fix: Don't record SQL within an existing event

Author: kgilpin

lib/appmap/handler/rails/sql_handler.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'appmap/event'
+require 'appmap/hook/method'
 
 module AppMap
   module Handler
@@ -21,6 +22,7 @@ def to_h
                 sql: payload[:sql],
                 database_type: payload[:database_type]
               }.tap do |sql_query|
+                sql_query[:query_plan] = payload[:query_plan] if payload[:query_plan]
                 %i[server_version].each do |attribute|
                   sql_query[attribute] = payload[attribute] if payload[attribute]
                 end
@@ -44,15 +46,30 @@ def examine(payload, sql:)
               return unless (examiner = build_examiner)
 
               if AppMap.explain_queries? && examiner.in_transaction? && examiner.database_type == :postgres
-                if sql =~ /\A(SELECT|INSERT|DELETE|UPDATE|WITH)/i
-                  examiner.execute_query 'SAVEPOINT appmap_sql_examiner'
-                  begin
-                    plan = examiner.execute_query(%(EXPLAIN #{sql}))
-                    payload[:query_plan] = plan.map { |line| line[:'QUERY PLAN'] }.join("\n")
-                    examiner.execute_query 'RELEASE SAVEPOINT appmap_sql_examiner'
-                  rescue
-                    warn "Exception occurred explaining query: #{$!}"
-                    examiner.execute_query 'ROLLBACK TO SAVEPOINT appmap_sql_examiner'
+                if sql =~ /\A(SELECT|INSERT|UPDATE|DELETE|WITH)/i
+                  savepoint_established = \
+                    begin
+                      examiner.execute_query 'SAVEPOINT appmap_sql_examiner'
+                      true
+                    rescue
+                      # Probably: Sequel::DatabaseError: PG::InFailedSqlTransaction
+                      byebug
+                      warn $!
+                      false
+                    end
+
+                  if savepoint_established
+                    plan = nil
+                    begin
+                      plan = examiner.execute_query(%(EXPLAIN #{sql}))
+                    rescue
+                      warn "Exception occurred explaining query: #{$!}"
+                      examiner.execute_query 'ROLLBACK TO SAVEPOINT appmap_sql_examiner'
+                    end
+                    if plan
+                      payload[:query_plan] = plan.map { |line| line[:'QUERY PLAN'] }.join("\n")
+                      examiner.execute_query 'RELEASE SAVEPOINT appmap_sql_examiner'
+                    end
                   end
                 end
               end
@@ -124,6 +141,8 @@ def execute_query(sql)
         def call(_, started, finished, _, payload) # (name, started, finished, unique_id, payload)
           return if AppMap.tracing.empty?
 
+          return if Thread.current[AppMap::Hook::Method::HOOK_DISABLE_KEY] == true
+
           reentry_key = "#{self.class.name}#call"
           return if Thread.current[reentry_key] == true
 

lib/appmap/hook/method.rb

@@ -24,7 +24,6 @@ class Method
       attr_reader :hook_package, :hook_class, :hook_method, :parameters, :arity
 
       HOOK_DISABLE_KEY = 'AppMap::Hook.disable'
-      private_constant :HOOK_DISABLE_KEY
 
       def initialize(hook_package, hook_class, hook_method)
         @hook_package = hook_package