diff --git a/src/main/java/edu/caltech/nanodb/server/NanoDBServer.java b/src/main/java/edu/caltech/nanodb/server/NanoDBServer.java
index a9cd65576b3f315923996b1f2640862f7bb2cfd4..0034fbde2f64a778e03b754f90dc9d288fdb48fd 100644
--- a/src/main/java/edu/caltech/nanodb/server/NanoDBServer.java
+++ b/src/main/java/edu/caltech/nanodb/server/NanoDBServer.java
@@ -72,69 +72,6 @@ public class NanoDBServer implements ServerProperties {
private ReentrantReadWriteLock schemaLock;
- /**
- * Initialize all of the properties that the database server knows about.
- * Some of these properties are read-write, and others are read-only and
- * are initialized right at database startup, before any other steps
- * occur.
- */
- private void initProperties() {
- propertyRegistry.addProperty(PROP_BASE_DIRECTORY,
- new StringValueValidator(), DEFAULT_BASE_DIRECTORY,
- /* readonly */ true);
-
- propertyRegistry.addProperty(PROP_PAGECACHE_SIZE,
- new IntegerValueValidator(MIN_PAGECACHE_SIZE, MAX_PAGECACHE_SIZE),
- DEFAULT_PAGECACHE_SIZE);
-
- propertyRegistry.addProperty(PROP_PAGECACHE_POLICY,
- new StringEnumValidator(PAGECACHE_POLICY_VALUES),
- DEFAULT_PAGECACHE_POLICY);
-
- propertyRegistry.addProperty(PROP_PAGE_SIZE,
- new IntegerValueValidator(DBFile::isValidPageSize,
- "Specified page-size %d is invalid."), DEFAULT_PAGE_SIZE);
-
- propertyRegistry.addProperty(PROP_ENABLE_TRANSACTIONS,
- new BooleanFlagValidator(), false, /* readonly */ true);
-
- propertyRegistry.addProperty(PROP_ENFORCE_KEY_CONSTRAINTS,
- new BooleanFlagValidator(), true);
-
- propertyRegistry.addProperty(PROP_ENABLE_INDEXES,
- new BooleanFlagValidator(), false, /* reaadonly */ true);
-
- propertyRegistry.addProperty(PROP_CREATE_INDEXES_ON_KEYS,
- new BooleanFlagValidator(), false);
-
- propertyRegistry.addProperty(PROP_PLANNER_CLASS,
- new PlannerClassValidator(), DEFAULT_PLANNER_CLASS);
-
- propertyRegistry.addProperty(PROP_FLUSH_AFTER_CMD,
- new BooleanFlagValidator(), true);
- }
-
-
- /**
- * This helper function sets the NanoDB server properties based on the
- * contents of a Java {@code Properties} object. This allows us to set
- * NanoDB properties from system properties and/or other sources of
- * properties.
- *
- * @param properties the properties to apply to NanoDB's configuration.
- */
- private void setProperties(Properties properties) {
- if (properties == null)
- throw new IllegalArgumentException("properties cannot be null");
-
- for (String name : properties.stringPropertyNames()) {
- if (propertyRegistry.hasProperty(name))
- propertyRegistry.setPropertyValue(name,
- properties.getProperty(name));
- }
- }
-
-
/**
* This static method encapsulates all of the operations necessary for
* cleanly starting the NanoDB server. Database server properties are
@@ -166,13 +103,12 @@ public class NanoDBServer implements ServerProperties {
// Everything needs configuration.
propertyRegistry = new PropertyRegistry();
- initProperties();
// Apply system properties first (populated from e.g. command line),
// then override with any arguments to this function.
- setProperties(System.getProperties());
+ propertyRegistry.setProperties(System.getProperties());
if (initialProperties != null)
- setProperties(initialProperties);
+ propertyRegistry.setProperties(initialProperties);
propertyRegistry.setupCompleted();
diff --git a/src/main/java/edu/caltech/nanodb/server/properties/PropertyObserver.java b/src/main/java/edu/caltech/nanodb/server/properties/PropertyObserver.java
new file mode 100644
index 0000000000000000000000000000000000000000..b783c7ef09db6c0e9771a2ec86d384cfd5791310
--- /dev/null
+++ b/src/main/java/edu/caltech/nanodb/server/properties/PropertyObserver.java
@@ -0,0 +1,18 @@
+package edu.caltech.nanodb.server.properties;
+
+
+/**
+ * An interface that components can implement to be notified of changes to
+ * property-values during system operation.
+ */
+public interface PropertyObserver {
+ /**
+ * This method is called on all property observers when a given property
+ * is changed to a new value.
+ *
+ * @param propertyName the name of the property that was changed
+ *
+ * @param newValue the new value of the property
+ */
+ void propertyChanged(String propertyName, Object newValue);
+}
diff --git a/src/main/java/edu/caltech/nanodb/server/properties/PropertyRegistry.java b/src/main/java/edu/caltech/nanodb/server/properties/PropertyRegistry.java
index 2fd22b628e3d630ed2e410d7d298f186a0c3312e..734c40e67288d1caf04fb8b3d2c927b3a90ca222 100644
--- a/src/main/java/edu/caltech/nanodb/server/properties/PropertyRegistry.java
+++ b/src/main/java/edu/caltech/nanodb/server/properties/PropertyRegistry.java
@@ -1,10 +1,14 @@
package edu.caltech.nanodb.server.properties;
+import java.util.ArrayList;
import java.util.Collections;
+import java.util.Properties;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
+import edu.caltech.nanodb.storage.DBFile;
+
/**
* This is the central location where all properties exposed by the database
@@ -12,7 +16,7 @@ import java.util.concurrent.ConcurrentHashMap;
* configurable properties with the registry, and then they can be accessed
* and/or set from the SQL prompt.
*/
-public class PropertyRegistry {
+public class PropertyRegistry implements ServerProperties {
private class PropertyDescriptor {
/** The name of the property. */
@@ -69,6 +73,13 @@ public class PropertyRegistry {
new ConcurrentHashMap<>();
+ /**
+ * A collection of property observers to be informed when property values
+ * change.
+ */
+ private ArrayList<PropertyObserver> observers = new ArrayList<>();
+
+
/**
* This flag indicates whether the database is still in "start-up mode"
* or not. During start-up mode, all read-only properties may also be
@@ -77,6 +88,75 @@ public class PropertyRegistry {
private boolean setup = true;
+ public PropertyRegistry() {
+ initProperties();
+ }
+
+
+ /**
+ * Initialize all of the properties that the database server knows about.
+ * Some of these properties are read-write, and others are read-only and
+ * are initialized right at database startup, before any other steps
+ * occur.
+ *
+ * @review (donnie) It's not great that this configuration is in here.
+ * Someday, should probably migrate it back into
+ * {@code NanoDBServer}.
+ */
+ private void initProperties() {
+ addProperty(PROP_BASE_DIRECTORY,
+ new StringValueValidator(), DEFAULT_BASE_DIRECTORY,
+ /* readonly */ true);
+
+ addProperty(PROP_PAGECACHE_SIZE,
+ new IntegerValueValidator(MIN_PAGECACHE_SIZE, MAX_PAGECACHE_SIZE),
+ DEFAULT_PAGECACHE_SIZE);
+
+ addProperty(PROP_PAGECACHE_POLICY,
+ new StringEnumValidator(PAGECACHE_POLICY_VALUES),
+ DEFAULT_PAGECACHE_POLICY, /* readonly */ true);
+
+ addProperty(PROP_PAGE_SIZE,
+ new IntegerValueValidator(DBFile::isValidPageSize,
+ "Specified page-size %d is invalid."), DEFAULT_PAGE_SIZE);
+
+ addProperty(PROP_ENABLE_TRANSACTIONS,
+ new BooleanFlagValidator(), false, /* readonly */ true);
+
+ addProperty(PROP_ENFORCE_KEY_CONSTRAINTS,
+ new BooleanFlagValidator(), true);
+
+ addProperty(PROP_ENABLE_INDEXES,
+ new BooleanFlagValidator(), false, /* reaadonly */ true);
+
+ addProperty(PROP_CREATE_INDEXES_ON_KEYS,
+ new BooleanFlagValidator(), false);
+
+ addProperty(PROP_PLANNER_CLASS,
+ new PlannerClassValidator(), DEFAULT_PLANNER_CLASS);
+
+ addProperty(PROP_FLUSH_AFTER_CMD, new BooleanFlagValidator(), true);
+ }
+
+
+ /**
+ * This helper function sets the server properties based on the contents
+ * of a Java {@code Properties} object. This allows us to set NanoDB
+ * properties from system properties and/or other sources of properties.
+ *
+ * @param properties the properties to apply to NanoDB's configuration.
+ */
+ public void setProperties(Properties properties) {
+ if (properties == null)
+ throw new IllegalArgumentException("properties cannot be null");
+
+ for (String name : properties.stringPropertyNames()) {
+ if (hasProperty(name))
+ setPropertyValue(name, properties.getProperty(name));
+ }
+ }
+
+
/**
* Records that setup has been completed, and read-only properties
* should no longer be allowed to change.
@@ -86,6 +166,19 @@ public class PropertyRegistry {
}
+ /**
+ * Records a property-change observer on the property registry.
+ *
+ * @param observer the observer to receive property-change notifications
+ */
+ public void addObserver(PropertyObserver observer) {
+ if (observer == null)
+ throw new IllegalArgumentException("observer cannot be null");
+
+ observers.add(observer);
+ }
+
+
/**
* Add a read-only or read-write property to the registry, along with a
* type and an initial value.
@@ -168,6 +261,9 @@ public class PropertyRegistry {
}
properties.get(name).setValue(value);
+
+ for (PropertyObserver obs : observers)
+ obs.propertyChanged(name, value);
}
diff --git a/src/main/java/edu/caltech/nanodb/storage/BufferManager.java b/src/main/java/edu/caltech/nanodb/storage/BufferManager.java
index cb738e0d712665b1014d08b54c8e2470bcc6925a..e8b33c85a70bf094ab80baef0edecaccbfbfd466 100644
--- a/src/main/java/edu/caltech/nanodb/storage/BufferManager.java
+++ b/src/main/java/edu/caltech/nanodb/storage/BufferManager.java
@@ -14,6 +14,9 @@ import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;
import edu.caltech.nanodb.server.SessionState;
+import edu.caltech.nanodb.server.properties.PropertyObserver;
+import edu.caltech.nanodb.server.properties.PropertyRegistry;
+import edu.caltech.nanodb.server.properties.ServerProperties;
/**
@@ -29,35 +32,15 @@ import edu.caltech.nanodb.server.SessionState;
*/
public class BufferManager {
- /** The default page-cache size is defined to be 20MiB. */
- public static final int DEFAULT_PAGECACHE_SIZE = 20 * 1024 * 1024;
-
- /**
- * The minimum page-cache size is defined to be 32KiB, which is really
- * only sufficient to run smaller queries when page-pinning is working
- * properly.
- */
- public static final int MIN_PAGECACHE_SIZE = 32 * 1024;
-
- /**
- * The system property that can be used to specify the page replacement
- * policy in the buffer manager.
- */
- public static final String PROP_PAGECACHE_POLICY = "nanodb.pagecache.policy";
-
- /** The default page-cache policy is LRU. */
- public static final String DEFAULT_PAGECACHE_POLICY = "lru";
-
-
/**
* This helper class keeps track of a data page that is currently cached.
*/
private static class CachedPageInfo {
- public DBFile dbFile;
+ DBFile dbFile;
- public int pageNo;
+ int pageNo;
- public CachedPageInfo(DBFile dbFile, int pageNo) {
+ CachedPageInfo(DBFile dbFile, int pageNo) {
if (dbFile == null)
throw new IllegalArgumentException("dbFile cannot be null");
@@ -154,34 +137,39 @@ public class BufferManager {
/**
* A string indicating the buffer manager's page replacement policy.
- * Currently it can be "lru" or "fifo".
+ * Currently it can be "LRU" or "FIFO".
*/
private String replacementPolicy;
- public BufferManager(FileManager fileManager) {
- this.fileManager = fileManager;
+ private class BufferPropertyObserver
+ implements PropertyObserver, ServerProperties {
+ public void propertyChanged(String propertyName, Object newValue) {
+ // We only care about the pagecache-size value.
+ if (PROP_PAGECACHE_SIZE.equals(propertyName)) {
+ setMaxCacheSize((Integer) newValue);
+ }
+ }
+ }
- maxCacheSize = DEFAULT_PAGECACHE_SIZE;
- /* TODO: Factor out the replacement policy implementation so that
- * it's easier to replace/configure in the future.
- */
- replacementPolicy = configureReplacementPolicy();
- cachedPages = new LinkedHashMap<>(16, 0.75f, "lru".equals(replacementPolicy));
- totalBytesCached = 0;
+ public BufferManager(FileManager fileManager,
+ PropertyRegistry propertyRegistry) {
+ this.fileManager = fileManager;
+ propertyRegistry.addObserver(new BufferPropertyObserver());
- /* TODO: Get rid of this. Something outside of this class should
- * configure it when it is initialized.
+ maxCacheSize = propertyRegistry.getIntProperty(
+ ServerProperties.PROP_PAGECACHE_SIZE);
- if (server != null) {
- // Register properties that the Buffer Manager exposes.
- server.getPropertyRegistry().registerProperties(
- new BufferManagerPropertyHandler(),
- PROP_PAGECACHE_POLICY, PROP_PAGECACHE_SIZE);
- }
- */
+ // TODO: Factor out the replacement policy implementation so that
+ // it's easier to replace/configure in the future.
+ replacementPolicy = propertyRegistry.getStringProperty(
+ ServerProperties.PROP_PAGECACHE_POLICY);
+ cachedPages =
+ new LinkedHashMap<>(16, 0.75f, "LRU".equals(replacementPolicy));
+
+ totalBytesCached = 0;
}
@@ -193,9 +181,10 @@ public class BufferManager {
* @param maxCacheSize the maximum size for the buffer cache.
*/
public void setMaxCacheSize(int maxCacheSize) {
- if (maxCacheSize < MIN_PAGECACHE_SIZE) {
+ if (maxCacheSize < ServerProperties.MIN_PAGECACHE_SIZE) {
throw new IllegalArgumentException(
- "maxCacheSize must be at least " + MIN_PAGECACHE_SIZE);
+ "maxCacheSize must be at least " +
+ ServerProperties.MIN_PAGECACHE_SIZE);
}
synchronized (guard) {
@@ -223,21 +212,6 @@ public class BufferManager {
}
- private String configureReplacementPolicy() {
- String str = DEFAULT_PAGECACHE_POLICY;
- str = str.trim().toLowerCase();
-
- if (!("lru".equals(str) || "fifo".equals(str))) {
- logger.error(String.format(
- "Unrecognized value \"%s\" for page-cache replacement " +
- "policy; using default value of LRU.",
- System.getProperty(PROP_PAGECACHE_POLICY)));
- }
-
- return str;
- }
-
-
/**
* Add another observer to the buffer manager.
*
diff --git a/src/main/java/edu/caltech/nanodb/storage/StorageManager.java b/src/main/java/edu/caltech/nanodb/storage/StorageManager.java
index e795de0a4ae57f40d3d67dad5e6e882c6d42dabe..a4f65ce659c80132137053cfedd60561c529f9e4 100755
--- a/src/main/java/edu/caltech/nanodb/storage/StorageManager.java
+++ b/src/main/java/edu/caltech/nanodb/storage/StorageManager.java
@@ -13,7 +13,6 @@ import edu.caltech.nanodb.indexes.IndexManager;
import edu.caltech.nanodb.indexes.IndexUpdater;
import edu.caltech.nanodb.relations.DatabaseConstraintEnforcer;
import edu.caltech.nanodb.server.EventDispatcher;
-import edu.caltech.nanodb.server.NanoDBException;
import edu.caltech.nanodb.server.NanoDBServer;
import edu.caltech.nanodb.server.properties.PropertyRegistry;
import edu.caltech.nanodb.server.properties.ServerProperties;
@@ -22,7 +21,8 @@ import edu.caltech.nanodb.transactions.TransactionManager;
/**
- *
+ * The Storage Manager provides facilities for managing files of tuples,
+ * including in-memory buffering of data pages and support for transactions.
*
* @todo This class requires synchronization, once we support multiple clients.
*/
@@ -32,11 +32,6 @@ public class StorageManager {
private static Logger logger = LogManager.getLogger(StorageManager.class);
- /*========================================================================
- * STATIC FIELDS AND METHODS
- */
-
-
/*========================================================================
* NON-STATIC FIELDS AND METHODS
*/
@@ -139,7 +134,7 @@ public class StorageManager {
logger.info("Using base directory " + baseDir);
fileManager = new FileManagerImpl(baseDir);
- bufferManager = new BufferManager(fileManager);
+ bufferManager = new BufferManager(fileManager, serverProps);
tupleFileManagers.put(DBFileType.HEAP_TUPLE_FILE,
new HeapTupleFileManager(this));
diff --git a/src/test/java/edu/caltech/test/nanodb/storage/TestBufferManager.java b/src/test/java/edu/caltech/test/nanodb/storage/TestBufferManager.java
index 5f8cb76f1406fad0a54cf2de6a0338b5c4c36904..88f168a421554ce10f904f817cd89221fe1b9f7f 100644
--- a/src/test/java/edu/caltech/test/nanodb/storage/TestBufferManager.java
+++ b/src/test/java/edu/caltech/test/nanodb/storage/TestBufferManager.java
@@ -9,6 +9,7 @@ import org.apache.commons.io.FileUtils;
import static org.mockito.Mockito.*;
+import edu.caltech.nanodb.server.properties.PropertyRegistry;
import edu.caltech.test.nanodb.framework.Concurrent;
import org.testng.annotations.Test;
@@ -34,7 +35,8 @@ public class TestBufferManager extends StorageTestCase {
FileUtils.cleanDirectory(testBaseDir);
FileManager fileMgr = spy(new FileManagerImpl(testBaseDir));
- BufferManager bufMgr = new BufferManager(fileMgr);
+ BufferManager bufMgr =
+ new BufferManager(fileMgr, new PropertyRegistry());
DBFile file = fileMgr.createDBFile("TestBufferManager_testBuffering",
DBFileType.TEST_FILE, 4096);
@@ -72,7 +74,8 @@ public class TestBufferManager extends StorageTestCase {
FileUtils.cleanDirectory(testBaseDir);
FileManager fileMgr = spy(new FileManagerImpl(testBaseDir));
- BufferManager bufMgr = new BufferManager(fileMgr);
+ BufferManager bufMgr =
+ new BufferManager(fileMgr, new PropertyRegistry());
// Set the Buffer Manager's pool size to 4MiB. This will force a
// significant number of pool evictions during the test.
diff --git a/src/test/java/edu/caltech/test/nanodb/storage/TestDBPage.java b/src/test/java/edu/caltech/test/nanodb/storage/TestDBPage.java
index 01b5157816c21be24ca83272280d3939301c8998..fbabf6a99e566f2703c8405bf80b3fa1aa82d6fa 100644
--- a/src/test/java/edu/caltech/test/nanodb/storage/TestDBPage.java
+++ b/src/test/java/edu/caltech/test/nanodb/storage/TestDBPage.java
@@ -1,6 +1,7 @@
package edu.caltech.test.nanodb.storage;
+import edu.caltech.nanodb.server.properties.PropertyRegistry;
import org.testng.annotations.Test;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.AfterClass;
@@ -48,7 +49,8 @@ public class TestDBPage extends StorageTestCase {
public void beforeClass() {
fileMgr = new FileManagerImpl(testBaseDir);
- BufferManager bufMgr = new BufferManager(fileMgr);
+ BufferManager bufMgr =
+ new BufferManager(fileMgr, new PropertyRegistry());
// Get DBFile
DBFileType type = DBFileType.HEAP_TUPLE_FILE;
diff --git a/src/test/java/edu/caltech/test/nanodb/storage/TestFileManager.java b/src/test/java/edu/caltech/test/nanodb/storage/TestFileManager.java
index f9365a867ca87efb47e1dd4ff496f3dcd648cc63..8fd10d045c87ad0597bfd64b986fbc97b531032d 100644
--- a/src/test/java/edu/caltech/test/nanodb/storage/TestFileManager.java
+++ b/src/test/java/edu/caltech/test/nanodb/storage/TestFileManager.java
@@ -4,6 +4,7 @@ package edu.caltech.test.nanodb.storage;
import java.io.File;
import java.io.IOException;
+import edu.caltech.nanodb.server.properties.PropertyRegistry;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;
@@ -29,7 +30,7 @@ public class TestFileManager extends StorageTestCase {
@BeforeClass
public void beforeClass() {
fileMgr = new FileManagerImpl(testBaseDir);
- bufMgr = new BufferManager(fileMgr);
+ bufMgr = new BufferManager(fileMgr, new PropertyRegistry());
}