Add modular filter interface.

Similarly to the servo interface, allow multiple filters to be
used for delay filtering. Convert mave to the new interface.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>

clock.c

@@ -27,7 +27,7 @@
 #include "clockadj.h"
 #include "clockcheck.h"
 #include "foreign.h"
-#include "mave.h"
+#include "filter.h"
 #include "missing.h"
 #include "msg.h"
 #include "phc.h"
@@ -86,7 +86,7 @@ struct clock {
 	enum servo_state servo_state;
 	tmv_t master_offset;
 	tmv_t path_delay;
-	struct mave *avg_delay;
+	struct filter *delay_filter;
 	struct freq_estimator fest;
 	struct time_status_np status;
 	double nrr;
@@ -121,7 +121,7 @@ void clock_destroy(struct clock *c)
 		phc_close(c->clkid);
 	}
 	servo_destroy(c->servo);
-	mave_destroy(c->avg_delay);
+	filter_destroy(c->delay_filter);
 	stats_destroy(c->stats.offset);
 	stats_destroy(c->stats.freq);
 	stats_destroy(c->stats.delay);
@@ -632,9 +632,9 @@ struct clock *clock_create(int phc_index, struct interface *iface, int count,
 		return NULL;
 	}
 	c->servo_state = SERVO_UNLOCKED;
-	c->avg_delay = mave_create(MAVE_LENGTH);
+	c->delay_filter = filter_create(FILTER_MOVING_AVERAGE, MAVE_LENGTH);
-	if (!c->avg_delay) {
+	if (!c->delay_filter) {
-		pr_err("Failed to create moving average");
+		pr_err("Failed to create delay filter");
 		return NULL;
 	}
 	c->stats_interval = dds->stats_interval;
@@ -992,7 +992,7 @@ void clock_path_delay(struct clock *c, struct timespec req, struct timestamp rx,
 		pr_warning("c3 %10lld", c3);
 	}
 
-	c->path_delay = mave_accumulate(c->avg_delay, pd);
+	c->path_delay = filter_sample(c->delay_filter, pd);
 
 	c->cur.meanPathDelay = tmv_to_TimeInterval(c->path_delay);
 
@@ -1170,7 +1170,7 @@ static void handle_state_decision_event(struct clock *c)
 
 	if (!cid_eq(&best_id, &c->best_id)) {
 		clock_freq_est_reset(c);
-		mave_reset(c->avg_delay);
+		filter_reset(c->delay_filter);
 		c->t1 = tmv_zero();
 		c->t2 = tmv_zero();
 		c->path_delay = 0;

filter.c

@@ -0,0 +1,46 @@
+/**
+ * @file filter.c
+ * @note Copyright (C) 2013 Miroslav Lichvar <mlichvar@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "filter_private.h"
+#include "mave.h"
+
+struct filter *filter_create(enum filter_type type, int length)
+{
+	switch (type) {
+	case FILTER_MOVING_AVERAGE:
+		return mave_create(length);
+	default:
+		return NULL;
+	}
+}
+
+void filter_destroy(struct filter *filter)
+{
+	filter->destroy(filter);
+}
+
+tmv_t filter_sample(struct filter *filter, tmv_t sample)
+{
+	return filter->sample(filter, sample);
+}
+
+void filter_reset(struct filter *filter)
+{
+	filter->reset(filter);
+}

filter.h

@@ -0,0 +1,63 @@
+/**
+ * @file filter.h
+ * @brief Implements a generic filter interface.
+ * @note Copyright (C) 2013 Miroslav Lichvar <mlichvar@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef HAVE_FILTER_H
+#define HAVE_FILTER_H
+
+#include "tmv.h"
+
+/** Opaque type */
+struct filter;
+
+/**
+ * Defines the available filters.
+ */
+enum filter_type {
+	FILTER_MOVING_AVERAGE,
+};
+
+/**
+ * Create a new instance of a filter.
+ * @param type    The type of the filter to create.
+ * @param length  The filter's length.
+ * @return A pointer to a new filter on success, NULL otherwise.
+ */
+struct filter *filter_create(enum filter_type type, int length);
+
+/**
+ * Destroy an instance of a filter.
+ * @param filter Pointer to a filter obtained via @ref filter_create().
+ */
+void filter_destroy(struct filter *filter);
+
+/**
+ * Feed a sample into a filter.
+ * @param filter    Pointer to a filter obtained via @ref filter_create().
+ * @param sample    The input sample.
+ * @return The output value.
+ */
+tmv_t filter_sample(struct filter *filter, tmv_t sample);
+
+/**
+ * Reset a filter.
+ * @param filter   Pointer to a filter obtained via @ref filter_create().
+ */
+void filter_reset(struct filter *filter);
+
+#endif

filter_private.h

@@ -0,0 +1,33 @@
+/**
+ * @file filter_private.h
+ * @note Copyright (C) 2013 Miroslav Lichvar <mlichvar@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef HAVE_FILTER_PRIVATE_H
+#define HAVE_FILTER_PRIVATE_H
+
+#include "tmv.h"
+#include "contain.h"
+
+struct filter {
+	void (*destroy)(struct filter *filter);
+
+	tmv_t (*sample)(struct filter *filter, tmv_t sample);
+
+	void (*reset)(struct filter *filter);
+};
+
+#endif

makefile

@@ -24,8 +24,9 @@ CFLAGS	= -Wall $(VER) $(incdefs) $(DEBUG) $(EXTRA_CFLAGS)
 LDLIBS	= -lm -lrt $(EXTRA_LDFLAGS)
 PRG	= ptp4l pmc phc2sys hwstamp_ctl
 OBJ     = bmc.o clock.o clockadj.o clockcheck.o config.o fault.o \
- fsm.o ptp4l.o mave.o msg.o phc.o pi.o port.o print.o raw.o servo.o \
+ filter.o fsm.o mave.o msg.o phc.o pi.o port.o print.o \
- sk.o stats.o tlv.o tmtab.o transport.o udp.o udp6.o uds.o util.o version.o
+ ptp4l.o raw.o servo.o sk.o stats.o tlv.o tmtab.o transport.o udp.o \
+ udp6.o uds.o util.o version.o
 
 OBJECTS	= $(OBJ) hwstamp_ctl.o phc2sys.o pmc.o pmc_common.o sysoff.o
 SRC	= $(OBJECTS:.o=.c)

mave.c

@@ -20,8 +20,10 @@
 #include <string.h>
 
 #include "mave.h"
+#include "filter_private.h"
 
 struct mave {
+	struct filter filter;
 	int cnt;
 	int len;
 	int index;
@@ -29,30 +31,17 @@ struct mave {
 	tmv_t *val;
 };
 
-struct mave *mave_create(int length)
+static void mave_destroy(struct filter *filter)
-{
-	struct mave *m;
-	m = calloc(1, sizeof(*m));
-	if (!m) {
-		return NULL;
-	}
-	m->val = calloc(1, length * sizeof(*m->val));
-	if (!m->val) {
-		free(m);
-		return NULL;
-	}
-	m->len = length;
-	return m;
-}
-
-void mave_destroy(struct mave *m)
 {
+	struct mave *m = container_of(filter, struct mave, filter);
 	free(m->val);
 	free(m);
 }
 
-tmv_t mave_accumulate(struct mave *m, tmv_t val)
+static tmv_t mave_accumulate(struct filter *filter, tmv_t val)
 {
+	struct mave *m = container_of(filter, struct mave, filter);
+
 	m->sum = tmv_sub(m->sum, m->val[m->index]);
 	m->val[m->index] = val;
 	m->index = (1 + m->index) % m->len;
@@ -63,10 +52,31 @@ tmv_t mave_accumulate(struct mave *m, tmv_t val)
 	return tmv_div(m->sum, m->cnt);
 }
 
-void mave_reset(struct mave *m)
+static void mave_reset(struct filter *filter)
 {
+	struct mave *m = container_of(filter, struct mave, filter);
+
 	m->cnt = 0;
 	m->index = 0;
 	m->sum = 0;
 	memset(m->val, 0, m->len * sizeof(*m->val));
 }
+
+struct filter *mave_create(int length)
+{
+	struct mave *m;
+	m = calloc(1, sizeof(*m));
+	if (!m) {
+		return NULL;
+	}
+	m->filter.destroy = mave_destroy;
+	m->filter.sample = mave_accumulate;
+	m->filter.reset = mave_reset;
+	m->val = calloc(1, length * sizeof(*m->val));
+	if (!m->val) {
+		free(m);
+		return NULL;
+	}
+	m->len = length;
+	return &m->filter;
+}

mave.h

@@ -20,16 +20,8 @@
 #ifndef HAVE_MAVE_H
 #define HAVE_MAVE_H
 
-#include "tmv.h"
+#include "filter.h"
 
-struct mave;
+struct filter *mave_create(int length);
-
-struct mave *mave_create(int length);
-
-void mave_destroy(struct mave *m);
-
-tmv_t mave_accumulate(struct mave *m, tmv_t val);
-
-void mave_reset(struct mave *m);
 
 #endif

port.c

@@ -25,7 +25,7 @@
 
 #include "bmc.h"
 #include "clock.h"
-#include "mave.h"
+#include "filter.h"
 #include "missing.h"
 #include "msg.h"
 #include "port.h"
@@ -82,7 +82,7 @@ struct port {
 	} seqnum;
 	struct tmtab tmtab;
 	tmv_t peer_delay;
-	struct mave *avg_delay;
+	struct filter *delay_filter;
 	int log_sync_interval;
 	struct nrate_estimator nrate;
 	unsigned int pdr_missing;
@@ -1716,7 +1716,7 @@ calc:
 	pd = tmv_sub(pd, c2);
 	pd = tmv_div(pd, 2);
 
-	p->peer_delay = mave_accumulate(p->avg_delay, pd);
+	p->peer_delay = filter_sample(p->delay_filter, pd);
 
 	p->peerMeanPathDelay = tmv_to_TimeInterval(p->peer_delay);
 
@@ -1845,7 +1845,7 @@ void port_close(struct port *p)
 		port_disable(p);
 	}
 	transport_destroy(p->trp);
-	mave_destroy(p->avg_delay);
+	filter_destroy(p->delay_filter);
 	free(p);
 }
 
@@ -2306,9 +2306,9 @@ struct port *port_open(int phc_index,
 	p->delayMechanism = interface->dm;
 	p->versionNumber = PTP_VERSION;
 
-	p->avg_delay = mave_create(PORT_MAVE_LENGTH);
+	p->delay_filter = filter_create(FILTER_MOVING_AVERAGE, PORT_MAVE_LENGTH);
-	if (!p->avg_delay) {
+	if (!p->delay_filter) {
-		pr_err("Failed to create moving average");
+		pr_err("Failed to create delay filter");
 		transport_destroy(p->trp);
 		free(p);
 		return NULL;