def add_spelling(ix, fieldnames, commit=True):
"""Adds spelling files to an existing index that was created without
them, and modifies the schema so the given fields have the ``spelling``
attribute. Only works on filedb indexes.
>>> ix = index.open_dir("testindex")
>>> add_spelling(ix, ["content", "tags"])
:param ix: a :class:`whoosh.filedb.fileindex.FileIndex` object.
:param fieldnames: a list of field names to create word graphs for.
:param force: if True, overwrites existing word graph files. This is only
useful for debugging.
"""
from whoosh.filedb.filereading import SegmentReader
writer = ix.writer()
storage = writer.storage
schema = writer.schema
segments = writer.segments
for segment in segments:
r = SegmentReader(storage, schema, segment)
f = segment.create_file(storage, ".dag")
dawg = DawgBuilder(f, field_root=True)
for fieldname in fieldnames:
ft = (fieldname,)
for word in r.lexicon(fieldname):
dawg.insert(ft + tuple(word))
dawg.close()
for fieldname in fieldnames:
schema[fieldname].spelling = True
if commit:
writer.commit(merge=False)
class StdFieldWriter(base.FieldWriter):
def __init__(self,
storage,
segment,
blocklimit=128,
compression=3,
inlinelimit=1):
self.storage = storage
self.segment = segment
self.fieldname = None
self.text = None
self.field = None
self.format = None
self.spelling = False
tifile = segment.create_file(storage, StdCodec.TERMS_EXT)
self.termsindex = TermIndexWriter(tifile)
self.postfile = segment.create_file(storage, StdCodec.POSTS_EXT)
# We'll wait to create the DAWG builder until someone actually adds
# a spelled field
self.dawg = None
self.blocklimit = blocklimit
self.compression = compression
self.inlinelimit = inlinelimit
self.block = None
self.terminfo = None
def _make_dawg_files(self):
dawgfile = self.segment.create_file(self.storage, StdCodec.DAWG_EXT)
self.dawg = DawgBuilder(dawgfile, field_root=True)
def _reset_block(self):
self.block = StdBlock(self.format.posting_size)
def _write_block(self):
self.terminfo.add_block(self.block)
self.block.to_file(self.postfile, compression=self.compression)
self._reset_block()
self.blockcount += 1
def _start_blocklist(self):
postfile = self.postfile
self._reset_block()
# Magic number
self.startoffset = postfile.tell()
postfile.write(StdBlock.magic)
# Placeholder for block count
self.blockcount = 0
postfile.write_uint(0)
def _finish_blocklist(self):
if self.block:
self._write_block()
# Seek back to the start of this list of posting blocks and write the
# number of blocks
postfile = self.postfile
postfile.flush()
here = postfile.tell()
postfile.seek(self.startoffset + 4)
postfile.write_uint(self.blockcount)
postfile.seek(here)
self.block = None
def start_field(self, fieldname, fieldobj):
self.fieldname = fieldname
self.field = fieldobj
self.format = fieldobj.format
self.spelling = fieldobj.spelling and not fieldobj.separate_spelling()
def start_term(self, text):
if self.block is not None:
raise Exception("Called start_term in a block")
self.text = text
self.terminfo = base.FileTermInfo()
if self.spelling:
if self.dawg is None:
self._make_dawg_files()
self.dawg.insert((self.fieldname, ) + tuple(text))
self._start_blocklist()
def add(self, docnum, weight, valuestring, length):
self.block.add(docnum, weight, valuestring, length)
if len(self.block) > self.blocklimit:
self._write_block()
def add_spell_word(self, fieldname, text):
if self.dawg is None:
self._make_dawg_files()
self.dawg.insert((fieldname, ) + tuple(text))
def finish_term(self):
if self.block is None:
raise Exception("Called finish_term when not in a block")
block = self.block
terminfo = self.terminfo
if self.blockcount < 1 and block and len(block) < self.inlinelimit:
# Inline the single block
terminfo.add_block(block)
vals = None if not block.values else tuple(block.values)
postings = (tuple(block.ids), tuple(block.weights), vals)
else:
self._finish_blocklist()
postings = self.startoffset
self.block = None
terminfo.postings = postings
self.termsindex.add((self.fieldname, self.text), terminfo)
def close(self):
self.termsindex.close()
self.postfile.close()
if self.dawg is not None:
self.dawg.close()
class StdFieldWriter(base.FieldWriter):
def __init__(self, storage, segment, blocklimit=128, compression=3,
inlinelimit=1):
self.storage = storage
self.segment = segment
self.fieldname = None
self.text = None
self.field = None
self.format = None
self.spelling = False
tifile = segment.create_file(storage, StdCodec.TERMS_EXT)
self.termsindex = TermIndexWriter(tifile)
self.postfile = segment.create_file(storage, StdCodec.POSTS_EXT)
# We'll wait to create the DAWG builder until someone actually adds
# a spelled field
self.dawg = None
self.blocklimit = blocklimit
self.compression = compression
self.inlinelimit = inlinelimit
self.block = None
self.terminfo = None
def _make_dawg_files(self):
dawgfile = self.segment.create_file(self.storage, StdCodec.DAWG_EXT)
self.dawg = DawgBuilder(dawgfile, field_root=True)
def _reset_block(self):
self.block = StdBlock(self.format.posting_size)
def _write_block(self):
self.terminfo.add_block(self.block)
self.block.to_file(self.postfile, compression=self.compression)
self._reset_block()
self.blockcount += 1
def _start_blocklist(self):
postfile = self.postfile
self._reset_block()
# Magic number
self.startoffset = postfile.tell()
postfile.write(StdBlock.magic)
# Placeholder for block count
self.blockcount = 0
postfile.write_uint(0)
def _finish_blocklist(self):
if self.block:
self._write_block()
# Seek back to the start of this list of posting blocks and write the
# number of blocks
postfile = self.postfile
postfile.flush()
here = postfile.tell()
postfile.seek(self.startoffset + 4)
postfile.write_uint(self.blockcount)
postfile.seek(here)
self.block = None
def start_field(self, fieldname, fieldobj):
self.fieldname = fieldname
self.field = fieldobj
self.format = fieldobj.format
self.spelling = fieldobj.spelling and not fieldobj.separate_spelling()
def start_term(self, text):
if self.block is not None:
raise Exception("Called start_term in a block")
self.text = text
self.terminfo = base.FileTermInfo()
if self.spelling:
if self.dawg is None:
self._make_dawg_files()
self.dawg.insert((self.fieldname,) + tuple(text))
self._start_blocklist()
def add(self, docnum, weight, valuestring, length):
self.block.add(docnum, weight, valuestring, length)
if len(self.block) > self.blocklimit:
self._write_block()
def add_spell_word(self, fieldname, text):
if self.dawg is None:
self._make_dawg_files()
self.dawg.insert((fieldname,) + tuple(text))
def finish_term(self):
if self.block is None:
raise Exception("Called finish_term when not in a block")
block = self.block
terminfo = self.terminfo
if self.blockcount < 1 and block and len(block) < self.inlinelimit:
# Inline the single block
terminfo.add_block(block)
vals = None if not block.values else tuple(block.values)
postings = (tuple(block.ids), tuple(block.weights), vals)
else:
self._finish_blocklist()
postings = self.startoffset
self.block = None
terminfo.postings = postings
self.termsindex.add((self.fieldname, self.text), terminfo)
def close(self):
self.termsindex.close()
self.postfile.close()
if self.dawg is not None:
self.dawg.close()