/usr/lib/python2.7/dist-packages/xlwt/CompoundDoc.py is in python-xlwt 0.7.5+debian1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | # -*- coding: windows-1252 -*-
import struct
# This implementation writes only 'Root Entry', 'Workbook' streams
# and 2 empty streams for aligning directory stream on sector boundary
#
# LAYOUT:
# 0 header
# 76 MSAT (1st part: 109 SID)
# 512 workbook stream
# ... additional MSAT sectors if streams' size > about 7 Mb == (109*512 * 128)
# ... SAT
# ... directory stream
#
# NOTE: this layout is "ad hoc". It can be more general. RTFM
class XlsDoc:
SECTOR_SIZE = 0x0200
MIN_LIMIT = 0x1000
SID_FREE_SECTOR = -1
SID_END_OF_CHAIN = -2
SID_USED_BY_SAT = -3
SID_USED_BY_MSAT = -4
def __init__(self):
#self.book_stream = '' # padded
self.book_stream_sect = []
self.dir_stream = ''
self.dir_stream_sect = []
self.packed_SAT = ''
self.SAT_sect = []
self.packed_MSAT_1st = ''
self.packed_MSAT_2nd = ''
self.MSAT_sect_2nd = []
self.header = ''
def __build_directory(self): # align on sector boundary
self.dir_stream = ''
dentry_name = '\x00'.join('Root Entry\x00') + '\x00'
dentry_name_sz = len(dentry_name)
dentry_name_pad = '\x00'*(64 - dentry_name_sz)
dentry_type = 0x05 # root storage
dentry_colour = 0x01 # black
dentry_did_left = -1
dentry_did_right = -1
dentry_did_root = 1
dentry_start_sid = -2
dentry_stream_sz = 0
self.dir_stream += struct.pack('<64s H 2B 3l 9L l L L',
dentry_name + dentry_name_pad,
dentry_name_sz,
dentry_type,
dentry_colour,
dentry_did_left,
dentry_did_right,
dentry_did_root,
0, 0, 0, 0, 0, 0, 0, 0, 0,
dentry_start_sid,
dentry_stream_sz,
0
)
dentry_name = '\x00'.join('Workbook\x00') + '\x00'
dentry_name_sz = len(dentry_name)
dentry_name_pad = '\x00'*(64 - dentry_name_sz)
dentry_type = 0x02 # user stream
dentry_colour = 0x01 # black
dentry_did_left = -1
dentry_did_right = -1
dentry_did_root = -1
dentry_start_sid = 0
dentry_stream_sz = self.book_stream_len
self.dir_stream += struct.pack('<64s H 2B 3l 9L l L L',
dentry_name + dentry_name_pad,
dentry_name_sz,
dentry_type,
dentry_colour,
dentry_did_left,
dentry_did_right,
dentry_did_root,
0, 0, 0, 0, 0, 0, 0, 0, 0,
dentry_start_sid,
dentry_stream_sz,
0
)
# padding
dentry_name = ''
dentry_name_sz = len(dentry_name)
dentry_name_pad = '\x00'*(64 - dentry_name_sz)
dentry_type = 0x00 # empty
dentry_colour = 0x01 # black
dentry_did_left = -1
dentry_did_right = -1
dentry_did_root = -1
dentry_start_sid = -2
dentry_stream_sz = 0
self.dir_stream += struct.pack('<64s H 2B 3l 9L l L L',
dentry_name + dentry_name_pad,
dentry_name_sz,
dentry_type,
dentry_colour,
dentry_did_left,
dentry_did_right,
dentry_did_root,
0, 0, 0, 0, 0, 0, 0, 0, 0,
dentry_start_sid,
dentry_stream_sz,
0
) * 2
def __build_sat(self):
# Build SAT
book_sect_count = self.book_stream_len >> 9
dir_sect_count = len(self.dir_stream) >> 9
total_sect_count = book_sect_count + dir_sect_count
SAT_sect_count = 0
MSAT_sect_count = 0
SAT_sect_count_limit = 109
while total_sect_count > 128*SAT_sect_count or SAT_sect_count > SAT_sect_count_limit:
SAT_sect_count += 1
total_sect_count += 1
if SAT_sect_count > SAT_sect_count_limit:
MSAT_sect_count += 1
total_sect_count += 1
SAT_sect_count_limit += 127
SAT = [self.SID_FREE_SECTOR]*128*SAT_sect_count
sect = 0
while sect < book_sect_count - 1:
self.book_stream_sect.append(sect)
SAT[sect] = sect + 1
sect += 1
self.book_stream_sect.append(sect)
SAT[sect] = self.SID_END_OF_CHAIN
sect += 1
while sect < book_sect_count + MSAT_sect_count:
self.MSAT_sect_2nd.append(sect)
SAT[sect] = self.SID_USED_BY_MSAT
sect += 1
while sect < book_sect_count + MSAT_sect_count + SAT_sect_count:
self.SAT_sect.append(sect)
SAT[sect] = self.SID_USED_BY_SAT
sect += 1
while sect < book_sect_count + MSAT_sect_count + SAT_sect_count + dir_sect_count - 1:
self.dir_stream_sect.append(sect)
SAT[sect] = sect + 1
sect += 1
self.dir_stream_sect.append(sect)
SAT[sect] = self.SID_END_OF_CHAIN
sect += 1
self.packed_SAT = struct.pack('<%dl' % (SAT_sect_count*128), *SAT)
MSAT_1st = [self.SID_FREE_SECTOR]*109
for i, SAT_sect_num in zip(range(0, 109), self.SAT_sect):
MSAT_1st[i] = SAT_sect_num
self.packed_MSAT_1st = struct.pack('<109l', *MSAT_1st)
MSAT_2nd = [self.SID_FREE_SECTOR]*128*MSAT_sect_count
if MSAT_sect_count > 0:
MSAT_2nd[- 1] = self.SID_END_OF_CHAIN
i = 109
msat_sect = 0
sid_num = 0
while i < SAT_sect_count:
if (sid_num + 1) % 128 == 0:
#print 'link: ',
msat_sect += 1
if msat_sect < len(self.MSAT_sect_2nd):
MSAT_2nd[sid_num] = self.MSAT_sect_2nd[msat_sect]
else:
#print 'sid: ',
MSAT_2nd[sid_num] = self.SAT_sect[i]
i += 1
#print sid_num, MSAT_2nd[sid_num]
sid_num += 1
self.packed_MSAT_2nd = struct.pack('<%dl' % (MSAT_sect_count*128), *MSAT_2nd)
#print vars()
#print zip(range(0, sect), SAT)
#print self.book_stream_sect
#print self.MSAT_sect_2nd
#print MSAT_2nd
#print self.SAT_sect
#print self.dir_stream_sect
def __build_header(self):
doc_magic = '\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1'
file_uid = '\x00'*16
rev_num = '\x3E\x00'
ver_num = '\x03\x00'
byte_order = '\xFE\xFF'
log_sect_size = struct.pack('<H', 9)
log_short_sect_size = struct.pack('<H', 6)
not_used0 = '\x00'*10
total_sat_sectors = struct.pack('<L', len(self.SAT_sect))
dir_start_sid = struct.pack('<l', self.dir_stream_sect[0])
not_used1 = '\x00'*4
min_stream_size = struct.pack('<L', 0x1000)
ssat_start_sid = struct.pack('<l', -2)
total_ssat_sectors = struct.pack('<L', 0)
if len(self.MSAT_sect_2nd) == 0:
msat_start_sid = struct.pack('<l', -2)
else:
msat_start_sid = struct.pack('<l', self.MSAT_sect_2nd[0])
total_msat_sectors = struct.pack('<L', len(self.MSAT_sect_2nd))
self.header = ''.join([ doc_magic,
file_uid,
rev_num,
ver_num,
byte_order,
log_sect_size,
log_short_sect_size,
not_used0,
total_sat_sectors,
dir_start_sid,
not_used1,
min_stream_size,
ssat_start_sid,
total_ssat_sectors,
msat_start_sid,
total_msat_sectors
])
def save(self, file_name_or_filelike_obj, stream):
# 1. Align stream on 0x1000 boundary (and therefore on sector boundary)
padding = '\x00' * (0x1000 - (len(stream) % 0x1000))
self.book_stream_len = len(stream) + len(padding)
self.__build_directory()
self.__build_sat()
self.__build_header()
f = file_name_or_filelike_obj
we_own_it = not hasattr(f, 'write')
if we_own_it:
f = open(file_name_or_filelike_obj, 'w+b')
f.write(self.header)
f.write(self.packed_MSAT_1st)
# There are reports of large writes failing when writing to "network shares" on Windows.
# MS says in KB899149 that it happens at 32KB less than 64MB.
# This is said to be alleviated by using "w+b" mode instead of "wb".
# One xlwt user has reported anomalous results at much smaller sizes,
# The fallback is to write the stream in 4 MB chunks.
try:
f.write(stream)
except IOError, e:
if e.errno != 22: # "Invalid argument" i.e. 'stream' is too big
raise # some other problem
chunk_size = 4 * 1024 * 1024
for offset in xrange(0, len(stream), chunk_size):
f.write(buffer(stream, offset, chunk_size))
f.write(padding)
f.write(self.packed_MSAT_2nd)
f.write(self.packed_SAT)
f.write(self.dir_stream)
if we_own_it:
f.close()
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