File: readfile.py

package info (click to toggle)
python-rosettasciio 0.7.1-2
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 144,644 kB
  • sloc: python: 36,638; xml: 2,582; makefile: 20; ansic: 4
file content (256 lines) | stat: -rw-r--r-- 7,317 bytes parent folder | download
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
# -*- coding: utf-8 -*-

# Copyright 2010 Stefano Mazzucco
#
# This file is part of dm3_data_plugin.
#
# dm3_data_plugin is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# dm3_data_plugin 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with RosettaSciIO; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301
# USA

# general functions for reading data from files

import logging
import struct

from rsciio.utils.exceptions import ByteOrderError

_logger = logging.getLogger(__name__)

# Declare simple TagDataType structures for faster execution.
# The variables are named as following:
# Endianness_type
# Endianness = B (big) or L (little)
# type = (u)short, (u)long, float, double, bool (unsigned char),
# byte (signed char), char

B_short = struct.Struct(">h")
L_short = struct.Struct("<h")

B_ushort = struct.Struct(">H")
L_ushort = struct.Struct("<H")

B_long = struct.Struct(">l")
L_long = struct.Struct("<l")

B_long_long = struct.Struct(">q")
L_long_long = struct.Struct("<q")

B_ulong = struct.Struct(">L")
L_ulong = struct.Struct("<L")

B_ulong_long = struct.Struct(">Q")
L_ulong_long = struct.Struct("<Q")

B_float = struct.Struct(">f")
L_float = struct.Struct("<f")

B_double = struct.Struct(">d")
L_double = struct.Struct("<d")

B_bool = struct.Struct(">B")  # use unsigned char
L_bool = struct.Struct("<B")

B_byte = struct.Struct(">b")  # use signed char
L_byte = struct.Struct("<b")

B_char = struct.Struct(">c")
L_char = struct.Struct("<c")


def read_short(f, endian):
    """Read a 2-Byte integer from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(2)  # hexadecimal representation
        if endian == "big":
            s = B_short
        elif endian == "little":
            s = L_short
        return s.unpack(data)[0]  # struct.unpack returns a tuple


def read_ushort(f, endian):
    """Read a 2-Byte integer from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(2)
        if endian == "big":
            s = B_ushort
        elif endian == "little":
            s = L_ushort
        return s.unpack(data)[0]


def read_long(f, endian):
    """Read a 4-Byte integer from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(4)
        if endian == "big":
            s = B_long
        elif endian == "little":
            s = L_long
        return s.unpack(data)[0]


def read_long_long(f, endian):
    """Read a 8-Byte integer from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(8)
        if endian == "big":
            s = B_long_long
        elif endian == "little":
            s = L_long_long
        return s.unpack(data)[0]


def read_ulong(f, endian):
    """Read a 4-Byte integer from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(4)
        if endian == "big":
            s = B_ulong
        elif endian == "little":
            s = L_ulong
        return s.unpack(data)[0]


def read_ulong_long(f, endian):
    """Read a 8-Byte integer from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(8)
        if endian == "big":
            s = B_ulong_long
        elif endian == "little":
            s = L_ulong_long
        return s.unpack(data)[0]


def read_float(f, endian):
    """Read a 4-Byte floating point from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(4)
        if endian == "big":
            s = B_float
        elif endian == "little":
            s = L_float
        return s.unpack(data)[0]


def read_double(f, endian):
    """Read a 8-Byte floating point from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(8)
        if endian == "big":
            s = B_double
        elif endian == "little":
            s = L_double
        return s.unpack(data)[0]


def read_boolean(f, endian):
    """Read a 1-Byte charater from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(1)
        if endian == "big":
            s = B_bool
        elif endian == "little":
            s = L_bool
        return s.unpack(data)[0]


def read_byte(f, endian):
    """Read a 1-Byte charater from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(1)
        if endian == "big":
            s = B_byte
        elif endian == "little":
            s = L_byte
        return s.unpack(data)[0]


def read_char(f, endian):
    """Read a 1-Byte charater from file f
    with a given endianness (byte order).
    endian can be either 'big' or 'little'.
    """
    if (endian != "little") and (endian != "big"):
        _logger.debug("File address:", f.tell())
        raise ByteOrderError(endian)
    else:
        data = f.read(1)
        if endian == "big":
            s = B_char
        elif endian == "little":
            s = L_char
        return s.unpack(data)[0]