feat: support PG show transaction isolation level (#1777)

olavloite · web-flow · commit 111f74c36776 · 2022-03-24T19:02:36.000+01:00
* feat: support PG show transaction isolation level

Adds support for the PostgreSQL statement SHOW TRANSACTION ISOLATION
LEVEL. This statement is used by the PG JDBC driver to get the isolation
level of a connection. The statement will always return the static
string 'serializable', as that is the only isolation level Spangres
supports.

* build: force rebuild
diff --git a/google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ConnectionStatementExecutor.java b/google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ConnectionStatementExecutor.java
@@ -109,4 +109,6 @@ StatementResult statementSetPgSessionCharacteristicsTransactionMode(
   StatementResult statementSetRPCPriority(Priority priority);
 
   StatementResult statementShowRPCPriority();
+
+  StatementResult statementShowTransactionIsolationLevel();
 }
diff --git a/google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ConnectionStatementExecutorImpl.java b/google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/ConnectionStatementExecutorImpl.java
@@ -49,6 +49,7 @@
 import static com.google.cloud.spanner.connection.StatementResult.ClientSideStatementType.SHOW_RPC_PRIORITY;
 import static com.google.cloud.spanner.connection.StatementResult.ClientSideStatementType.SHOW_STATEMENT_TAG;
 import static com.google.cloud.spanner.connection.StatementResult.ClientSideStatementType.SHOW_STATEMENT_TIMEOUT;
+import static com.google.cloud.spanner.connection.StatementResult.ClientSideStatementType.SHOW_TRANSACTION_ISOLATION_LEVEL;
 import static com.google.cloud.spanner.connection.StatementResult.ClientSideStatementType.SHOW_TRANSACTION_TAG;
 import static com.google.cloud.spanner.connection.StatementResult.ClientSideStatementType.START_BATCH_DDL;
 import static com.google.cloud.spanner.connection.StatementResult.ClientSideStatementType.START_BATCH_DML;
@@ -436,4 +437,9 @@ public StatementResult statementShowRPCPriority() {
             : getConnection().getRPCPriority(),
         SHOW_RPC_PRIORITY);
   }
+
+  @Override
+  public StatementResult statementShowTransactionIsolationLevel() {
+    return resultSet("transaction_isolation", "serializable", SHOW_TRANSACTION_ISOLATION_LEVEL);
+  }
 }
diff --git a/google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/StatementResult.java b/google-cloud-spanner/src/main/java/com/google/cloud/spanner/connection/StatementResult.java
@@ -82,7 +82,8 @@ enum ClientSideStatementType {
     RUN_BATCH,
     ABORT_BATCH,
     SET_RPC_PRIORITY,
-    SHOW_RPC_PRIORITY
+    SHOW_RPC_PRIORITY,
+    SHOW_TRANSACTION_ISOLATION_LEVEL
   }
 
   /**
diff --git a/google-cloud-spanner/src/main/resources/com/google/cloud/spanner/connection/PG_ClientSideStatements.json b/google-cloud-spanner/src/main/resources/com/google/cloud/spanner/connection/PG_ClientSideStatements.json
@@ -125,6 +125,14 @@
       "method": "statementShowRPCPriority",
       "exampleStatements": ["show spanner.rpc_priority","show variable spanner.rpc_priority"]
     },
+    {
+      "name": "SHOW [VARIABLE] TRANSACTION ISOLATION LEVEL",
+      "executorName": "ClientSideStatementNoParamExecutor",
+      "resultType": "RESULT_SET",
+      "regex": "(?is)\\A\\s*show\\s+(?:variable\\s+)?transaction\\s*isolation\\s*level\\s*\\z",
+      "method": "statementShowTransactionIsolationLevel",
+      "exampleStatements": ["show transaction isolation level","show variable transaction isolation level"]
+    },
     {
       "name": "{START | BEGIN} [TRANSACTION | WORK] [{ (READ ONLY|READ WRITE) | (ISOLATION LEVEL (DEFAULT|SERIALIZABLE)) }]",
       "executorName": "ClientSideStatementPgBeginExecutor",
diff --git a/google-cloud-spanner/src/test/resources/com/google/cloud/spanner/connection/ConnectionImplGeneratedSqlScriptTest.sql b/google-cloud-spanner/src/test/resources/com/google/cloud/spanner/connection/ConnectionImplGeneratedSqlScriptTest.sql
diff --git a/google-cloud-spanner/src/test/resources/com/google/cloud/spanner/connection/postgresql/ConnectionImplGeneratedSqlScriptTest.sql b/google-cloud-spanner/src/test/resources/com/google/cloud/spanner/connection/postgresql/ConnectionImplGeneratedSqlScriptTest.sql

Original file line number	Diff line number	Diff line change
`@@ -109,4 +109,6 @@ StatementResult statementSetPgSessionCharacteristicsTransactionMode(`
`109`	`109`	`StatementResult statementSetRPCPriority(Priority priority);`
`110`	`110`
`111`	`111`	`StatementResult statementShowRPCPriority();`
	`112`	`+`
	`113`	`+ StatementResult statementShowTransactionIsolationLevel();`
`112`	`114`	`}`
Original file line number	Diff line number	Diff line change
`@@ -82,7 +82,8 @@ enum ClientSideStatementType {`
`82`	`82`	`RUN_BATCH,`
`83`	`83`	`ABORT_BATCH,`
`84`	`84`	`SET_RPC_PRIORITY,`
`85`		`- SHOW_RPC_PRIORITY`
	`85`	`+ SHOW_RPC_PRIORITY,`
	`86`	`+ SHOW_TRANSACTION_ISOLATION_LEVEL`
`86`	`87`	`}`
`87`	`88`
`88`	`89`	`/**`