From edb36629e7356f70f42b9d37fea5dfe9cc3c364a Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Mon, 27 May 2019 11:41:44 -0700
Subject: [PATCH] Database.get_outbound_foreign_keys() refactor

Following this, the only module that ever makes calls to the low-level
execute_against_connection_in_thread() method is datasette/database.py
---
 datasette/database.py    |  5 +++++
 datasette/facets.py      | 11 ++++-------
 datasette/views/table.py | 13 ++++---------
 3 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/datasette/database.py b/datasette/database.py
index 45006cbe..5fac4925 100644
--- a/datasette/database.py
+++ b/datasette/database.py
@@ -205,6 +205,11 @@ class Database:
             self.name, get_all_foreign_keys
         )
 
+    async def get_outbound_foreign_keys(self, table):
+        return await self.ds.execute_against_connection_in_thread(
+            self.name, lambda conn: get_outbound_foreign_keys(conn, table)
+        )
+
     async def get_table_definition(self, table, type_="table"):
         table_definition_rows = list(
             await self.ds.execute(
diff --git a/datasette/facets.py b/datasette/facets.py
index 7d7bd6d4..c37bb650 100644
--- a/datasette/facets.py
+++ b/datasette/facets.py
@@ -4,7 +4,6 @@ import re
 from datasette import hookimpl
 from datasette.utils import (
     escape_sqlite,
-    get_all_foreign_keys,
     path_with_added_args,
     path_with_removed_args,
     detect_json1,
@@ -486,9 +485,8 @@ class ManyToManyFacet(Facet):
         # This is calculated based on foreign key relationships to this table
         # Are there any many-to-many tables pointing here?
         suggested_facets = []
-        all_foreign_keys = await self.ds.execute_against_connection_in_thread(
-            self.database, get_all_foreign_keys
-        )
+        db = self.ds.databases[self.database]
+        all_foreign_keys = await db.get_all_foreign_keys()
         if not all_foreign_keys.get(self.table):
             # It's probably a view
             return []
@@ -528,9 +526,8 @@ class ManyToManyFacet(Facet):
         facets_timed_out = []
         args = set(self.get_querystring_pairs())
         facet_size = self.ds.config("default_facet_size")
-        all_foreign_keys = await self.ds.execute_against_connection_in_thread(
-            self.database, get_all_foreign_keys
-        )
+        db = self.ds.databases[self.database]
+        all_foreign_keys = await db.get_all_foreign_keys()
         if not all_foreign_keys.get(self.table):
             return [], []
         # We care about three tables: self.table, middle_table and destination_table
diff --git a/datasette/views/table.py b/datasette/views/table.py
index 2d704670..e109856a 100644
--- a/datasette/views/table.py
+++ b/datasette/views/table.py
@@ -14,8 +14,6 @@ from datasette.utils import (
     compound_keys_after_sql,
     escape_sqlite,
     filters_should_redirect,
-    get_all_foreign_keys,
-    get_outbound_foreign_keys,
     is_url,
     path_from_row_pks,
     path_with_added_args,
@@ -293,9 +291,8 @@ class TableView(RowTableShared):
                 through_table = through_data["table"]
                 other_column = through_data["column"]
                 value = through_data["value"]
-                outgoing_foreign_keys = await self.ds.execute_against_connection_in_thread(
-                    database,
-                    lambda conn: get_outbound_foreign_keys(conn, through_table),
+                outgoing_foreign_keys = await db.get_outbound_foreign_keys(
+                    through_table
                 )
                 try:
                     fk_to_us = [
@@ -843,10 +840,8 @@ class RowView(RowTableShared):
     async def foreign_key_tables(self, database, table, pk_values):
         if len(pk_values) != 1:
             return []
-
-        all_foreign_keys = await self.ds.execute_against_connection_in_thread(
-            database, get_all_foreign_keys
-        )
+        db = self.ds.databases[database]
+        all_foreign_keys = await db.get_all_foreign_keys()
         foreign_keys = all_foreign_keys[table]["incoming"]
         if len(foreign_keys) == 0:
             return []