Renames - minimal functional/logical code changes

Author: rPraml

…atasource/pool/FreeConnectionBuffer.java …an/datasource/pool/ConnectionBuffer.javaebean-datasource/src/main/java/io/ebean/datasource/pool/FreeConnectionBuffer.java renamed to ebean-datasource/src/main/java/io/ebean/datasource/pool/ConnectionBuffer.java ebean-datasource/src/main/java/io/ebean/datasource/pool/FreeConnectionBuffer.java renamed to ebean-datasource/src/main/java/io/ebean/datasource/pool/ConnectionBuffer.java

@@ -3,57 +3,62 @@
 import java.util.*;
 
 /**
- * A buffer designed especially to hold free pooled connections.
+ * A buffer designed especially to hold pooled connections (free and busy ones)
  * <p>
  * All thread safety controlled externally (by PooledConnectionQueue).
  * </p>
  */
-final class FreeConnectionBuffer {
+final class ConnectionBuffer {
 
 
   private final Node free = Node.init();
 
-  int size = 0;
+  int freeSize = 0;
 
   /**
    * Return the number of entries in the buffer.
    */
-  int size() {
-    return size;
+  int freeSize() {
+    return freeSize;
   }
 
   /**
    * Return true if the buffer is empty.
    */
-  boolean isEmpty() {
-    return size == 0;
+  boolean hasFreeConnections() {
+    return freeSize > 0;
   }
 
   /**
    * Add connection to the free list.
    */
-  void add(PooledConnection pc) {
+  void addFree(PooledConnection pc) {
     new Node(pc).addAfter(free);
-    size++;
+    freeSize++;
   }
 
   /**
-   * Remove a connection from the free list.
+   * Remove a connection from the free list. Returns <code>null</code> if there is not any.
    */
-  PooledConnection remove() {
+  PooledConnection popFree () {
     Node node = free.next;
+    if (node.isBoundaryNode()) {
+      return null;
+    }
     node.remove();
-    size--;
+    freeSize--;
     return node.pc;
   }
 
   /**
-   * Close all connections in this buffer.
+   * Close all connections in the free list.
    */
-  void closeAll(boolean logErrors) {
+  void closeAllFree(boolean logErrors) {
     List<PooledConnection> tempList = new ArrayList<>();
-    while (size > 0) {
-      tempList.add(remove());
+    PooledConnection c = popFree();
+    while (c != null) {
+      tempList.add(c);
+      c = popFree();
     }
 
     if (Log.isLoggable(System.Logger.Level.TRACE)) {
@@ -79,7 +84,7 @@ int trim(int minSize, long usedSince, long createdSince) {
       node = node.next;
       if (current.pc.shouldTrim(usedSince, createdSince)) {
         current.remove();
-        size--;
+        freeSize--;
         current.pc.closeConnectionFully(true);
         trimCount++;
       }

ebean-datasource/src/main/java/io/ebean/datasource/pool/PooledConnectionQueue.java

@@ -20,7 +20,7 @@ final class PooledConnectionQueue {
   /**
    * A 'circular' buffer designed specifically for free connections.
    */
-  private final FreeConnectionBuffer freeList;
+  private final ConnectionBuffer buffer;
   /**
    * A 'slots' buffer designed specifically for busy connections.
    * Fast add remove based on slot id.
@@ -75,13 +75,13 @@ final class PooledConnectionQueue {
     this.maxAgeMillis = pool.maxAgeMillis();
     this.validateStaleMillis = pool.validateStaleMillis();
     this.busyList = new BusyConnectionBuffer(maxSize, 20);
-    this.freeList = new FreeConnectionBuffer();
+    this.buffer = new ConnectionBuffer();
     this.lock = new ReentrantLock(false);
     this.notEmpty = lock.newCondition();
   }
 
   private PoolStatus createStatus() {
-    return new Status(minSize, maxSize, freeList.size(), busyList.size(), waitingThreads, highWaterMark,
+    return new Status(minSize, maxSize, buffer.freeSize(), busyList.size(), waitingThreads, highWaterMark,
       waitCount, hitCount, totalAcquireNanos, maxAcquireNanos);
   }
 
@@ -126,7 +126,7 @@ void setMaxSize(int maxSize) {
   }
 
   private int totalConnections() {
-    return freeList.size() + busyList.size();
+    return buffer.freeSize() + busyList.size();
   }
 
   void ensureMinimumConnections() throws SQLException {
@@ -135,7 +135,7 @@ void ensureMinimumConnections() throws SQLException {
       int add = minSize - totalConnections();
       if (add > 0) {
         for (int i = 0; i < add; i++) {
-          freeList.add(pool.createConnectionForQueue(connectionId++));
+          buffer.addFree(pool.createConnectionForQueue(connectionId++));
         }
         notEmpty.signal();
       }
@@ -156,7 +156,7 @@ void returnPooledConnection(PooledConnection c, boolean forceClose) {
       if (forceClose || c.shouldTrimOnReturn(lastResetTime, maxAgeMillis)) {
         c.closeConnectionFully(false);
       } else {
-        freeList.add(c);
+        buffer.addFree(c);
         notEmpty.signal();
       }
     } finally {
@@ -165,10 +165,11 @@ void returnPooledConnection(PooledConnection c, boolean forceClose) {
   }
 
   private PooledConnection extractFromFreeList() {
-    if (freeList.isEmpty()) {
+
+    PooledConnection c = buffer.popFree();
+    if (c == null) {
       return null;
     }
-    final PooledConnection c = freeList.remove();
     if (validateStaleMillis > 0 && staleEviction(c)) {
       c.closeConnectionFully(false);
       return null;
@@ -291,7 +292,7 @@ private PooledConnection _obtainConnectionWaitLoop() throws SQLException, Interr
 
       try {
         nanos = notEmpty.awaitNanos(nanos);
-        if (!freeList.isEmpty()) {
+        if (buffer.hasFreeConnections()) {
           // successfully waited
           return extractFromFreeList();
         }
@@ -373,20 +374,20 @@ void trim(long maxInactiveMillis, long maxAgeMillis) {
   private boolean trimInactiveConnections(long maxInactiveMillis, long maxAgeMillis) {
     final long createdSince = (maxAgeMillis == 0) ? 0 : System.currentTimeMillis() - maxAgeMillis;
     final int trimmedCount;
-    if (freeList.size() > minSize) {
+    if (buffer.freeSize() > minSize) {
       // trim on maxInactive and maxAge
       long usedSince = System.currentTimeMillis() - maxInactiveMillis;
-      trimmedCount = freeList.trim(minSize, usedSince, createdSince);
+      trimmedCount = buffer.trim(minSize, usedSince, createdSince);
     } else if (createdSince > 0) {
       // trim only on maxAge
-      trimmedCount = freeList.trim(0, createdSince, createdSince);
+      trimmedCount = buffer.trim(0, createdSince, createdSince);
     } else {
       trimmedCount = 0;
     }
     if (trimmedCount > 0 && Log.isLoggable(DEBUG)) {
       Log.debug("DataSource [{0}] trimmed [{1}] inactive connections. New size[{2}]", name, trimmedCount, totalConnections());
     }
-    return trimmedCount > 0 && freeList.size() < minSize;
+    return trimmedCount > 0 && buffer.freeSize() < minSize;
   }
 
   /**
@@ -395,7 +396,7 @@ private boolean trimInactiveConnections(long maxInactiveMillis, long maxAgeMilli
   private void closeFreeConnections(boolean logErrors) {
     lock.lock();
     try {
-      freeList.closeAll(logErrors);
+      buffer.closeAllFree(logErrors);
     } finally {
       lock.unlock();
     }

…ource/pool/FreeConnectionBufferTest.java …atasource/pool/ConnectionBufferTest.javaebean-datasource/src/test/java/io/ebean/datasource/pool/FreeConnectionBufferTest.java renamed to ebean-datasource/src/test/java/io/ebean/datasource/pool/ConnectionBufferTest.java ebean-datasource/src/test/java/io/ebean/datasource/pool/FreeConnectionBufferTest.java renamed to ebean-datasource/src/test/java/io/ebean/datasource/pool/ConnectionBufferTest.java

@@ -9,70 +9,70 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.*;
 
-class FreeConnectionBufferTest {
+class ConnectionBufferTest {
 
   @Test
   void test() {
 
-    FreeConnectionBuffer b = new FreeConnectionBuffer();
+    ConnectionBuffer b = new ConnectionBuffer();
 
     PooledConnection p0 = new PooledConnection("0");
     PooledConnection p1 = new PooledConnection("1");
     PooledConnection p2 = new PooledConnection("2");
     // PooledConnection p3 = new PooledConnection("3");
 
-    assertEquals(0, b.size());
-    assertTrue(b.isEmpty());
+    assertEquals(0, b.freeSize());
+    assertFalse(b.hasFreeConnections());
 
-    b.add(p0);
+    b.addFree(p0);
 
-    assertEquals(1, b.size());
-    assertFalse(b.isEmpty());
+    assertEquals(1, b.freeSize());
+    assertTrue(b.hasFreeConnections());
 
-    PooledConnection r0 = b.remove();
+    PooledConnection r0 = b.popFree();
     assertThat(p0).isSameAs(r0);
 
-    assertEquals(0, b.size());
-    assertTrue(b.isEmpty());
+    assertEquals(0, b.freeSize());
+    assertFalse(b.hasFreeConnections());
 
-    b.add(p0);
-    b.add(p1);
-    b.add(p2);
+    b.addFree(p0);
+    b.addFree(p1);
+    b.addFree(p2);
 
-    assertEquals(3, b.size());
+    assertEquals(3, b.freeSize());
 
-    PooledConnection r1 = b.remove();
+    PooledConnection r1 = b.popFree();
     assertSame(p2, r1);
-    PooledConnection r2 = b.remove();
+    PooledConnection r2 = b.popFree();
     assertSame(p1, r2);
 
-    assertEquals(1, b.size());
-    b.add(p2);
-    assertEquals(2, b.size());
-    PooledConnection r3 = b.remove();
+    assertEquals(1, b.freeSize());
+    b.addFree(p2);
+    assertEquals(2, b.freeSize());
+    PooledConnection r3 = b.popFree();
     assertSame(p2, r3);
-    assertEquals(1, b.size());
-    PooledConnection r4 = b.remove();
+    assertEquals(1, b.freeSize());
+    PooledConnection r4 = b.popFree();
     assertSame(p0, r4);
-    assertEquals(0, b.size());
+    assertEquals(0, b.freeSize());
 
-    b.add(p2);
-    b.add(p1);
-    b.add(p0);
+    b.addFree(p2);
+    b.addFree(p1);
+    b.addFree(p0);
 
-    assertEquals(3, b.size());
+    assertEquals(3, b.freeSize());
 
-    PooledConnection r5 = b.remove();
+    PooledConnection r5 = b.popFree();
     assertSame(p0, r5);
-    assertEquals(2, b.size());
+    assertEquals(2, b.freeSize());
 
-    PooledConnection r6 = b.remove();
+    PooledConnection r6 = b.popFree();
     assertSame(p1, r6);
-    assertEquals(1, b.size());
+    assertEquals(1, b.freeSize());
 
-    PooledConnection r7 = b.remove();
+    PooledConnection r7 = b.popFree();
     assertSame(p2, r7);
-    assertEquals(0, b.size());
+    assertEquals(0, b.freeSize());
 
   }