Message-ID: <gh-pgjdbc-pgjdbc-3049-c1834407304@github.com>
From: "beikov (@beikov)" <noreply+beikov@github.com>
To: "pgjdbc/pgjdbc" <noreply+pgjdbc-pgjdbc@github.com>
Date: Thu, 30 Nov 2023 19:19:56 +0000
Subject: Re: [pgjdbc/pgjdbc] issue #3049: TypeInfoCache should be clearable/resetable
In-Reply-To: <gh-pgjdbc-pgjdbc-3049@github.com>
References: <gh-pgjdbc-pgjdbc-3049@github.com>
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X-GitHub-Issue: 3049
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In case anyone else runs into the same issue, here is the code I'm using to clear the cache:

```java
final Class<?> pgConnection = Class.forName( "org.postgresql.jdbc.PgConnection" );
final Object connection = c.unwrap( pgConnection );
final Object typeInfo = pgConnection.getMethod( "getTypeInfo" ).invoke( connection );
final Class<?> typeInfoCacheClass = Class.forName( "org.postgresql.jdbc.TypeInfoCache" );
final Field oidToPgNameField = typeInfoCacheClass.getDeclaredField( "oidToPgName" );
final Field pgNameToOidField = typeInfoCacheClass.getDeclaredField( "pgNameToOid" );
final Field pgNameToSQLTypeField = typeInfoCacheClass.getDeclaredField( "pgNameToSQLType" );
final Field oidToSQLTypeField = typeInfoCacheClass.getDeclaredField( "oidToSQLType" );
oidToPgNameField.setAccessible( true );
pgNameToOidField.setAccessible( true );
pgNameToSQLTypeField.setAccessible( true );
oidToSQLTypeField.setAccessible( true );
//noinspection unchecked
final Map<Integer, String> oidToPgName = (Map<Integer, String>) oidToPgNameField.get( typeInfo );
//noinspection unchecked
final Map<String, Integer> pgNameToOid = (Map<String, Integer>) pgNameToOidField.get( typeInfo );
//noinspection unchecked
final Map<String, Integer> pgNameToSQLType = (Map<String, Integer>) pgNameToSQLTypeField.get( typeInfo );
//noinspection unchecked
final Map<Integer, Integer> oidToSQLType = (Map<Integer, Integer>) oidToSQLTypeField.get( typeInfo );
for ( Iterator<Map.Entry<String, Integer>> iter = pgNameToOid.entrySet().iterator(); iter.hasNext(); ) {
	Map.Entry<String, Integer> entry = iter.next();
	final String typeName = entry.getKey();
	if ( !PGJDBC_STANDARD_TYPE_NAMES.contains( typeName ) ) {
		final Integer oid = entry.getValue();
		oidToPgName.remove( oid );
		oidToSQLType.remove( oid );
		pgNameToSQLType.remove( typeName );
		iter.remove();
	}
}
```

with this utility:

```java
private static final Set<String> PGJDBC_STANDARD_TYPE_NAMES = buildTypeNames( Set.of(
			"int2",
			"int4",
			"oid",
			"int8",
			"money",
			"numeric",
			"float4",
			"float8",
			"char",
			"bpchar",
			"varchar",
			"text",
			"name",
			"bytea",
			"bool",
			"bit",
			"date",
			"time",
			"timetz",
			"timestamp",
			"timestamptz",
			"refcursor",
			"json",
			"jsonb",
			"box",
			"point",
			"uuid",
			"xml"
	) );

	private static Set<String> buildTypeNames(Set<String> baseTypeNames) {
		final HashSet<String> typeNames = new HashSet<>( baseTypeNames.size() * 3 );
		for ( String baseTypeName : baseTypeNames ) {
			typeNames.add( baseTypeName );
			typeNames.add( "_" + baseTypeName );
			typeNames.add( baseTypeName + "[]" );
		}
		return typeNames;
	}
```