WIP update for migration runner

src/main/java/com/avaje/ebean/dbmigration/MigrationRunner.java

@@ -53,7 +53,7 @@ public class MigrationRunner {
         if (i > 0) {
           priorVersion = localVersions.get(i-1);
         }
-        if (!table.shouldRun(i, localVersion, priorVersion)) {
+        if (!table.shouldRun(localVersion, priorVersion)) {
           break;
         }
       }

src/main/java/com/avaje/ebean/dbmigration/runner/Checksum.java

@@ -0,0 +1,32 @@
+package com.avaje.ebean.dbmigration.runner;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.zip.CRC32;
+
+/**
+ * Calculates the checksum for the given string content.
+ */
+public class Checksum {
+
+  /**
+   * Returns the checksum of this string.
+   */
+  public static int calculate(String str) {
+
+    final CRC32 crc32 = new CRC32();
+
+    BufferedReader bufferedReader = new BufferedReader(new StringReader(str));
+    try {
+      String line;
+      while ((line = bufferedReader.readLine()) != null) {
+        crc32.update(line.getBytes("UTF-8"));
+      }
+    } catch (IOException e) {
+      throw new RuntimeException("Failed to calculate checksum", e);
+    }
+
+    return (int) crc32.getValue();
+  }
+}

src/main/java/com/avaje/ebean/dbmigration/runner/MigrationMetaRow.java

@@ -0,0 +1,27 @@
+package com.avaje.ebean.dbmigration.runner;
+
+import java.sql.Timestamp;
+
+/**
+ *
+ */
+public class MigrationMetaRow implements Comparable<MigrationMetaRow> {
+
+  int id;
+  String status;
+  String runVersion;
+  String depVersion;
+  String comment;
+  int checksum;
+  Timestamp runOn;
+  String runBy;
+
+  @Override
+  public int compareTo(MigrationMetaRow o) {
+    return (id < o.id) ? -1 : ((id == o.id) ? 0 : 1);
+  }
+
+
+  //String sql = "insert into ebean_migration (id,status,run_version,dep_version,comment,checksum,run_on,run_by,run_ip) "+
+  //    "values (?,?,?,?,?,?,?,?,?)";
+}

src/main/java/com/avaje/ebean/dbmigration/runner/MigrationTable.java

@@ -42,7 +42,7 @@ public class MigrationTable {
   private final ServerConfig serverConfig;
   private final String envUserName;
 
-  int metaRowPosition;
+  int currentSearchPosition;
 
   List<SqlRow> metaRows;
 
@@ -96,25 +96,39 @@ public class MigrationTable {
   }
 
 
-  public boolean shouldRun(int runPosition, LocalMigrationResource localVersion, LocalMigrationResource priorVersion) {
+  public boolean shouldRun(LocalMigrationResource localVersion, LocalMigrationResource priorVersion) {
 
     // if prior != null check previous version installed
     //    if previous version not installed ... error - missing version (prior version)
 
-    // if localVersion installed
-    //    check checksum and return ok, or re-installable?
-    // else
-    //    install version and continue
-
-    if (runPosition >= metaRows.size()) {
-      logger.debug("No matching row");
-      runMigration(runPosition, localVersion);
-      return true;
-    }
+//    if (!priorVersionNotInstalled(priorVersion)) {
+//
+//    }
+//
+//    // if localVersion installed
+//    //    check checksum and return ok, or re-installable?
+//    // else
+//    //    install version and continue
+//
+//    if (runPosition >= metaRows.size()) {
+//      logger.debug("No matching row");
+//      runMigration(runPosition, localVersion);
+//      return true;
+//    }
 
     return false;
   }
 
+  private void checkInstalled(LocalMigrationResource priorVersion) {
+    if (priorVersion != null) {
+      searchFor(priorVersion);
+    }
+  }
+
+  private void searchFor(LocalMigrationResource priorVersion) {
+
+  }
+
   public void commit() throws SQLException {
     connection.commit();
   }