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: 2012-06-19T20:19:02Z
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 Tue, Jun 19, 2012 at 11:02 PM, Andres Freund <andres@2ndquadrant.com> wrote:
> On Tuesday, June 19, 2012 09:59:48 PM Marko Kreen wrote:
>> 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.
> Thats the single linked list, not the double linked one. Thats why it has a
> O(n) warning tacked on...

Oh, you have several list implementations there.
Sorry, I was just browsing and it caught my eye.

-- 
marko