def __init__(self, storage, schema, segment, generation=None, codec=None):
self.storage = storage
self.schema = schema
self.segment = segment
self._gen = generation
self.is_closed = False
# Copy info from underlying segment
self._has_deletions = segment.has_deletions()
self._dc = segment.doc_count()
self._dc_all = segment.doc_count_all()
if hasattr(self.segment, "segment_id"):
self.segid = self.segment.segment_id()
else:
from whoosh.codec.base import Segment
self.segid = Segment._random_id()
# self.files is a storage object from which to load the segment files.
# This is different from the general storage (which will be used for
# cahces) if the segment is in a compound file.
if segment.is_compound():
# Use an overlay here instead of just the compound storage because
# in rare circumstances a segment file may be added after the
# segment is written
self.files = OverlayStorage(segment.open_compound_file(storage),
self.storage)
else:
self.files = storage
# Get microreaders from codec
if codec is None:
from whoosh.codec import default_codec
codec = default_codec()
self._codec = codec
self._terms = codec.terms_reader(self.files, self.segment)
self._lengths = codec.lengths_reader(self.files, self.segment)
self._stored = codec.stored_fields_reader(self.files, self.segment)
self._vectors = None # Lazy open with self._open_vectors()
self._graph = None # Lazy open with self._open_dawg()
self.set_caching_policy()
def __init__(self, storage, schema, segment, generation=None, codec=None):
self.storage = storage
self.schema = schema
self.segment = segment
self._gen = generation
self.is_closed = False
# Copy info from underlying segment
self._has_deletions = segment.has_deletions()
self._dc = segment.doc_count()
self._dc_all = segment.doc_count_all()
if hasattr(self.segment, "segment_id"):
self.segid = self.segment.segment_id()
else:
from whoosh.codec.base import Segment
self.segid = Segment._random_id()
# self.files is a storage object from which to load the segment files.
# This is different from the general storage (which will be used for
# cahces) if the segment is in a compound file.
if segment.is_compound():
# Use an overlay here instead of just the compound storage because
# in rare circumstances a segment file may be added after the
# segment is written
self.files = OverlayStorage(segment.open_compound_file(storage),
self.storage)
else:
self.files = storage
# Get microreaders from codec
if codec is None:
from whoosh.codec import default_codec
codec = default_codec()
self._codec = codec
self._terms = codec.terms_reader(self.files, self.segment)
self._lengths = codec.lengths_reader(self.files, self.segment)
self._stored = codec.stored_fields_reader(self.files, self.segment)
self._vectors = None # Lazy open with self._open_vectors()
self._graph = None # Lazy open with self._open_dawg()
self.set_caching_policy()
class SegmentReader(IndexReader):
GZIP_CACHES = False
def __init__(self, storage, schema, segment, generation=None, codec=None):
self.storage = storage
self.schema = schema
self.segment = segment
self._gen = generation
self.is_closed = False
# Copy info from underlying segment
self._has_deletions = segment.has_deletions()
self._dc = segment.doc_count()
self._dc_all = segment.doc_count_all()
if hasattr(self.segment, "segment_id"):
self.segid = self.segment.segment_id()
else:
from whoosh.codec.base import Segment
self.segid = Segment._random_id()
# self.files is a storage object from which to load the segment files.
# This is different from the general storage (which will be used for
# cahces) if the segment is in a compound file.
if segment.is_compound():
# Use an overlay here instead of just the compound storage because
# in rare circumstances a segment file may be added after the
# segment is written
self.files = OverlayStorage(segment.open_compound_file(storage),
self.storage)
else:
self.files = storage
# Get microreaders from codec
if codec is None:
from whoosh.codec import default_codec
codec = default_codec()
self._codec = codec
self._terms = codec.terms_reader(self.files, self.segment)
self._lengths = codec.lengths_reader(self.files, self.segment)
self._stored = codec.stored_fields_reader(self.files, self.segment)
self._vectors = None # Lazy open with self._open_vectors()
self._graph = None # Lazy open with self._open_dawg()
self.set_caching_policy()
def _open_vectors(self):
if self._vectors:
return
self._vectors = self._codec.vector_reader(self.files, self.segment)
def _open_dawg(self):
if self._graph:
return
self._graph = self._codec.graph_reader(self.files, self.segment)
def has_deletions(self):
return self._has_deletions
def doc_count(self):
return self._dc
def doc_count_all(self):
return self._dc_all
def is_deleted(self, docnum):
return self.segment.is_deleted(docnum)
def generation(self):
return self._gen
def __repr__(self):
return "%s(%s)" % (self.__class__.__name__, self.segment)
def __contains__(self, term):
return term in self._terms
def close(self):
self._terms.close()
self._stored.close()
if self._lengths:
self._lengths.close()
if self._vectors:
self._vectors.close()
if self._graph:
self._graph.close()
self.files.close()
self.caching_policy = None
self.is_closed = True
def stored_fields(self, docnum):
assert docnum >= 0
schema = self.schema
return dict(item for item in iteritems(self._stored[docnum])
if item[0] in schema)
def all_stored_fields(self):
is_deleted = self.segment.is_deleted
sf = self.stored_fields
for docnum in xrange(self._dc_all):
if not is_deleted(docnum):
yield sf(docnum)
def field_length(self, fieldname):
return self._lengths.field_length(fieldname)
def min_field_length(self, fieldname):
return self._lengths.min_field_length(fieldname)
def max_field_length(self, fieldname):
return self._lengths.max_field_length(fieldname)
def doc_field_length(self, docnum, fieldname, default=0):
return self._lengths.doc_field_length(docnum, fieldname,
default=default)
def has_vector(self, docnum, fieldname):
if self.schema[fieldname].vector:
try:
self._open_vectors()
except (NameError, IOError):
return False
return (docnum, fieldname) in self._vectors
else:
return False
def _test_field(self, fieldname):
if fieldname not in self.schema:
raise TermNotFound("No field %r" % fieldname)
if self.schema[fieldname].format is None:
raise TermNotFound("Field %r is not indexed" % fieldname)
def all_terms(self):
schema = self.schema
return ((fieldname, text) for fieldname, text in self._terms.keys()
if fieldname in schema)
def terms_from(self, fieldname, prefix):
self._test_field(fieldname)
schema = self.schema
return ((fname, text) for fname, text
in self._terms.keys_from((fieldname, prefix))
if fname in schema)
def term_info(self, fieldname, text):
self._test_field(fieldname)
try:
return self._terms[fieldname, text]
except KeyError:
raise TermNotFound("%s:%r" % (fieldname, text))
def _texts_in_fieldcache(self, fieldname, prefix=''):
# The first value in a fieldcache is the default
texts = self.fieldcache(fieldname).texts[1:]
if prefix:
i = bisect_left(texts, prefix)
while i < len(texts) and texts[i].startswith(prefix):
yield texts[i]
i += 1
else:
for text in texts:
yield text
def expand_prefix(self, fieldname, prefix):
self._test_field(fieldname)
# If a fieldcache for the field is already loaded, we already have the
# values for the field in memory, so just yield them from there
if self.fieldcache_loaded(fieldname):
return self._texts_in_fieldcache(fieldname, prefix)
else:
# Call super
return IndexReader.expand_prefix(self, fieldname, prefix)
def lexicon(self, fieldname):
self._test_field(fieldname)
# If a fieldcache for the field is already loaded, we already have the
# values for the field in memory, so just yield them from there
if self.fieldcache_loaded(fieldname):
return self._texts_in_fieldcache(fieldname)
else:
# Call super
return IndexReader.lexicon(self, fieldname)
def __iter__(self):
schema = self.schema
return ((term, terminfo) for term, terminfo in self._terms.items()
if term[0] in schema)
def iter_from(self, fieldname, text):
schema = self.schema
self._test_field(fieldname)
for term, terminfo in self._terms.items_from((fieldname, text)):
if term[0] not in schema:
continue
yield (term, terminfo)
def frequency(self, fieldname, text):
self._test_field(fieldname)
try:
return self._terms.frequency((fieldname, text))
except KeyError:
return 0
def doc_frequency(self, fieldname, text):
self._test_field(fieldname)
try:
return self._terms.doc_frequency((fieldname, text))
except KeyError:
return 0
def postings(self, fieldname, text, scorer=None):
if fieldname not in self.schema:
raise TermNotFound("No field %r" % fieldname)
format_ = self.schema[fieldname].format
matcher = self._terms.matcher(fieldname, text, format_, scorer=scorer)
deleted = self.segment.deleted
if deleted:
matcher = FilterMatcher(matcher, deleted, exclude=True)
return matcher
def vector(self, docnum, fieldname):
if fieldname not in self.schema:
raise TermNotFound("No field %r" % fieldname)
vformat = self.schema[fieldname].vector
if not vformat:
raise Exception("No vectors are stored for field %r" % fieldname)
self._open_vectors()
return self._vectors.matcher(docnum, fieldname, vformat)
# DAWG methods
def has_word_graph(self, fieldname):
if fieldname not in self.schema:
return False
if not self.schema[fieldname].spelling:
return False
try:
self._open_dawg()
except (NameError, IOError, dawg.FileVersionError):
return False
return self._graph.has_root(fieldname)
def word_graph(self, fieldname):
if not self.has_word_graph(fieldname):
raise KeyError("No word graph for field %r" % fieldname)
return dawg.Node(self._graph, self._graph.root(fieldname))
def terms_within(self, fieldname, text, maxdist, prefix=0):
if not self.has_word_graph(fieldname):
# This reader doesn't have a graph stored, use the slow method
return IndexReader.terms_within(self, fieldname, text, maxdist,
prefix=prefix)
return dawg.within(self._graph, text, k=maxdist, prefix=prefix,
address=self._graph.root(fieldname))
# Field cache methods
def supports_caches(self):
return True
def set_caching_policy(self, cp=None, save=True, storage=None):
"""This method lets you control the caching policy of the reader. You
can either pass a :class:`whoosh.filedb.fieldcache.FieldCachingPolicy`
as the first argument, *or* use the `save` and `storage` keywords to
alter the default caching policy::
# Use a custom field caching policy object
reader.set_caching_policy(MyPolicy())
# Use the default caching policy but turn off saving caches to disk
reader.set_caching_policy(save=False)
# Use the default caching policy but save caches to a custom
# storage
from whoosh.filedb.filestore import FileStorage
mystorage = FileStorage("path/to/cachedir")
reader.set_caching_policy(storage=mystorage)
:param cp: a :class:`whoosh.filedb.fieldcache.FieldCachingPolicy`
object. If this argument is not given, the default caching policy
is used.
:param save: save field caches to disk for re-use. If a caching policy
object is specified using `cp`, this argument is ignored.
:param storage: a custom :class:`whoosh.store.Storage` object to use
for saving field caches. If a caching policy object is specified
using `cp` or `save` is `False`, this argument is ignored.
"""
if not cp:
if save and storage is None:
storage = self.storage
elif not save:
storage = None
cp = DefaultFieldCachingPolicy(self.segment.segment_id(),
storage=storage)
if type(cp) is type:
cp = cp()
self.caching_policy = cp
def _fieldkey(self, fieldname):
return "%s/%s" % (self.segid, fieldname)
def fieldcache(self, fieldname, save=SAVE_BY_DEFAULT):
"""Returns a :class:`whoosh.filedb.fieldcache.FieldCache` object for
the given field.
:param fieldname: the name of the field to get a cache for.
:param save: if True (the default), the cache is saved to disk if it
doesn't already exist.
"""
key = self._fieldkey(fieldname)
fc = self.caching_policy.get(key)
if not fc:
fc = FieldCache.from_field(self, fieldname)
self.caching_policy.put(key, fc, save=save)
return fc
def fieldcache_available(self, fieldname):
"""Returns True if a field cache exists for the given field (either in
memory already or on disk).
"""
return self._fieldkey(fieldname) in self.caching_policy
def fieldcache_loaded(self, fieldname):
"""Returns True if a field cache for the given field is in memory.
"""
return self.caching_policy.is_loaded(self._fieldkey(fieldname))
def unload_fieldcache(self, name):
self.caching_policy.delete(self._fieldkey(name))
class SegmentReader(IndexReader):
GZIP_CACHES = False
def __init__(self, storage, schema, segment, generation=None, codec=None):
self.storage = storage
self.schema = schema
self.segment = segment
self._gen = generation
self.is_closed = False
# Copy info from underlying segment
self._has_deletions = segment.has_deletions()
self._dc = segment.doc_count()
self._dc_all = segment.doc_count_all()
if hasattr(self.segment, "segment_id"):
self.segid = self.segment.segment_id()
else:
from whoosh.codec.base import Segment
self.segid = Segment._random_id()
# self.files is a storage object from which to load the segment files.
# This is different from the general storage (which will be used for
# cahces) if the segment is in a compound file.
if segment.is_compound():
# Use an overlay here instead of just the compound storage because
# in rare circumstances a segment file may be added after the
# segment is written
self.files = OverlayStorage(segment.open_compound_file(storage),
self.storage)
else:
self.files = storage
# Get microreaders from codec
if codec is None:
from whoosh.codec import default_codec
codec = default_codec()
self._codec = codec
self._terms = codec.terms_reader(self.files, self.segment)
self._lengths = codec.lengths_reader(self.files, self.segment)
self._stored = codec.stored_fields_reader(self.files, self.segment)
self._vectors = None # Lazy open with self._open_vectors()
self._graph = None # Lazy open with self._open_dawg()
self.set_caching_policy()
def _open_vectors(self):
if self._vectors:
return
self._vectors = self._codec.vector_reader(self.files, self.segment)
def _open_dawg(self):
if self._graph:
return
self._graph = self._codec.graph_reader(self.files, self.segment)
def has_deletions(self):
return self._has_deletions
def doc_count(self):
return self._dc
def doc_count_all(self):
return self._dc_all
def is_deleted(self, docnum):
return self.segment.is_deleted(docnum)
def generation(self):
return self._gen
def __repr__(self):
return "%s(%s)" % (self.__class__.__name__, self.segment)
def __contains__(self, term):
return term in self._terms
def close(self):
self._terms.close()
self._stored.close()
if self._lengths:
self._lengths.close()
if self._vectors:
self._vectors.close()
if self._graph:
self._graph.close()
self.files.close()
self.caching_policy = None
self.is_closed = True
def stored_fields(self, docnum):
assert docnum >= 0
schema = self.schema
return dict(item for item in iteritems(self._stored[docnum])
if item[0] in schema)
def all_stored_fields(self):
is_deleted = self.segment.is_deleted
sf = self.stored_fields
for docnum in xrange(self._dc_all):
if not is_deleted(docnum):
yield sf(docnum)
def field_length(self, fieldname):
return self._lengths.field_length(fieldname)
def min_field_length(self, fieldname):
return self._lengths.min_field_length(fieldname)
def max_field_length(self, fieldname):
return self._lengths.max_field_length(fieldname)
def doc_field_length(self, docnum, fieldname, default=0):
return self._lengths.doc_field_length(docnum,
fieldname,
default=default)
def has_vector(self, docnum, fieldname):
if self.schema[fieldname].vector:
try:
self._open_vectors()
except (NameError, IOError):
return False
return (docnum, fieldname) in self._vectors
else:
return False
def _test_field(self, fieldname):
if fieldname not in self.schema:
raise TermNotFound("No field %r" % fieldname)
if self.schema[fieldname].format is None:
raise TermNotFound("Field %r is not indexed" % fieldname)
def all_terms(self):
schema = self.schema
return ((fieldname, text) for fieldname, text in self._terms.keys()
if fieldname in schema)
def terms_from(self, fieldname, prefix):
self._test_field(fieldname)
schema = self.schema
return ((fname, text)
for fname, text in self._terms.keys_from((fieldname, prefix))
if fname in schema)
def term_info(self, fieldname, text):
self._test_field(fieldname)
try:
return self._terms[fieldname, text]
except KeyError:
raise TermNotFound("%s:%r" % (fieldname, text))
def _texts_in_fieldcache(self, fieldname, prefix=''):
# The first value in a fieldcache is the default
texts = self.fieldcache(fieldname).texts[1:]
if prefix:
i = bisect_left(texts, prefix)
while i < len(texts) and texts[i].startswith(prefix):
yield texts[i]
i += 1
else:
for text in texts:
yield text
def expand_prefix(self, fieldname, prefix):
self._test_field(fieldname)
# If a fieldcache for the field is already loaded, we already have the
# values for the field in memory, so just yield them from there
if self.fieldcache_loaded(fieldname):
return self._texts_in_fieldcache(fieldname, prefix)
else:
# Call super
return IndexReader.expand_prefix(self, fieldname, prefix)
def lexicon(self, fieldname):
self._test_field(fieldname)
# If a fieldcache for the field is already loaded, we already have the
# values for the field in memory, so just yield them from there
if self.fieldcache_loaded(fieldname):
return self._texts_in_fieldcache(fieldname)
else:
# Call super
return IndexReader.lexicon(self, fieldname)
def __iter__(self):
schema = self.schema
return ((term, terminfo) for term, terminfo in self._terms.items()
if term[0] in schema)
def iter_from(self, fieldname, text):
schema = self.schema
self._test_field(fieldname)
for term, terminfo in self._terms.items_from((fieldname, text)):
if term[0] not in schema:
continue
yield (term, terminfo)
def frequency(self, fieldname, text):
self._test_field(fieldname)
try:
return self._terms.frequency((fieldname, text))
except KeyError:
return 0
def doc_frequency(self, fieldname, text):
self._test_field(fieldname)
try:
return self._terms.doc_frequency((fieldname, text))
except KeyError:
return 0
def postings(self, fieldname, text, scorer=None):
if fieldname not in self.schema:
raise TermNotFound("No field %r" % fieldname)
format_ = self.schema[fieldname].format
matcher = self._terms.matcher(fieldname, text, format_, scorer=scorer)
deleted = self.segment.deleted
if deleted:
matcher = FilterMatcher(matcher, deleted, exclude=True)
return matcher
def vector(self, docnum, fieldname):
if fieldname not in self.schema:
raise TermNotFound("No field %r" % fieldname)
vformat = self.schema[fieldname].vector
if not vformat:
raise Exception("No vectors are stored for field %r" % fieldname)
self._open_vectors()
return self._vectors.matcher(docnum, fieldname, vformat)
# DAWG methods
def has_word_graph(self, fieldname):
if fieldname not in self.schema:
return False
if not self.schema[fieldname].spelling:
return False
try:
self._open_dawg()
except (NameError, IOError, dawg.FileVersionError):
return False
return self._graph.has_root(fieldname)
def word_graph(self, fieldname):
if not self.has_word_graph(fieldname):
raise KeyError("No word graph for field %r" % fieldname)
return dawg.Node(self._graph, self._graph.root(fieldname))
def terms_within(self, fieldname, text, maxdist, prefix=0):
if not self.has_word_graph(fieldname):
# This reader doesn't have a graph stored, use the slow method
return IndexReader.terms_within(self,
fieldname,
text,
maxdist,
prefix=prefix)
return dawg.within(self._graph,
text,
k=maxdist,
prefix=prefix,
address=self._graph.root(fieldname))
# Field cache methods
def supports_caches(self):
return True
def set_caching_policy(self, cp=None, save=True, storage=None):
"""This method lets you control the caching policy of the reader. You
can either pass a :class:`whoosh.filedb.fieldcache.FieldCachingPolicy`
as the first argument, *or* use the `save` and `storage` keywords to
alter the default caching policy::
# Use a custom field caching policy object
reader.set_caching_policy(MyPolicy())
# Use the default caching policy but turn off saving caches to disk
reader.set_caching_policy(save=False)
# Use the default caching policy but save caches to a custom
# storage
from whoosh.filedb.filestore import FileStorage
mystorage = FileStorage("path/to/cachedir")
reader.set_caching_policy(storage=mystorage)
:param cp: a :class:`whoosh.filedb.fieldcache.FieldCachingPolicy`
object. If this argument is not given, the default caching policy
is used.
:param save: save field caches to disk for re-use. If a caching policy
object is specified using `cp`, this argument is ignored.
:param storage: a custom :class:`whoosh.store.Storage` object to use
for saving field caches. If a caching policy object is specified
using `cp` or `save` is `False`, this argument is ignored.
"""
if not cp:
if save and storage is None:
storage = self.storage
elif not save:
storage = None
cp = DefaultFieldCachingPolicy(self.segment.segment_id(),
storage=storage)
if type(cp) is type:
cp = cp()
self.caching_policy = cp
def _fieldkey(self, fieldname):
return "%s/%s" % (self.segid, fieldname)
def fieldcache(self, fieldname, save=SAVE_BY_DEFAULT):
"""Returns a :class:`whoosh.filedb.fieldcache.FieldCache` object for
the given field.
:param fieldname: the name of the field to get a cache for.
:param save: if True (the default), the cache is saved to disk if it
doesn't already exist.
"""
key = self._fieldkey(fieldname)
fc = self.caching_policy.get(key)
if not fc:
fc = FieldCache.from_field(self, fieldname)
self.caching_policy.put(key, fc, save=save)
return fc
def fieldcache_available(self, fieldname):
"""Returns True if a field cache exists for the given field (either in
memory already or on disk).
"""
return self._fieldkey(fieldname) in self.caching_policy
def fieldcache_loaded(self, fieldname):
"""Returns True if a field cache for the given field is in memory.
"""
return self.caching_policy.is_loaded(self._fieldkey(fieldname))
def unload_fieldcache(self, name):
self.caching_policy.delete(self._fieldkey(name))
