[magnusp]

Closes #50

Part of #54.

What changed

LibsqlConnection.getMetaData() now creates LibsqlDatabaseMetaData on first use and returns the same instance for the lifetime of the connection. Separate connections get separate instances. A closed connection still throws. The method Javadoc documents the caching contract.

The behavior test LibsqlConnectionTest#getMetaDataIsCachedPerConnection pins both halves: repeated calls on one connection return the same object, and another connection returns a different object.

Contract decision

Parity with xerial sqlite-jdbc 3.53.4.0. SQLiteConnection.getSQLiteDatabaseMetaData() caches its metadata object in a meta field and getMetaData() delegates to it, so the same instance is returned per connection. This change matches that behavior. No Hrana or sqld constraint makes parity impossible.

Evidence

Failing before the fix:

./mvnw -q -pl libsql-jdbc -am -Dtest=LibsqlConnectionTest#getMetaDataIsCachedPerConnection -Dsurefire.failIfNoSpecifiedTests=false test

[ERROR] Tests run: 1, Failures: 1, Errors: 0, Skipped: 0
java.lang.AssertionError:
Expecting actual:
  com.github.magnusp.libsql.jdbc.LibsqlDatabaseMetaData@58c34bb3
and:
  com.github.magnusp.libsql.jdbc.LibsqlDatabaseMetaData@56a4479a
to refer to the same object

Passing after the fix:

./mvnw -q -pl libsql-jdbc -am -Dtest=LibsqlConnectionTest#getMetaDataIsCachedPerConnection -Dsurefire.failIfNoSpecifiedTests=false test

No failures (exit 0).

Full module suite after the fix:

./mvnw -pl libsql-jdbc -am test

Tests run: 170, Failures: 0, Errors: 0, Skipped: 0
BUILD SUCCESS

Formatting:

./mvnw spotless:apply
BUILD SUCCESS

libsql-itests and libsql-conformance were not run: the #50 Steering evidence asks for ./mvnw -pl libsql-jdbc -am test and ./mvnw spotless:apply, and this change touches no live-sqld or conformance path.

Deviations

None.

Defect coverage

This is defect (4) of the four sequenced defects under #50: getMetaData caching. It does not reopen the earlier three defects, which were delivered in #90 (getTableTypes), #91 (statement leaks), and #93 (getIndexInfo escaping).

Files touched:

• libsql-jdbc/src/main/java/com/github/magnusp/libsql/jdbc/LibsqlConnection.java
• libsql-jdbc/src/test/java/com/github/magnusp/libsql/jdbc/LibsqlConnectionTest.java