Skip to content

Revert "Remove no longer needed optimization" #22950

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
merged 3 commits into from
Aug 6, 2024
Merged

Revert "Remove no longer needed optimization" #22950

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
ab1c91b
Revert "Remove no longer needed optimization"
wendigo Aug 6, 2024
47ca4f6
Remove redundant copy in JsonUtil
pettyjamesm Aug 5, 2024
b40f4e8
Add clarifying comment to JsonUtil
wendigo Aug 6, 2024
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
13 changes: 13 additions & 0 deletions core/trino-main/src/main/java/io/trino/util/JsonUtil.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -63,6 +63,7 @@
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.StringReader;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.HashMap;
Expand Down Expand Up @@ -105,6 +106,9 @@

public final class JsonUtil
{
// StringReader outperforms InputStreamReader for small inputs. Limit based on Jackson benchmarks {@link https://github.com/FasterXML/jackson-benchmarks/pull/9}
private static final int STRING_READER_LENGTH_LIMIT = 8192;

private JsonUtil() {}

// This object mapper is constructed without .configure(ORDER_MAP_ENTRIES_BY_KEYS, true) because
Expand All @@ -123,6 +127,15 @@ public static JsonFactory createJsonFactory()
public static JsonParser createJsonParser(JsonFactory factory, Slice json)
throws IOException
{
// Jackson tries to detect the character encoding automatically when using InputStream
// so we pass StringReader or an InputStreamReader instead.
// Despite the https://github.com/FasterXML/jackson-core/pull/1081, the below performance optimization
// is still valid for small inputs.
if (json.length() < STRING_READER_LENGTH_LIMIT) {
// StringReader is more performant than InputStreamReader for small inputs
return factory.createParser(new StringReader(json.toStringUtf8()));
}

return factory.createParser(new InputStreamReader(json.getInput(), UTF_8));
}

Expand Down