Re: Patch: EMI UUCP DLRs (final)

[Nikos Balkanas]

Here it is. Added support for dest also for cimd2 as reported by Byron.





Thanks,
Nikos

To: "Nikos Balkanas" <nbalka...@gmail.com>
Cc: <devel@kannel.org>
Sent: Wednesday, July 07, 2010 6:11 PM
Subject: Re: Patch: EMI UUCP DLRs (final)


Hi,

sorry for delay... I have limited inet access now... see answers bellow.

Am 30.06.2010 um 19:30 schrieb Nikos Balkanas:

I have tested thoroughly dlr_mem.c, but only compilation for DBs, since i have no access to them. @Byron: Could you please test patch for CIMD2 against some of the DBs you use? ----- Original Message ----- From: "Alexander Malysh" <amal...@kannel.org>

Hi,

Please see inlined answers.


BR,
Nikos
----- Original Message ----- From: "Alexander Malysh" <amal...@kannel.org>
To: "Nikos Balkanas" <nbalka...@gmail.com>
Cc: <devel@kannel.org>
Sent: Wednesday, June 30, 2010 12:02 PM
Subject: Re: Patch: EMI UUCP DLRs (final)

Thanks for the comments and corrections. Please confirm a few remaining choices.

Hi,

IMO we don't need to handle no destination case in DLR lookup but maybe it's not a wrong idea to be able to ignore destination for some

reasons when SMSC send some junk to us.

Not doing it, could miss some queries altogether. It would still work for the large majority, but could miss a few matches that would have gotten otherwise.

this is ok for me, we make it optional...

ok here is the review for your patch:
+    if (dst){
+       int len = octstr_len(dst);
+       char *p = octstr_get_cstr(dst);

+       if (len > MIN_DST_LEN)

+       like = octstr_create(strcat("%", p));
+       gwlist_append(binds, like);
+    }

+ p += len - MIN_DST_LEN; /* get last MIN_DST_LEN digits */

why is this in every dlr implementation? we have abstraction for this, see dlr.c

I don't know where in dlr.c you are referring, but I see your reasoning.

This is leftover from a previous implementation, where I passed use_dest in the dlr_<DB>. I considered it at the time important to pass the whole dest to dlr_<db> so that debug messages get the whole dest. Since I started passing NULL for dest, this serves no more purpose. I will abstract it in dlr_find and use octstr_delete instead. Will also correct debug messages accordingly in dlr_db.c.

you have to abstract it in dlr_find and not repeat the same code in each dlr_db driver.

- sql = octstr_format("SELECT `%S`, `%S`, `%S`, `%S`, `%S`, `%S` FROM `%S` WHERE `%S`=? AND `%S`=? LIMIT 1",

+    if (dst)

                      fields->field_mask, fields->field_serv,
                       fields->field_url, fields->field_src,
                       fields->field_dst, fields->field_boxc,
                       fields->table, fields->field_smsc,
+                        fields->field_ts, fields->field_dst);
...

+ sql = octstr_format("SELECT `%S`, `%S`, `%S`, `%S`, `%S`, `%S` FROM `%S` WHERE `%S`=? AND `%S`=? AND `%S` >LIKE ? LIMIT 1", First of all: like ? doesn't work as you expect... it should be something like: LIKE CONCAT('%%', ?) and

Thanks. I will look into it.

this is too much maintenance for SQL that defined two times, how about like this:

if (dst)
  like = octstr_format('LIKE CONCAT('%%', ?)' ...);
else
  like = octstr_create("");

You probably mean:

like = octstr_create("=?");

no, I mean octstr_create("") or better use octstr_imm("")

sql = ...(".... %S", like)

This is a classical maintenance vs overhead. Malloc is expensive, much more so in Linux than in Solaris. Furthermore, sql="%s%S" is more difficult to read and understand, since SQL mechanism is not explicit, but hidden in variables. Do you really want that?

needed.

yes, because maintenance is then easier and malloc overhead is in linux not so much expensive as you think because glibc has preallocated memory pools and not always is system call

The same is for DELETE, UPDATE...

+        if (like) octstr_destroy(like);

octstr_destroy will check for NULL for you...

I am aware of that, but it costs a function call and a few more statements...Either way is fine. I can change it.

function call is not really issue against code readability... and if this is really your argument then convert all calls to if (..!=NULL) bla... (just a joke)

+       if (octstr_compare(dlr->smsc, smsc) == 0 && octstr_compare(dlr->

+           size) == 0)
+           return 0;

+ timestamp, ts) == 0 && memcmp(p1 + len1 - size, p2 + len2 - size,

memcmp??? why not just use truncated destination and do: octstr_search???

Actually octstr_truncate won't work since it truncates from the end. octstr_delete, would work, however, destroying the original Octstr in the process, unless I duplicated them. It would need to be done on both destinations to work. Code would be more, and the malloc, free and copy, have an overhead. Memcmp doesn't change the original Octstr and is natural for such operations. However, it is out of kannel style, so you have every right to ask me to change it. Do you?

yes, please change it.

+Msg *dlr_find(const Octstr *smsc, const Octstr *ts, const Octstr *dst, int typ, int use_dst)

you don't need to change function. Just use dst = NULL and check it.

No. dst is needed for debug msgs inside dlr_find. Furthermore, use_dst, currently is set only for EMI. Decision is made at driver level so it can easily change to an smsc configuration variable if needed.

ok, maybe you are right. What other people think about this ?

Am 26.06.2010 um 10:23 schrieb Nikos Balkanas:

Hi,



This patch will povide:



Enjoy,
Nikos
<kannel.diff>

I believe I have accounted for almost all your comments to produce the final working patch. I have no way of testing, other than compilation. 1) Align dlr_oracle.c with the rest. Currently, Oracle does a full dst find/remove/update on each DLR. 2) Dst use on find/remove/update is controlled in dlr_find by a single variable, use_dst. This is currently set only at driver level and only in the emi driver, while everyone else has it false. However, very easily, if need arises, it can be set in smsc configuration. 3) All DLR handling for all smscs will remain as it used to be till now. Only emi handling changes, hopefully for the better (that is the purpose of the patch :-)). 4) It will try to match the last 7 digits of the destination or the length of the destination if it smaller. This is defined in gw/dlr_p.h as MIN_DST_LEN. Didn't want to make it larger, wanted to avoid prefix territory at all costs, since I have seen a lot of mangling there by the SMScs. Besides, I believe that 7 digits give enough resolution 5) People using emi, should rebuild their indeces, especially if they are running large batch jobs through EMI. The LIKE % construction is not very efficient.

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