resolver: copy fetch responses and send events in one go

Instead of first copying query response data into each fetch response
and then iterating again to send the response to the caller, perform
both operations in one go.

Also removed some duplicate code.

diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index aae71053f0590531e6cbc7196fc11e976b2443cf..dbc3a3bb8df4258baebd06a62f4080d4a8aee945 100644 (file)
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -1624,35 +1624,41 @@ static void
 spillattimer_countdown(void *arg);
 
 static void
-clone_results(fetchctx_t *fctx) {
-       REQUIRE(!ISC_LIST_EMPTY(fctx->resps));
+copy_to_resp(fetchctx_t *fctx, dns_fetchresponse_t *resp) {
+       resp->result = fctx->resp_result;
 
-       /*
-        * Set up any other resps to have the same data as the first.
-        * Caller must be holding the appropriate lock.
-        */
+       dns_name_copy(dns_fixedname_name(&fctx->resp_foundname),
+                     resp->foundname);
 
-       FCTXTRACE("clone_results");
+       dns_db_attach(fctx->resp_db, &resp->db);
+       dns_db_attachnode(fctx->resp_node, &resp->node);
 
-       ISC_LIST_FOREACH(fctx->resps, resp, link) {
-               resp->result = fctx->resp_result;
-               dns_name_copy(dns_fixedname_name(&fctx->resp_foundname),
-                             resp->foundname);
-               dns_db_attach(fctx->resp_db, &resp->db);
-               dns_db_attachnode(fctx->resp_node, &resp->node);
-
-               if (dns_rdataset_isassociated(&fctx->resp_rdataset)) {
-                       dns_rdataset_clone(&fctx->resp_rdataset,
-                                          resp->rdataset);
-               }
+       if (dns_rdataset_isassociated(&fctx->resp_rdataset)) {
+               dns_rdataset_clone(&fctx->resp_rdataset, resp->rdataset);
+       }
+       if (resp->sigrdataset != NULL &&
+           dns_rdataset_isassociated(&fctx->resp_sigrdataset))
+       {
+               dns_rdataset_clone(&fctx->resp_sigrdataset, resp->sigrdataset);
+       }
+}
 
-               if (resp->sigrdataset != NULL &&
-                   dns_rdataset_isassociated(&fctx->resp_sigrdataset))
-               {
-                       dns_rdataset_clone(&fctx->resp_sigrdataset,
-                                          resp->sigrdataset);
-               }
+static void
+pull_from_resp(dns_fetchresponse_t *resp, fetchctx_t *fctx) {
+       if (dns_rdataset_isassociated(resp->rdataset)) {
+               dns_rdataset_clone(resp->rdataset, &fctx->resp_rdataset);
+       }
+       if (dns_rdataset_isassociated(resp->sigrdataset)) {
+               dns_rdataset_clone(resp->sigrdataset, &fctx->resp_sigrdataset);
+       }
+       if (resp->db != NULL) {
+               dns_db_attach(resp->db, &fctx->resp_db);
        }
+       if (resp->node != NULL) {
+               dns_db_attachnode(resp->node, &fctx->resp_node);
+       }
+       dns_name_copy(resp->foundname,
+                     dns_fixedname_name(&fctx->resp_foundname));
 }
 
 static void
@@ -1668,9 +1674,6 @@ fctx_sendevents(fetchctx_t *fctx, isc_result_t result) {
 
        REQUIRE(fctx->state == fetchstate_done);
 
-       if (result == ISC_R_SUCCESS) {
-               clone_results(fctx);
-       }
        FCTXTRACE("sendevents");
 
        /*
@@ -1683,6 +1686,9 @@ fctx_sendevents(fetchctx_t *fctx, isc_result_t result) {
        ISC_LIST_FOREACH(fctx->resps, resp, link) {
                ISC_LIST_UNLINK(fctx->resps, resp, link);
 
+               if (result == ISC_R_SUCCESS) {
+                       copy_to_resp(fctx, resp);
+               }
                count++;
 
                resp->vresult = fctx->vresult;
@@ -4331,6 +4337,26 @@ done:
        }
 }
 
+static void
+clear_resp(dns_fetchresponse_t **respp) {
+       dns_fetchresponse_t *resp = *respp;
+
+       if (resp == NULL) {
+               return;
+       }
+
+       if (resp->node != NULL) {
+               dns_db_detachnode(&resp->node);
+       }
+       if (resp->db != NULL) {
+               dns_db_detach(&resp->db);
+       }
+       dns_rdataset_cleanup(resp->rdataset);
+       dns_rdataset_cleanup(resp->sigrdataset);
+
+       dns_resolver_freefresp(respp);
+}
+
 static void
 resume_qmin(void *arg) {
        dns_fetchresponse_t *resp = (dns_fetchresponse_t *)arg;
@@ -4340,10 +4366,6 @@ resume_qmin(void *arg) {
        unsigned int findoptions = 0;
        dns_name_t *fname = NULL, *dcname = NULL;
        dns_fixedname_t ffixed, dcfixed;
-       dns_rdataset_t rdataset;
-       dns_rdataset_t sigrdataset;
-       dns_db_t *db = NULL;
-       dns_dbnode_t *node = NULL;
 
        REQUIRE(VALID_FCTX(fctx));
 
@@ -4356,32 +4378,8 @@ resume_qmin(void *arg) {
        fname = dns_fixedname_initname(&ffixed);
        dcname = dns_fixedname_initname(&dcfixed);
 
-       dns_rdataset_init(&rdataset);
-       dns_rdataset_init(&sigrdataset);
-
-       if (resp->node != NULL) {
-               dns_db_attachnode(resp->node, &node);
-               dns_db_detachnode(&resp->node);
-       }
-       if (resp->db != NULL) {
-               dns_db_attach(resp->db, &db);
-               dns_db_detach(&resp->db);
-       }
-
-       if (dns_rdataset_isassociated(resp->rdataset)) {
-               dns_rdataset_clone(resp->rdataset, &rdataset);
-               dns_rdataset_disassociate(resp->rdataset);
-       }
-       if (dns_rdataset_isassociated(resp->sigrdataset)) {
-               dns_rdataset_clone(resp->sigrdataset, &sigrdataset);
-               dns_rdataset_disassociate(resp->sigrdataset);
-       }
-       dns_name_copy(resp->foundname, fname);
-
        result = resp->result;
 
-       dns_resolver_freefresp(&resp);
-
        LOCK(&fctx->lock);
        if (SHUTTINGDOWN(fctx)) {
                result = ISC_R_SHUTTINGDOWN;
@@ -4413,22 +4411,7 @@ resume_qmin(void *arg) {
                if (result == DNS_R_NXDOMAIN &&
                    fctx->qmin_labels == dns_name_countlabels(fctx->name))
                {
-                       if (dns_rdataset_isassociated(&rdataset)) {
-                               dns_rdataset_clone(&rdataset,
-                                                  &fctx->resp_rdataset);
-                       }
-                       if (dns_rdataset_isassociated(&sigrdataset)) {
-                               dns_rdataset_clone(&sigrdataset,
-                                                  &fctx->resp_sigrdataset);
-                       }
-                       if (db != NULL) {
-                               dns_db_attach(db, &fctx->resp_db);
-                       }
-                       if (node != NULL) {
-                               dns_db_attachnode(node, &fctx->resp_node);
-                       }
-                       dns_name_copy(fname, dns_fixedname_name(
-                                                    &fctx->resp_foundname));
+                       pull_from_resp(resp, fctx);
                        goto cleanup;
                }
 
@@ -4472,25 +4455,10 @@ resume_qmin(void *arg) {
                    fctx->type != dns_rdatatype_sig &&
                    fctx->type != dns_rdatatype_rrsig)
                {
-                       if (dns_rdataset_isassociated(&rdataset)) {
-                               dns_rdataset_clone(&rdataset,
-                                                  &fctx->resp_rdataset);
-                       }
-                       if (dns_rdataset_isassociated(&sigrdataset)) {
-                               dns_rdataset_clone(&sigrdataset,
-                                                  &fctx->resp_sigrdataset);
-                       }
-                       if (db != NULL) {
-                               dns_db_attach(db, &fctx->resp_db);
-                       }
-                       if (node != NULL) {
-                               dns_db_attachnode(node, &fctx->resp_node);
-                       }
-                       dns_name_copy(fname, dns_fixedname_name(
-                                                    &fctx->resp_foundname));
+                       pull_from_resp(resp, fctx);
 
                        if (result == DNS_R_CNAME &&
-                           dns_rdataset_isassociated(&rdataset) &&
+                           dns_rdataset_isassociated(resp->rdataset) &&
                            fctx->type == dns_rdatatype_cname)
                        {
                                LOCK(&fctx->lock);
@@ -4525,6 +4493,7 @@ resume_qmin(void *arg) {
                break;
        }
 
+       clear_resp(&resp);
        dns_rdataset_cleanup(&fctx->nameservers);
 
        if (dns_rdatatype_atparent(fctx->type)) {
@@ -4564,14 +4533,8 @@ resume_qmin(void *arg) {
        fctx_try(fctx, true);
 
 cleanup:
-       if (node != NULL) {
-               dns_db_detachnode(&node);
-       }
-       if (db != NULL) {
-               dns_db_detach(&db);
-       }
-       dns_rdataset_cleanup(&rdataset);
-       dns_rdataset_cleanup(&sigrdataset);
+       clear_resp(&resp);
+
        if (result != ISC_R_SUCCESS) {
                /* An error occurred, tear down whole fctx */
                fctx_failure_unref(fctx, result);
@@ -10859,7 +10822,7 @@ dns_resolver_freefresp(dns_fetchresponse_t **frespp) {
        }
 
        dns_fetchresponse_t *fresp = *frespp;
-
        *frespp = NULL;
+
        isc_mem_putanddetach(&fresp->mctx, fresp, sizeof(*fresp));
 }