perf: improve performance of PgResultSet getByte/getShort/getInt/getLong for float-typed columns

[john9x]

Hi!

When we call PgResultSet.getInt for float-typed columns fast number parser (getFastInt) fails on dot symbol and then we go to very slow path: Integer.parseInt throw new NumberFormatException (with stacktrace) that immediately swallowed and finally we parse integer through BigDecimal/BigInteger.
I propose to not fail fast parsing or fraction part but just discard it.

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[davecramer]

Thanks for the PR!
Can you add a test for this condition please ?

[john9x]

Can you add a test for this condition please ?

Ok, to this class org.postgresql.test.jdbc2.ResultSetTest ?

[john9x]

Tests in org.postgresql.test.jdbc2.ResultSetTest

testgetLong
testgetInt
testgetShort
testgetByte

already covers this conditions

[davecramer]

@john9x Is there a way to test for the specific thing you are fixing ?

[john9x]

@davecramer "getByte/getShort/getInt/getLong from numeric column with fraction part" is not so specific thing :) And it is already tested!

org.postgresql.test.jdbc2.ResultSetTest
...
setUp() throws Exception {
TestUtil.createTable(con, "testnumeric", "a numeric");
stmt.executeUpdate("INSERT INTO testnumeric VALUES('1.0')");
stmt.executeUpdate("INSERT INTO testnumeric VALUES('0.0')");
stmt.executeUpdate("INSERT INTO testnumeric VALUES('-1.0')");
stmt.executeUpdate("INSERT INTO testnumeric VALUES('1.2')");
stmt.executeUpdate("INSERT INTO testnumeric VALUES('-2.5')");
stmt.executeUpdate("INSERT INTO testnumeric VALUES('0.000000000000000000000000000990')");
...
}

testgetInt() throws SQLException {
    ResultSet rs = con.createStatement().executeQuery("select * from testnumeric");
    assertTrue(rs.next());
    assertEquals(1, rs.getInt(1));
    assertTrue(rs.next());
    assertEquals(0, rs.getInt(1));
    assertTrue(rs.next());
    assertEquals(-1, rs.getInt(1));
    assertTrue(rs.next());
    assertEquals(1, rs.getInt(1));
    assertTrue(rs.next());
    assertEquals(-2, rs.getInt(1));
    assertTrue(rs.next());
    assertEquals(0, rs.getInt(1));
...
}