Allow statements to auto close when consumed if no cache (#198)

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Brian J. Cardiff 2023-11-29 18:39:44 -03:00 committed by GitHub
parent 76d8bb6a6e
commit d3dd978e24
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8 changed files with 100 additions and 4 deletions

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@ -34,14 +34,20 @@ class DummyDriver < DB::Driver
end
def build_prepared_statement(query) : DB::Statement
assert_not_closed!
DummyStatement.new(self, query, true)
end
def build_unprepared_statement(query) : DB::Statement
assert_not_closed!
DummyStatement.new(self, query, false)
end
def last_insert_id : Int64
assert_not_closed!
0
end
@ -54,12 +60,18 @@ class DummyDriver < DB::Driver
end
def create_transaction
assert_not_closed!
DummyTransaction.new(self)
end
protected def do_close
super
end
private def assert_not_closed!
raise "Statement is closed" if closed?
end
end
class DummyTransaction < DB::TopLevelTransaction
@ -114,6 +126,8 @@ class DummyDriver < DB::Driver
end
protected def perform_query(args : Enumerable) : DB::ResultSet
assert_not_closed!
Fiber.yield
@connection.as(DummyConnection).check
set_params args
@ -121,6 +135,8 @@ class DummyDriver < DB::Driver
end
protected def perform_exec(args : Enumerable) : DB::ExecResult
assert_not_closed!
@connection.as(DummyConnection).check
set_params args
raise DB::Error.new("forced exception due to query") if command == "raise"
@ -153,6 +169,10 @@ class DummyDriver < DB::Driver
protected def do_close
super
end
private def assert_not_closed!
raise "Statement is closed" if closed?
end
end
class DummyResultSet < DB::ResultSet

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@ -43,6 +43,17 @@ describe DB::Statement do
end
end
it "should leave statements open to be reused if true" do
with_dummy_connection("prepared_statements=true&prepared_statements_cache=true") do |cnn|
rs = cnn.query("the query")
# do not close while iterating
rs.statement.closed?.should be_false
rs.close
# do not close to be reused
rs.statement.closed?.should be_false
end
end
it "should not reuse prepared statements if false" do
with_dummy_connection("prepared_statements=true&prepared_statements_cache=false") do |cnn|
stmt1 = cnn.query("the query").statement
@ -50,6 +61,31 @@ describe DB::Statement do
stmt1.object_id.should_not eq(stmt2.object_id)
end
end
it "should close statements if false" do
with_dummy_connection("prepared_statements=true&prepared_statements_cache=false") do |cnn|
rs = cnn.query("the query")
# do not close while iterating
rs.statement.closed?.should be_false
rs.close
# do close after iterating
rs.statement.closed?.should be_true
end
end
it "should not close statements if false and created explicitly" do
with_dummy_connection("prepared_statements=true&prepared_statements_cache=false") do |cnn|
stmt = cnn.prepared("the query")
rs = stmt.query
# do not close while iterating
stmt.closed?.should be_false
rs.close
# do not close after iterating
stmt.closed?.should be_false
end
end
end
it "should initialize positional params in query" do

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@ -50,6 +50,10 @@ module DB
@options.prepared_statements
end
def prepared_statements_cache? : Bool
@options.prepared_statements_cache
end
# :nodoc:
def fetch_or_build_prepared_statement(query) : Statement
if @options.prepared_statements_cache

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@ -59,6 +59,10 @@ module DB
@connection_options.prepared_statements
end
def prepared_statements_cache? : Bool
@connection_options.prepared_statements_cache
end
# Run the specified block every time a new connection is established, yielding the new connection
# to the block.
#

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@ -15,7 +15,14 @@ module DB
# otherwise the preparation is delayed until the first execution.
# After the first initialization the connection must be released
# it will be checked out when executing it.
statement_with_retry &.release_connection
# This only happens if the db is configured to use prepared statements cache.
# Without that there is no reference to the already prepared statement we can
# take advantage of.
if db.prepared_statements_cache?
statement_with_retry &.release_connection
end
# TODO use a round-robin selection in the pool so multiple sequentially
# initialized statements are assigned to different connections.
end
@ -46,7 +53,7 @@ module DB
conn.release
raise ex
end
unless existing
if !existing && @db.prepared_statements_cache?
@mutex.synchronize do
@connections << WeakRef.new(conn)
end
@ -55,6 +62,8 @@ module DB
end
private def clean_connections
return unless @db.prepared_statements_cache?
@mutex.synchronize do
# remove disposed or closed connections
@connections.each do |ref|

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@ -29,7 +29,7 @@ module DB
end
protected def do_close
statement.release_connection
statement.release_from_result_set
end
# TODO add_next_result_set : Bool

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@ -14,13 +14,27 @@ module DB
# be prepared or not.
abstract def prepared_statements? : Bool
abstract def prepared_statements_cache? : Bool
abstract def fetch_or_build_prepared_statement(query) : Stmt
abstract def build_unprepared_statement(query) : Stmt
def build(query) : Stmt
if prepared_statements?
fetch_or_build_prepared_statement(query)
stmt = fetch_or_build_prepared_statement(query)
# #build is a :nodoc: method used on QueryMethods where
# the statements are not exposed. As such if the cache
# is disabled we should auto_close the statement.
# When the statements are build explicitly the #prepared
# and #unprepared methods are used. In that case the
# statement is closed by the user explicitly also.
if !prepared_statements_cache?
stmt.auto_close = true if stmt.responds_to?(:auto_close=)
end
stmt
else
build_unprepared_statement(query)
end

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@ -56,6 +56,15 @@ module DB
def initialize(@connection : Connection, @command : String)
end
# :nodoc:
property auto_close : Bool = false
# :nodoc:
def release_from_result_set
self.close if @auto_close
self.release_connection
end
def release_connection
@connection.release_from_statement
end