Re: Binary tx format for an array?

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Michael Guyver" <kenevel(at)googlemail(dot)com>
Cc: pgsql-jdbc(at)postgresql(dot)org
Subject: Re: Binary tx format for an array?
Date: 2006-06-22 16:55:09
Message-ID: 1048.1150995309@sss.pgh.pa.us
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"Michael Guyver" <kenevel(at)googlemail(dot)com> writes:
> are the bytes representing an int4 Oid simply 23, represented in variable buf as

> [0x17][0x00][0x00][0x00]

No, in the buffer they'll be in network (big-endian) byte order,

[0x00][0x00][0x00][0x17]

If you are running in a little-endian architecture (eg Intel) then at
some point you'll be wanting to reverse the byte order to make a native
integer. In C you'd use ntohl() to do this. I'm not sure what's the
appropriate thing in Java --- I was under the impression that Java tried
to hide hardware details like endianness, so there may be some
convention about how you turn a sequence of bytes into a native integer.

regards, tom lane

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