msi: Use a hash table for reordering rows in a WHERE query to conserve space.

dlls/msi/where.c

@@ -35,6 +35,14 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(msidb);
 
+#define MSI_HASH_TABLE_SIZE 37
+
+typedef struct tagMSIHASHENTRY
+{
+    struct tagMSIHASHENTRY *next;
+    UINT value;
+    UINT row;
+} MSIHASHENTRY;
 
 /* below is the query interface to a table */
 
@@ -44,14 +52,78 @@ typedef struct tagMSIWHEREVIEW
     MSIDATABASE   *db;
     MSIVIEW       *table;
     UINT           row_count;
-    UINT          *reorder;
+    MSIHASHENTRY **reorder;
     struct expr   *cond;
     UINT           rec_index;
 } MSIWHEREVIEW;
 
+static void free_hash_table(MSIHASHENTRY **table)
+{
+    MSIHASHENTRY *new, *old;
+    int i;
+
+    if (!table)
+        return;
+
+    for (i = 0; i < MSI_HASH_TABLE_SIZE; i++)
+    {
+        new = table[i];
+
+        while (new)
+        {
+            old = new;
+            new = old->next;
+            msi_free(old);
+        }
+
+        table[i] = NULL;
+    }
+
+    msi_free(table);
+}
+
+static UINT find_entry_in_hash(MSIHASHENTRY **table, UINT row, UINT *val)
+{
+    MSIHASHENTRY *entry;
+
+    if (!(entry = table[row % MSI_HASH_TABLE_SIZE]))
+    {
+        ERR("Row not found in hash table!\n");
+        return ERROR_FUNCTION_FAILED;
+    }
+
+    while (entry && entry->row != row)
+        entry = entry->next;
+
+    if (entry) *val = entry->value;
+    return ERROR_SUCCESS;
+}
+
+static UINT add_entry_to_hash(MSIHASHENTRY **table, UINT row, UINT val)
+{
+    MSIHASHENTRY *new = msi_alloc(sizeof(MSIHASHENTRY));
+    MSIHASHENTRY *prev;
+
+    if (!new)
+        return ERROR_OUTOFMEMORY;
+
+    new->next = NULL;
+    new->value = val;
+    new->row = row;
+
+    prev = table[row % MSI_HASH_TABLE_SIZE];
+    if (prev)
+        new->next = prev;
+
+    table[row % MSI_HASH_TABLE_SIZE] = new;
+
+    return ERROR_SUCCESS;
+}
+
 static UINT WHERE_fetch_int( struct tagMSIVIEW *view, UINT row, UINT col, UINT *val )
 {
     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
+    UINT r;
 
     TRACE("%p %d %d %p\n", wv, row, col, val );
 
@@ -61,7 +133,9 @@ static UINT WHERE_fetch_int( struct tagMSIVIEW *view, UINT row, UINT col, UINT *
     if( row > wv->row_count )
         return ERROR_NO_MORE_ITEMS;
 
-    row = wv->reorder[ row ];
+    r = find_entry_in_hash(wv->reorder, row, &row);
+    if (r != ERROR_SUCCESS)
+        return r;
 
     return wv->table->ops->fetch_int( wv->table, row, col, val );
 }
@@ -69,6 +143,7 @@ static UINT WHERE_fetch_int( struct tagMSIVIEW *view, UINT row, UINT col, UINT *
 static UINT WHERE_fetch_stream( struct tagMSIVIEW *view, UINT row, UINT col, IStream **stm )
 {
     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
+    UINT r;
 
     TRACE("%p %d %d %p\n", wv, row, col, stm );
 
@@ -78,7 +153,9 @@ static UINT WHERE_fetch_stream( struct tagMSIVIEW *view, UINT row, UINT col, ISt
     if( row > wv->row_count )
         return ERROR_NO_MORE_ITEMS;
 
-    row = wv->reorder[ row ];
+    r = find_entry_in_hash(wv->reorder, row, &row);
+    if (r != ERROR_SUCCESS)
+        return r;
 
     return wv->table->ops->fetch_stream( wv->table, row, col, stm );
 }
@@ -86,6 +163,7 @@ static UINT WHERE_fetch_stream( struct tagMSIVIEW *view, UINT row, UINT col, ISt
 static UINT WHERE_get_row( struct tagMSIVIEW *view, UINT row, MSIRECORD **rec )
 {
     MSIWHEREVIEW *wv = (MSIWHEREVIEW *)view;
+    UINT r;
 
     TRACE("%p %d %p\n", wv, row, rec );
 
@@ -95,7 +173,9 @@ static UINT WHERE_get_row( struct tagMSIVIEW *view, UINT row, MSIRECORD **rec )
     if (row > wv->row_count)
         return ERROR_NO_MORE_ITEMS;
 
-    row = wv->reorder[row];
+    r = find_entry_in_hash(wv->reorder, row, &row);
+    if (r != ERROR_SUCCESS)
+        return r;
 
     return wv->table->ops->get_row(view, row, rec);
 }
@@ -103,6 +183,7 @@ static UINT WHERE_get_row( struct tagMSIVIEW *view, UINT row, MSIRECORD **rec )
 static UINT WHERE_set_row( struct tagMSIVIEW *view, UINT row, MSIRECORD *rec, UINT mask )
 {
     MSIWHEREVIEW *wv = (MSIWHEREVIEW*)view;
+    UINT r;
 
     TRACE("%p %d %p %08x\n", wv, row, rec, mask );
 
@@ -112,7 +193,9 @@ static UINT WHERE_set_row( struct tagMSIVIEW *view, UINT row, MSIRECORD *rec, UI
     if( row > wv->row_count )
         return ERROR_NO_MORE_ITEMS;
 
-    row = wv->reorder[ row ];
+    r = find_entry_in_hash(wv->reorder, row, &row);
+    if (r != ERROR_SUCCESS)
+        return r;
 
     return wv->table->ops->set_row( wv->table, row, rec, mask );
 }
@@ -264,7 +347,6 @@ static UINT WHERE_evaluate( MSIWHEREVIEW *wv, UINT row,
     }
 
     return ERROR_SUCCESS;
-
 }
 
 static UINT WHERE_execute( struct tagMSIVIEW *view, MSIRECORD *record )
@@ -287,10 +369,10 @@ static UINT WHERE_execute( struct tagMSIVIEW *view, MSIRECORD *record )
     if( r != ERROR_SUCCESS )
         return r;
 
-    msi_free( wv->reorder );
-    wv->reorder = msi_alloc( count*sizeof(UINT) );
+    free_hash_table(wv->reorder);
+    wv->reorder = msi_alloc_zero(MSI_HASH_TABLE_SIZE * sizeof(MSIHASHENTRY *));
     if( !wv->reorder )
-        return ERROR_FUNCTION_FAILED;
+        return ERROR_OUTOFMEMORY;
 
     wv->row_count = 0;
     if (wv->cond->type == EXPR_STRCMP)
@@ -327,7 +409,7 @@ static UINT WHERE_execute( struct tagMSIVIEW *view, MSIRECORD *record )
             {
                 r = table->ops->find_matching_rows(table, col, value, &row, &handle);
                 if (r == ERROR_SUCCESS)
-                    wv->reorder[ wv->row_count ++ ] = row;
+                    add_entry_to_hash(wv->reorder, wv->row_count++, row);
             } while (r == ERROR_SUCCESS);
 
             if (r == ERROR_NO_MORE_ITEMS)
@@ -346,7 +428,7 @@ static UINT WHERE_execute( struct tagMSIVIEW *view, MSIRECORD *record )
         if( r != ERROR_SUCCESS )
             return r;
         if( val )
-            wv->reorder[ wv->row_count ++ ] = i;
+            add_entry_to_hash( wv->reorder, wv->row_count++, i );
     }
 
     return ERROR_SUCCESS;
@@ -359,10 +441,7 @@ static UINT WHERE_close( struct tagMSIVIEW *view )
     TRACE("%p\n", wv );
 
     if( !wv->table )
-         return ERROR_FUNCTION_FAILED;
-
-    msi_free( wv->reorder );
-    wv->reorder = NULL;
+        return ERROR_FUNCTION_FAILED;
 
     return wv->table->ops->close( wv->table );
 }
@@ -422,7 +501,7 @@ static UINT WHERE_delete( struct tagMSIVIEW *view )
         wv->table->ops->delete( wv->table );
     wv->table = 0;
 
-    msi_free( wv->reorder );
+    free_hash_table(wv->reorder);
     wv->reorder = NULL;
     wv->row_count = 0;
 
@@ -444,13 +523,13 @@ static UINT WHERE_find_matching_rows( struct tagMSIVIEW *view, UINT col,
          return ERROR_FUNCTION_FAILED;
 
     r = wv->table->ops->find_matching_rows( wv->table, col, val, row, handle );
+    if (r != ERROR_SUCCESS)
+        return r;
 
     if( *row > wv->row_count )
         return ERROR_NO_MORE_ITEMS;
 
-    *row = wv->reorder[ *row ];
-
-    return r;
+    return find_entry_in_hash(wv->reorder, *row, row);
 }