Re: [PATCH 04/16] Add embedded list interface (header only)

Marko Kreen <markokr@gmail.com>

From: Marko Kreen <markokr@gmail.com>
To: Andres Freund <andres@2ndquadrant.com>
Cc: pgsql-hackers@postgresql.org
Date: 2012-06-19T19:59:48Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Don't waste the last segment of each 4GB logical log file.

  2. Stamp HEAD as 9.3devel.

  3. Wake WALSender to reduce data loss at failover for async commit.

  4. Make the visibility map crash-safe.

On Wed, Jun 13, 2012 at 2:28 PM, Andres Freund <andres@2ndquadrant.com> wrote:
> +/*
> + * removes a node from a list
> + * Attention: O(n)
> + */
> +static inline void ilist_s_remove(ilist_s_head *head,
> +                                  ilist_s_node *node)
> +{
> +       ilist_s_node *last = &head->head;
> +       ilist_s_node *cur;
> +#ifndef NDEBUG
> +       bool found = false;
> +#endif
> +       while ((cur = last->next))
> +       {
> +               if (cur == node)
> +               {
> +                       last->next = cur->next;
> +#ifndef NDEBUG
> +                       found = true;
> +#endif
> +                       break;
> +               }
> +               last = cur;
> +       }
> +       assert(found);
> +}

This looks weird.

In cyclic list removal is:

  node->prev->next = node->next;
  node->next->prev = node->prev;

And thats it.

-- 
marko