[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

Re: svn commit: r13063 - trunk/subversion/libsvn_fs_base

From: Branko ─îibej <brane_at_xbc.nu>
Date: 2005-02-25 23:32:23 CET

kfogel@collab.net wrote:

>brane@tigris.org writes:
>
>
>>Log:
>>Expand self-compressed deltas in BDB before combining. This is similar
>>to the r13016 change in FSFS. It doesn't improve performance much by
>>itself now that we use xdelta instead of vdelta in most cases, but
>>opens the door for storing self-compressed deltas instead of fulltexts
>>in BDB in the future.
>>
>>* subversion/libsvn_fs_base/reps-strings.c (compose_handler_baton):
>> New member source_buf.
>> (compose_handler): Expand self-compressed windows into source_buf.
>> (rep_undeltify_range): Use the expanded fulltext provided by the
>> combiner if available.
>>
>>
>>--- trunk/subversion/libsvn_fs_base/reps-strings.c (original)
>>+++ trunk/subversion/libsvn_fs_base/reps-strings.c Sat Feb 19 06:06:16 2005
>>@@ -150,6 +150,11 @@
>> svn_txdelta_window_t *window;
>> apr_pool_t *window_pool;
>>
>>+ /* If the incoming window was self-compressed, and the combined WINDOW
>>+ exists from previous iterations, SOURCE_BUF will point to the
>>+ expanded self-compressed window. */
>>+ char *source_buf;
>>+
>> /* The trail for this operation. WINDOW_POOL will be a child of
>> TRAIL->pool. No allocations will be made from TRAIL->pool itself. */
>> trail_t *trail;
>>
>>
>
>Here source_buf is declared as 'char *', but...
>
>
>
>>@@ -331,8 +364,7 @@
>> }
>> else
>> {
>>- static char empty_buf[] = "";
>>- source_buf = empty_buf; /* Won't read anything from here. */
>>+ source_buf = ""; /* Won't read anything from here. */
>> }
>>
>> if (offset > 0)
>>
>>
>
>...here it is the assignee of a 'const char *' value, thus causing a
>compiler warning.
>
>
String literals have type "char*" in C, not "const char*". The warning
(turned on by -Wwrite-strings, IIRC) is possibly too much of a good
think in this case.

>Ordinarily, I wouldn't just cast over the situation, because of
>writeable string concerns. But in this case, I cast it in 13159 in
>the obvious way
>
> source_buf = (char *) "";
>
>because it looks like source_buf[0] would never be overwritten after
>that point. If this was wrong, please let me know.
>
>
This cast is safe. But I'd rather put in the original code instead.

-- Brane

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@subversion.tigris.org
For additional commands, e-mail: dev-help@subversion.tigris.org
Received on Fri Feb 25 23:33:29 2005

This is an archived mail posted to the Subversion Dev mailing list.