From 1e814b1df1670f0a19a77d55848fe6f836fa4e6b Mon Sep 17 00:00:00 2001
From: "Brian S. O'Neill" <bronee@gmail.com>
Date: Mon, 4 Sep 2006 23:02:22 +0000
Subject: OrderingScore supports automatic ordering direction when unspecified.
---
.../com/amazon/carbonado/info/OrderedProperty.java | 20 +++++-------
.../com/amazon/carbonado/qe/OrderingScore.java | 38 +++++++++++++++-------
2 files changed, 35 insertions(+), 23 deletions(-)
(limited to 'src/main/java/com/amazon/carbonado')
diff --git a/src/main/java/com/amazon/carbonado/info/OrderedProperty.java b/src/main/java/com/amazon/carbonado/info/OrderedProperty.java
index 7de07c0..fe53c60 100644
--- a/src/main/java/com/amazon/carbonado/info/OrderedProperty.java
+++ b/src/main/java/com/amazon/carbonado/info/OrderedProperty.java
@@ -56,8 +56,8 @@ public class OrderedProperty<S extends Storable> implements Appender {
/**
* Parses an ordering property, which may start with a '+' or '-' to
- * indicate direction. If ordering prefix not specified, default direction
- * is ascending.
+ * indicate direction. Prefix of '~' indicates unspecified direction. If
+ * ordering prefix not specified, default direction is ascending.
*
* @param info Info for Storable type containing property
* @param str string to parse
@@ -73,7 +73,7 @@ public class OrderedProperty<S extends Storable> implements Appender {
/**
* Parses an ordering property, which may start with a '+' or '-' to
- * indicate direction.
+ * indicate direction. Prefix of '~' indicates unspecified direction.
*
* @param info Info for Storable type containing property
* @param str string to parse
@@ -98,6 +98,9 @@ public class OrderedProperty<S extends Storable> implements Appender {
} else if (str.charAt(0) == '-') {
direction = Direction.DESCENDING;
str = str.substring(1);
+ } else if (str.charAt(0) == '~') {
+ direction = Direction.UNSPECIFIED;
+ str = str.substring(1);
}
}
if (direction == null) {
@@ -158,9 +161,6 @@ public class OrderedProperty<S extends Storable> implements Appender {
*/
@Override
public String toString() {
- if (mDirection == Direction.UNSPECIFIED) {
- return mProperty.toString();
- }
StringBuilder buf = new StringBuilder();
buf.append(mDirection.toCharacter());
try {
@@ -172,11 +172,7 @@ public class OrderedProperty<S extends Storable> implements Appender {
}
public void appendTo(Appendable app) throws IOException {
- if (mDirection == Direction.UNSPECIFIED) {
- mProperty.appendTo(app);
- } else {
- app.append(mDirection.toCharacter());
- mProperty.appendTo(app);
- }
+ app.append(mDirection.toCharacter());
+ mProperty.appendTo(app);
}
}
diff --git a/src/main/java/com/amazon/carbonado/qe/OrderingScore.java b/src/main/java/com/amazon/carbonado/qe/OrderingScore.java
index ed52cfc..ce85cb6 100644
--- a/src/main/java/com/amazon/carbonado/qe/OrderingScore.java
+++ b/src/main/java/com/amazon/carbonado/qe/OrderingScore.java
@@ -177,18 +177,32 @@ public class OrderingScore<S extends Storable> {
ChainedProperty<S> indexChained = indexProp.getChainedProperty();
if (chained.equals(indexChained)) {
- if (property.getDirection() != UNSPECIFIED) {
- Direction indexDir = indexProp.getDirection();
- if (indexDir == UNSPECIFIED) {
- indexDir = ASCENDING;
- }
+ Direction indexDir = indexProp.getDirection();
+ if (indexDir == UNSPECIFIED) {
+ // Assume index natural order is ascending.
+ indexDir = ASCENDING;
+ }
+
+ if (shouldReverseOrder != null && shouldReverseOrder) {
+ indexDir = indexDir.reverse();
+ }
- if (shouldReverseOrder == null) {
- shouldReverseOrder = indexDir != property.getDirection();
- } else if ((indexDir != property.getDirection()) ^ shouldReverseOrder) {
- // Direction mismatch, so cannot be handled.
- break indexPosMatch;
+ if (property.getDirection() == UNSPECIFIED) {
+ // Set handled property direction to match index.
+ property = property.direction(indexDir);
+ } else if (shouldReverseOrder == null) {
+ shouldReverseOrder = indexDir != property.getDirection();
+ // Any properies already in the list had been
+ // originally unspecified. They might need to be
+ // reversed now.
+ if (shouldReverseOrder) {
+ for (int hpi = 0; hpi < handledProperties.size(); hpi++) {
+ handledProperties.set(hpi, handledProperties.get(hpi).reverse());
+ }
}
+ } else if (indexDir != property.getDirection()) {
+ // Direction mismatch, so cannot be handled.
+ break indexPosMatch;
}
handledProperties.add(property);
@@ -281,7 +295,9 @@ public class OrderingScore<S extends Storable> {
/**
* Returns the ordering properties that the evaluated index supports. The
- * list of orderings is reduced to eliminate redundancies.
+ * list of orderings is reduced to eliminate redundancies. If any handled
+ * ordering properties originally had an unspecified direction, the correct
+ * direction is specified in this list.
*
* @return handled orderings, never null
*/
--
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