Re: [JDBC] Re: no way in LargeObject API to detect short read?

Hmmm, what's the performance issues with this? Is there going to be a problem
with very large LargeObject's?

Quoting "Paul M. Aoki" <aoki(at)acm(dot)org>:

> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > Anyone able to fix this?
>
> here's a hack we've been using in-house (written by Jun Gabayan,
> <jgabayan(at)pahv(dot)xerox(dot)com>).
>
> you may not like the style but it's a stab at a solution.
> --
> Paul M. Aoki / Xerox Palo Alto Research Center / 3333 Coyote Hill Road
> aoki(at)acm(dot)org / Computer Science Laboratory / Palo Alto, CA
> 94304-1314
>
> Index: LargeObject.java
> ===================================================================
> RCS file:
> /project/placeless/cvsroot/placeless2/src/org/postgresql/largeobject/LargeObje
ct.java,v
> retrieving revision 1.1
> retrieving revision 1.3
> diff -r1.1 -r1.3
> 64c64,67
> <
> ---
> >
> > private int pos = 0; //current position
> > private int size = 0;
> >
> 85a89,90
> > pos = tell();
> > size = size();
> 102a108
> > if(fd == 0) return;
> 105a112
> > fd = 0;
> 118a126,132
> > // calculate available data to read to avoid reading pass the
> end
> > // to avoid an exception
> > pos = tell();
> > int avail = size - pos;
> > if(avail == 0) return null;
> > if(avail < len) len = avail;
> > try {
> 123c137,141
> <
> ---
> > }catch(SQLException se) {
> > System.out.println("***LargeObject.read: Caught
> SQLException: " + se.getMessage());
> > return null;
> > }
> >
> 157c175
> < public void read(byte buf[],int off,int len) throws SQLException
> ---
> > public int read(byte buf[],int off,int len) throws SQLException
> 159c177,180
> < System.arraycopy(read(len),0,buf,off,len);
> ---
> > byte mybuf[] = read(len);
> > int sz = (mybuf != null) ? mybuf.length : -1; //must return -1 for
> end of data
> > if(sz > 0) System.arraycopy(mybuf,0,buf,off,sz);
> > return sz;
>

--
Peter Mount peter(at)retep(dot)org(dot)uk
PostgreSQL JDBC Driver: http://www.retep.org.uk/postgres/
RetepPDF PDF library for Java: http://www.retep.org.uk/pdf/