From 6db79feab78af8ddf472d2723c90a67dd13c9a7e Mon Sep 17 00:00:00 2001
From: Donal McBreen <donal@basecamp.com>
Date: Wed, 28 Feb 2024 08:45:42 +0000
Subject: [PATCH] Disable the query cache without workarounds

Use the new `dirties: false` option to `uncached` to disable the query
cache and avoid the messy workarounds.

Currently only available in Rails edge so this will need to wait for its
release. Will be part of Solid Cache v1.0, which will drop support for
Rails 7.1 and earlier.
---
 app/models/solid_cache/entry.rb | 61 +++++++++------------------------
 1 file changed, 16 insertions(+), 45 deletions(-)

diff --git a/app/models/solid_cache/entry.rb b/app/models/solid_cache/entry.rb
index a3d3752..fdc3153 100644
--- a/app/models/solid_cache/entry.rb
+++ b/app/models/solid_cache/entry.rb
@@ -49,7 +49,7 @@ def clear_delete
 
       def lock_and_write(key, &block)
         transaction do
-          uncached do
+          without_query_cache do
             result = lock.where(key_hash: key_hash_for(key)).pick(:key, :value)
             new_value = block.call(result&.first == key ? result[1] : nil)
             write(key, new_value)
@@ -59,31 +59,24 @@ def lock_and_write(key, &block)
       end
 
       def id_range
-        uncached do
+        without_query_cache do
           pick(Arel.sql("max(id) - min(id) + 1")) || 0
         end
       end
 
       private
         def upsert_all_no_query_cache(payloads)
-          args = [ self,
-                   connection_for_insert_all,
-                   add_key_hash_and_byte_size(payloads) ].compact
-          options = { unique_by: upsert_unique_by,
-                      on_duplicate: :update,
-                      update_only: upsert_update_only }
-          insert_all = ActiveRecord::InsertAll.new(*args, **options)
-          sql = connection.build_insert_sql(ActiveRecord::InsertAll::Builder.new(insert_all))
-
-          message = +"#{self} "
-          message << "Bulk " if payloads.many?
-          message << "Upsert"
-          # exec_query_method does not clear the query cache, exec_insert_all does
-          connection.send exec_query_method, sql, message
+          without_query_cache do
+            upsert_all \
+              add_key_hash_and_byte_size(payloads),
+              unique_by: upsert_unique_by, on_duplicate: :update, update_only: [ :key, :value, :byte_size ]
+          end
         end
 
-        def connection_for_insert_all
-          Rails.version >= "7.2" ? connection : nil
+        def delete_no_query_cache(attribute, values)
+          without_query_cache do
+            where(attribute => values).delete_all
+          end
         end
 
         def add_key_hash_and_byte_size(payloads)
@@ -95,18 +88,10 @@ def add_key_hash_and_byte_size(payloads)
           end
         end
 
-        def exec_query_method
-          connection.respond_to?(:internal_exec_query) ? :internal_exec_query : :exec_query
-        end
-
         def upsert_unique_by
           connection.supports_insert_conflict_target? ? :key_hash : nil
         end
 
-        def upsert_update_only
-          [ :key, :value, :byte_size ]
-        end
-
         def get_sql
           @get_sql ||= build_sql(where(key_hash: 1).select(:key, :value))
         end
@@ -130,7 +115,7 @@ def build_sql(relation)
         end
 
         def select_all_no_query_cache(query, values)
-          uncached do
+          without_query_cache do
             if connection.prepared_statements?
               result = connection.select_all(sanitize_sql(query), "#{name} Load", Array(values), preparable: true)
             else
@@ -141,24 +126,6 @@ def select_all_no_query_cache(query, values)
           end
         end
 
-        def delete_no_query_cache(attribute, values)
-          uncached do
-            relation = where(attribute => values)
-            sql = connection.to_sql(relation.arel.compile_delete(relation.table[primary_key]))
-
-            # exec_delete does not clear the query cache
-            if connection.prepared_statements?
-              connection.exec_delete(sql, "#{name} Delete All", Array(values))
-            else
-              connection.exec_delete(sql, "#{name} Delete All")
-            end
-          end
-        end
-
-        def to_binary(key)
-          ActiveModel::Type::Binary.new.serialize(key)
-        end
-
         def key_hash_for(key)
           # Need to unpack this as a signed integer - Postgresql and SQLite don't support unsigned integers
           Digest::SHA256.digest(key.to_s).unpack("q>").first
@@ -167,6 +134,10 @@ def key_hash_for(key)
         def byte_size_for(payload)
           payload[:key].to_s.bytesize + payload[:value].to_s.bytesize + ESTIMATED_ROW_OVERHEAD
         end
+
+        def without_query_cache(&block)
+          uncached(dirties: false, &block)
+        end
     end
   end
 end