new dbcore.query module

Splitting off the Query hierarchy for easier navigation.

beets/dbcore/__init__.py

@@ -15,4 +15,5 @@
 """DBCore is an abstract database package that forms the basis for beets'
 Library.
 """
-from .db import Type, Model, Database, Query, FieldQuery, MatchQuery
+from .db import Type, Model, Database
+from .query import Query, FieldQuery, MatchQuery

beets/dbcore/db.py

@@ -23,6 +23,7 @@ import contextlib
 
 import beets
 from beets.util.functemplate import Template
+from .query import MatchQuery
 
 
 # Path element formatting for templating.
@@ -404,73 +405,6 @@ class Model(object):
 
 
 
-# Basic query classes.
-
-
-class Query(object):
-    """An abstract class representing a query into the item database.
-    """
-    def clause(self):
-        """Generate an SQLite expression implementing the query.
-        Return a clause string, a sequence of substitution values for
-        the clause, and a Query object representing the "remainder"
-        Returns (clause, subvals) where clause is a valid sqlite
-        WHERE clause implementing the query and subvals is a list of
-        items to be substituted for ?s in the clause.
-        """
-        return None, ()
-
-    def match(self, item):
-        """Check whether this query matches a given Item. Can be used to
-        perform queries on arbitrary sets of Items.
-        """
-        raise NotImplementedError
-
-
-class FieldQuery(Query):
-    """An abstract query that searches in a specific field for a
-    pattern. Subclasses must provide a `value_match` class method, which
-    determines whether a certain pattern string matches a certain value
-    string. Subclasses may also provide `col_clause` to implement the
-    same matching functionality in SQLite.
-    """
-    def __init__(self, field, pattern, fast=True):
-        self.field = field
-        self.pattern = pattern
-        self.fast = fast
-
-    def col_clause(self):
-        return None, ()
-
-    def clause(self):
-        if self.fast:
-            return self.col_clause()
-        else:
-            # Matching a flexattr. This is a slow query.
-            return None, ()
-
-    @classmethod
-    def value_match(cls, pattern, value):
-        """Determine whether the value matches the pattern. Both
-        arguments are strings.
-        """
-        raise NotImplementedError()
-
-    def match(self, item):
-        return self.value_match(self.pattern, item.get(self.field))
-
-
-class MatchQuery(FieldQuery):
-    """A query that looks for exact matches in an item field."""
-    def col_clause(self):
-        return self.field + " = ?", [self.pattern]
-
-    @classmethod
-    def value_match(cls, pattern, value):
-        return pattern == value
-
-
-
 # Database controller and supporting interfaces.
 
 

beets/dbcore/query.py

@@ -0,0 +1,77 @@
+# This file is part of beets.
+# Copyright 2014, 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.
+
+"""The Query type hierarchy for DBCore.
+"""
+class Query(object):
+    """An abstract class representing a query into the item database.
+    """
+    def clause(self):
+        """Generate an SQLite expression implementing the query.
+        Return a clause string, a sequence of substitution values for
+        the clause, and a Query object representing the "remainder"
+        Returns (clause, subvals) where clause is a valid sqlite
+        WHERE clause implementing the query and subvals is a list of
+        items to be substituted for ?s in the clause.
+        """
+        return None, ()
+
+    def match(self, item):
+        """Check whether this query matches a given Item. Can be used to
+        perform queries on arbitrary sets of Items.
+        """
+        raise NotImplementedError
+
+
+class FieldQuery(Query):
+    """An abstract query that searches in a specific field for a
+    pattern. Subclasses must provide a `value_match` class method, which
+    determines whether a certain pattern string matches a certain value
+    string. Subclasses may also provide `col_clause` to implement the
+    same matching functionality in SQLite.
+    """
+    def __init__(self, field, pattern, fast=True):
+        self.field = field
+        self.pattern = pattern
+        self.fast = fast
+
+    def col_clause(self):
+        return None, ()
+
+    def clause(self):
+        if self.fast:
+            return self.col_clause()
+        else:
+            # Matching a flexattr. This is a slow query.
+            return None, ()
+
+    @classmethod
+    def value_match(cls, pattern, value):
+        """Determine whether the value matches the pattern. Both
+        arguments are strings.
+        """
+        raise NotImplementedError()
+
+    def match(self, item):
+        return self.value_match(self.pattern, item.get(self.field))
+
+
+class MatchQuery(FieldQuery):
+    """A query that looks for exact matches in an item field."""
+    def col_clause(self):
+        return self.field + " = ?", [self.pattern]
+
+    @classmethod
+    def value_match(cls, pattern, value):
+        return pattern == value