forked from ragnar-johannsson/CloudStack
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathcloud_sxp.py
More file actions
763 lines (649 loc) · 18.7 KB
/
cloud_sxp.py
File metadata and controls
763 lines (649 loc) · 18.7 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
#!/usr/bin/env python
#============================================================================
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#============================================================================
# Copyright (C) 2004, 2005 Mike Wray <mike.wray@hp.com>
#============================================================================
"""
Input-driven parsing for s-expression (sxp) format.
Create a parser: pin = Parser();
Then call pin.input(buf) with your input.
Call pin.input_eof() when done.
Use pin.read() to see if a value has been parsed, pin.get_val()
to get a parsed value. You can call ready and get_val at any time -
you don't have to wait until after calling input_eof.
"""
from __future__ import generators
import sys
import types
import errno
import string
from StringIO import StringIO
__all__ = [
"mime_type",
"ParseError",
"Parser",
"atomp",
"show",
"show_xml",
"elementp",
"name",
"attributes",
"attribute",
"children",
"child",
"child_at",
"child0",
"child1",
"child2",
"child3",
"child4",
"child_value",
"has_id",
"with_id",
"child_with_id",
"elements",
"merge",
"to_string",
"from_string",
"all_from_string",
"parse",
]
mime_type = "application/sxp"
escapes = {
'a': '\a',
'b': '\b',
't': '\t',
'n': '\n',
'v': '\v',
'f': '\f',
'r': '\r',
'\\': '\\',
'\'': '\'',
'\"': '\"'}
k_list_open = "("
k_list_close = ")"
k_attr_open = "@"
k_eval = "!"
escapes_rev = {}
for k in escapes:
escapes_rev[escapes[k]] = k
class ParseError(StandardError):
def __init__(self, parser, value):
self.parser = parser
self.value = value
def __str__(self):
return self.value
class ParserState:
def __init__(self, fn, parent=None):
self.parent = parent
self.buf = ''
self.val = []
self.delim = None
self.fn = fn
def push(self, fn):
return ParserState(fn, parent=self)
class Parser:
def __init__(self):
self.error = sys.stderr
self.reset()
def reset(self):
self.val = []
self.eof = 0
self.err = 0
self.line_no = 0
self.char_no = 0
self.state = None
def push_state(self, fn):
self.state = self.state.push(fn)
def pop_state(self):
val = self.state
self.state = self.state.parent
if self.state and self.state.fn == self.state_start:
# Return to start state - produce the value.
self.val += self.state.val
self.state.val = []
return val
def in_class(self, c, s):
return s.find(c) >= 0
def in_space_class(self, c):
return self.in_class(c, ' \t\n\v\f\r')
def is_separator(self, c):
return self.in_class(c, '{}()<>[]!;')
def in_comment_class(self, c):
return self.in_class(c, '#')
def in_string_quote_class(self, c):
return self.in_class(c, '"\'')
def in_printable_class(self, c):
return self.in_class(c, string.printable)
def set_error_stream(self, error):
self.error = error
def has_error(self):
return self.err > 0
def at_eof(self):
return self.eof
def input_eof(self):
self.eof = 1
self.input_char(-1)
def input(self, buf):
if not buf or len(buf) == 0:
self.input_eof()
else:
for c in buf:
self.input_char(c)
def input_char(self, c):
if self.at_eof():
pass
elif c == '\n':
self.line_no += 1
self.char_no = 0
else:
self.char_no += 1
if self.state is None:
self.begin_start(None)
self.state.fn(c)
def ready(self):
return len(self.val) > 0
def get_val(self):
v = self.val[0]
self.val = self.val[1:]
return v
def get_all(self):
return self.val
def begin_start(self, c):
self.state = ParserState(self.state_start)
def end_start(self):
self.val += self.state.val
self.pop_state()
def state_start(self, c):
if self.at_eof():
self.end_start()
elif self.in_space_class(c):
pass
elif self.in_comment_class(c):
self.begin_comment(c)
elif c == k_list_open:
self.begin_list(c)
elif c == k_list_close:
raise ParseError(self, "syntax error: "+c)
elif self.in_string_quote_class(c):
self.begin_string(c)
elif self.in_printable_class(c):
self.begin_atom(c)
elif c == chr(4):
# ctrl-D, EOT: end-of-text.
self.input_eof()
else:
raise ParseError(self, "invalid character: code %d" % ord(c))
def begin_comment(self, c):
self.push_state(self.state_comment)
self.state.buf += c
def end_comment(self):
self.pop_state()
def state_comment(self, c):
if c == '\n' or self.at_eof():
self.end_comment()
else:
self.state.buf += c
def begin_string(self, c):
self.push_state(self.state_string)
self.state.delim = c
def end_string(self):
val = self.state.buf
self.state.parent.val.append(val)
self.pop_state()
def state_string(self, c):
if self.at_eof():
raise ParseError(self, "unexpected EOF")
elif c == self.state.delim:
self.end_string()
elif c == '\\':
self.push_state(self.state_escape)
else:
self.state.buf += c
def state_escape(self, c):
if self.at_eof():
raise ParseError(self, "unexpected EOF")
d = escapes.get(c)
if d:
self.state.parent.buf += d
self.pop_state()
elif c == 'x':
self.state.fn = self.state_hex
self.state.val = 0
elif c in string.octdigits:
self.state.fn = self.state_octal
self.state.val = 0
self.input_char(c)
else:
# ignore escape if it doesn't match anything we know
self.state.parent.buf += '\\'
self.pop_state()
def state_octal(self, c):
def octaldigit(c):
self.state.val *= 8
self.state.val += ord(c) - ord('0')
self.state.buf += c
if self.state.val < 0 or self.state.val > 0xff:
raise ParseError(self, "invalid octal escape: out of range " + self.state.buf)
if len(self.state.buf) == 3:
octaldone()
def octaldone():
d = chr(self.state.val)
self.state.parent.buf += d
self.pop_state()
if self.at_eof():
raise ParseError(self, "unexpected EOF")
elif '0' <= c <= '7':
octaldigit(c)
elif len(self.state.buf):
octaldone()
self.input_char(c)
def state_hex(self, c):
def hexdone():
d = chr(self.state.val)
self.state.parent.buf += d
self.pop_state()
def hexdigit(c, d):
self.state.val *= 16
self.state.val += ord(c) - ord(d)
self.state.buf += c
if self.state.val < 0 or self.state.val > 0xff:
raise ParseError(self, "invalid hex escape: out of range " + self.state.buf)
if len(self.state.buf) == 2:
hexdone()
if self.at_eof():
raise ParseError(self, "unexpected EOF")
elif '0' <= c <= '9':
hexdigit(c, '0')
elif 'A' <= c <= 'F':
hexdigit(c, 'A')
elif 'a' <= c <= 'f':
hexdigit(c, 'a')
elif len(buf):
hexdone()
self.input_char(c)
def begin_atom(self, c):
self.push_state(self.state_atom)
self.state.buf = c
def end_atom(self):
val = self.state.buf
self.state.parent.val.append(val)
self.pop_state()
def state_atom(self, c):
if self.at_eof():
self.end_atom()
elif (self.is_separator(c) or
self.in_space_class(c) or
self.in_comment_class(c)):
self.end_atom()
self.input_char(c)
else:
self.state.buf += c
def begin_list(self, c):
self.push_state(self.state_list)
def end_list(self):
val = self.state.val
self.state.parent.val.append(val)
self.pop_state()
def state_list(self, c):
if self.at_eof():
raise ParseError(self, "unexpected EOF")
elif c == k_list_close:
self.end_list()
else:
self.state_start(c)
def atomp(sxpr):
"""Check if an sxpr is an atom.
"""
if sxpr.isalnum() or sxpr == '@':
return 1
for c in sxpr:
if c in string.whitespace: return 0
if c in '"\'\\(){}[]<>$#&%^': return 0
if c in string.ascii_letters: continue
if c in string.digits: continue
if c in '.-_:/~': continue
return 0
return 1
def show(sxpr, out=sys.stdout):
"""Print an sxpr in bracketed (lisp-style) syntax.
"""
if isinstance(sxpr, (types.ListType, types.TupleType)):
out.write(k_list_open)
i = 0
for x in sxpr:
if i: out.write(' ')
show(x, out)
i += 1
out.write(k_list_close)
elif isinstance(sxpr, (types.IntType, types.FloatType)):
out.write(str(sxpr))
elif isinstance(sxpr, types.StringType) and atomp(sxpr):
out.write(sxpr)
else:
out.write(repr(str(sxpr)))
def show_xml(sxpr, out=sys.stdout):
"""Print an sxpr in XML syntax.
"""
if isinstance(sxpr, (types.ListType, types.TupleType)):
element = name(sxpr)
out.write('<%s' % element)
for attr in attributes(sxpr):
out.write(' %s=%s' % (attr[0], attr[1]))
out.write('>')
i = 0
for x in children(sxpr):
if i: out.write(' ')
show_xml(x, out)
i += 1
out.write('</%s>' % element)
elif isinstance(sxpr, types.StringType) and atomp(sxpr):
out.write(sxpr)
else:
out.write(str(sxpr))
def elementp(sxpr, elt=None):
"""Check if an sxpr is an element of the given type.
sxpr sxpr
elt element type
"""
return (isinstance(sxpr, (types.ListType, types.TupleType))
and len(sxpr)
and (None == elt or sxpr[0] == elt))
def name(sxpr):
"""Get the element name of an sxpr.
If the sxpr is not an element (i.e. it's an atomic value) its name
is None.
sxpr
returns name (None if not an element).
"""
val = None
if isinstance(sxpr, types.StringType):
val = sxpr
elif isinstance(sxpr, (types.ListType, types.TupleType)) and len(sxpr):
val = sxpr[0]
return val
def attributes(sxpr):
"""Get the attribute list of an sxpr.
sxpr
returns attribute list
"""
val = []
if isinstance(sxpr, (types.ListType, types.TupleType)) and len(sxpr) > 1:
attr = sxpr[1]
if elementp(attr, k_attr_open):
val = attr[1:]
return val
def attribute(sxpr, key, val=None):
"""Get an attribute of an sxpr.
sxpr sxpr
key attribute key
val default value (default None)
returns attribute value
"""
for x in attributes(sxpr):
if x[0] == key:
val = x[1]
break
return val
def children(sxpr, elt=None):
"""Get children of an sxpr.
sxpr sxpr
elt optional element type to filter by
returns children (filtered by elt if specified)
"""
val = []
if isinstance(sxpr, (types.ListType, types.TupleType)) and len(sxpr) > 1:
i = 1
x = sxpr[i]
if elementp(x, k_attr_open):
i += 1
val = sxpr[i : ]
if elt:
def iselt(x):
return elementp(x, elt)
val = filter(iselt, val)
return val
def child(sxpr, elt, val=None):
"""Get the first child of the given element type.
sxpr sxpr
elt element type
val default value
"""
for x in children(sxpr):
if elementp(x, elt):
val = x
break
return val
def child_at(sxpr, index, val=None):
"""Get the child at the given index (zero-based).
sxpr sxpr
index index
val default value
"""
kids = children(sxpr)
if len(kids) > index:
val = kids[index]
return val
def child0(sxpr, val=None):
"""Get the zeroth child.
"""
return child_at(sxpr, 0, val)
def child1(sxpr, val=None):
"""Get the first child.
"""
return child_at(sxpr, 1, val)
def child2(sxpr, val=None):
"""Get the second child.
"""
return child_at(sxpr, 2, val)
def child3(sxpr, val=None):
"""Get the third child.
"""
return child_at(sxpr, 3, val)
def child4(sxpr, val=None):
"""Get the fourth child.
"""
return child_at(sxpr, 4, val)
def child_value(sxpr, elt, val=None):
"""Get the value of the first child of the given element type.
Assumes the child has an atomic value.
sxpr sxpr
elt element type
val default value
"""
kid = child(sxpr, elt)
if kid:
val = child_at(kid, 0, val)
return val
def has_id(sxpr, id):
"""Test if an s-expression has a given id.
"""
return attribute(sxpr, 'id') == id
def with_id(sxpr, id, val=None):
"""Find the first s-expression with a given id, at any depth.
sxpr s-exp or list
id id
val value if not found (default None)
return s-exp or val
"""
if isinstance(sxpr, (types.ListType, types.TupleType)):
for n in sxpr:
if has_id(n, id):
val = n
break
v = with_id(n, id)
if v is None: continue
val = v
break
return val
def child_with_id(sxpr, id, val=None):
"""Find the first child with a given id.
sxpr s-exp or list
id id
val value if not found (default None)
return s-exp or val
"""
if isinstance(sxpr, (types.ListType, types.TupleType)):
for n in sxpr:
if has_id(n, id):
val = n
break
return val
def elements(sxpr, ctxt=None):
"""Generate elements (at any depth).
Visit elements in pre-order.
Values generated are (node, context)
The context is None if there is no parent, otherwise
(index, parent, context) where index is the node's index w.r.t its parent,
and context is the parent's context.
sxpr s-exp
returns generator
"""
yield (sxpr, ctxt)
i = 0
for n in children(sxpr):
if isinstance(n, (types.ListType, types.TupleType)):
# Calling elements() recursively does not generate recursively,
# it just returns a generator object. So we must iterate over it.
for v in elements(n, (i, sxpr, ctxt)):
yield v
i += 1
def merge(s1, s2):
"""Merge sxprs s1 and s2.
Returns an sxpr containing all the fields from s1 and s2, with
entries in s1 overriding s2. Recursively merges fields.
@param s1 sxpr
@param s2 sxpr
@return merged sxpr
"""
if s1 is None:
val = s2
elif s2 is None:
val = s1
elif elementp(s1):
name1 = name(s1)
(m1, v1) = child_map(s1)
(m2, v2) = child_map(s2)
val = [name1]
for (k1, f1) in m1.items():
merge_list(val, f1, m2.get(k1, []))
for (k2, f2) in m2.items():
if k2 in m1: continue
val.extend(f2)
val.extend(v1)
else:
val = s1
return val
def merge_list(sxpr, l1, l2):
"""Merge element lists l1 and l2 into sxpr.
The lists l1 and l2 are all element with the same name.
Values from l1 are merged with values in l2 and stored in sxpr.
If one list is longer than the other the excess values are used
as they are.
@param sxpr to merge into
@param l1 sxpr list
@param l2 sxpr list
@return modified sxpr
"""
n1 = len(l1)
n2 = len(l2)
nmin = min(n1, n2)
for i in range(0, nmin):
sxpr.append(merge(l1[i], l2[i]))
for i in range(nmin, n1):
sxpr.append(l1[i])
for i in range(nmin, n2):
sxpr.append(l2[i])
return sxpr
def child_map(sxpr):
"""Get a dict of the elements in sxpr and a list of its values.
The dict maps element name to the list of elements with that name,
and the list is the non-element children.
@param sxpr
@return (dict, list)
"""
m = {}
v = []
for x in children(sxpr):
if elementp(x):
n = name(x)
l = m.get(n, [])
l.append(x)
m[n] = l
else:
v.append(x)
return (m, v)
def to_string(sxpr):
"""Convert an sxpr to a string.
sxpr sxpr
returns string
"""
io = StringIO()
show(sxpr, io)
io.seek(0)
val = io.getvalue()
io.close()
return val
def from_string(s):
"""Create an sxpr by parsing a string.
s string
returns sxpr
"""
if s == '':
return []
io = StringIO(s)
vals = parse(io)
if vals is []:
return None
else:
return vals[0]
def all_from_string(s):
"""Create an sxpr list by parsing a string.
s string
returns sxpr list
"""
io = StringIO(s)
vals = parse(io)
return vals
def parse(io):
"""Completely parse all input from 'io'.
io input file object
returns list of values, None if incomplete
raises ParseError on parse error
"""
pin = Parser()
while 1:
buf = io.readline()
pin.input(buf)
if len(buf) == 0:
break
if pin.ready():
val = pin.get_all()
else:
val = None
return val
if __name__ == '__main__':
print ">main"
pin = Parser()
while 1:
buf = sys.stdin.read(1024)
#buf = sys.stdin.readline()
pin.input(buf)
while pin.ready():
val = pin.get_val()
print
print '****** val=', val
if len(buf) == 0:
break