From 404056c33b047e8ec75b0f6def90b4a27bf8079b Mon Sep 17 00:00:00 2001
From: James Ahlborn <jtahlborn@yahoo.com>
Date: Tue, 18 Mar 2008 20:11:48 +0000
Subject: [PATCH] clean up updating of the index uniqueEntryCount

git-svn-id: https://svn.code.sf.net/p/jackcess/code/jackcess/trunk@283 f203690c-595d-4dc9-a70b-905162fa7fd2
---
 .../healthmarketscience/jackcess/Index.java   | 38 +++++++++++--------
 .../healthmarketscience/jackcess/Table.java   | 16 +++++---
 2 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/src/java/com/healthmarketscience/jackcess/Index.java b/src/java/com/healthmarketscience/jackcess/Index.java
index df2445f..944866d 100644
--- a/src/java/com/healthmarketscience/jackcess/Index.java
+++ b/src/java/com/healthmarketscience/jackcess/Index.java
@@ -151,10 +151,13 @@ public class Index implements Comparable<Index> {
   private final Table _table;
   /** Page number of the index data */
   private int _pageNumber;
-  /** Number of rows in the index
-      NOTE: this does not actually seem to be the row count, unclear what the
-      value means*/
-  private int _rowCount;
+  /** offset within the tableDefinition buffer of the uniqueEntryCount for
+      this index */
+  private final int _uniqueEntryCountOffset;
+  /** The number of unique entries which have been added to this index.  note,
+      however, that it is never decremented, only incremented (as observed in
+      Access). */
+  private int _uniqueEntryCount;
   /** sorted collection of index entries.  this is kept in a list instead of a
       SortedSet because the SortedSet has lame traversal utilities */
   private final List<Entry> _entries = new ArrayList<Entry>();
@@ -180,8 +183,10 @@ public class Index implements Comparable<Index> {
   /** FIXME, for now, we can't write multi-page indexes or indexes using the funky primary key compression scheme */
   boolean _readOnly;
   
-  public Index(Table table) {
+  public Index(Table table, int uniqueEntryCount, int uniqueEntryCountOffset) {
     _table  = table;
+    _uniqueEntryCount = uniqueEntryCount;
+    _uniqueEntryCountOffset = uniqueEntryCountOffset;
   }
 
   public Table getTable() {
@@ -212,12 +217,12 @@ public class Index implements Comparable<Index> {
     return _indexFlags;
   }
   
-  public void setRowCount(int rowCount) {
-    _rowCount = rowCount;
+  public int getUniqueEntryCount() {
+    return _uniqueEntryCount;
   }
 
-  public int getRowCount() {
-    return _rowCount;
+  public int getUniqueEntryCountOffset() {
+    return _uniqueEntryCountOffset;
   }
 
   public String getName() {
@@ -587,7 +592,6 @@ public class Index implements Comparable<Index> {
 
     Entry newEntry = new Entry(createEntryBytes(row), rowId);
     if(addEntry(newEntry, isNullEntry, row)) {
-      ++_rowCount;
       ++_modCount;
     } else {
       LOG.warn("Added duplicate index entry " + newEntry + " for row: " +
@@ -617,7 +621,6 @@ public class Index implements Comparable<Index> {
 
     Entry oldEntry = new Entry(createEntryBytes(row), rowId);
     if(removeEntry(oldEntry)) {
-      --_rowCount;
       ++_modCount;
     } else {
       LOG.warn("Failed removing index entry " + oldEntry + " for row: " +
@@ -710,16 +713,21 @@ public class Index implements Comparable<Index> {
       // determine if the addition of this entry would break the uniqueness
       // constraint.  See isUnique() for some notes about uniqueness as
       // defined by Access.
-      if(isUnique() && !isNullEntry &&
-         (((idx > 0) &&
-           newEntry.equalsEntryBytes(_entries.get(idx - 1))) ||
+      boolean isDupeEntry =
+        (((idx > 0) &&
+          newEntry.equalsEntryBytes(_entries.get(idx - 1))) ||
           ((idx < _entries.size()) &&
-           newEntry.equalsEntryBytes(_entries.get(idx)))))
+           newEntry.equalsEntryBytes(_entries.get(idx))));
+      if(isUnique() && !isNullEntry && isDupeEntry)
       {
         throw new IOException(
             "New row " + Arrays.asList(row) +
             " violates uniqueness constraint for index " + this);
       }
+
+      if(!isDupeEntry) {
+        ++_uniqueEntryCount;
+      }
       
       _entries.add(idx, newEntry);
       return true;
diff --git a/src/java/com/healthmarketscience/jackcess/Table.java b/src/java/com/healthmarketscience/jackcess/Table.java
index d850349..96926cc 100644
--- a/src/java/com/healthmarketscience/jackcess/Table.java
+++ b/src/java/com/healthmarketscience/jackcess/Table.java
@@ -950,10 +950,11 @@ public class Table
     _freeSpacePages = UsageMap.read(getDatabase(), pageNum, rowNum, false);
     
     for (int i = 0; i < _indexCount; i++) {
-      Index index = new Index(this);
-      _indexes.add(index);
-      index.setRowCount(tableBuffer.getInt(getFormat().OFFSET_INDEX_DEF_BLOCK +
-          i * getFormat().SIZE_INDEX_DEFINITION + 4));
+      int uniqueEntryCountOffset =
+        (getFormat().OFFSET_INDEX_DEF_BLOCK +
+         (i * getFormat().SIZE_INDEX_DEFINITION) + 4);
+      int uniqueEntryCount = tableBuffer.getInt(uniqueEntryCountOffset);
+      _indexes.add(new Index(this, uniqueEntryCount, uniqueEntryCountOffset));
     }
     
     int colOffset = getFormat().OFFSET_INDEX_DEF_BLOCK +
@@ -1202,9 +1203,12 @@ public class Table
     // write any index changes
     Iterator<Index> indIter = _indexes.iterator();
     for (int i = 0; i < _indexes.size(); i++) {
-      tdefPage.putInt(getFormat().OFFSET_INDEX_DEF_BLOCK +
-          (i * getFormat().SIZE_INDEX_DEFINITION) + 4, _rowCount);
       Index index = indIter.next();
+      // write the unique entry count for the index to the table definition
+      // page
+      tdefPage.putInt(index.getUniqueEntryCountOffset(),
+                      index.getUniqueEntryCount());
+      // write the entry page for the index
       index.update();
     }
 
-- 
2.39.5