ocrd.processor.base.Processor.resolve_resource() - Code Metrics - Inspection of "resmgr: No downloading on-demand" - OCR-D/core - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#663)

by Konstantin

created 2021-01-27 15:37 UTC

ocrd.processor.base.Processor.resolve_resource() A

↳ Parent: ocrd.processor.base

Complexity

Conditions

Size

Total Lines	14
Code Lines	7

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
eloc	7
dl	0
loc	14
rs	10
c	0
b	0
f	0
cc	2
nop	2

"""
Processor base class and helper functions
"""

__all__ = [
    'Processor',
    'generate_processor_help',
    'run_cli',
    'run_processor'
]

from os import makedirs
from os.path import exists, isdir, join
from shutil import copyfileobj
import json
import os
import re
import sys

import requests

from ocrd_utils import (
    VERSION as OCRD_VERSION,
    MIMETYPE_PAGE,
    getLogger,
    initLogging,
    list_resource_candidates,
    list_all_resources,
)
from ocrd_validators import ParameterValidator
from ocrd_models.ocrd_page import MetadataItemType, LabelType, LabelsType
from ..resource_manager import OcrdResourceManager

# XXX imports must remain for backwards-compatibilty
from .helpers import run_cli, run_processor, generate_processor_help # pylint: disable=unused-import

class Processor():
    """
    A processor is an OCR-D compliant command-line-interface for executing
    a single workflow step on the workspace (represented by local METS). It
    reads input files for all or requested physical pages of the input fileGrp(s),
    and writes output files for them into the output fileGrp(s). It may take 
    a number of optional or mandatory parameters.
    """

    def __init__(
            self,
            workspace,
            ocrd_tool=None,
            parameter=None,
            # TODO OCR-D/core#274
            # input_file_grp=None,
            # output_file_grp=None,
            input_file_grp="INPUT",
            output_file_grp="OUTPUT",
            page_id=None,
            show_resource=None,
            list_resources=False,
            show_help=False,
            show_version=False,
            dump_json=False,
            version=None
    ):
        if parameter is None:
            parameter = {}
        if dump_json:
            print(json.dumps(ocrd_tool, indent=True))
            return
        if list_resources:
            for res in list_all_resources(ocrd_tool['executable']):
                print(res)
            return
        if show_resource:
            res_fname = list_resource_candidates(ocrd_tool['executable'], show_resource, is_file=True)
            if not res_fname:
                initLogging()
                logger = getLogger('ocrd.%s.__init__' % ocrd_tool['executable'])
                logger.error("Failed to resolve %s for processort %s" % (show_resource, ocrd_tool['executable']))
            else:
                with open(res_fname[0], 'rb') as f:
                    copyfileobj(f, sys.stdout.buffer)
            return
        self.ocrd_tool = ocrd_tool
        if show_help:
            self.show_help()
            return
        self.version = version
        if show_version:
            self.show_version()
            return
        self.workspace = workspace
        # FIXME HACK would be better to use pushd_popd(self.workspace.directory)
        # but there is no way to do that in process here since it's an
        # overridden method. chdir is almost always an anti-pattern.
        if self.workspace:
            os.chdir(self.workspace.directory)
        self.input_file_grp = input_file_grp
        self.output_file_grp = output_file_grp
        self.page_id = None if page_id == [] or page_id is None else page_id
        parameterValidator = ParameterValidator(ocrd_tool)
        report = parameterValidator.validate(parameter)
        if not report.is_valid:
            raise Exception("Invalid parameters %s" % report.errors)
        self.parameter = parameter

    def show_help(self):
        print(generate_processor_help(self.ocrd_tool, processor_instance=self))

    def show_version(self):
        print("Version %s, ocrd/core %s" % (self.version, OCRD_VERSION))

    def verify(self):
        """
        Verify that the input fulfills the processor's requirements.
        """
        return True

    def process(self):
        """
        Process the workspace
        """
        raise Exception("Must be implemented")


    def add_metadata(self, pcgts):
        """
        Adds PAGE-XML MetadataItem describing the processing step
        """
        pcgts.get_Metadata().add_MetadataItem(
                MetadataItemType(type_="processingStep",
                    name=self.ocrd_tool['steps'][0],
                    value=self.ocrd_tool['executable'],
                    Labels=[LabelsType(
                        externalModel="ocrd-tool",
                        externalId="parameters",
                        Label=[LabelType(type_=name,
                                         value=self.parameter[name])
                               for name in self.parameter.keys()]),
                            LabelsType(
                        externalModel="ocrd-tool",
                        externalId="version",
                        Label=[LabelType(type_=self.ocrd_tool['executable'],
                                         value=self.version),
                               LabelType(type_='ocrd/core',
                                         value=OCRD_VERSION)])
                    ]))

    def resolve_resource(self, val):
        """
        Resolve a resource name to an absolute file path with the algorithm in
        https://ocr-d.de/en/spec/ocrd_tool#file-parameters

        Args:
            val (string): resource value to resolve
        """
        executable = self.ocrd_tool['executable']
        ret = [cand for cand in list_resource_candidates(executable, val) if exists(cand)]
        if ret:
            return ret[0]
        raise FileNotFoundError("Could not find resource '%s' for executable '%s'. Try 'ocrd resmgr download %s %s' to download this resource." %
                (val, executable, executable, val))

    def list_all_resources(self):
        """
        List all resources found in the filesystem
        """
        return list_all_resources(self.ocrd_tool['executable'])

    @property
    def input_files(self):
        """
        List the input files (for single input file groups).

        For each physical page:
        - If there is a single PAGE-XML for the page, take it (and forget about all
          other files for that page)
        - Else if there is a single image file, take it (and forget about all other
          files for that page)
        - Otherwise raise an error (complaining that only PAGE-XML warrants
          having multiple images for a single page)
        (https://github.com/cisocrgroup/ocrd_cis/pull/57#issuecomment-656336593)
        """
        if not self.input_file_grp:
            raise ValueError("Processor is missing input fileGrp")
        ret = self.zip_input_files(mimetype=None, on_error='abort')
        if not ret:
            return []
        assert len(ret[0]) == 1, 'Use zip_input_files() instead of input_files when processing multiple input fileGrps'
        return [tuples[0] for tuples in ret]

    def zip_input_files(self, require_first=True, mimetype=None, on_error='skip'):
        """
        List tuples of input files (for multiple input file groups).

        Processors that expect/need multiple input file groups,
        cannot use ``input_files``. They must align (zip) input files
        across pages. This includes the case where not all pages
        are equally present in all file groups. It also requires
        making a consistent selection if there are multiple files
        per page.

        Following the OCR-D functional model, this function tries to
        find a single PAGE file per page, or fall back to a single
        image file per page. In either case, multiple matches per page
        are an error (see error handling below).
        This default behaviour can be changed by using a fixed MIME
        type filter via ``mimetype``. But still, multiple matching
        files per page are an error.

        Single-page multiple-file errors are handled according to
        ``on_error``:
        - if ``skip``, then the page for the respective fileGrp will be
          silently skipped (as if there was no match at all)
        - if ``first``, then the first matching file for the page will be
          silently selected (as if the first was the only match)
        - if ``last``, then the last matching file for the page will be
          silently selected (as if the last was the only match)
        - if ``abort``, then an exception will be raised.
        Multiple matches for PAGE-XML will always raise an exception.

        Args:
             require_first (bool): If true, then skip a page entirely
             whenever it is not available in the first input fileGrp.

             mimetype (str): If not None, filter by the specified MIME
             type (literal or regex prefixed by ``//``.
             Otherwise prefer PAGE or image.
        """
        if not self.input_file_grp:
            raise ValueError("Processor is missing input fileGrp")

        LOG = getLogger('ocrd.processor.base')
        ifgs = self.input_file_grp.split(",")
        # Iterating over all files repeatedly may seem inefficient at first sight,
        # but the unnecessary OcrdFile instantiations for posterior fileGrp filtering
        # can actually be much more costly than traversing the ltree.
        # This might depend on the number of pages vs number of fileGrps.

        pages = dict()
        for i, ifg in enumerate(ifgs):
            for file_ in sorted(self.workspace.mets.find_all_files(
                    pageId=self.page_id, fileGrp=ifg, mimetype=mimetype),
                                # sort by MIME type so PAGE comes before images
                                key=lambda file_: file_.mimetype):
                if not file_.pageId:
                    continue
                ift = pages.setdefault(file_.pageId, [None]*len(ifgs))
                if ift[i]:
                    LOG.debug("another file %s for page %s in input file group %s", file_.ID, file_.pageId, ifg)
                    # fileGrp has multiple files for this page ID
                    if mimetype:
                        # filter was active, this must not happen
                        if on_error == 'skip':

                            ift[i] = None
                        elif on_error == 'first':
                            pass # keep first match
                        elif on_error == 'last':
                            ift[i] = file_
                        elif on_error == 'abort':
                            raise ValueError(
                                "Multiple '%s' matches for page '%s' in fileGrp '%s'." % (
                                    mimetype, file_.pageId, ifg))
                        else:
                            raise Exception("Unknown 'on_error' strategy '%s'" % on_error)
                    elif (ift[i].mimetype == MIMETYPE_PAGE and
                          file_.mimetype != MIMETYPE_PAGE):
                        pass # keep PAGE match
                    elif (ift[i].mimetype == MIMETYPE_PAGE and
                          file_.mimetype == MIMETYPE_PAGE):
                            raise ValueError(
                                "Multiple PAGE-XML matches for page '%s' in fileGrp '%s'." % (
                                    file_.pageId, ifg))
                    else:
                        # filter was inactive but no PAGE is in control, this must not happen
                        if on_error == 'skip':

                            ift[i] = None
                        elif on_error == 'first':
                            pass # keep first match
                        elif on_error == 'last':
                            ift[i] = file_
                        elif on_error == 'abort':
                            raise ValueError(
                                "No PAGE-XML for page '%s' in fileGrp '%s' but multiple matches." % (
                                    file_.pageId, ifg))
                        else:
                            raise Exception("Unknown 'on_error' strategy '%s'" % on_error)
                else:
                    LOG.debug("adding file %s for page %s to input file group %s", file_.ID, file_.pageId, ifg)
                    ift[i] = file_
        ifts = list()
        for page, ifiles in pages.items():
            for i, ifg in enumerate(ifgs):
                if not ifiles[i]:
                    # other fallback options?
                    LOG.error('found no page %s in file group %s',
                              page, ifg)
            if ifiles[0] or not require_first:
                ifts.append(tuple(ifiles))
        return ifts


1		"""
2		Processor base class and helper functions
3		"""
4
5		__all__ = [
6		'Processor',
7		'generate_processor_help',
8		'run_cli',
9		'run_processor'
10		]
11
12		from os import makedirs
13		from os.path import exists, isdir, join
14		from shutil import copyfileobj
15		import json
16		import os
17		import re
18		import sys
19
20		import requests
21
22		from ocrd_utils import (
23		VERSION as OCRD_VERSION,
24		MIMETYPE_PAGE,
25		getLogger,
26		initLogging,
27		list_resource_candidates,
28		list_all_resources,
29		)
30		from ocrd_validators import ParameterValidator
31		from ocrd_models.ocrd_page import MetadataItemType, LabelType, LabelsType
32		from ..resource_manager import OcrdResourceManager
33
34		# XXX imports must remain for backwards-compatibilty
35		from .helpers import run_cli, run_processor, generate_processor_help # pylint: disable=unused-import
36
37		class Processor():
38		"""
39		A processor is an OCR-D compliant command-line-interface for executing
40		a single workflow step on the workspace (represented by local METS). It
41		reads input files for all or requested physical pages of the input fileGrp(s),
42		and writes output files for them into the output fileGrp(s). It may take
43		a number of optional or mandatory parameters.
44		"""
45
46		def __init__(
47		self,
48		workspace,
49		ocrd_tool=None,
50		parameter=None,
51		# TODO OCR-D/core#274
52		# input_file_grp=None,
53		# output_file_grp=None,
54		input_file_grp="INPUT",
55		output_file_grp="OUTPUT",
56		page_id=None,
57		show_resource=None,
58		list_resources=False,
59		show_help=False,
60		show_version=False,
61		dump_json=False,
62		version=None
63		):
64		if parameter is None:
65		parameter = {}
66		if dump_json:
67		print(json.dumps(ocrd_tool, indent=True))
68		return
69		if list_resources:
70		for res in list_all_resources(ocrd_tool['executable']):
71		print(res)
72		return
73		if show_resource:
74		res_fname = list_resource_candidates(ocrd_tool['executable'], show_resource, is_file=True)
75		if not res_fname:
76		initLogging()
77		logger = getLogger('ocrd.%s.__init__' % ocrd_tool['executable'])
78		logger.error("Failed to resolve %s for processort %s" % (show_resource, ocrd_tool['executable']))
79		else:
80		with open(res_fname[0], 'rb') as f:
81		copyfileobj(f, sys.stdout.buffer)
82		return
83		self.ocrd_tool = ocrd_tool
84		if show_help:
85		self.show_help()
86		return
87		self.version = version
88		if show_version:
89		self.show_version()
90		return
91		self.workspace = workspace
92		# FIXME HACK would be better to use pushd_popd(self.workspace.directory)
93		# but there is no way to do that in process here since it's an
94		# overridden method. chdir is almost always an anti-pattern.
95		if self.workspace:
96		os.chdir(self.workspace.directory)
97		self.input_file_grp = input_file_grp
98		self.output_file_grp = output_file_grp
99		self.page_id = None if page_id == [] or page_id is None else page_id
100		parameterValidator = ParameterValidator(ocrd_tool)
101		report = parameterValidator.validate(parameter)
102		if not report.is_valid:
103		raise Exception("Invalid parameters %s" % report.errors)
104		self.parameter = parameter
105
106		def show_help(self):
107		print(generate_processor_help(self.ocrd_tool, processor_instance=self))
108
109		def show_version(self):
110		print("Version %s, ocrd/core %s" % (self.version, OCRD_VERSION))
111
112		def verify(self):
113		"""
114		Verify that the input fulfills the processor's requirements.
115		"""
116		return True
117
118		def process(self):
119		"""
120		Process the workspace
121		"""
122		raise Exception("Must be implemented")
123
124
125		def add_metadata(self, pcgts):
126		"""
127		Adds PAGE-XML MetadataItem describing the processing step
128		"""
129		pcgts.get_Metadata().add_MetadataItem(
130		MetadataItemType(type_="processingStep",
131		name=self.ocrd_tool['steps'][0],
132		value=self.ocrd_tool['executable'],
133		Labels=[LabelsType(
134		externalModel="ocrd-tool",
135		externalId="parameters",
136		Label=[LabelType(type_=name,
137		value=self.parameter[name])
138		for name in self.parameter.keys()]),
139		LabelsType(
140		externalModel="ocrd-tool",
141		externalId="version",
142		Label=[LabelType(type_=self.ocrd_tool['executable'],
143		value=self.version),
144		LabelType(type_='ocrd/core',
145		value=OCRD_VERSION)])
146		]))
147
148		def resolve_resource(self, val):
149		"""
150		Resolve a resource name to an absolute file path with the algorithm in
151		https://ocr-d.de/en/spec/ocrd_tool#file-parameters
152
153		Args:
154		val (string): resource value to resolve
155		"""
156		executable = self.ocrd_tool['executable']
157		ret = [cand for cand in list_resource_candidates(executable, val) if exists(cand)]
158		if ret:
159		return ret[0]
160		raise FileNotFoundError("Could not find resource '%s' for executable '%s'. Try 'ocrd resmgr download %s %s' to download this resource." %
161		(val, executable, executable, val))
162
163		def list_all_resources(self):
164		"""
165		List all resources found in the filesystem
166		"""
167		return list_all_resources(self.ocrd_tool['executable'])
168
169		@property
170		def input_files(self):
171		"""
172		List the input files (for single input file groups).
173
174		For each physical page:
175		- If there is a single PAGE-XML for the page, take it (and forget about all
176		other files for that page)
177		- Else if there is a single image file, take it (and forget about all other
178		files for that page)
179		- Otherwise raise an error (complaining that only PAGE-XML warrants
180		having multiple images for a single page)
181		(https://github.com/cisocrgroup/ocrd_cis/pull/57#issuecomment-656336593)
182		"""
183		if not self.input_file_grp:
184		raise ValueError("Processor is missing input fileGrp")
185		ret = self.zip_input_files(mimetype=None, on_error='abort')
186		if not ret:
187		return []
188		assert len(ret[0]) == 1, 'Use zip_input_files() instead of input_files when processing multiple input fileGrps'
189		return [tuples[0] for tuples in ret]
190
191		def zip_input_files(self, require_first=True, mimetype=None, on_error='skip'):
192		"""
193		List tuples of input files (for multiple input file groups).
194
195		Processors that expect/need multiple input file groups,
196		cannot use ``input_files``. They must align (zip) input files
197		across pages. This includes the case where not all pages
198		are equally present in all file groups. It also requires
199		making a consistent selection if there are multiple files
200		per page.
201
202		Following the OCR-D functional model, this function tries to
203		find a single PAGE file per page, or fall back to a single
204		image file per page. In either case, multiple matches per page
205		are an error (see error handling below).
206		This default behaviour can be changed by using a fixed MIME
207		type filter via ``mimetype``. But still, multiple matching
208		files per page are an error.
209
210		Single-page multiple-file errors are handled according to
211		``on_error``:
212		- if ``skip``, then the page for the respective fileGrp will be
213		silently skipped (as if there was no match at all)
214		- if ``first``, then the first matching file for the page will be
215		silently selected (as if the first was the only match)
216		- if ``last``, then the last matching file for the page will be
217		silently selected (as if the last was the only match)
218		- if ``abort``, then an exception will be raised.
219		Multiple matches for PAGE-XML will always raise an exception.
220
221		Args:
222		require_first (bool): If true, then skip a page entirely
223		whenever it is not available in the first input fileGrp.
224
225		mimetype (str): If not None, filter by the specified MIME
226		type (literal or regex prefixed by ``//``.
227		Otherwise prefer PAGE or image.
228		"""
229		if not self.input_file_grp:
230		raise ValueError("Processor is missing input fileGrp")
231
232		LOG = getLogger('ocrd.processor.base')
233		ifgs = self.input_file_grp.split(",")
234		# Iterating over all files repeatedly may seem inefficient at first sight,
235		# but the unnecessary OcrdFile instantiations for posterior fileGrp filtering
236		# can actually be much more costly than traversing the ltree.
237		# This might depend on the number of pages vs number of fileGrps.
238
239		pages = dict()
240		for i, ifg in enumerate(ifgs):
241		for file_ in sorted(self.workspace.mets.find_all_files(
242		pageId=self.page_id, fileGrp=ifg, mimetype=mimetype),
243		# sort by MIME type so PAGE comes before images
244		key=lambda file_: file_.mimetype):
245		if not file_.pageId:
246		continue
247		ift = pages.setdefault(file_.pageId, [None]*len(ifgs))
248		if ift[i]:
249		LOG.debug("another file %s for page %s in input file group %s", file_.ID, file_.pageId, ifg)
250		# fileGrp has multiple files for this page ID
251		if mimetype:
252		# filter was active, this must not happen
253	View Code Duplication	if on_error == 'skip':
		0 ignored issues – show Duplication introduced 2020-11-02 16:44 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
254		ift[i] = None
255		elif on_error == 'first':
256		pass # keep first match
257		elif on_error == 'last':
258		ift[i] = file_
259		elif on_error == 'abort':
260		raise ValueError(
261		"Multiple '%s' matches for page '%s' in fileGrp '%s'." % (
262		mimetype, file_.pageId, ifg))
263		else:
264		raise Exception("Unknown 'on_error' strategy '%s'" % on_error)
265		elif (ift[i].mimetype == MIMETYPE_PAGE and
266		file_.mimetype != MIMETYPE_PAGE):
267		pass # keep PAGE match
268		elif (ift[i].mimetype == MIMETYPE_PAGE and
269		file_.mimetype == MIMETYPE_PAGE):
270		raise ValueError(
271		"Multiple PAGE-XML matches for page '%s' in fileGrp '%s'." % (
272		file_.pageId, ifg))
273		else:
274		# filter was inactive but no PAGE is in control, this must not happen
275	View Code Duplication	if on_error == 'skip':
		0 ignored issues – show Duplication introduced 2020-11-02 16:44 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
276		ift[i] = None
277		elif on_error == 'first':
278		pass # keep first match
279		elif on_error == 'last':
280		ift[i] = file_
281		elif on_error == 'abort':
282		raise ValueError(
283		"No PAGE-XML for page '%s' in fileGrp '%s' but multiple matches." % (
284		file_.pageId, ifg))
285		else:
286		raise Exception("Unknown 'on_error' strategy '%s'" % on_error)
287		else:
288		LOG.debug("adding file %s for page %s to input file group %s", file_.ID, file_.pageId, ifg)
289		ift[i] = file_
290		ifts = list()
291		for page, ifiles in pages.items():
292		for i, ifg in enumerate(ifgs):
293		if not ifiles[i]:
294		# other fallback options?
295		LOG.error('found no page %s in file group %s',
296		page, ifg)
297		if ifiles[0] or not require_first:
298		ifts.append(tuple(ifiles))
299		return ifts
300

OCR-D / core

Pull Request — master (#663)

ocrd.processor.base.Processor.resolve_resource() A

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