refinement[ats_ATS309927]: Remove race condition in id generation

Change-Id: I3405d2b5e6a8a700e55ff983fef09715a7c67c4a

1 files changed, 41 insertions, 81 deletions

diff --git a/plugins/org.eclipse.osee.jdbc/src/org/eclipse/osee/jdbc/internal/JdbcSequenceProvider.java b/plugins/org.eclipse.osee.jdbc/src/org/eclipse/osee/jdbc/internal/JdbcSequenceProvider.java
index 05ac30acbca..b824bb7d54e 100644
--- a/plugins/org.eclipse.osee.jdbc/src/org/eclipse/osee/jdbc/internal/JdbcSequenceProvider.java
+++ b/plugins/org.eclipse.osee.jdbc/src/org/eclipse/osee/jdbc/internal/JdbcSequenceProvider.java
@@ -14,15 +14,15 @@ import java.util.HashMap;
 import org.eclipse.osee.framework.core.data.OseeData;
 import org.eclipse.osee.framework.jdk.core.type.OseeCoreException;
 import org.eclipse.osee.jdbc.JdbcClient;
-import org.eclipse.osee.jdbc.JdbcConnection;
-import org.eclipse.osee.jdbc.JdbcTransaction;
 
 /**
- * This should be modified to use native database sequences
- *
  * @author Ryan D. Brooks
  */
 public class JdbcSequenceProvider {
+   private static final String QUERY_SEQUENCE = "SELECT last_sequence FROM osee_sequence WHERE sequence_name = ?";
+   public static final String INSERT_SEQUENCE = "INSERT INTO osee_sequence (last_sequence, sequence_name) VALUES (?,?)";
+   private static final String UPDATE_SEQUENCE =
+      "UPDATE osee_sequence SET last_sequence = ? WHERE sequence_name = ? AND last_sequence = ?";
 
    private final HashMap<String, SequenceRange> sequences = new HashMap<>(30);
 
@@ -31,98 +31,59 @@ public class JdbcSequenceProvider {
    }
 
    public synchronized long getNextSequence(JdbcClient client, String sequenceName, boolean aggressiveFetch) throws OseeCoreException {
-      JdbcSequenceTx sequenceTx = new JdbcSequenceTx(client, sequenceName, aggressiveFetch);
-      client.runTransaction(sequenceTx);
-      return sequenceTx.getNextSequence();
-   }
-
-   private final class JdbcSequenceTx extends JdbcTransaction {
-
-      private static final String QUERY_SEQUENCE = "SELECT last_sequence FROM osee_sequence WHERE sequence_name = ?";
-      public static final String INSERT_SEQUENCE =
-         "INSERT INTO osee_sequence (last_sequence, sequence_name) VALUES (?,?)";
-      private static final String UPDATE_SEQUENCE =
-         "UPDATE osee_sequence SET last_sequence = ? WHERE sequence_name = ? AND last_sequence = ?";
-
-      private final JdbcClient client;
-      private final String sequenceName;
-      private long nextSequence;
-      private final boolean aggressiveFetch;
-
-      public JdbcSequenceTx(JdbcClient client, String sequenceName, boolean aggressiveFetch) {
-         super();
-         this.client = client;
-         this.sequenceName = sequenceName;
-         this.aggressiveFetch = aggressiveFetch;
-      }
-
-      public long getNextSequence() {
-         return nextSequence;
-      }
-
-      public boolean isAggressiveFetch() {
-         return aggressiveFetch;
-      }
-
-      private SequenceRange getRange(String sequenceName) {
-         SequenceRange range = sequences.get(sequenceName);
-         if (range == null) {
-            range = new SequenceRange(isAggressiveFetch());
-            sequences.put(sequenceName, range);
+      SequenceRange range = getRange(sequenceName);
+      if (range.lastAvailable == 0) {
+         long lastValue = -1L;
+         boolean gotSequence = false;
+         while (!gotSequence) {
+            long currentValue = client.fetch(lastValue, QUERY_SEQUENCE, sequenceName);
+            if (currentValue == lastValue) {
+               internalInitializeSequence(client, sequenceName);
+               lastValue = 0;
+            } else {
+               lastValue = currentValue;
+            }
+            gotSequence =
+               client.runPreparedUpdate(UPDATE_SEQUENCE, lastValue + range.prefetchSize, sequenceName, lastValue) == 1;
          }
-         return range;
+         range.updateRange(lastValue, aggressiveFetch);
+      }
+      range.currentValue++;
+      if (range.currentValue == range.lastAvailable) {
+         range.lastAvailable = 0;
       }
+      return range.currentValue;
+   }
 
-      @Override
-      public void handleTxWork(JdbcConnection connection) {
-         SequenceRange range = getRange(sequenceName);
-         if (range.lastAvailable == 0) {
-            long lastValue = -1L;
-            boolean gotSequence = false;
-            while (!gotSequence) {
-               long currentValue = client.fetch(connection, lastValue, QUERY_SEQUENCE, sequenceName);
-               if (currentValue == lastValue) {
-                  internalInitializeSequence(connection, sequenceName);
-                  lastValue = 0;
-               } else {
-                  lastValue = currentValue;
-               }
-               gotSequence = client.runPreparedUpdate(connection, UPDATE_SEQUENCE, lastValue + range.prefetchSize,
-                  sequenceName, lastValue) == 1;
-            }
-            range.updateRange(lastValue);
-         }
-         range.currentValue++;
-         if (range.currentValue == range.lastAvailable) {
-            range.lastAvailable = 0;
-         }
-         nextSequence = range.currentValue;
+   private SequenceRange getRange(String sequenceName) {
+      SequenceRange range = sequences.get(sequenceName);
+      if (range == null) {
+         range = new SequenceRange();
+         sequences.put(sequenceName, range);
       }
+      return range;
+   }
 
-      private void internalInitializeSequence(JdbcConnection connection, String sequenceName) throws OseeCoreException {
-         SequenceRange range = getRange(sequenceName);
-         range.lastAvailable = 0;
-         int initalValue = 0;
-         if (sequenceName.equals(OseeData.ART_ID_SEQ)) {
-            initalValue = 200000;
-         }
-         client.runPreparedUpdate(connection, INSERT_SEQUENCE, initalValue, sequenceName);
+   private void internalInitializeSequence(JdbcClient client, String sequenceName) throws OseeCoreException {
+      SequenceRange range = getRange(sequenceName);
+      range.lastAvailable = 0;
+      int initalValue = 0;
+      if (sequenceName.equals(OseeData.ART_ID_SEQ)) {
+         initalValue = 200000;
       }
+      client.runPreparedUpdate(INSERT_SEQUENCE, initalValue, sequenceName);
    }
 
    private static final class SequenceRange {
       private long currentValue;
       private long lastAvailable;
       private int prefetchSize;
-      private final boolean aggressiveFetch;
 
-      public SequenceRange(boolean aggressiveFetch) {
-         super();
+      public SequenceRange() {
          this.prefetchSize = 1;
-         this.aggressiveFetch = aggressiveFetch;
       }
 
-      public void updateRange(long lastValue) {
+      public void updateRange(long lastValue, boolean aggressiveFetch) {
          currentValue = lastValue;
          lastAvailable = lastValue + prefetchSize;
 
@@ -131,5 +92,4 @@ public class JdbcSequenceProvider {
          }
       }
    }
-
 }
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