Re: pg_filedump 9.3: checksums (and a few other fixes)

Alvaro Herrera <alvherre@2ndquadrant.com>

From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Jeff Davis <pgsql@j-davis.com>
Cc: pgsql-hackers@postgresql.org, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2013-06-10T05:28:10Z
Lists: pgsql-hackers
Jeff Davis wrote:

> --- 1000,1015 ----
>   	    strcat (flagString, "HASEXTERNAL|");
>   	  if (infoMask & HEAP_HASOID)
>   	    strcat (flagString, "HASOID|");
> + 	  if (infoMask & HEAP_XMAX_KEYSHR_LOCK)
> + 	    strcat (flagString, "XMAX_KEYSHR_LOCK|");
>   	  if (infoMask & HEAP_COMBOCID)
>   	    strcat (flagString, "COMBOCID|");
>   	  if (infoMask & HEAP_XMAX_EXCL_LOCK)
>   	    strcat (flagString, "XMAX_EXCL_LOCK|");
> ! 	  if (infoMask & HEAP_XMAX_SHR_LOCK)
> ! 	    strcat (flagString, "XMAX_SHR_LOCK|");
> ! 	  if (infoMask & HEAP_XMAX_LOCK_ONLY)
> ! 	    strcat (flagString, "XMAX_LOCK_ONLY|");
>   	  if (infoMask & HEAP_XMIN_COMMITTED)
>   	    strcat (flagString, "XMIN_COMMITTED|");
>   	  if (infoMask & HEAP_XMIN_INVALID)

Hm, note that XMAX_SHR_LOCK is two bits, so when that flag is present
you will get the three lock modes displayed with the above code, which is
probably going to be misleading.  htup_details.h does this:

/*
 * Use these to test whether a particular lock is applied to a tuple
 */
#define HEAP_XMAX_IS_SHR_LOCKED(infomask) \
	(((infomask) & HEAP_LOCK_MASK) == HEAP_XMAX_SHR_LOCK)
#define HEAP_XMAX_IS_EXCL_LOCKED(infomask) \
	(((infomask) & HEAP_LOCK_MASK) == HEAP_XMAX_EXCL_LOCK)
#define HEAP_XMAX_IS_KEYSHR_LOCKED(infomask) \
	(((infomask) & HEAP_LOCK_MASK) == HEAP_XMAX_KEYSHR_LOCK)

Presumably it'd be better to do something similar.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services


Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Refactor checksumming code to make it easier to use externally.