must be the name of a property in this class, or a
506 KeyError is raised. That property must be a Link or Multilink
507 property, or a TypeError is raised.
509 Any node in this class whose 'propname' property links to any of the
510 nodeids will be returned. Used by the full text indexing, which knows
511 that "foo" occurs in msg1, msg3 and file7, so we have hits on these
512 issues:
514 db.issue.find(messages={'1':1,'3':1}, files={'7':1})
515 """
516 raise NotImplementedError
518 def filter(self, search_matches, filterspec, sort=(None,None),
519 group=(None,None)):
520 ''' Return a list of the ids of the active nodes in this class that
521 match the 'filter' spec, sorted by the group spec and then the
522 sort spec.
524 "filterspec" is {propname: value(s)}
525 "sort" and "group" are (dir, prop) where dir is '+', '-' or None
526 and prop is a prop name or None
527 "search_matches" is {nodeid: marker}
529 The filter must match all properties specificed - but if the
530 property value to match is a list, any one of the values in the
531 list may match for that property to match.
532 '''
533 raise NotImplementedError
535 def count(self):
536 """Get the number of nodes in this class.
538 If the returned integer is 'numnodes', the ids of all the nodes
539 in this class run from 1 to numnodes, and numnodes+1 will be the
540 id of the next node to be created in this class.
541 """
542 raise NotImplementedError
544 # Manipulating properties:
545 def getprops(self, protected=1):
546 """Return a dictionary mapping property names to property objects.
547 If the "protected" flag is true, we include protected properties -
548 those which may not be modified.
549 """
550 raise NotImplementedError
552 def addprop(self, **properties):
553 """Add properties to this class.
555 The keyword arguments in 'properties' must map names to property
556 objects, or a TypeError is raised. None of the keys in 'properties'
557 may collide with the names of existing properties, or a ValueError
558 is raised before any properties have been added.
559 """
560 raise NotImplementedError
562 def index(self, nodeid):
563 '''Add (or refresh) the node to search indexes
564 '''
565 raise NotImplementedError
567 class FileClass:
568 ''' A class that requires the "content" property and stores it on
569 disk.
570 '''
571 pass
573 class Node:
574 ''' A convenience wrapper for the given node
575 '''
576 def __init__(self, cl, nodeid, cache=1):
577 self.__dict__['cl'] = cl
578 self.__dict__['nodeid'] = nodeid
579 def keys(self, protected=1):
580 return self.cl.getprops(protected=protected).keys()
581 def values(self, protected=1):
582 l = []
583 for name in self.cl.getprops(protected=protected).keys():
584 l.append(self.cl.get(self.nodeid, name))
585 return l
586 def items(self, protected=1):
587 l = []
588 for name in self.cl.getprops(protected=protected).keys():
589 l.append((name, self.cl.get(self.nodeid, name)))
590 return l
591 def has_key(self, name):
592 return self.cl.getprops().has_key(name)
593 def get(self, name, default=None):
594 if self.has_key(name):
595 return self[name]
596 else:
597 return default
598 def __getattr__(self, name):
599 if self.__dict__.has_key(name):
600 return self.__dict__[name]
601 try:
602 return self.cl.get(self.nodeid, name)
603 except KeyError, value:
604 # we trap this but re-raise it as AttributeError - all other
605 # exceptions should pass through untrapped
606 pass
607 # nope, no such attribute
608 raise AttributeError, str(value)
609 def __getitem__(self, name):
610 return self.cl.get(self.nodeid, name)
611 def __setattr__(self, name, value):
612 try:
613 return self.cl.set(self.nodeid, **{name: value})
614 except KeyError, value:
615 raise AttributeError, str(value)
616 def __setitem__(self, name, value):
617 self.cl.set(self.nodeid, **{name: value})
618 def history(self):
619 return self.cl.history(self.nodeid)
620 def retire(self):
621 return self.cl.retire(self.nodeid)
624 def Choice(name, db, *options):
625 '''Quick helper to create a simple class with choices
626 '''
627 cl = Class(db, name, name=String(), order=String())
628 for i in range(len(options)):
629 cl.create(name=options[i], order=i)
630 return hyperdb.Link(name)
632 # vim: set filetype=python ts=4 sw=4 et si