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-rw-r--r--src/main/java/com/amazon/carbonado/cursor/GroupedCursor.java2
-rw-r--r--src/main/java/com/amazon/carbonado/cursor/JoinedCursorFactory.java248
-rw-r--r--src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java3
-rw-r--r--src/main/java/com/amazon/carbonado/cursor/TransformedCursor.java3
4 files changed, 136 insertions, 120 deletions
diff --git a/src/main/java/com/amazon/carbonado/cursor/GroupedCursor.java b/src/main/java/com/amazon/carbonado/cursor/GroupedCursor.java
index bf838b1..5ec8a56 100644
--- a/src/main/java/com/amazon/carbonado/cursor/GroupedCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/GroupedCursor.java
@@ -35,6 +35,8 @@ import com.amazon.carbonado.FetchInterruptedException;
*
* @author Brian S O'Neill
* @see SortedCursor
+ * @param <S> source type, can be anything
+ * @param <G> aggregate type, can be anything
*/
public abstract class GroupedCursor<S, G> extends AbstractCursor<G> {
private final Cursor<S> mCursor;
diff --git a/src/main/java/com/amazon/carbonado/cursor/JoinedCursorFactory.java b/src/main/java/com/amazon/carbonado/cursor/JoinedCursorFactory.java
index ae98a95..b689c7e 100644
--- a/src/main/java/com/amazon/carbonado/cursor/JoinedCursorFactory.java
+++ b/src/main/java/com/amazon/carbonado/cursor/JoinedCursorFactory.java
@@ -56,12 +56,13 @@ import com.amazon.carbonado.spi.CodeBuilderUtil;
import static com.amazon.carbonado.spi.CommonMethodNames.*;
/**
- * Given two joined types <i>A</i> and <i>B</i>, this factory converts a cursor
- * over type <i>A</i> into a cursor over type <i>B</i>. For example, consider
- * two storable types, Employer and Person. A query filter for persons with a
- * given employer might look like: {@code "employer.name = ?" } The join can be
- * manually implemented by querying for employers and then using this factory
- * to produce persons:
+ * Given two joined types <i>source</i> and <i>target</i>, this factory
+ * converts a cursor over type <i>source</i> into a cursor over type
+ * <i>target</i>. For example, consider two storable types, Employer and
+ * Person. A query filter for persons with a given employer might look like:
+ * {@code "employer.name = ?" } The join can be manually implemented by
+ * querying for employers (the source) and then using this factory to produce
+ * persons (the target):
*
* <pre>
* JoinedCursorFactory&lt;Employer, Person&gt; factory = new JoinedCursorFactory&lt;Employer, Person&gt;
@@ -88,12 +89,16 @@ import static com.amazon.carbonado.spi.CommonMethodNames.*;
* </pre>
*
* @author Brian S O'Neill
+ * @see TransformedCursor
+ * @see MultiTransformedCursor
+ * @param <S> source type, can be anything
+ * @param <T> target type, must be a Storable
*/
-public class JoinedCursorFactory<A, B extends Storable> {
+public class JoinedCursorFactory<S, T extends Storable> {
private static final String STORAGE_FIELD_NAME = "storage";
private static final String QUERY_FIELD_NAME = "query";
private static final String QUERY_FILTER_FIELD_NAME = "queryFilter";
- private static final String ACTIVE_A_FIELD_NAME = "active";
+ private static final String ACTIVE_SOURCE_FIELD_NAME = "active";
private static final Map<Object, Class> cJoinerCursorClassCache;
@@ -101,63 +106,63 @@ public class JoinedCursorFactory<A, B extends Storable> {
cJoinerCursorClassCache = new SoftValuedHashMap();
}
- private static synchronized <B extends Storable> Joiner<?, B>
- newBasicJoiner(StorableProperty<B> bToAProperty, Storage<B> bStorage)
+ private static synchronized <T extends Storable> Joiner<?, T>
+ newBasicJoiner(StorableProperty<T> targetToSourceProperty, Storage<T> targetStorage)
throws FetchException
{
- Class<?> aType = bToAProperty.getType();
+ Class<?> sourceType = targetToSourceProperty.getType();
final Object key = KeyFactory.createKey
- (new Object[] {aType,
- bToAProperty.getEnclosingType(),
- bToAProperty.getName()});
+ (new Object[] {sourceType,
+ targetToSourceProperty.getEnclosingType(),
+ targetToSourceProperty.getName()});
Class clazz = cJoinerCursorClassCache.get(key);
if (clazz == null) {
- clazz = generateBasicJoinerCursor(aType, bToAProperty);
+ clazz = generateBasicJoinerCursor(sourceType, targetToSourceProperty);
cJoinerCursorClassCache.put(key, clazz);
}
// Transforming cursor class may need a Query to operate on.
- Query<B> bQuery = null;
+ Query<T> targetQuery = null;
try {
String filter = (String) clazz.getField(QUERY_FILTER_FIELD_NAME).get(null);
- bQuery = bStorage.query(filter);
+ targetQuery = targetStorage.query(filter);
} catch (NoSuchFieldException e) {
} catch (IllegalAccessException e) {
}
- BasicJoiner.Factory<?, B> factory = (BasicJoiner.Factory<?, B>) QuickConstructorGenerator
+ BasicJoiner.Factory<?, T> factory = (BasicJoiner.Factory<?, T>) QuickConstructorGenerator
.getInstance(clazz, BasicJoiner.Factory.class);
- return new BasicJoiner(factory, bStorage, bQuery);
+ return new BasicJoiner(factory, targetStorage, targetQuery);
}
- private static <B extends Storable> Class<Cursor<B>>
- generateBasicJoinerCursor(Class<?> aType, StorableProperty<B> bToAProperty)
+ private static <T extends Storable> Class<Cursor<T>>
+ generateBasicJoinerCursor(Class<?> sourceType, StorableProperty<T> targetToSourceProperty)
{
- final int propCount = bToAProperty.getJoinElementCount();
+ final int propCount = targetToSourceProperty.getJoinElementCount();
// Determine if join is one-to-one, in which case slightly more optimal
// code can be generated.
boolean isOneToOne = true;
for (int i=0; i<propCount; i++) {
- if (!bToAProperty.getInternalJoinElement(i).isPrimaryKeyMember()) {
+ if (!targetToSourceProperty.getInternalJoinElement(i).isPrimaryKeyMember()) {
isOneToOne = false;
break;
}
- if (!bToAProperty.getExternalJoinElement(i).isPrimaryKeyMember()) {
+ if (!targetToSourceProperty.getExternalJoinElement(i).isPrimaryKeyMember()) {
isOneToOne = false;
break;
}
}
- Class<B> bType = bToAProperty.getEnclosingType();
+ Class<T> targetType = targetToSourceProperty.getEnclosingType();
String packageName;
{
- String name = bType.getName();
+ String name = targetType.getName();
int index = name.lastIndexOf('.');
if (index >= 0) {
packageName = name.substring(0, index);
@@ -166,7 +171,7 @@ public class JoinedCursorFactory<A, B extends Storable> {
}
}
- ClassLoader loader = bType.getClassLoader();
+ ClassLoader loader = targetType.getClassLoader();
ClassInjector ci = ClassInjector.create(packageName + ".JoinedCursor", loader);
Class superclass = isOneToOne ? TransformedCursor.class : MultiTransformedCursor.class;
@@ -183,15 +188,16 @@ public class JoinedCursorFactory<A, B extends Storable> {
if (isOneToOne) {
cf.addField(Modifiers.PRIVATE.toFinal(true), STORAGE_FIELD_NAME, storageType);
} else {
- // Field to hold query which fetches type B.
+ // Field to hold query which fetches type T.
cf.addField(Modifiers.PRIVATE.toFinal(true), QUERY_FIELD_NAME, queryType);
}
- boolean canSetAReference = bToAProperty.getWriteMethod() != null;
+ boolean canSetSourceReference = targetToSourceProperty.getWriteMethod() != null;
- if (canSetAReference && !isOneToOne) {
- // Field to hold active A storable.
- cf.addField(Modifiers.PRIVATE, ACTIVE_A_FIELD_NAME, TypeDesc.forClass(aType));
+ if (canSetSourceReference && !isOneToOne) {
+ // Field to hold active S storable.
+ cf.addField(Modifiers.PRIVATE, ACTIVE_SOURCE_FIELD_NAME,
+ TypeDesc.forClass(sourceType));
}
// Constructor accepts a Storage and Query, but Storage is only used
@@ -202,16 +208,16 @@ public class JoinedCursorFactory<A, B extends Storable> {
CodeBuilder b = new CodeBuilder(mi);
b.loadThis();
- b.loadLocal(b.getParameter(0)); // pass A cursor to superclass
+ b.loadLocal(b.getParameter(0)); // pass S cursor to superclass
b.invokeSuperConstructor(new TypeDesc[] {cursorType});
if (isOneToOne) {
b.loadThis();
- b.loadLocal(b.getParameter(1)); // push B storage to stack
+ b.loadLocal(b.getParameter(1)); // push T storage to stack
b.storeField(STORAGE_FIELD_NAME, storageType);
} else {
b.loadThis();
- b.loadLocal(b.getParameter(2)); // push B query to stack
+ b.loadLocal(b.getParameter(2)); // push T query to stack
b.storeField(QUERY_FIELD_NAME, queryType);
}
@@ -227,7 +233,7 @@ public class JoinedCursorFactory<A, B extends Storable> {
if (i > 0) {
queryBuilder.append(" & ");
}
- queryBuilder.append(bToAProperty.getInternalJoinElement(i).getName());
+ queryBuilder.append(targetToSourceProperty.getInternalJoinElement(i).getName());
queryBuilder.append(" = ?");
}
@@ -243,32 +249,32 @@ public class JoinedCursorFactory<A, B extends Storable> {
mi.addException(TypeDesc.forClass(FetchException.class));
CodeBuilder b = new CodeBuilder(mi);
- LocalVariable aVar = b.createLocalVariable(null, storableType);
+ LocalVariable sourceVar = b.createLocalVariable(null, storableType);
b.loadLocal(b.getParameter(0));
- b.checkCast(TypeDesc.forClass(aType));
- b.storeLocal(aVar);
+ b.checkCast(TypeDesc.forClass(sourceType));
+ b.storeLocal(sourceVar);
- // Prepare B storable.
+ // Prepare T storable.
b.loadThis();
b.loadField(STORAGE_FIELD_NAME, storageType);
b.invokeInterface(storageType, PREPARE_METHOD_NAME, storableType, null);
- LocalVariable bVar = b.createLocalVariable(null, storableType);
- b.checkCast(TypeDesc.forClass(bType));
- b.storeLocal(bVar);
+ LocalVariable targetVar = b.createLocalVariable(null, storableType);
+ b.checkCast(TypeDesc.forClass(targetType));
+ b.storeLocal(targetVar);
- // Copy pk property values from A to B.
+ // Copy pk property values from S to T.
for (int i=0; i<propCount; i++) {
- StorableProperty<B> internal = bToAProperty.getInternalJoinElement(i);
- StorableProperty<?> external = bToAProperty.getExternalJoinElement(i);
+ StorableProperty<T> internal = targetToSourceProperty.getInternalJoinElement(i);
+ StorableProperty<?> external = targetToSourceProperty.getExternalJoinElement(i);
- b.loadLocal(bVar);
- b.loadLocal(aVar);
+ b.loadLocal(targetVar);
+ b.loadLocal(sourceVar);
b.invoke(external.getReadMethod());
b.invoke(internal.getWriteMethod());
}
- // tryLoad b.
- b.loadLocal(bVar);
+ // tryLoad target.
+ b.loadLocal(targetVar);
b.invokeInterface(storableType, TRY_LOAD_METHOD_NAME, TypeDesc.BOOLEAN, null);
Label wasLoaded = b.createLabel();
b.ifZeroComparisonBranch(wasLoaded, "!=");
@@ -278,13 +284,13 @@ public class JoinedCursorFactory<A, B extends Storable> {
wasLoaded.setLocation();
- if (canSetAReference) {
- b.loadLocal(bVar);
- b.loadLocal(aVar);
- b.invoke(bToAProperty.getWriteMethod());
+ if (canSetSourceReference) {
+ b.loadLocal(targetVar);
+ b.loadLocal(sourceVar);
+ b.invoke(targetToSourceProperty.getWriteMethod());
}
- b.loadLocal(bVar);
+ b.loadLocal(targetVar);
b.returnValue(storableType);
} else {
MethodInfo mi = cf.addMethod(Modifiers.PROTECTED, "transform", cursorType,
@@ -292,15 +298,15 @@ public class JoinedCursorFactory<A, B extends Storable> {
mi.addException(TypeDesc.forClass(FetchException.class));
CodeBuilder b = new CodeBuilder(mi);
- LocalVariable aVar = b.createLocalVariable(null, storableType);
+ LocalVariable sourceVar = b.createLocalVariable(null, storableType);
b.loadLocal(b.getParameter(0));
- b.checkCast(TypeDesc.forClass(aType));
- b.storeLocal(aVar);
+ b.checkCast(TypeDesc.forClass(sourceType));
+ b.storeLocal(sourceVar);
- if (canSetAReference) {
+ if (canSetSourceReference) {
b.loadThis();
- b.loadLocal(aVar);
- b.storeField(ACTIVE_A_FIELD_NAME, TypeDesc.forClass(aType));
+ b.loadLocal(sourceVar);
+ b.storeField(ACTIVE_SOURCE_FIELD_NAME, TypeDesc.forClass(sourceType));
}
// Populate query parameters.
@@ -308,8 +314,8 @@ public class JoinedCursorFactory<A, B extends Storable> {
b.loadField(QUERY_FIELD_NAME, queryType);
for (int i=0; i<propCount; i++) {
- StorableProperty<?> external = bToAProperty.getExternalJoinElement(i);
- b.loadLocal(aVar);
+ StorableProperty<?> external = targetToSourceProperty.getExternalJoinElement(i);
+ b.loadLocal(sourceVar);
b.invoke(external.getReadMethod());
TypeDesc bindType = CodeBuilderUtil.bindQueryParam(external.getType());
@@ -323,8 +329,8 @@ public class JoinedCursorFactory<A, B extends Storable> {
b.returnValue(cursorType);
}
- if (canSetAReference && !isOneToOne) {
- // Override the "next" method to set A object on B.
+ if (canSetSourceReference && !isOneToOne) {
+ // Override the "next" method to set S object on T.
MethodInfo mi = cf.addMethod(Modifiers.PUBLIC, "next", TypeDesc.OBJECT, null);
mi.addException(TypeDesc.forClass(FetchException.class));
CodeBuilder b = new CodeBuilder(mi);
@@ -332,128 +338,130 @@ public class JoinedCursorFactory<A, B extends Storable> {
b.loadThis();
b.invokeSuper(TypeDesc.forClass(MultiTransformedCursor.class),
"next", TypeDesc.OBJECT, null);
- b.checkCast(TypeDesc.forClass(bType));
+ b.checkCast(TypeDesc.forClass(targetType));
b.dup();
b.loadThis();
- b.loadField(ACTIVE_A_FIELD_NAME, TypeDesc.forClass(aType));
- b.invoke(bToAProperty.getWriteMethod());
+ b.loadField(ACTIVE_SOURCE_FIELD_NAME, TypeDesc.forClass(sourceType));
+ b.invoke(targetToSourceProperty.getWriteMethod());
b.returnValue(storableType);
}
- return (Class<Cursor<B>>) ci.defineClass(cf);
+ return (Class<Cursor<T>>) ci.defineClass(cf);
}
- private final Joiner<A, B> mJoiner;
+ private final Joiner<S, T> mJoiner;
/**
* @param repo access to storage instances for properties
- * @param bType type of <i>B</i> instances
- * @param bToAProperty property of <i>B</i> type which maps to instances of
- * <i>A</i> type.
- * @param aType type of <i>A</i> instances
- * @throws IllegalArgumentException if property type is not <i>A</i>
+ * @param targetType type of <i>target</i> instances
+ * @param targetToSourceProperty property of <i>target</i> type which maps
+ * to instances of <i>source</i> type.
+ * @param sourceType type of <i>source</i> instances
+ * @throws IllegalArgumentException if property type is not <i>source</i>
*/
public JoinedCursorFactory(Repository repo,
- Class<B> bType,
- String bToAProperty,
- Class<A> aType)
+ Class<T> targetType,
+ String targetToSourceProperty,
+ Class<S> sourceType)
throws SupportException, FetchException, RepositoryException
{
this(repo,
- ChainedProperty.parse(StorableIntrospector.examine(bType), bToAProperty),
- aType);
+ ChainedProperty.parse(StorableIntrospector.examine(targetType),
+ targetToSourceProperty),
+ sourceType);
}
/**
* @param repo access to storage instances for properties
- * @param bToAProperty property of <i>B</i> type which maps to instances of
- * <i>A</i> type.
- * @param aType type of <i>A</i> instances
- * @throws IllegalArgumentException if property type is not <i>A</i>
+ * @param targetToSourceProperty property of <i>target</i> type which maps
+ * to instances of <i>source</i> type.
+ * @param sourceType type of <i>source</i> instances
+ * @throws IllegalArgumentException if property type is not <i>source</i>
*/
public JoinedCursorFactory(Repository repo,
- ChainedProperty<B> bToAProperty,
- Class<A> aType)
+ ChainedProperty<T> targetToSourceProperty,
+ Class<S> sourceType)
throws SupportException, FetchException, RepositoryException
{
- if (bToAProperty.getType() != aType) {
+ if (targetToSourceProperty.getType() != sourceType) {
throw new IllegalArgumentException
- ("Property is not of type \"" + aType.getName() + "\": " +
- bToAProperty);
+ ("Property is not of type \"" + sourceType.getName() + "\": " +
+ targetToSourceProperty);
}
- StorableProperty<B> primeB = bToAProperty.getPrimeProperty();
- Storage<B> primeBStorage = repo.storageFor(primeB.getEnclosingType());
+ StorableProperty<T> primeTarget = targetToSourceProperty.getPrimeProperty();
+ Storage<T> primeTargetStorage = repo.storageFor(primeTarget.getEnclosingType());
- Joiner joiner = newBasicJoiner(primeB, primeBStorage);
+ Joiner joiner = newBasicJoiner(primeTarget, primeTargetStorage);
- int chainCount = bToAProperty.getChainCount();
+ int chainCount = targetToSourceProperty.getChainCount();
for (int i=0; i<chainCount; i++) {
- StorableProperty prop = bToAProperty.getChainedProperty(i);
+ StorableProperty prop = targetToSourceProperty.getChainedProperty(i);
Storage storage = repo.storageFor(prop.getEnclosingType());
joiner = new MultiJoiner(newBasicJoiner(prop, storage), joiner);
}
- mJoiner = (Joiner<A, B>) joiner;
+ mJoiner = (Joiner<S, T>) joiner;
}
/**
- * Given a cursor over <i>A</i>, returns a new cursor over joined property
- * of type <i>B</i>.
+ * Given a cursor over type <i>source</i>, returns a new cursor over joined
+ * property of type <i>target</i>.
*/
- public Cursor<B> join(Cursor<A> cursor) {
+ public Cursor<T> join(Cursor<S> cursor) {
return mJoiner.join(cursor);
}
- private static interface Joiner<A, B extends Storable> {
- Cursor<B> join(Cursor<A> cursor);
+ private static interface Joiner<S, T extends Storable> {
+ Cursor<T> join(Cursor<S> cursor);
}
/**
* Support for joins without an intermediate hop.
*/
- private static class BasicJoiner<A, B extends Storable> implements Joiner<A, B> {
- private final Factory<A, B> mJoinerFactory;
- private final Storage<B> mBStorage;
- private final Query<B> mBQuery;
+ private static class BasicJoiner<S, T extends Storable> implements Joiner<S, T> {
+ private final Factory<S, T> mJoinerFactory;
+ private final Storage<T> mTargetStorage;
+ private final Query<T> mTargetQuery;
- BasicJoiner(Factory<A, B> factory, Storage<B> bStorage, Query<B> bQuery) {
+ BasicJoiner(Factory<S, T> factory, Storage<T> targetStorage, Query<T> targetQuery) {
mJoinerFactory = factory;
- mBStorage = bStorage;
- mBQuery = bQuery;
+ mTargetStorage = targetStorage;
+ mTargetQuery = targetQuery;
}
- public Cursor<B> join(Cursor<A> cursor) {
- return mJoinerFactory.newJoinedCursor(cursor, mBStorage, mBQuery);
+ public Cursor<T> join(Cursor<S> cursor) {
+ return mJoinerFactory.newJoinedCursor(cursor, mTargetStorage, mTargetQuery);
}
/**
* Needs to be public for {@link QuickConstructorGenerator}.
*/
- public static interface Factory<A, B extends Storable> {
- Cursor<B> newJoinedCursor(Cursor<A> cursor, Storage<B> bStorage, Query<B> bQuery);
+ public static interface Factory<S, T extends Storable> {
+ Cursor<T> newJoinedCursor(Cursor<S> cursor,
+ Storage<T> targetStorage, Query<T> targetQuery);
}
}
/**
* Support for joins with an intermediate hop -- multi-way joins.
*/
- private static class MultiJoiner<A, X extends Storable, B extends Storable>
- implements Joiner<A, B>
+ private static class MultiJoiner<S, X extends Storable, T extends Storable>
+ implements Joiner<S, T>
{
- private final Joiner<A, X> mAToMid;
- private final Joiner<X, B> mMidToB;
+ private final Joiner<S, X> mSourceToMid;
+ private final Joiner<X, T> mMidToTarget;
- MultiJoiner(Joiner<A, X> aToMidJoiner, Joiner<X, B> midToBJoiner) {
- mAToMid = aToMidJoiner;
- mMidToB = midToBJoiner;
+ MultiJoiner(Joiner<S, X> sourceToMidJoiner, Joiner<X, T> midToTargetJoiner) {
+ mSourceToMid = sourceToMidJoiner;
+ mMidToTarget = midToTargetJoiner;
}
- public Cursor<B> join(Cursor<A> cursor) {
- return mMidToB.join(mAToMid.join(cursor));
+ public Cursor<T> join(Cursor<S> cursor) {
+ return mMidToTarget.join(mSourceToMid.join(cursor));
}
}
}
diff --git a/src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java b/src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java
index feeb414..3f06421 100644
--- a/src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/MultiTransformedCursor.java
@@ -31,6 +31,9 @@ import com.amazon.carbonado.FetchInterruptedException;
* joins.
*
* @author Brian S O'Neill
+ * @see JoinedCursorFactory
+ * @param <S> source type, can be anything
+ * @param <T> target type, can be anything
*/
public abstract class MultiTransformedCursor<S, T> extends AbstractCursor<T> {
private final Cursor<S> mCursor;
diff --git a/src/main/java/com/amazon/carbonado/cursor/TransformedCursor.java b/src/main/java/com/amazon/carbonado/cursor/TransformedCursor.java
index 9f9efe7..428e74e 100644
--- a/src/main/java/com/amazon/carbonado/cursor/TransformedCursor.java
+++ b/src/main/java/com/amazon/carbonado/cursor/TransformedCursor.java
@@ -30,6 +30,9 @@ import com.amazon.carbonado.FetchInterruptedException;
* one-to-one joins. Use {@link MultiTransformedCursor} for one-to-many joins.
*
* @author Brian S O'Neill
+ * @see JoinedCursorFactory
+ * @param <S> source type, can be anything
+ * @param <T> target type, can be anything
*/
public abstract class TransformedCursor<S, T> extends AbstractCursor<T> {
private final Cursor<S> mCursor;
generated by cgit v1.2.3 (git 2.39.1) at 2025-10-31 21:36:32 +0000