From 8cfa1424d4f6a95d612e2b5cb07a51cb77c8dcf8 Mon Sep 17 00:00:00 2001
From: Rick Balsano <rick@opower.com>
Date: Tue, 11 Feb 2014 14:33:54 -0500
Subject: [PATCH] Handle initializing >1 system in patches table.

---
 .../util/migration/jdbc/DatabaseType.java     |  1 +
 .../util/migration/jdbc/PatchTable.java       | 41 +++++++++---
 .../util/migration/jdbc/hsqldb.properties     |  1 +
 .../util/migration/jdbc/mysql.properties      |  3 +-
 .../util/migration/jdbc/oracle.properties     |  1 +
 .../util/migration/jdbc/postgres.properties   |  1 +
 .../util/migration/jdbc/sqlserver.properties  |  1 +
 .../util/migration/jdbc/sybase.properties     |  1 +
 .../util/migration/jdbc/PatchTableTest.java   | 64 ++++++++++++++++++-
 9 files changed, 103 insertions(+), 11 deletions(-)

diff --git a/src/main/java/com/tacitknowledge/util/migration/jdbc/DatabaseType.java b/src/main/java/com/tacitknowledge/util/migration/jdbc/DatabaseType.java
index 045ba27..74438c0 100644
--- a/src/main/java/com/tacitknowledge/util/migration/jdbc/DatabaseType.java
+++ b/src/main/java/com/tacitknowledge/util/migration/jdbc/DatabaseType.java
@@ -30,6 +30,7 @@
  * <ul>
  * <li>patches.create - DDL that creates the patches table</li>
  * <li>level.create - SQL that inserts a new patch level record for the system</li>
+ * <li>level.count - SQL that counts patches for the system</li>
  * <li>level.read - SQL that selects the current patch level of the system</li>
  * <li>level.update - SQL that updates the current patch level of the system</li>
  * <li>lock.read - Returns 'T' if the system patch lock is in use, 'F' otherwise</li>
diff --git a/src/main/java/com/tacitknowledge/util/migration/jdbc/PatchTable.java b/src/main/java/com/tacitknowledge/util/migration/jdbc/PatchTable.java
index 7f9b761..be3a5a1 100644
--- a/src/main/java/com/tacitknowledge/util/migration/jdbc/PatchTable.java
+++ b/src/main/java/com/tacitknowledge/util/migration/jdbc/PatchTable.java
@@ -131,9 +131,6 @@ public void createPatchStoreIfNeeded() throws MigrationException
                 }
                 stmt.execute();
                 context.commit();
-
-                // We don't yet have a patch record for this system; create one
-                createSystemPatchRecord();
             }
             catch (SQLException sqle)
             {
@@ -150,6 +147,20 @@ public void createPatchStoreIfNeeded() throws MigrationException
         {
             SqlUtil.close(conn, stmt, rs);
         }
+
+        try {
+            // We don't yet have a patch record for this system; create one
+            createSystemPatchRecord();
+        }
+        catch (Exception ex)
+        {
+            throw new MigrationException("Unexpected exception while creating system record.", ex);
+        }
+        finally
+        {
+            SqlUtil.close(conn, stmt, rs);
+        }
+
     }
 
     /**
@@ -361,14 +372,26 @@ private void createSystemPatchRecord() throws MigrationException, SQLException
         String systemName = context.getSystemName();
         Connection conn = null;
         PreparedStatement stmt = null;
+        ResultSet rs = null;
         try
         {
             conn = context.getConnection();
-            stmt = conn.prepareStatement(getSql("level.create"));
+            stmt = conn.prepareStatement(getSql("level.count"));
             stmt.setString(1, systemName);
-            stmt.execute();
-            context.commit();
-            log.info("Created patch record for " + systemName);
+            rs = stmt.executeQuery();
+            rs.next();
+            if (rs.getInt(1) == 0)
+            {
+                SqlUtil.close(null, stmt, null);
+                stmt = conn.prepareStatement(getSql("level.create"));
+                stmt.setString(1, systemName);
+                stmt.execute();
+                context.commit();
+                log.info("Created patch record for " + systemName);
+            } else
+            {
+                log.debug("Patch record already existed for " + systemName);
+            }
         }
         catch (SQLException e)
         {
@@ -377,7 +400,7 @@ private void createSystemPatchRecord() throws MigrationException, SQLException
         }
         finally
         {
-            SqlUtil.close(conn, stmt, null);
+            SqlUtil.close(conn, stmt, rs);
         }
     }
 
@@ -402,7 +425,7 @@ private boolean updatePatchLock(boolean lock) throws MigrationException
             stmt = conn.prepareStatement(getSql(sqlkey));
             if (log.isDebugEnabled())
             {
-                log.debug("Updating patch table lock: " + getSql(sqlkey));
+                log.debug("Updating patch table lock for system " + context.getSystemName() + ": " + getSql(sqlkey));
             }
             stmt.setString(1, context.getSystemName());
             if (lock)
diff --git a/src/main/resources/com/tacitknowledge/util/migration/jdbc/hsqldb.properties b/src/main/resources/com/tacitknowledge/util/migration/jdbc/hsqldb.properties
index 79d816a..4a9cb44 100644
--- a/src/main/resources/com/tacitknowledge/util/migration/jdbc/hsqldb.properties
+++ b/src/main/resources/com/tacitknowledge/util/migration/jdbc/hsqldb.properties
@@ -9,6 +9,7 @@ patches.create=CREATE TABLE patches ( \
 
 # Validates that a record exists for a given system
 level.create=INSERT INTO patches (system_name, patch_level) VALUES ( ?, 0)
+level.count=SELECT COUNT(*) FROM patches WHERE system_name = ?
 level.table.exists=SELECT patch_level FROM patches WHERE system_name = ?
 level.read=SELECT MAX(patch_level) FROM patches WHERE system_name = ?
 level.rollback=DELETE FROM patches WHERE patch_level = ? and system_name = ?
diff --git a/src/main/resources/com/tacitknowledge/util/migration/jdbc/mysql.properties b/src/main/resources/com/tacitknowledge/util/migration/jdbc/mysql.properties
index 058dfc8..5bf99a6 100644
--- a/src/main/resources/com/tacitknowledge/util/migration/jdbc/mysql.properties
+++ b/src/main/resources/com/tacitknowledge/util/migration/jdbc/mysql.properties
@@ -9,6 +9,7 @@ patches.create=CREATE TABLE IF NOT EXISTS patches ( \
 
 # Validates that a record exists for a given system
 level.create=INSERT INTO patches (system_name, patch_level) VALUES ( ?, 0 )
+level.count=SELECT COUNT(*) FROM patches WHERE system_name = ?
 level.table.exists=SELECT patch_level FROM patches WHERE system_name = ?
 level.read=SELECT MAX(patch_level) FROM patches WHERE system_name = ?
 level.rollback=DELETE FROM patches WHERE patch_level = ? and system_name = ?
@@ -21,4 +22,4 @@ patches.all=SELECT patch_level FROM patches WHERE system_name = ?
 # the system is currently locked.
 lock.read=SELECT patch_in_progress FROM patches WHERE system_name = ? AND ( patch_in_progress <> 'F' OR patch_level in ( SELECT MAX(patch_level) FROM patches WHERE system_name = ? ))
 lock.obtain=UPDATE patches SET patch_in_progress = 'T' WHERE system_name = ? AND patch_in_progress = 'F' AND patch_level in ( SELECT max_patch_level FROM (SELECT MAX(patch_level) AS max_patch_level FROM patches WHERE system_name = ? ) AS tmptable )
-lock.release=UPDATE patches SET patch_in_progress = 'F' WHERE system_name = ? AND patch_in_progress <> 'F'
\ No newline at end of file
+lock.release=UPDATE patches SET patch_in_progress = 'F' WHERE system_name = ? AND patch_in_progress <> 'F'
diff --git a/src/main/resources/com/tacitknowledge/util/migration/jdbc/oracle.properties b/src/main/resources/com/tacitknowledge/util/migration/jdbc/oracle.properties
index ca3f1ce..ff91c9b 100644
--- a/src/main/resources/com/tacitknowledge/util/migration/jdbc/oracle.properties
+++ b/src/main/resources/com/tacitknowledge/util/migration/jdbc/oracle.properties
@@ -9,6 +9,7 @@ patches.create=CREATE TABLE tk_patches (\
 
 # Validates that a record exists for a given system
 level.create=INSERT INTO tk_patches (system_name, patch_level) VALUES ( ?, 0 )
+level.count=SELECT COUNT(*) FROM tk_patches WHERE system_name = ?
 level.table.exists=SELECT patch_level FROM tk_patches WHERE system_name = ?
 level.read=SELECT MAX(patch_level) FROM tk_patches WHERE system_name = ?
 level.rollback=DELETE FROM tk_patches WHERE patch_level = ? and system_name = ?
diff --git a/src/main/resources/com/tacitknowledge/util/migration/jdbc/postgres.properties b/src/main/resources/com/tacitknowledge/util/migration/jdbc/postgres.properties
index 7eca275..fac1949 100644
--- a/src/main/resources/com/tacitknowledge/util/migration/jdbc/postgres.properties
+++ b/src/main/resources/com/tacitknowledge/util/migration/jdbc/postgres.properties
@@ -9,6 +9,7 @@ patches.create=CREATE TABLE patches ( \
 
 # Validates that a record exists for a given system
 level.create=INSERT INTO patches (system_name, patch_level) VALUES ( ?, 0 )
+level.count=SELECT COUNT(*) FROM patches WHERE system_name = ?
 level.table.exists=SELECT patch_level FROM patches WHERE system_name = ?
 level.read=SELECT MAX(patch_level) FROM patches WHERE system_name = ?
 level.rollback=DELETE FROM patches WHERE patch_level = ? and system_name = ?
diff --git a/src/main/resources/com/tacitknowledge/util/migration/jdbc/sqlserver.properties b/src/main/resources/com/tacitknowledge/util/migration/jdbc/sqlserver.properties
index 2a2b89b..c0888c1 100644
--- a/src/main/resources/com/tacitknowledge/util/migration/jdbc/sqlserver.properties
+++ b/src/main/resources/com/tacitknowledge/util/migration/jdbc/sqlserver.properties
@@ -9,6 +9,7 @@ patches.create=CREATE TABLE patches ( \
 
 # Validates that a record exists for a given system
 level.create=INSERT INTO patches (system_name, patch_level) VALUES ( ?, 0)
+level.count=SELECT COUNT(*) FROM patches WHERE system_name = ?
 level.table.exists=SELECT patch_level FROM patches WHERE system_name = ?
 level.read=SELECT MAX(patch_level) FROM patches WHERE system_name = ?
 level.rollback=DELETE FROM patches WHERE patch_level = ? and system_name = ?
diff --git a/src/main/resources/com/tacitknowledge/util/migration/jdbc/sybase.properties b/src/main/resources/com/tacitknowledge/util/migration/jdbc/sybase.properties
index 39e89b3..1d590ee 100644
--- a/src/main/resources/com/tacitknowledge/util/migration/jdbc/sybase.properties
+++ b/src/main/resources/com/tacitknowledge/util/migration/jdbc/sybase.properties
@@ -9,6 +9,7 @@ patches.create=CREATE TABLE patches (\
                 
 # Validates that a record exists for a given system
 level.create=INSERT INTO patches (system_name, patch_level) VALUES ( ?, 0 )
+level.count=SELECT COUNT(*) FROM patches WHERE system_name = ?
 level.table.exists=SELECT patch_level FROM patches WHERE system_name = ?
 level.read=SELECT MAX(patch_level) FROM patches WHERE system_name = ?
 level.rollback=DELETE FROM patches WHERE patch_level = ? and system_name = ?
diff --git a/src/test/java/com/tacitknowledge/util/migration/jdbc/PatchTableTest.java b/src/test/java/com/tacitknowledge/util/migration/jdbc/PatchTableTest.java
index 081affe..7aaba70 100644
--- a/src/test/java/com/tacitknowledge/util/migration/jdbc/PatchTableTest.java
+++ b/src/test/java/com/tacitknowledge/util/migration/jdbc/PatchTableTest.java
@@ -16,9 +16,11 @@
 package com.tacitknowledge.util.migration.jdbc;
 
 import java.sql.SQLException;
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
 
+import org.apache.commons.lang.BooleanUtils;
 import org.easymock.MockControl;
 
 import com.mockrunner.jdbc.JDBCTestCaseAdapter;
@@ -115,6 +117,7 @@ public void testCreatePatchesTable() throws Exception
         PreparedStatementResultSetHandler h = conn.getPreparedStatementResultSetHandler();
         h.prepareThrowsSQLException(table.getSql("level.table.exists"));
         
+        setupLevelCreatedMock(h, false);
         table.createPatchStoreIfNeeded();
 
         commonVerifications();
@@ -193,6 +196,18 @@ public void testGetPatchLevel() throws Exception
         verifyPreparedStatementNotPresent(table.getSql("level.create"));
     }
 
+    /**
+     * Adds a result set to a data source mock to simulate existence of a patch level record.
+     *
+     * @param handler prepared statement handler
+     * @param levelExists controls what the mock returns for whether a level was already created or not
+     */
+    private void setupLevelCreatedMock(PreparedStatementResultSetHandler handler, Boolean levelExists) {
+        MockResultSet rs = handler.createResultSet();
+        handler.prepareResultSet(table.getSql("level.count"), rs);
+        rs.addRow(new Integer[] {BooleanUtils.toInteger(levelExists)});
+    }
+
     /**
      * Validates that <code>getPatchLevel</code> works on a new system.
      * 
@@ -206,6 +221,7 @@ public void testGetPatchLevelFirstTime() throws Exception
         // empty result set
         handler.prepareResultSet(table.getSql("level.read"), rs);
         handler.prepareThrowsSQLException(table.getSql("level.table.exists"));
+        setupLevelCreatedMock(handler, false);
 
         int i = table.getPatchLevel();
 
@@ -227,6 +243,7 @@ public void testUpdatePatchLevel() throws Exception
         MockResultSet rs = handler.createResultSet();
         rs.addRow(new Integer[]{new Integer(12)});
         handler.prepareResultSet(table.getSql("level.read"), rs, new String[]{"milestone"});
+        setupLevelCreatedMock(handler, true);
 
         table.updatePatchLevel(13);
         
@@ -251,6 +268,7 @@ public void testIsPatchTableNotLocked() throws Exception
         MockResultSet rs = handler.createResultSet();
         rs.addRow(new String[]{"F"});
         handler.prepareResultSet(table.getSql("lock.read"), rs, new String[]{"milestone", "milestone"});
+        setupLevelCreatedMock(handler, true);
         
         assertFalse(table.isPatchStoreLocked());
         commonVerifications();
@@ -272,6 +290,7 @@ public void testIsPatchTableLocked() throws Exception
         MockResultSet rs = handler.createResultSet();
         rs.addRow(new String[]{"T"});
         handler.prepareResultSet(table.getSql("lock.read"), rs, new String[]{"milestone", "milestone"});
+        setupLevelCreatedMock(handler, true);
         
         assertTrue(table.isPatchStoreLocked());
         commonVerifications();
@@ -292,6 +311,7 @@ public void testLockPatchTableWhenAlreadyLocked() throws Exception
         // Return a non-empty set in response to the patch lock query
         handler = conn.getPreparedStatementResultSetHandler();
         handler.prepareUpdateCount(table.getSql("lock.obtain"), 0, new String[] {"milestone", "milestone"});
+        setupLevelCreatedMock(handler, true);
         
         try
         {
@@ -322,7 +342,7 @@ public void testLockPatchTableWhenNotAlreadyLocked() throws Exception
         // Test-specific setup
         // Return an empty set in response to the patch lock query
         handler = conn.getPreparedStatementResultSetHandler();
-        MockResultSet rs = handler.createResultSet();
+        setupLevelCreatedMock(handler, true);
         handler.prepareUpdateCount(table.getSql("lock.obtain"), 1, new String[] {"milestone", "milestone"});
         
         table.lockPatchStore();
@@ -407,6 +427,48 @@ public void testPatchRetrievesSetWithPatchesApplied () throws SQLException, Migr
         verifyPreparedStatementPresent(table.getSql("patches.all"));
     }
 
+    public void testSecondSystemInitialized () throws Exception, SQLException, MigrationException {
+        String systemName = "milestone";
+        // setup test like testGetPatchLevelFirstTime
+        handler = conn.getPreparedStatementResultSetHandler();
+        MockResultSet rs = handler.createResultSet();
+        // empty result set
+        handler.prepareResultSet(table.getSql("level.read"), rs, Arrays.asList(systemName));
+        handler.prepareThrowsSQLException(table.getSql("level.table.exists"));
+        setupLevelCreatedMock(handler, false);
+
+        int i = table.getPatchLevel();
+
+        assertEquals(0, i);
+        commonVerifications();
+        verifyPreparedStatementPresent(table.getSql("level.create"));
+        verifyPreparedStatementParameter(table.getSql("level.create"), 1, systemName);
+
+        // Test-specific setup
+        // setup a second system backed by the same database table and verify that it is initialized properly
+        systemName = "orders";
+        DataSourceMigrationContext context2 = new DataSourceMigrationContext();
+        context2.setDataSource(new ConnectionWrapperDataSource(conn));
+        context2.setSystemName(systemName);
+        context2.setDatabaseType(new DatabaseType("hsqldb"));
+        PatchTable table2 = new PatchTable(context2);
+
+        // clear the exception from above which caused the database table to be created
+        handler.clearThrowsSQLException();
+        // clear out prepared statements since one is for "patches.create"
+        handler.clearPreparedStatements();
+        // simulate the table existing (since it was created by the first system)
+        rs = handler.createResultSet();
+        handler.prepareResultSet(table2.getSql("level.table.exists"), rs, Arrays.asList(systemName));
+        rs = handler.createResultSet();
+        handler.prepareResultSet(table2.getSql("level.read"), rs, Arrays.asList(systemName));
+
+        i = table2.getPatchLevel();
+        assertEquals(0, i);
+        verifyPreparedStatementNotPresent(table2.getSql("patches.create"));
+        verifyPreparedStatementPresent(table2.getSql("level.create"));
+        verifyPreparedStatementParameter(table2.getSql("level.create"), 1, systemName);
+    }
 
     private void commonVerifications()
     {