Re: Postgres driver bug

IIRC this is due to the driver waiting for input from the client ?

What would you suggest it do ?

Dave Cramer

dave.cramer(at)credativ(dot)ca
http://www.credativ.ca

On 6 February 2015 at 09:19, Nikos Viorres <nviorres(at)gmail(dot)com> wrote:

> Hi Dave,
>
> I am using 9.3-1102-jdbc4 version of the driver. You are correct, getOutputStream()
> will always throw an exception after getInputStream has been called so as
> to avoid reading the bytes from the IS and releasing the internal lock that
> the driver keeps and thus always resulting in an infinite wait.
>
> regards
>
> On Fri, Feb 6, 2015 at 3:23 PM, Dave Cramer <pg(at)fastcrypt(dot)com> wrote:
>
>> Nikos,
>>
>> What version of the driver are you using ?
>>
>> From what I see getOutputStream() will always throw an exception ?
>>
>> Dave
>>
>> Dave Cramer
>>
>> dave.cramer(at)credativ(dot)ca
>> http://www.credativ.ca
>>
>> On 6 February 2015 at 03:57, Nikos Viorres <nviorres(at)gmail(dot)com> wrote:
>>
>>> Hi,
>>>
>>> The attached simple piece of code results always in a the driver going
>>> into a wait state that never receives a wake up signal and by looking at
>>> the code, even if it does it will loop again into the same wait state. If
>>> anyone else thinks this is a problem i could provide a fix
>>>
>>> regards
>>>
>>>
>>>
>>> package nvrs.test;
>>>
>>> import org.postgresql.PGConnection;
>>> import org.postgresql.copy.PGCopyInputStream;
>>>
>>> import java.io.FileNotFoundException;
>>> import java.io.IOException;
>>> import java.io.InputStream;
>>> import java.io.OutputStream;
>>> import java.sql.Connection;
>>> import java.sql.DriverManager;
>>> import java.sql.SQLException;
>>>
>>> /**
>>> * Date: 5/2/2015
>>> */
>>> public class PostgresDriverBug {
>>>
>>> public static void main(String...args) throws SQLException {
>>> PostgresConnectionFactory connectionFactory
>>> = new PostgresConnectionFactory("localhost", 5432, "postgres",
>>> "postgres", "postgres");
>>>
>>> Connection con = connectionFactory.getNewConnection();
>>>
>>>
>>> try (InputStream is = getPostgresInputStream("select * from
>>> public.some_table", con);
>>> OutputStream os = getOutputStream()) {
>>>
>>> final byte[] buffer = new byte[1024 * 4];
>>> int read = is.read(buffer);
>>>
>>> while (read > 0) {
>>> os.write(buffer, 0, read);
>>> read = is.read(buffer);
>>> }
>>>
>>> } catch (IOException e) {
>>> System.err.println("Something bad happened " + e.getMessage());
>>>
>>> con.rollback();
>>> }
>>>
>>> System.out.println("Done!");
>>> }
>>>
>>> private static OutputStream getOutputStream() throws IOException {
>>> throw new FileNotFoundException("ooops");
>>> }
>>>
>>> private static InputStream getPostgresInputStream(String selectQuery,
>>> Connection con)
>>> throws SQLException {
>>>
>>> return new PGCopyInputStream(PGConnection.class.cast(con),
>>> "COPY (" + selectQuery +") TO STDOUT");
>>> }
>>>
>>> public static class PostgresConnectionFactory {
>>> private final String host;
>>> private final int port;
>>> private final String database;
>>> private final String user;
>>> private final String password;
>>>
>>> public PostgresConnectionFactory(final String host, final int port,
>>> final String database,
>>> final String user, final String
>>> password) {
>>> this.host = host;
>>> this.port = port;
>>> this.database = database;
>>> this.user = user;
>>> this.password = password;
>>> }
>>>
>>> private String getConnectionUrl() {
>>> return "jdbc:postgresql://" + host + ":" + port + "/" + database;
>>> }
>>>
>>> public Connection getNewConnection() throws SQLException {
>>> Connection con = DriverManager.getConnection(getConnectionUrl(),
>>> user,
>>> password);
>>>
>>> con.setAutoCommit(false);
>>> return con;
>>> }
>>> }
>>>
>>> }
>>>
>>
>>
>