Re: Re: A bug when use get_bit() function for a long bytea string

From: "movead(dot)li(at)highgo(dot)ca" <movead(dot)li(at)highgo(dot)ca>
To: "Ashutosh Bapat" <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com>
Cc: pgsql-hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>, ashutosh(dot)bapat <ashutosh(dot)bapat(at)2ndquadrant(dot)com>
Subject: Re: Re: A bug when use get_bit() function for a long bytea string
Date: 2020-03-13 03:18:47
Message-ID: 20200313111842791351178@highgo.ca
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Thanks for the reply.

>Why have you used size? Shouldn't we use int64?
Yes, thanks for the point, I have changed the patch.

>If get_bit()/set_bit() accept the second argument as int32, it can not
>be used to set bits whose number does not fit 32 bits. I think we need
>to change the type of the second argument as well.
Because int32 can cover the length of bytea that PostgreSQL support,
and I have decided to follow your next point 'not use 64bit int for len',
so I think the second argument can keep int32.

>Also, I think declaring len to be int is fine since 1G would fit an
>int, but what does not fit is len * 8, when performing that
>calculation, we have to widen the result. So, instead of changing the
>datatype of len, it might be better to perform the calculation as
>(int64)len * 8. If we use int64, we could also use INT64_FORMAT
>instead of using %ld.
Have followed and changed the patch.

>Since this is a bug it shouldn't wait another commitfest, but still
>add this patch to the commitfest so that it's not forgotten.
Will do.

Highgo Software (Canada/China/Pakistan)
URL : www.highgo.ca
EMAIL: mailto:movead(dot)li(at)highgo(dot)ca

Attachment Content-Type Size
long_bytea_string_bug_fix_ver2.patch application/octet-stream 4.8 KB

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