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
|
# A class that makes each part of a multipart message "feel" like an
# ordinary file, as long as you use fp.readline(). Allows recursive
# use, for nested multipart messages. Probably best used together
# with module mimetools.
#
# Suggested use:
#
# real_fp = open(...)
# fp = MultiFile(real_fp)
#
# "read some lines from fp"
# fp.push(separator)
# while 1:
# "read lines from fp until it returns an empty string" (A)
# if not fp.next(): break
# fp.pop()
# "read remaining lines from fp until it returns an empty string"
#
# The latter sequence may be used recursively at (A).
# It is also allowed to use multiple push()...pop() sequences.
# Note that if a nested multipart message is terminated by a separator
# for an outer message, this is not reported, even though it is really
# illegal input.
import sys
import string
err = sys.stderr.write
Error = 'multifile.Error'
class MultiFile:
#
def __init__(self, fp):
self.fp = fp
self.stack = [] # Grows down
self.level = 0
self.last = 0
self.start = self.fp.tell()
self.posstack = [] # Grows down
#
def tell(self):
if self.level > 0:
return self.lastpos
return self.fp.tell() - self.start
#
def seek(self, pos, whence=0):
here = self.tell()
if whence:
if whence == 1:
pos = pos + here
elif whence == 2:
if self.level > 0:
pos = pos + self.lastpos
else:
raise Error, "can't use whence=2 yet"
if not 0 <= pos <= here or \
self.level > 0 and pos > self.lastpos:
raise Error, 'bad MultiFile.seek() call'
self.fp.seek(pos + self.start)
self.level = 0
self.last = 0
#
def readline(self):
if self.level > 0: return ''
line = self.fp.readline()
if not line:
self.level = len(self.stack)
self.last = (self.level > 0)
if self.last:
err('*** Sudden EOF in MultiFile.readline()\n')
return ''
if line[:2] <> '--': return line
n = len(line)
k = n
while k > 0 and line[k-1] in string.whitespace: k = k-1
mark = line[2:k]
if mark[-2:] == '--': mark1 = mark[:-2]
else: mark1 = None
for i in range(len(self.stack)):
sep = self.stack[i]
if sep == mark:
self.last = 0
break
elif mark1 <> None and sep == mark1:
self.last = 1
break
else:
return line
# Get here after break out of loop
self.lastpos = self.tell() - len(line)
self.level = i+1
if self.level > 1:
err('*** Missing endmarker in MultiFile.readline()\n')
return ''
#
def readlines(self):
list = []
while 1:
line = self.readline()
if not line: break
list.append(line)
return list
#
def read(self): # Note: no size argument -- read until EOF only!
return string.joinfields(self.readlines(), '')
#
def next(self):
while self.readline(): pass
if self.level > 1 or self.last:
return 0
self.level = 0
self.last = 0
self.start = self.fp.tell()
return 1
#
def push(self, sep):
if self.level > 0:
raise Error, 'bad MultiFile.push() call'
self.stack.insert(0, sep)
self.posstack.insert(0, self.start)
self.start = self.fp.tell()
#
def pop(self):
if self.stack == []:
raise Error, 'bad MultiFile.pop() call'
if self.level <= 1:
self.last = 0
else:
abslastpos = self.lastpos + self.start
self.level = max(0, self.level - 1)
del self.stack[0]
self.start = self.posstack[0]
del self.posstack[0]
if self.level > 0:
self.lastpos = abslastpos - self.start
#
|
