Branching for wide-area publishing work

  


git-svn-id: file:///home/lennart/svn/public/avahi/branches/federico@1344 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

1 files changed, 402 insertions, 0 deletions

diff --git a/trunk/avahi-core/probe-sched.c b/trunk/avahi-core/probe-sched.c
new file mode 100644
index 0000000..f430bce
--- /dev/null
+++ b/trunk/avahi-core/probe-sched.c
@@ -0,0 +1,402 @@
+/* $Id$ */
+
+/***
+  This file is part of avahi.
+ 
+  avahi is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+ 
+  avahi is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
+  Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with avahi; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+
+#include <avahi-common/domain.h>
+#include <avahi-common/timeval.h>
+#include <avahi-common/malloc.h>
+
+#include "probe-sched.h"
+#include "log.h"
+#include "rr-util.h"
+
+#define AVAHI_PROBE_HISTORY_MSEC 150
+#define AVAHI_PROBE_DEFER_MSEC 50
+
+typedef struct AvahiProbeJob AvahiProbeJob;
+
+struct AvahiProbeJob {
+    AvahiProbeScheduler *scheduler;
+    AvahiTimeEvent *time_event;
+    
+    int chosen; /* Use for packet assembling */
+    int done;
+    struct timeval delivery;
+
+    AvahiRecord *record;
+    
+    AVAHI_LLIST_FIELDS(AvahiProbeJob, jobs);
+};
+
+struct AvahiProbeScheduler {
+    AvahiInterface *interface;
+    AvahiTimeEventQueue *time_event_queue;
+
+    AVAHI_LLIST_HEAD(AvahiProbeJob, jobs);
+    AVAHI_LLIST_HEAD(AvahiProbeJob, history);
+};
+
+static AvahiProbeJob* job_new(AvahiProbeScheduler *s, AvahiRecord *record, int done) {
+    AvahiProbeJob *pj;
+    
+    assert(s);
+    assert(record);
+
+    if (!(pj = avahi_new(AvahiProbeJob, 1))) {
+        avahi_log_error(__FILE__": Out of memory");
+        return NULL; /* OOM */
+    }
+    
+    pj->scheduler = s;
+    pj->record = avahi_record_ref(record);
+    pj->time_event = NULL;
+    pj->chosen = 0;
+
+    if ((pj->done = done))
+        AVAHI_LLIST_PREPEND(AvahiProbeJob, jobs, s->history, pj);
+    else
+        AVAHI_LLIST_PREPEND(AvahiProbeJob, jobs, s->jobs, pj);
+
+    return pj;
+}
+
+static void job_free(AvahiProbeScheduler *s, AvahiProbeJob *pj) {
+    assert(pj);
+
+    if (pj->time_event)
+        avahi_time_event_free(pj->time_event);
+
+    if (pj->done)
+        AVAHI_LLIST_REMOVE(AvahiProbeJob, jobs, s->history, pj);
+    else
+        AVAHI_LLIST_REMOVE(AvahiProbeJob, jobs, s->jobs, pj);
+
+    avahi_record_unref(pj->record);
+    avahi_free(pj);
+}
+
+static void elapse_callback(AvahiTimeEvent *e, void* data);
+
+static void job_set_elapse_time(AvahiProbeScheduler *s, AvahiProbeJob *pj, unsigned msec, unsigned jitter) {
+    struct timeval tv;
+
+    assert(s);
+    assert(pj);
+
+    avahi_elapse_time(&tv, msec, jitter);
+
+    if (pj->time_event)
+        avahi_time_event_update(pj->time_event, &tv);
+    else
+        pj->time_event = avahi_time_event_new(s->time_event_queue, &tv, elapse_callback, pj);
+}
+
+static void job_mark_done(AvahiProbeScheduler *s, AvahiProbeJob *pj) {
+    assert(s);
+    assert(pj);
+
+    assert(!pj->done);
+
+    AVAHI_LLIST_REMOVE(AvahiProbeJob, jobs, s->jobs, pj);
+    AVAHI_LLIST_PREPEND(AvahiProbeJob, jobs, s->history, pj);
+
+    pj->done = 1;
+
+    job_set_elapse_time(s, pj, AVAHI_PROBE_HISTORY_MSEC, 0);
+    gettimeofday(&pj->delivery, NULL);
+}
+
+AvahiProbeScheduler *avahi_probe_scheduler_new(AvahiInterface *i) {
+    AvahiProbeScheduler *s;
+
+    assert(i);
+
+    if (!(s = avahi_new(AvahiProbeScheduler, 1))) {
+        avahi_log_error(__FILE__": Out of memory");
+        return NULL;
+    }
+        
+    s->interface = i;
+    s->time_event_queue = i->monitor->server->time_event_queue;
+
+    AVAHI_LLIST_HEAD_INIT(AvahiProbeJob, s->jobs);
+    AVAHI_LLIST_HEAD_INIT(AvahiProbeJob, s->history);
+    
+    return s;
+}
+
+void avahi_probe_scheduler_free(AvahiProbeScheduler *s) {
+    assert(s);
+
+    avahi_probe_scheduler_clear(s);
+    avahi_free(s);
+}
+
+void avahi_probe_scheduler_clear(AvahiProbeScheduler *s) {
+    assert(s);
+    
+    while (s->jobs)
+        job_free(s, s->jobs);
+    while (s->history)
+        job_free(s, s->history);
+}
+ 
+static int packet_add_probe_query(AvahiProbeScheduler *s, AvahiDnsPacket *p, AvahiProbeJob *pj) {
+    size_t size;
+    AvahiKey *k;
+    int b;
+
+    assert(s);
+    assert(p);
+    assert(pj);
+
+    assert(!pj->chosen);
+    
+    /* Estimate the size for this record */
+    size =
+        avahi_key_get_estimate_size(pj->record->key) +
+        avahi_record_get_estimate_size(pj->record);
+
+    /* Too large */
+    if (size > avahi_dns_packet_space(p))
+        return 0;
+
+    /* Create the probe query */
+    if (!(k = avahi_key_new(pj->record->key->name, pj->record->key->clazz, AVAHI_DNS_TYPE_ANY)))
+        return 0; /* OOM */
+            
+    b = !!avahi_dns_packet_append_key(p, k, 0);
+    assert(b);
+
+    /* Mark this job for addition to the packet */
+    pj->chosen = 1;
+
+    /* Scan for more jobs whith matching key pattern */
+    for (pj = s->jobs; pj; pj = pj->jobs_next) {
+        if (pj->chosen)
+            continue;
+
+        /* Does the record match the probe? */
+        if (k->clazz != pj->record->key->clazz || !avahi_domain_equal(k->name, pj->record->key->name))
+            continue;
+        
+        /* This job wouldn't fit in */
+        if (avahi_record_get_estimate_size(pj->record) > avahi_dns_packet_space(p))
+            break;
+
+        /* Mark this job for addition to the packet */
+        pj->chosen = 1;
+    }
+
+    avahi_key_unref(k);
+            
+    return 1;
+}
+
+static void elapse_callback(AVAHI_GCC_UNUSED AvahiTimeEvent *e, void* data) {
+    AvahiProbeJob *pj = data, *next;
+    AvahiProbeScheduler *s;
+    AvahiDnsPacket *p;
+    unsigned n;
+
+    assert(pj);
+    s = pj->scheduler;
+
+    if (pj->done) {
+        /* Lets remove it  from the history */
+        job_free(s, pj);
+        return;
+    }
+
+    if (!(p = avahi_dns_packet_new_query(s->interface->hardware->mtu)))
+        return; /* OOM */
+    n = 1;
+    
+    /* Add the import probe */
+    if (!packet_add_probe_query(s, p, pj)) {
+        size_t size;
+        AvahiKey *k;
+        int b;
+
+        avahi_dns_packet_free(p);
+
+        /* The probe didn't fit in the package, so let's allocate a larger one */
+
+        size =
+            avahi_key_get_estimate_size(pj->record->key) +
+            avahi_record_get_estimate_size(pj->record) +
+            AVAHI_DNS_PACKET_HEADER_SIZE;
+        
+        if (size > AVAHI_DNS_PACKET_SIZE_MAX)
+            size = AVAHI_DNS_PACKET_SIZE_MAX;
+
+        if (!(p = avahi_dns_packet_new_query(size)))
+            return; /* OOM */
+
+        if (!(k = avahi_key_new(pj->record->key->name, pj->record->key->clazz, AVAHI_DNS_TYPE_ANY))) {
+            avahi_dns_packet_free(p);
+            return;  /* OOM */
+        }
+        
+        b = avahi_dns_packet_append_key(p, k, 0) && avahi_dns_packet_append_record(p, pj->record, 0, 0);
+        avahi_key_unref(k);
+
+        if (b) {
+            avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_NSCOUNT, 1);
+            avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_QDCOUNT, 1);
+            avahi_interface_send_packet(s->interface, p);
+        } else
+            avahi_log_warn("Probe record too large, cannot send");   
+        
+        avahi_dns_packet_free(p);
+        job_mark_done(s, pj);
+
+        return;
+    }
+
+    /* Try to fill up packet with more probes, if available */
+    for (pj = s->jobs; pj; pj = pj->jobs_next) {
+
+        if (pj->chosen)
+            continue;
+        
+        if (!packet_add_probe_query(s, p, pj))
+            break;
+        
+        n++;
+    }
+
+    avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_QDCOUNT, n);
+
+    n = 0;
+
+    /* Now add the chosen records to the authorative section */
+    for (pj = s->jobs; pj; pj = next) {
+
+        next = pj->jobs_next;
+
+        if (!pj->chosen)
+            continue;
+
+        if (!avahi_dns_packet_append_record(p, pj->record, 0, 0)) {
+/*             avahi_log_warn("Bad probe size estimate!"); */
+
+            /* Unmark all following jobs */
+            for (; pj; pj = pj->jobs_next)
+                pj->chosen = 0;
+            
+            break;
+        }
+
+        job_mark_done(s, pj);
+        
+        n ++;
+    }
+    
+    avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_NSCOUNT, n);
+
+    /* Send it now */
+    avahi_interface_send_packet(s->interface, p);
+    avahi_dns_packet_free(p);
+}
+
+static AvahiProbeJob* find_scheduled_job(AvahiProbeScheduler *s, AvahiRecord *record) {
+    AvahiProbeJob *pj;
+
+    assert(s);
+    assert(record);
+
+    for (pj = s->jobs; pj; pj = pj->jobs_next) {
+        assert(!pj->done);
+        
+        if (avahi_record_equal_no_ttl(pj->record, record))
+            return pj;
+    }
+
+    return NULL;
+}
+
+static AvahiProbeJob* find_history_job(AvahiProbeScheduler *s, AvahiRecord *record) {
+    AvahiProbeJob *pj;
+    
+    assert(s);
+    assert(record);
+
+    for (pj = s->history; pj; pj = pj->jobs_next) {
+        assert(pj->done);
+
+        if (avahi_record_equal_no_ttl(pj->record, record)) {
+            /* Check whether this entry is outdated */
+
+            if (avahi_age(&pj->delivery) > AVAHI_PROBE_HISTORY_MSEC*1000) {
+                /* it is outdated, so let's remove it */
+                job_free(s, pj);
+                return NULL;
+            }
+                
+            return pj;
+        }
+    }
+
+    return NULL;
+}
+
+int avahi_probe_scheduler_post(AvahiProbeScheduler *s, AvahiRecord *record, int immediately) {
+    AvahiProbeJob *pj;
+    struct timeval tv;
+    
+    assert(s);
+    assert(record);
+    assert(!avahi_key_is_pattern(record->key));
+
+    if ((pj = find_history_job(s, record)))
+        return 0;
+
+    avahi_elapse_time(&tv, immediately ? 0 : AVAHI_PROBE_DEFER_MSEC, 0);
+
+    if ((pj = find_scheduled_job(s, record))) {
+
+        if (avahi_timeval_compare(&tv, &pj->delivery) < 0) {
+            /* If the new entry should be scheduled earlier, update the old entry */
+            pj->delivery = tv;
+            avahi_time_event_update(pj->time_event, &pj->delivery);
+        }
+
+        return 1;
+    } else {
+        /* Create a new job and schedule it */
+        if (!(pj = job_new(s, record, 0)))
+            return 0; /* OOM */
+        
+        pj->delivery = tv;
+        pj->time_event = avahi_time_event_new(s->time_event_queue, &pj->delivery, elapse_callback, pj);
+
+        
+/*     avahi_log_debug("Accepted new probe job."); */
+
+        return 1;
+    }
+}