Skip to content

Fix creating SQLServerDataTable being O(n^2) issue #514

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
peterbae merged 6 commits into from
Oct 11, 2017
Merged

Fix creating SQLServerDataTable being O(n^2) issue #514

Changes from 1 commit
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
e77a046
Implement checkDuplicateColumnName to check duplicate columns
peterbae Sep 26, 2017
8f69956
Revert "Implement checkDuplicateColumnName to check duplicate columns"
peterbae Sep 27, 2017
f8e89df
Revert "Revert "Implement checkDuplicateColumnName to check duplicate…
peterbae Sep 27, 2017
91a3eea
Apply same logic for TVP
peterbae Sep 27, 2017
8c0ebf2
remove null check and change Set object name
peterbae Oct 5, 2017
adf10ea
Refactoring the logic for checking duplicate column into Util class a…
peterbae Oct 6, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 25 additions & 2 deletions src/main/java/com/microsoft/sqlserver/jdbc/SQLServerDataTable.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -13,17 +13,20 @@
import java.time.OffsetDateTime;
import java.time.OffsetTime;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.UUID;

public final class SQLServerDataTable {

int rowCount = 0;
int columnCount = 0;
Map<Integer, SQLServerDataColumn> columnMetadata = null;
Set<String> columnList = null;

@alexnixon alexnixon Oct 3, 2017

Copy link
Copy Markdown

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think naming this columNames would be clearer

Map<Integer, Object[]> rows = null;

private String tvpName = null;
Expand All @@ -37,6 +40,7 @@ public final class SQLServerDataTable {
// Name used in CREATE TYPE
public SQLServerDataTable() throws SQLServerException {
columnMetadata = new LinkedHashMap<>();
columnList = new HashSet<>();
rows = new HashMap<>();
}

Expand Down Expand Up @@ -75,7 +79,7 @@ public synchronized Iterator<Entry<Integer, Object[]>> getIterator() {
public synchronized void addColumnMetadata(String columnName,
int sqlType) throws SQLServerException {
// column names must be unique
Util.checkDuplicateColumnName(columnName, columnMetadata);
checkDuplicateColumnName(columnName);
columnMetadata.put(columnCount++, new SQLServerDataColumn(columnName, sqlType));
}

Expand All @@ -89,10 +93,29 @@ public synchronized void addColumnMetadata(String columnName,
*/
public synchronized void addColumnMetadata(SQLServerDataColumn column) throws SQLServerException {
// column names must be unique
Util.checkDuplicateColumnName(column.columnName, columnMetadata);
checkDuplicateColumnName(column.columnName);
columnMetadata.put(columnCount++, column);
}

/**
* Checks if duplicate columns exists, in O(n) time.
*
* @param columnName
* the name of the column
* @throws SQLServerException
* when a duplicate column exists
*/
private void checkDuplicateColumnName(String columnName) throws SQLServerException {
if (null != columnList) {

@alexnixon alexnixon Oct 3, 2017

Copy link
Copy Markdown

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'd rather an NPE than silently fail to check dupes if someone messes up null handling.

Better IMO would be defining the local variable like Set<String> columnNames = new HashSet<>(); and omitting this check, but I don't know if that'd violate the project's coding style.

//columnList.add will return false if the same column name already exists
if (!columnList.add(columnName)) {
MessageFormat form = new MessageFormat(SQLServerException.getErrString("R_TVPDuplicateColumnName"));
Object[] msgArgs = {columnName};
throw new SQLServerException(null, form.format(msgArgs), null, 0, false);
}
}
}

/**
* Adds one row of data to the data table.
*
Expand Down