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magnusp merged 1 commit into from
Oct 24, 2026
Merged

refactor(jdbc): extract TableMetadataResolver #223

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164 changes: 8 additions & 156 deletions libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlResultSetMetaData.java
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Original file line number Diff line number Diff line change
Expand Up @@ -2,17 +2,12 @@

import com.github.magnusp.libsql.hrana.codec.Col;
import com.github.magnusp.libsql.hrana.codec.Row;
import com.github.magnusp.libsql.hrana.codec.Stmt;
import com.github.magnusp.libsql.hrana.codec.StmtResult;
import com.github.magnusp.libsql.hrana.codec.Value;

import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

public class LibsqlResultSetMetaData implements ResultSetMetaData {

Expand All @@ -21,10 +16,7 @@ public class LibsqlResultSetMetaData implements ResultSetMetaData {
private final String sql;
private final LibsqlConnection connection;
private final LibsqlResultSet resultSet;

private boolean tableContextResolved;
private SqlTableReference.Resolution columnOrigins;
private final Map<String, TableInfo> tableInfoCache = new LinkedHashMap<>();
private final TableMetadataResolver tableMetadata;

public LibsqlResultSetMetaData(List<Col> cols) {
this(cols, List.of(), null, null, null);
Expand All @@ -41,6 +33,7 @@ public LibsqlResultSetMetaData(List<Col> cols) {
this.sql = sql;
this.connection = connection;
this.resultSet = resultSet;
this.tableMetadata = new TableMetadataResolver(connection, sql, this.cols.size());
}

@Override
Expand All @@ -57,8 +50,9 @@ private Col getCol(int column) throws SQLException {

@Override
public boolean isAutoIncrement(int column) throws SQLException {
TableInfo table = tableForColumn(column);
ColumnInfo info = table != null ? table.columns().get(columnName(column)) : null;
TableMetadataResolver.TableInfo table = tableMetadata.tableForColumn(column);
TableMetadataResolver.ColumnInfo info =
table != null ? table.columns().get(columnName(column)) : null;
return info != null
&& info.primaryKey()
&& SqlAutoIncrement.isAutoIncrementColumn(table.createSql(), columnName(column));
Expand All @@ -84,11 +78,11 @@ public boolean isCurrency(int column) throws SQLException {

@Override
public int isNullable(int column) throws SQLException {
TableInfo table = tableForColumn(column);
TableMetadataResolver.TableInfo table = tableMetadata.tableForColumn(column);
if (table == null) {
return columnNullableUnknown;
}
ColumnInfo info = table.columns().get(columnName(column));
TableMetadataResolver.ColumnInfo info = table.columns().get(columnName(column));
if (info == null) {
return columnNullable;
}
Expand Down Expand Up @@ -147,7 +141,7 @@ public int getScale(int column) throws SQLException {

@Override
public String getTableName(int column) throws SQLException {
TableInfo table = tableForColumn(column);
TableMetadataResolver.TableInfo table = tableMetadata.tableForColumn(column);
return table != null ? table.name() : "";
}

Expand Down Expand Up @@ -220,148 +214,6 @@ private Value sampleValue(int column) {
return null;
}

private TableInfo tableForColumn(int column) throws SQLException {
getCol(column);
SqlTableReference.TableRef reference = originTable(column);
return reference != null ? tableInfo(reference) : null;
}

private SqlTableReference.TableRef originTable(int column) throws SQLException {
SqlTableReference.Resolution resolution = resolveColumnOrigins();
return resolution != null ? resolution.table(column - 1) : null;
}

private SqlTableReference.Resolution resolveColumnOrigins() throws SQLException {
if (!tableContextResolved) {
SqlTableReference.Resolution resolved = null;
if (connection != null && sql != null) {
resolved = SqlTableReference.resolve(sql, reference -> {
TableInfo info = tableInfo(reference);
if (info == null) {
return null;
}
return new SqlTableReference.TableDefinition(
info.createSql(), new ArrayList<>(info.columns().keySet()));
}, cols.size());
}
columnOrigins = resolved;
tableContextResolved = true;
}
return columnOrigins;
}

private TableInfo tableInfo(SqlTableReference.TableRef reference) throws SQLException {
String schema = reference.schema() != null ? reference.schema().toLowerCase(Locale.ROOT) : "";
String table = reference.table() != null ? reference.table().toLowerCase(Locale.ROOT) : "";
String key = schema + "." + table;
if (tableInfoCache.containsKey(key)) {
return tableInfoCache.get(key);
}
TableInfo info = loadTableInfo(reference);
tableInfoCache.put(key, info);
return info;
}

private TableInfo loadTableInfo(SqlTableReference.TableRef reference) throws SQLException {
String schema = reference.schema();
String table = reference.table();
if (schema == null) {
TableInfo temp = loadTableInfo("temp", table);
if (temp != null) {
return temp;
}
return loadTableInfo("main", table);
}
return switch (schema.toLowerCase(Locale.ROOT)) {
case "main" -> loadTableInfo("main", table);
case "temp" -> loadTableInfo("temp", table);
default -> loadAttachedTableInfo(schema, table);
};
}

private TableInfo loadTableInfo(String schema, String table) throws SQLException {
String master = schema.equals("temp") ? "sqlite_temp_master" : "sqlite_master";
String query = "SELECT m.name, m.sql, p.name, p.\"notnull\", p.pk "
+ "FROM " + master + " m JOIN pragma_table_xinfo(?, ?) p "
+ "WHERE m.type IN ('table', 'view') AND m.name COLLATE NOCASE = ? "
+ "AND p.hidden != 1 "
+ "ORDER BY p.cid";
StmtResult result = connection.executeStatement(
new Stmt(query, List.of(Value.of(table), Value.of(schema), Value.of(table))));
return toTableInfo(result, table);
}

private TableInfo loadAttachedTableInfo(String schema, String table) throws SQLException {
String actualSchema = findSchema(schema);
if (actualSchema == null) {
return null;
}
String quotedSchema = "\"" + actualSchema.replace("\"", "\"\"") + "\"";
String query = "SELECT m.name, m.sql, p.name, p.\"notnull\", p.pk "
+ "FROM " + quotedSchema + ".sqlite_master m JOIN pragma_table_xinfo(?, ?) p "
+ "WHERE m.type IN ('table', 'view') AND m.name COLLATE NOCASE = ? "
+ "AND p.hidden != 1 "
+ "ORDER BY p.cid";
StmtResult result = connection.executeStatement(new Stmt(
query, List.of(Value.of(table), Value.of(actualSchema), Value.of(table))));
return toTableInfo(result, table);
}

private String findSchema(String schema) throws SQLException {
StmtResult databases =
connection.executeStatement(new Stmt("SELECT name FROM pragma_database_list"));
if (databases == null || databases.rows() == null) {
return null;
}
for (Row row : databases.rows()) {
List<Value> values = row.values();
if (values == null || values.isEmpty()) {
continue;
}
String name = text(values.get(0));
if (name != null && name.equalsIgnoreCase(schema)) {
return name;
}
}
return null;
}

private static TableInfo toTableInfo(StmtResult result, String fallbackName) {
if (result == null || result.rows() == null || result.rows().isEmpty()) {
return null;
}
String tableName = null;
String createSql = null;
Map<String, ColumnInfo> columns = new LinkedHashMap<>();
for (Row row : result.rows()) {
List<Value> values = row.values();
if (values == null || values.size() < 5) {
continue;
}
if (tableName == null) {
tableName = text(values.get(0));
createSql = text(values.get(1));
}
String columnName = text(values.get(2));
if (columnName != null) {
columns.put(
columnName.toLowerCase(Locale.ROOT),
new ColumnInfo(
XerialColumnType.integer(values.get(3)) != 0,
XerialColumnType.integer(values.get(4)) != 0));
}
}
return new TableInfo(tableName != null ? tableName : fallbackName, createSql, columns);
}

private static String text(Value value) {
return value instanceof Value.Text t ? t.value() : null;
}

private record ColumnInfo(boolean notNull, boolean primaryKey) {}

private record TableInfo(String name, String createSql, Map<String, ColumnInfo> columns) {}

@Override
public <T> T unwrap(Class<T> iface) throws SQLException {
if (iface.isInstance(this)) return iface.cast(this);
Expand Down
174 changes: 174 additions & 0 deletions libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/TableMetadataResolver.java
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Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,174 @@
package com.github.magnusp.libsql.jdbc;

import com.github.magnusp.libsql.hrana.codec.Row;
import com.github.magnusp.libsql.hrana.codec.Stmt;
import com.github.magnusp.libsql.hrana.codec.StmtResult;
import com.github.magnusp.libsql.hrana.codec.Value;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

class TableMetadataResolver {

private final LibsqlConnection connection;
private final String sql;
private final int columnCount;
private final Map<String, TableInfo> tableInfoCache = new LinkedHashMap<>();

private boolean tableContextResolved;
private SqlTableReference.Resolution columnOrigins;

TableMetadataResolver(LibsqlConnection connection, String sql, int columnCount) {
this.connection = connection;
this.sql = sql;
this.columnCount = columnCount;
}

TableInfo tableForColumn(int column) throws SQLException {
if (column < 1 || column > columnCount) {
throw new SQLException("Invalid column index: " + column + ", must be between 1 and " + columnCount);
}
SqlTableReference.TableRef reference = originTable(column);
return reference != null ? tableInfo(reference) : null;
}

private SqlTableReference.TableRef originTable(int column) throws SQLException {
SqlTableReference.Resolution resolution = resolveColumnOrigins();
return resolution != null ? resolution.table(column - 1) : null;
}

private SqlTableReference.Resolution resolveColumnOrigins() throws SQLException {
if (!tableContextResolved) {
SqlTableReference.Resolution resolved = null;
if (connection != null && sql != null) {
resolved = SqlTableReference.resolve(sql, reference -> {
TableInfo info = tableInfo(reference);
if (info == null) {
return null;
}
return new SqlTableReference.TableDefinition(
info.createSql(), new ArrayList<>(info.columns().keySet()));
}, columnCount);
}
columnOrigins = resolved;
tableContextResolved = true;
}
return columnOrigins;
}

private TableInfo tableInfo(SqlTableReference.TableRef reference) throws SQLException {
String schema = reference.schema() != null ? reference.schema().toLowerCase(Locale.ROOT) : "";
String table = reference.table() != null ? reference.table().toLowerCase(Locale.ROOT) : "";
String key = schema + "." + table;
if (tableInfoCache.containsKey(key)) {
return tableInfoCache.get(key);
}
TableInfo info = loadTableInfo(reference);
tableInfoCache.put(key, info);
return info;
}

private TableInfo loadTableInfo(SqlTableReference.TableRef reference) throws SQLException {
String schema = reference.schema();
String table = reference.table();
if (schema == null) {
TableInfo temp = loadTableInfo("temp", table);
if (temp != null) {
return temp;
}
return loadTableInfo("main", table);
}
return switch (schema.toLowerCase(Locale.ROOT)) {
case "main" -> loadTableInfo("main", table);
case "temp" -> loadTableInfo("temp", table);
default -> loadAttachedTableInfo(schema, table);
};
}

private TableInfo loadTableInfo(String schema, String table) throws SQLException {
String master = schema.equals("temp") ? "sqlite_temp_master" : "sqlite_master";
String query = "SELECT m.name, m.sql, p.name, p.\"notnull\", p.pk "
+ "FROM " + master + " m JOIN pragma_table_xinfo(?, ?) p "
+ "WHERE m.type IN ('table', 'view') AND m.name COLLATE NOCASE = ? "
+ "AND p.hidden != 1 "
+ "ORDER BY p.cid";
StmtResult result = connection.executeStatement(
new Stmt(query, List.of(Value.of(table), Value.of(schema), Value.of(table))));
return toTableInfo(result, table);
}

private TableInfo loadAttachedTableInfo(String schema, String table) throws SQLException {
String actualSchema = findSchema(schema);
if (actualSchema == null) {
return null;
}
String quotedSchema = "\"" + actualSchema.replace("\"", "\"\"") + "\"";
String query = "SELECT m.name, m.sql, p.name, p.\"notnull\", p.pk "
+ "FROM " + quotedSchema + ".sqlite_master m JOIN pragma_table_xinfo(?, ?) p "
+ "WHERE m.type IN ('table', 'view') AND m.name COLLATE NOCASE = ? "
+ "AND p.hidden != 1 "
+ "ORDER BY p.cid";
StmtResult result = connection.executeStatement(new Stmt(
query, List.of(Value.of(table), Value.of(actualSchema), Value.of(table))));
return toTableInfo(result, table);
}

private String findSchema(String schema) throws SQLException {
StmtResult databases =
connection.executeStatement(new Stmt("SELECT name FROM pragma_database_list"));
if (databases == null || databases.rows() == null) {
return null;
}
for (Row row : databases.rows()) {
List<Value> values = row.values();
if (values == null || values.isEmpty()) {
continue;
}
String name = text(values.get(0));
if (name != null && name.equalsIgnoreCase(schema)) {
return name;
}
}
return null;
}

private static TableInfo toTableInfo(StmtResult result, String fallbackName) {
if (result == null || result.rows() == null || result.rows().isEmpty()) {
return null;
}
String tableName = null;
String createSql = null;
Map<String, ColumnInfo> columns = new LinkedHashMap<>();
for (Row row : result.rows()) {
List<Value> values = row.values();
if (values == null || values.size() < 5) {
continue;
}
if (tableName == null) {
tableName = text(values.get(0));
createSql = text(values.get(1));
}
String columnName = text(values.get(2));
if (columnName != null) {
columns.put(
columnName.toLowerCase(Locale.ROOT),
new ColumnInfo(
XerialColumnType.integer(values.get(3)) != 0,
XerialColumnType.integer(values.get(4)) != 0));
}
}
return new TableInfo(tableName != null ? tableName : fallbackName, createSql, columns);
}

private static String text(Value value) {
return value instanceof Value.Text t ? t.value() : null;
}

record ColumnInfo(boolean notNull, boolean primaryKey) {}

record TableInfo(String name, String createSql, Map<String, ColumnInfo> columns) {}
}
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