1 | """ |
---|
2 | File handler to support different file extensions. |
---|
3 | Uses reflectometer registry utility. |
---|
4 | |
---|
5 | The default readers are found in the 'readers' sub-module |
---|
6 | and registered by default at initialization time. |
---|
7 | |
---|
8 | To add a new default reader, one must register it in |
---|
9 | the register_readers method found in readers/__init__.py. |
---|
10 | |
---|
11 | A utility method (find_plugins) is available to inspect |
---|
12 | a directory (for instance, a user plug-in directory) and |
---|
13 | look for new readers/writers. |
---|
14 | """ |
---|
15 | ##################################################################### |
---|
16 | # This software was developed by the University of Tennessee as part of the |
---|
17 | # Distributed Data Analysis of Neutron Scattering Experiments (DANSE) |
---|
18 | # project funded by the US National Science Foundation. |
---|
19 | # See the license text in license.txt |
---|
20 | # copyright 2008, University of Tennessee |
---|
21 | ###################################################################### |
---|
22 | |
---|
23 | import os |
---|
24 | import sys |
---|
25 | import logging |
---|
26 | import time |
---|
27 | from zipfile import ZipFile |
---|
28 | |
---|
29 | from sas.sascalc.data_util.registry import ExtensionRegistry |
---|
30 | |
---|
31 | # Default readers are defined in the readers sub-module |
---|
32 | from . import readers |
---|
33 | from .loader_exceptions import NoKnownLoaderException, FileContentsException,\ |
---|
34 | DefaultReaderException |
---|
35 | from .readers import ascii_reader |
---|
36 | from .readers import cansas_reader |
---|
37 | from .readers import cansas_reader_HDF5 |
---|
38 | |
---|
39 | logger = logging.getLogger(__name__) |
---|
40 | |
---|
41 | |
---|
42 | class Registry(ExtensionRegistry): |
---|
43 | """ |
---|
44 | Registry class for file format extensions. |
---|
45 | Readers and writers are supported. |
---|
46 | """ |
---|
47 | def __init__(self): |
---|
48 | super(Registry, self).__init__() |
---|
49 | |
---|
50 | # Writers |
---|
51 | self.writers = {} |
---|
52 | |
---|
53 | # List of wildcards |
---|
54 | self.wildcards = ['All (*.*)|*.*'] |
---|
55 | |
---|
56 | # Creation time, for testing |
---|
57 | self._created = time.time() |
---|
58 | |
---|
59 | # Register default readers |
---|
60 | readers.read_associations(self) |
---|
61 | |
---|
62 | def load(self, path, format=None): |
---|
63 | """ |
---|
64 | Call the loader for the file type of path. |
---|
65 | |
---|
66 | :param path: file path |
---|
67 | :param format: explicit extension, to force the use |
---|
68 | of a particular reader |
---|
69 | |
---|
70 | Defaults to the ascii (multi-column), cansas XML, and cansas NeXuS |
---|
71 | readers if no reader was registered for the file's extension. |
---|
72 | """ |
---|
73 | # Gets set to a string if the file has an associated reader that fails |
---|
74 | msg_from_reader = None |
---|
75 | try: |
---|
76 | return super(Registry, self).load(path, format=format) |
---|
77 | except NoKnownLoaderException as nkl_e: |
---|
78 | pass # Try the ASCII reader |
---|
79 | except FileContentsException as fc_exc: |
---|
80 | # File has an associated reader but it failed. |
---|
81 | # Save the error message to display later, but try the 3 default loaders |
---|
82 | msg_from_reader = fc_exc.message |
---|
83 | except Exception: |
---|
84 | pass |
---|
85 | |
---|
86 | # File has no associated reader, or the associated reader failed. |
---|
87 | # Try the ASCII reader |
---|
88 | try: |
---|
89 | ascii_loader = ascii_reader.Reader() |
---|
90 | return ascii_loader.read(path) |
---|
91 | except DefaultReaderException: |
---|
92 | pass # Loader specific error to try the cansas XML reader |
---|
93 | except FileContentsException as e: |
---|
94 | if msg_from_reader is None: |
---|
95 | raise RuntimeError(e.message) |
---|
96 | |
---|
97 | # ASCII reader failed - try CanSAS xML reader |
---|
98 | try: |
---|
99 | cansas_loader = cansas_reader.Reader() |
---|
100 | return cansas_loader.read(path) |
---|
101 | except DefaultReaderException: |
---|
102 | pass # Loader specific error to try the NXcanSAS reader |
---|
103 | except FileContentsException as e: |
---|
104 | if msg_from_reader is None: |
---|
105 | raise RuntimeError(e.message) |
---|
106 | except Exception: |
---|
107 | pass |
---|
108 | |
---|
109 | # CanSAS XML reader failed - try NXcanSAS reader |
---|
110 | try: |
---|
111 | cansas_nexus_loader = cansas_reader_HDF5.Reader() |
---|
112 | return cansas_nexus_loader.read(path) |
---|
113 | except DefaultReaderException as e: |
---|
114 | logging.error("No default loader can load the data") |
---|
115 | # No known reader available. Give up and throw an error |
---|
116 | if msg_from_reader is None: |
---|
117 | msg = "\nUnknown data format: {}.\nThe file is not a ".format(path) |
---|
118 | msg += "known format that can be loaded by SasView.\n" |
---|
119 | raise NoKnownLoaderException(msg) |
---|
120 | else: |
---|
121 | # Associated reader and default readers all failed. |
---|
122 | # Show error message from associated reader |
---|
123 | raise RuntimeError(msg_from_reader) |
---|
124 | except FileContentsException as e: |
---|
125 | err_msg = msg_from_reader if msg_from_reader is not None else e.message |
---|
126 | raise RuntimeError(err_msg) |
---|
127 | |
---|
128 | def find_plugins(self, dir): |
---|
129 | """ |
---|
130 | Find readers in a given directory. This method |
---|
131 | can be used to inspect user plug-in directories to |
---|
132 | find new readers/writers. |
---|
133 | |
---|
134 | :param dir: directory to search into |
---|
135 | :return: number of readers found |
---|
136 | """ |
---|
137 | readers_found = 0 |
---|
138 | temp_path = os.path.abspath(dir) |
---|
139 | if not os.path.isdir(temp_path): |
---|
140 | temp_path = os.path.join(os.getcwd(), dir) |
---|
141 | if not os.path.isdir(temp_path): |
---|
142 | temp_path = os.path.join(os.path.dirname(__file__), dir) |
---|
143 | if not os.path.isdir(temp_path): |
---|
144 | temp_path = os.path.join(os.path.dirname(sys.path[0]), dir) |
---|
145 | |
---|
146 | dir = temp_path |
---|
147 | # Check whether the directory exists |
---|
148 | if not os.path.isdir(dir): |
---|
149 | msg = "DataLoader couldn't locate DataLoader plugin folder." |
---|
150 | msg += """ "%s" does not exist""" % dir |
---|
151 | logger.warning(msg) |
---|
152 | return readers_found |
---|
153 | |
---|
154 | for item in os.listdir(dir): |
---|
155 | full_path = os.path.join(dir, item) |
---|
156 | if os.path.isfile(full_path): |
---|
157 | |
---|
158 | # Process python files |
---|
159 | if item.endswith('.py'): |
---|
160 | toks = os.path.splitext(os.path.basename(item)) |
---|
161 | try: |
---|
162 | sys.path.insert(0, os.path.abspath(dir)) |
---|
163 | module = __import__(toks[0], globals(), locals()) |
---|
164 | if self._identify_plugin(module): |
---|
165 | readers_found += 1 |
---|
166 | except: |
---|
167 | msg = "Loader: Error importing " |
---|
168 | msg += "%s\n %s" % (item, sys.exc_value) |
---|
169 | logger.error(msg) |
---|
170 | |
---|
171 | # Process zip files |
---|
172 | elif item.endswith('.zip'): |
---|
173 | try: |
---|
174 | # Find the modules in the zip file |
---|
175 | zfile = ZipFile(item) |
---|
176 | nlist = zfile.namelist() |
---|
177 | |
---|
178 | sys.path.insert(0, item) |
---|
179 | for mfile in nlist: |
---|
180 | try: |
---|
181 | # Change OS path to python path |
---|
182 | fullname = mfile.replace('/', '.') |
---|
183 | fullname = os.path.splitext(fullname)[0] |
---|
184 | module = __import__(fullname, globals(), |
---|
185 | locals(), [""]) |
---|
186 | if self._identify_plugin(module): |
---|
187 | readers_found += 1 |
---|
188 | except: |
---|
189 | msg = "Loader: Error importing" |
---|
190 | msg += " %s\n %s" % (mfile, sys.exc_value) |
---|
191 | logger.error(msg) |
---|
192 | |
---|
193 | except: |
---|
194 | msg = "Loader: Error importing " |
---|
195 | msg += " %s\n %s" % (item, sys.exc_value) |
---|
196 | logger.error(msg) |
---|
197 | |
---|
198 | return readers_found |
---|
199 | |
---|
200 | def associate_file_type(self, ext, module): |
---|
201 | """ |
---|
202 | Look into a module to find whether it contains a |
---|
203 | Reader class. If so, APPEND it to readers and (potentially) |
---|
204 | to the list of writers for the given extension |
---|
205 | |
---|
206 | :param ext: file extension [string] |
---|
207 | :param module: module object |
---|
208 | """ |
---|
209 | reader_found = False |
---|
210 | |
---|
211 | if hasattr(module, "Reader"): |
---|
212 | try: |
---|
213 | # Find supported extensions |
---|
214 | loader = module.Reader() |
---|
215 | if ext not in self.loaders: |
---|
216 | self.loaders[ext] = [] |
---|
217 | # Append the new reader to the list |
---|
218 | self.loaders[ext].append(loader.read) |
---|
219 | |
---|
220 | reader_found = True |
---|
221 | |
---|
222 | # Keep track of wildcards |
---|
223 | type_name = module.__name__ |
---|
224 | if hasattr(loader, 'type_name'): |
---|
225 | type_name = loader.type_name |
---|
226 | |
---|
227 | wcard = "%s files (*%s)|*%s" % (type_name, ext.lower(), |
---|
228 | ext.lower()) |
---|
229 | if wcard not in self.wildcards: |
---|
230 | self.wildcards.append(wcard) |
---|
231 | |
---|
232 | # Check whether writing is supported |
---|
233 | if hasattr(loader, 'write'): |
---|
234 | if ext not in self.writers: |
---|
235 | self.writers[ext] = [] |
---|
236 | # Append the new writer to the list |
---|
237 | self.writers[ext].append(loader.write) |
---|
238 | |
---|
239 | except: |
---|
240 | msg = "Loader: Error accessing" |
---|
241 | msg += " Reader in %s\n %s" % (module.__name__, sys.exc_value) |
---|
242 | logger.error(msg) |
---|
243 | return reader_found |
---|
244 | |
---|
245 | def associate_file_reader(self, ext, loader): |
---|
246 | """ |
---|
247 | Append a reader object to readers |
---|
248 | |
---|
249 | :param ext: file extension [string] |
---|
250 | :param module: reader object |
---|
251 | """ |
---|
252 | reader_found = False |
---|
253 | |
---|
254 | try: |
---|
255 | # Find supported extensions |
---|
256 | if ext not in self.loaders: |
---|
257 | self.loaders[ext] = [] |
---|
258 | # Append the new reader to the list |
---|
259 | self.loaders[ext].append(loader.read) |
---|
260 | |
---|
261 | reader_found = True |
---|
262 | |
---|
263 | # Keep track of wildcards |
---|
264 | if hasattr(loader, 'type_name'): |
---|
265 | type_name = loader.type_name |
---|
266 | |
---|
267 | wcard = "%s files (*%s)|*%s" % (type_name, ext.lower(), |
---|
268 | ext.lower()) |
---|
269 | if wcard not in self.wildcards: |
---|
270 | self.wildcards.append(wcard) |
---|
271 | |
---|
272 | except: |
---|
273 | msg = "Loader: Error accessing Reader " |
---|
274 | msg += "in %s\n %s" % (loader.__name__, sys.exc_value) |
---|
275 | logger.error(msg) |
---|
276 | return reader_found |
---|
277 | |
---|
278 | def _identify_plugin(self, module): |
---|
279 | """ |
---|
280 | Look into a module to find whether it contains a |
---|
281 | Reader class. If so, add it to readers and (potentially) |
---|
282 | to the list of writers. |
---|
283 | :param module: module object |
---|
284 | |
---|
285 | """ |
---|
286 | reader_found = False |
---|
287 | |
---|
288 | if hasattr(module, "Reader"): |
---|
289 | try: |
---|
290 | # Find supported extensions |
---|
291 | loader = module.Reader() |
---|
292 | for ext in loader.ext: |
---|
293 | if ext not in self.loaders: |
---|
294 | self.loaders[ext] = [] |
---|
295 | # When finding a reader at run time, |
---|
296 | # treat this reader as the new default |
---|
297 | self.loaders[ext].insert(0, loader.read) |
---|
298 | |
---|
299 | reader_found = True |
---|
300 | |
---|
301 | # Keep track of wildcards |
---|
302 | type_name = module.__name__ |
---|
303 | if hasattr(loader, 'type_name'): |
---|
304 | type_name = loader.type_name |
---|
305 | wcard = "%s files (*%s)|*%s" % (type_name, ext.lower(), |
---|
306 | ext.lower()) |
---|
307 | if wcard not in self.wildcards: |
---|
308 | self.wildcards.append(wcard) |
---|
309 | |
---|
310 | # Check whether writing is supported |
---|
311 | if hasattr(loader, 'write'): |
---|
312 | for ext in loader.ext: |
---|
313 | if ext not in self.writers: |
---|
314 | self.writers[ext] = [] |
---|
315 | self.writers[ext].insert(0, loader.write) |
---|
316 | |
---|
317 | except: |
---|
318 | msg = "Loader: Error accessing Reader" |
---|
319 | msg += " in %s\n %s" % (module.__name__, sys.exc_value) |
---|
320 | logger.error(msg) |
---|
321 | return reader_found |
---|
322 | |
---|
323 | def lookup_writers(self, path): |
---|
324 | """ |
---|
325 | :return: the loader associated with the file type of path. |
---|
326 | :Raises ValueError: if file type is not known. |
---|
327 | """ |
---|
328 | # Find matching extensions |
---|
329 | extlist = [ext for ext in self.extensions() if path.endswith(ext)] |
---|
330 | # Sort matching extensions by decreasing order of length |
---|
331 | extlist.sort(lambda a, b: len(a) < len(b)) |
---|
332 | # Combine loaders for matching extensions into one big list |
---|
333 | writers = [] |
---|
334 | for L in [self.writers[ext] for ext in extlist]: |
---|
335 | writers.extend(L) |
---|
336 | # Remove duplicates if they exist |
---|
337 | if len(writers) != len(set(writers)): |
---|
338 | result = [] |
---|
339 | for L in writers: |
---|
340 | if L not in result: |
---|
341 | result.append(L) |
---|
342 | writers = L |
---|
343 | # Raise an error if there are no matching extensions |
---|
344 | if len(writers) == 0: |
---|
345 | raise ValueError("Unknown file type for " + path) |
---|
346 | # All done |
---|
347 | return writers |
---|
348 | |
---|
349 | def save(self, path, data, format=None): |
---|
350 | """ |
---|
351 | Call the writer for the file type of path. |
---|
352 | |
---|
353 | Raises ValueError if no writer is available. |
---|
354 | Raises KeyError if format is not available. |
---|
355 | May raise a writer-defined exception if writer fails. |
---|
356 | """ |
---|
357 | if format is None: |
---|
358 | writers = self.lookup_writers(path) |
---|
359 | else: |
---|
360 | writers = self.writers[format] |
---|
361 | for fn in writers: |
---|
362 | try: |
---|
363 | return fn(path, data) |
---|
364 | except Exception: |
---|
365 | pass # give other loaders a chance to succeed |
---|
366 | # If we get here it is because all loaders failed |
---|
367 | raise # reraises last exception |
---|
368 | |
---|
369 | |
---|
370 | class Loader(object): |
---|
371 | """ |
---|
372 | Utility class to use the Registry as a singleton. |
---|
373 | """ |
---|
374 | ## Registry instance |
---|
375 | __registry = Registry() |
---|
376 | |
---|
377 | def associate_file_type(self, ext, module): |
---|
378 | """ |
---|
379 | Look into a module to find whether it contains a |
---|
380 | Reader class. If so, append it to readers and (potentially) |
---|
381 | to the list of writers for the given extension |
---|
382 | |
---|
383 | :param ext: file extension [string] |
---|
384 | :param module: module object |
---|
385 | """ |
---|
386 | return self.__registry.associate_file_type(ext, module) |
---|
387 | |
---|
388 | def associate_file_reader(self, ext, loader): |
---|
389 | """ |
---|
390 | Append a reader object to readers |
---|
391 | |
---|
392 | :param ext: file extension [string] |
---|
393 | :param module: reader object |
---|
394 | """ |
---|
395 | return self.__registry.associate_file_reader(ext, loader) |
---|
396 | |
---|
397 | def load(self, file, format=None): |
---|
398 | """ |
---|
399 | Load a file |
---|
400 | |
---|
401 | :param file: file name (path) |
---|
402 | :param format: specified format to use (optional) |
---|
403 | :return: DataInfo object |
---|
404 | """ |
---|
405 | return self.__registry.load(file, format) |
---|
406 | |
---|
407 | def save(self, file, data, format): |
---|
408 | """ |
---|
409 | Save a DataInfo object to file |
---|
410 | :param file: file name (path) |
---|
411 | :param data: DataInfo object |
---|
412 | :param format: format to write the data in |
---|
413 | """ |
---|
414 | return self.__registry.save(file, data, format) |
---|
415 | |
---|
416 | def _get_registry_creation_time(self): |
---|
417 | """ |
---|
418 | Internal method used to test the uniqueness |
---|
419 | of the registry object |
---|
420 | """ |
---|
421 | return self.__registry._created |
---|
422 | |
---|
423 | def find_plugins(self, directory): |
---|
424 | """ |
---|
425 | Find plugins in a given directory |
---|
426 | |
---|
427 | :param dir: directory to look into to find new readers/writers |
---|
428 | """ |
---|
429 | return self.__registry.find_plugins(directory) |
---|
430 | |
---|
431 | def get_wildcards(self): |
---|
432 | """ |
---|
433 | Return the list of wildcards |
---|
434 | """ |
---|
435 | return self.__registry.wildcards |
---|