1 # Copyright (C) 2012 W. Trevor King <wking@tremily.us>
3 # This file is part of igor.
5 # igor is free software: you can redistribute it and/or modify it under the
6 # terms of the GNU Lesser General Public License as published by the Free
7 # Software Foundation, either version 3 of the License, or (at your option) any
10 # igor is distributed in the hope that it will be useful, but WITHOUT ANY
11 # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12 # A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
15 # You should have received a copy of the GNU Lesser General Public License
16 # along with igor. If not, see <http://www.gnu.org/licenses/>.
18 "Read IGOR Packed Experiment files files into records."
20 from . import LOG as _LOG
21 from .struct import Structure as _Structure
22 from .struct import Field as _Field
23 from .util import byte_order as _byte_order
24 from .util import need_to_reorder_bytes as _need_to_reorder_bytes
25 from .util import _bytes
26 from .record import RECORD_TYPE as _RECORD_TYPE
27 from .record.base import UnknownRecord as _UnknownRecord
28 from .record.base import UnusedRecord as _UnusedRecord
29 from .record.folder import FolderStartRecord as _FolderStartRecord
30 from .record.folder import FolderEndRecord as _FolderEndRecord
31 from .record.variables import VariablesRecord as _VariablesRecord
32 from .record.wave import WaveRecord as _WaveRecord
36 # Igor writes other kinds of records in a packed experiment file, for
37 # storing things like pictures, page setup records, and miscellaneous
38 # settings. The format for these records is quite complex and is not
39 # described in PTN003. If you are writing a program to read packed
40 # files, you must skip any record with a record type that is not
43 PackedFileRecordHeader = _Structure(
44 name='PackedFileRecordHeader',
46 _Field('H', 'recordType', help='Record type plus superceded flag.'),
47 _Field('h', 'version', help='Version information depends on the type of record.'),
48 _Field('l', 'numDataBytes', help='Number of data bytes in the record following this record header.'),
53 PACKEDRECTYPE_MASK = 0x7FFF # Record type = (recordType & PACKEDREC_TYPE_MASK)
54 SUPERCEDED_MASK = 0x8000 # Bit is set if the record is superceded by
55 # a later record in the packed file.
58 def load(filename, strict=True, ignore_unknown=True):
59 _LOG.debug('loading a packed experiment file from {}'.format(filename))
61 if hasattr(filename, 'read'):
62 f = filename # filename is actually a stream object
64 f = open(filename, 'rb')
66 initial_byte_order = '='
69 PackedFileRecordHeader.byte_order = initial_byte_order
70 PackedFileRecordHeader.setup()
71 b = bytes(f.read(PackedFileRecordHeader.size))
74 if len(b) < PackedFileRecordHeader.size:
76 ('not enough data for the next record header ({} < {})'
77 ).format(len(b), PackedFileRecordHeader.size))
78 _LOG.debug('reading a new packed experiment file record')
79 header = PackedFileRecordHeader.unpack_from(b)
80 if header['version'] and not byte_order:
81 need_to_reorder = _need_to_reorder_bytes(header['version'])
82 byte_order = initial_byte_order = _byte_order(need_to_reorder)
84 'get byte order from version: {} (reorder? {})'.format(
85 byte_order, need_to_reorder))
87 PackedFileRecordHeader.byte_order = byte_order
88 PackedFileRecordHeader.setup()
89 header = PackedFileRecordHeader.unpack_from(b)
91 'reordered version: {}'.format(header['version']))
92 data = bytes(f.read(header['numDataBytes']))
93 if len(data) < header['numDataBytes']:
95 ('not enough data for the next record ({} < {})'
96 ).format(len(b), header['numDataBytes']))
97 record_type = _RECORD_TYPE.get(
98 header['recordType'] & PACKEDRECTYPE_MASK, _UnknownRecord)
99 _LOG.debug('the new record has type {} ({}).'.format(
100 record_type, header['recordType']))
101 if record_type in [_UnknownRecord, _UnusedRecord
102 ] and not ignore_unknown:
103 raise KeyError('unkown record type {}'.format(
104 header['recordType']))
105 records.append(record_type(header, data, byte_order=byte_order))
107 _LOG.debug('finished loading {} records from {}'.format(
108 len(records), filename))
109 if not hasattr(filename, 'read'):
112 filesystem = _build_filesystem(records)
114 return (records, filesystem)
116 def _build_filesystem(records):
118 """The name must be a valid Igor data folder name. See Object
119 Names in the Igor Reference help file for name rules.
121 When Igor Pro reads the data folder start record, it creates a new
122 data folder with the specified name. Any subsequent variable, wave
123 or data folder start records cause Igor to create data objects in
124 this new data folder, until Igor Pro reads a corresponding data
125 folder end record."""
126 # From the Igor Manual, chapter 2, section 8, page II-123
127 # http://www.wavemetrics.net/doc/igorman/II-08%20Data%20Folders.pdf
128 """Like the Macintosh file system, Igor Pro's data folders use the
129 colon character (:) to separate components of a path to an
130 object. This is analogous to Unix which uses / and Windows which
131 uses \. (Reminder: Igor's data folders exist wholly in memory
132 while an experiment is open. It is not a disk file system!)
134 A data folder named "root" always exists and contains all other
137 # From the Igor Manual, chapter 4, page IV-2
138 # http://www.wavemetrics.net/doc/igorman/IV-01%20Commands.pdf
139 """For waves and data folders only, you can also use "liberal"
140 names. Liberal names can include almost any character, including
141 spaces and dots (see Liberal Object Names on page III-415 for
144 # From the Igor Manual, chapter 3, section 16, page III-416
145 # http://www.wavemetrics.net/doc/igorman/III-16%20Miscellany.pdf
146 """Liberal names have the same rules as standard names except you
147 may use any character except control characters and the following:
151 filesystem = {'root': {}}
152 dir_stack = [('root', filesystem['root'])]
153 for record in records:
154 cwd = dir_stack[-1][-1]
155 if isinstance(record, _FolderStartRecord):
156 name = record.null_terminated_text
158 dir_stack.append((name, cwd[name]))
159 elif isinstance(record, _FolderEndRecord):
161 elif isinstance(record, (_VariablesRecord, _WaveRecord)):
162 if isinstance(record, _VariablesRecord):
163 sys_vars = record.variables['variables']['sysVars'].keys()
164 for filename,value in record.namespace.items():
165 if len(dir_stack) > 1 and filename in sys_vars:
167 """When reading a packed file, any system
168 variables encountered while the current data
169 folder is not the root should be ignored.
172 _check_filename(dir_stack, filename)
173 cwd[filename] = value
175 filename = record.wave['wave']['wave_header']['bname']
176 _check_filename(dir_stack, filename)
177 cwd[filename] = record
180 def _check_filename(dir_stack, filename):
181 cwd = dir_stack[-1][-1]
183 raise ValueError('collision on name {} in {}'.format(
184 filename, ':'.join(d for d,cwd in dir_stack)))
186 def walk(filesystem, callback, dirpath=None):
187 """Walk a packed experiment filesystem, operating on each key,value pair.
191 for key,value in sorted((_bytes(k),v) for k,v in filesystem.items()):
192 callback(dirpath, key, value)
193 if isinstance(value, dict):
194 walk(filesystem=value, callback=callback, dirpath=dirpath+[key])