mirror of
https://github.com/clinton-hall/nzbToMedia.git
synced 2025-07-07 05:31:11 -07:00
250 lines
9.2 KiB
Python
250 lines
9.2 KiB
Python
# -*- coding: utf-8 -*-
|
|
# This file is part of beets.
|
|
# Copyright 2016, Adrian Sampson.
|
|
#
|
|
# Permission is hereby granted, free of charge, to any person obtaining
|
|
# a copy of this software and associated documentation files (the
|
|
# "Software"), to deal in the Software without restriction, including
|
|
# without limitation the rights to use, copy, modify, merge, publish,
|
|
# distribute, sublicense, and/or sell copies of the Software, and to
|
|
# permit persons to whom the Software is furnished to do so, subject to
|
|
# the following conditions:
|
|
#
|
|
# The above copyright notice and this permission notice shall be
|
|
# included in all copies or substantial portions of the Software.
|
|
|
|
"""Parsing of strings into DBCore queries.
|
|
"""
|
|
from __future__ import division, absolute_import, print_function
|
|
|
|
import re
|
|
import itertools
|
|
from . import query
|
|
import beets
|
|
|
|
PARSE_QUERY_PART_REGEX = re.compile(
|
|
# Non-capturing optional segment for the keyword.
|
|
r'(-|\^)?' # Negation prefixes.
|
|
|
|
r'(?:'
|
|
r'(\S+?)' # The field key.
|
|
r'(?<!\\):' # Unescaped :
|
|
r')?'
|
|
|
|
r'(.*)', # The term itself.
|
|
|
|
re.I # Case-insensitive.
|
|
)
|
|
|
|
|
|
def parse_query_part(part, query_classes={}, prefixes={},
|
|
default_class=query.SubstringQuery):
|
|
"""Parse a single *query part*, which is a chunk of a complete query
|
|
string representing a single criterion.
|
|
|
|
A query part is a string consisting of:
|
|
- A *pattern*: the value to look for.
|
|
- Optionally, a *field name* preceding the pattern, separated by a
|
|
colon. So in `foo:bar`, `foo` is the field name and `bar` is the
|
|
pattern.
|
|
- Optionally, a *query prefix* just before the pattern (and after the
|
|
optional colon) indicating the type of query that should be used. For
|
|
example, in `~foo`, `~` might be a prefix. (The set of prefixes to
|
|
look for is given in the `prefixes` parameter.)
|
|
- Optionally, a negation indicator, `-` or `^`, at the very beginning.
|
|
|
|
Both prefixes and the separating `:` character may be escaped with a
|
|
backslash to avoid their normal meaning.
|
|
|
|
The function returns a tuple consisting of:
|
|
- The field name: a string or None if it's not present.
|
|
- The pattern, a string.
|
|
- The query class to use, which inherits from the base
|
|
:class:`Query` type.
|
|
- A negation flag, a bool.
|
|
|
|
The three optional parameters determine which query class is used (i.e.,
|
|
the third return value). They are:
|
|
- `query_classes`, which maps field names to query classes. These
|
|
are used when no explicit prefix is present.
|
|
- `prefixes`, which maps prefix strings to query classes.
|
|
- `default_class`, the fallback when neither the field nor a prefix
|
|
indicates a query class.
|
|
|
|
So the precedence for determining which query class to return is:
|
|
prefix, followed by field, and finally the default.
|
|
|
|
For example, assuming the `:` prefix is used for `RegexpQuery`:
|
|
- `'stapler'` -> `(None, 'stapler', SubstringQuery, False)`
|
|
- `'color:red'` -> `('color', 'red', SubstringQuery, False)`
|
|
- `':^Quiet'` -> `(None, '^Quiet', RegexpQuery, False)`, because
|
|
the `^` follows the `:`
|
|
- `'color::b..e'` -> `('color', 'b..e', RegexpQuery, False)`
|
|
- `'-color:red'` -> `('color', 'red', SubstringQuery, True)`
|
|
"""
|
|
# Apply the regular expression and extract the components.
|
|
part = part.strip()
|
|
match = PARSE_QUERY_PART_REGEX.match(part)
|
|
|
|
assert match # Regex should always match
|
|
negate = bool(match.group(1))
|
|
key = match.group(2)
|
|
term = match.group(3).replace('\:', ':')
|
|
|
|
# Check whether there's a prefix in the query and use the
|
|
# corresponding query type.
|
|
for pre, query_class in prefixes.items():
|
|
if term.startswith(pre):
|
|
return key, term[len(pre):], query_class, negate
|
|
|
|
# No matching prefix, so use either the query class determined by
|
|
# the field or the default as a fallback.
|
|
query_class = query_classes.get(key, default_class)
|
|
return key, term, query_class, negate
|
|
|
|
|
|
def construct_query_part(model_cls, prefixes, query_part):
|
|
"""Parse a *query part* string and return a :class:`Query` object.
|
|
|
|
:param model_cls: The :class:`Model` class that this is a query for.
|
|
This is used to determine the appropriate query types for the
|
|
model's fields.
|
|
:param prefixes: A map from prefix strings to :class:`Query` types.
|
|
:param query_part: The string to parse.
|
|
|
|
See the documentation for `parse_query_part` for more information on
|
|
query part syntax.
|
|
"""
|
|
# A shortcut for empty query parts.
|
|
if not query_part:
|
|
return query.TrueQuery()
|
|
|
|
# Use `model_cls` to build up a map from field names to `Query`
|
|
# classes.
|
|
query_classes = {}
|
|
for k, t in itertools.chain(model_cls._fields.items(),
|
|
model_cls._types.items()):
|
|
query_classes[k] = t.query
|
|
|
|
# Parse the string.
|
|
key, pattern, query_class, negate = \
|
|
parse_query_part(query_part, query_classes, prefixes)
|
|
|
|
# If there's no key (field name) specified, this is a "match
|
|
# anything" query.
|
|
if key is None:
|
|
if issubclass(query_class, query.FieldQuery):
|
|
# The query type matches a specific field, but none was
|
|
# specified. So we use a version of the query that matches
|
|
# any field.
|
|
q = query.AnyFieldQuery(pattern, model_cls._search_fields,
|
|
query_class)
|
|
if negate:
|
|
return query.NotQuery(q)
|
|
else:
|
|
return q
|
|
else:
|
|
# Non-field query type.
|
|
if negate:
|
|
return query.NotQuery(query_class(pattern))
|
|
else:
|
|
return query_class(pattern)
|
|
|
|
# Otherwise, this must be a `FieldQuery`. Use the field name to
|
|
# construct the query object.
|
|
key = key.lower()
|
|
q = query_class(key.lower(), pattern, key in model_cls._fields)
|
|
if negate:
|
|
return query.NotQuery(q)
|
|
return q
|
|
|
|
|
|
def query_from_strings(query_cls, model_cls, prefixes, query_parts):
|
|
"""Creates a collection query of type `query_cls` from a list of
|
|
strings in the format used by parse_query_part. `model_cls`
|
|
determines how queries are constructed from strings.
|
|
"""
|
|
subqueries = []
|
|
for part in query_parts:
|
|
subqueries.append(construct_query_part(model_cls, prefixes, part))
|
|
if not subqueries: # No terms in query.
|
|
subqueries = [query.TrueQuery()]
|
|
return query_cls(subqueries)
|
|
|
|
|
|
def construct_sort_part(model_cls, part):
|
|
"""Create a `Sort` from a single string criterion.
|
|
|
|
`model_cls` is the `Model` being queried. `part` is a single string
|
|
ending in ``+`` or ``-`` indicating the sort.
|
|
"""
|
|
assert part, "part must be a field name and + or -"
|
|
field = part[:-1]
|
|
assert field, "field is missing"
|
|
direction = part[-1]
|
|
assert direction in ('+', '-'), "part must end with + or -"
|
|
is_ascending = direction == '+'
|
|
|
|
case_insensitive = beets.config['sort_case_insensitive'].get(bool)
|
|
if field in model_cls._sorts:
|
|
sort = model_cls._sorts[field](model_cls, is_ascending,
|
|
case_insensitive)
|
|
elif field in model_cls._fields:
|
|
sort = query.FixedFieldSort(field, is_ascending, case_insensitive)
|
|
else:
|
|
# Flexible or computed.
|
|
sort = query.SlowFieldSort(field, is_ascending, case_insensitive)
|
|
return sort
|
|
|
|
|
|
def sort_from_strings(model_cls, sort_parts):
|
|
"""Create a `Sort` from a list of sort criteria (strings).
|
|
"""
|
|
if not sort_parts:
|
|
sort = query.NullSort()
|
|
elif len(sort_parts) == 1:
|
|
sort = construct_sort_part(model_cls, sort_parts[0])
|
|
else:
|
|
sort = query.MultipleSort()
|
|
for part in sort_parts:
|
|
sort.add_sort(construct_sort_part(model_cls, part))
|
|
return sort
|
|
|
|
|
|
def parse_sorted_query(model_cls, parts, prefixes={}):
|
|
"""Given a list of strings, create the `Query` and `Sort` that they
|
|
represent.
|
|
"""
|
|
# Separate query token and sort token.
|
|
query_parts = []
|
|
sort_parts = []
|
|
|
|
# Split up query in to comma-separated subqueries, each representing
|
|
# an AndQuery, which need to be joined together in one OrQuery
|
|
subquery_parts = []
|
|
for part in parts + [u',']:
|
|
if part.endswith(u','):
|
|
# Ensure we can catch "foo, bar" as well as "foo , bar"
|
|
last_subquery_part = part[:-1]
|
|
if last_subquery_part:
|
|
subquery_parts.append(last_subquery_part)
|
|
# Parse the subquery in to a single AndQuery
|
|
# TODO: Avoid needlessly wrapping AndQueries containing 1 subquery?
|
|
query_parts.append(query_from_strings(
|
|
query.AndQuery, model_cls, prefixes, subquery_parts
|
|
))
|
|
del subquery_parts[:]
|
|
else:
|
|
# Sort parts (1) end in + or -, (2) don't have a field, and
|
|
# (3) consist of more than just the + or -.
|
|
if part.endswith((u'+', u'-')) \
|
|
and u':' not in part \
|
|
and len(part) > 1:
|
|
sort_parts.append(part)
|
|
else:
|
|
subquery_parts.append(part)
|
|
|
|
# Avoid needlessly wrapping single statements in an OR
|
|
q = query.OrQuery(query_parts) if len(query_parts) > 1 else query_parts[0]
|
|
s = sort_from_strings(model_cls, sort_parts)
|
|
return q, s
|