db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Stefan Guggisberg (JIRA)" <derby-...@db.apache.org>
Subject [jira] Commented: (DERBY-797) ResultSet.getBinaryStream() fails to read chunks of size > 32k
Date Wed, 04 Jan 2006 16:55:06 GMT
    [ http://issues.apache.org/jira/browse/DERBY-797?page=comments#action_12361762 ] 

Stefan Guggisberg commented on DERBY-797:
-----------------------------------------

please resolve this issue as INVALID. the code in question is absolutely correct.
i was wrong about the semantics of InputStream.read(byte[]).

mea culpa, please excuse the noise.

> ResultSet.getBinaryStream() fails to read chunks of size > 32k
> --------------------------------------------------------------
>
>          Key: DERBY-797
>          URL: http://issues.apache.org/jira/browse/DERBY-797
>      Project: Derby
>         Type: Bug
>   Components: JDBC
>     Versions: 10.1.2.1
>  Environment: Derby embedded engine
> Windows 2k
> JRE 1.4.2_03
>     Reporter: Stefan Guggisberg

>
> assume the following table:
> create table TEST (TEST_ID integer not null, TEST_DATA blob not null);
> insert a record with a blob value larger than 32k, e.g. of size 100000
> read that record using a stmt like "select TEST_DATA from TEST where TEST_ID = ?"
> the following code fragment demonstrates the issue:
> InputStream in = resultSet.getBinaryStream(1);
> byte[] buf = new byte[33000];
> int n = in.read(buf);
> ==> n == 32668, i.e. < buf.length !
> the problem occurs with all chunked reads that cross the boundary at offset 32668, e.g.
> InputStream in = resultSet.getBinaryStream(1);
> byte[] buf 1= new byte[32660];
> int n = in.read(buf1);
> // ok, n == buf1.length
> byte[] buf 2= new byte[20];
> n = in.read(buf2);
> // n == 8, i.e. < buf2.length !
> workarounds for this bug:
> - read byte by byte i.e. using in.read()
> - use resultSet.getBytes()
> the faulty code seems to be in org.apache.derby.impl.store.raw.data.MemByteHolder

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
   http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
   http://www.atlassian.com/software/jira


Mime
View raw message