3 "Read IGOR Packed Experiment files files into records."
5 from .struct import Structure as _Structure
6 from .struct import Field as _Field
7 from .util import byte_order as _byte_order
8 from .util import need_to_reorder_bytes as _need_to_reorder_bytes
9 from .record import RECORD_TYPE as _RECORD_TYPE
10 from .record.base import UnknownRecord as _UnknownRecord
11 from .record.base import UnusedRecord as _UnusedRecord
12 from .record.folder import FolderStartRecord as _FolderStartRecord
13 from .record.folder import FolderEndRecord as _FolderEndRecord
14 from .record.variables import VariablesRecord as _VariablesRecord
15 from .record.wave import WaveRecord as _WaveRecord
19 # Igor writes other kinds of records in a packed experiment file, for
20 # storing things like pictures, page setup records, and miscellaneous
21 # settings. The format for these records is quite complex and is not
22 # described in PTN003. If you are writing a program to read packed
23 # files, you must skip any record with a record type that is not
26 PackedFileRecordHeader = _Structure(
27 name='PackedFileRecordHeader',
29 _Field('H', 'recordType', help='Record type plus superceded flag.'),
30 _Field('h', 'version', help='Version information depends on the type of record.'),
31 _Field('l', 'numDataBytes', help='Number of data bytes in the record following this record header.'),
36 PACKEDRECTYPE_MASK = 0x7FFF # Record type = (recordType & PACKEDREC_TYPE_MASK)
37 SUPERCEDED_MASK = 0x8000 # Bit is set if the record is superceded by
38 # a later record in the packed file.
41 def load(filename, strict=True, ignore_unknown=True):
43 if hasattr(filename, 'read'):
44 f = filename # filename is actually a stream object
46 f = open(filename, 'rb')
48 initial_byte_order = '='
51 b = buffer(f.read(PackedFileRecordHeader.size))
54 PackedFileRecordHeader.set_byte_order(initial_byte_order)
55 header = PackedFileRecordHeader.unpack_from(b)
56 if header['version'] and not byte_order:
57 need_to_reorder = _need_to_reorder_bytes(header['version'])
58 byte_order = initial_byte_order = _byte_order(need_to_reorder)
60 PackedFileRecordHeader.set_byte_order(byte_order)
61 header = PackedFileRecordHeader.unpack_from(b)
62 data = buffer(f.read(header['numDataBytes']))
63 record_type = _RECORD_TYPE.get(
64 header['recordType'] & PACKEDRECTYPE_MASK, _UnknownRecord)
65 if record_type in [_UnknownRecord, _UnusedRecord
66 ] and not ignore_unknown:
67 raise KeyError('unkown record type {}'.format(
68 header['recordType']))
69 records.append(record_type(header, data, byte_order=byte_order))
71 if not hasattr(filename, 'read'):
74 filesystem = _build_filesystem(records)
76 return (records, filesystem)
78 def _build_filesystem(records):
80 """The name must be a valid Igor data folder name. See Object
81 Names in the Igor Reference help file for name rules.
83 When Igor Pro reads the data folder start record, it creates a new
84 data folder with the specified name. Any subsequent variable, wave
85 or data folder start records cause Igor to create data objects in
86 this new data folder, until Igor Pro reads a corresponding data
88 # From the Igor Manual, chapter 2, section 8, page II-123
89 # http://www.wavemetrics.net/doc/igorman/II-08%20Data%20Folders.pdf
90 """Like the Macintosh file system, Igor Pro's data folders use the
91 colon character (:) to separate components of a path to an
92 object. This is analogous to Unix which uses / and Windows which
93 uses \. (Reminder: Igor's data folders exist wholly in memory
94 while an experiment is open. It is not a disk file system!)
96 A data folder named "root" always exists and contains all other
99 # From the Igor Manual, chapter 4, page IV-2
100 # http://www.wavemetrics.net/doc/igorman/IV-01%20Commands.pdf
101 """For waves and data folders only, you can also use "liberal"
102 names. Liberal names can include almost any character, including
103 spaces and dots (see Liberal Object Names on page III-415 for
106 # From the Igor Manual, chapter 3, section 16, page III-416
107 # http://www.wavemetrics.net/doc/igorman/III-16%20Miscellany.pdf
108 """Liberal names have the same rules as standard names except you
109 may use any character except control characters and the following:
113 filesystem = {'root': {}}
114 dir_stack = [('root', filesystem['root'])]
115 for record in records:
116 cwd = dir_stack[-1][-1]
117 if isinstance(record, _FolderStartRecord):
118 name = record.null_terminated_text
120 dir_stack.append((name, cwd[name]))
121 elif isinstance(record, _FolderEndRecord):
123 elif isinstance(record, (_VariablesRecord, _WaveRecord)):
124 if isinstance(record, _VariablesRecord):
125 _add_variables(dir_stack, cwd, record)
126 # start with an invalid character to avoid collisions
128 #filename = ':variables'
129 #_check_filename(dir_stack, filename)
130 #cwd[filename] = record
132 filename = ''.join(c for c in record.wave_info['bname']
133 ).split('\x00', 1)[0]
134 _check_filename(dir_stack, filename)
135 cwd[filename] = record
138 def _check_filename(dir_stack, filename):
139 cwd = dir_stack[-1][-1]
141 raise ValueError('collision on name {} in {}'.format(
142 filename, ':'.join(d for d,cwd in dir_stack)))
144 def _add_variables(dir_stack, cwd, record):
145 if len(dir_stack) == 1:
147 """When reading a packed file, any system variables
148 encountered while the current data folder is not the root
151 for i,value in enumerate(record.variables['sysVars']):
152 name = 'K{}'.format(i)
153 _check_filename(dir_stack, name)
156 record.variables['userVars'].items() +
157 record.variables['userStrs'].items()):
158 _check_filename(dir_stack, name)
160 if record.variables['header']['version'] == 2:
161 raise NotImplementedError('add dependent variables to filesystem')