Add helper functions for software limits

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

Makefile.am

@@ -65,7 +65,8 @@ libsigrok_la_SOURCES = \
 	src/log.c \
 	src/version.c \
 	src/error.c \
-	src/std.c
+	src/std.c \
+	src/sw_limits.c
 
 # Input modules
 libsigrok_la_SOURCES += \

src/libsigrok-internal.h

@@ -1258,4 +1258,23 @@ SR_PRIV gboolean sr_kern_packet_valid(const uint8_t *buf);
 SR_PRIV int sr_kern_parse(const uint8_t *buf, float *floatval,
 		struct sr_datafeed_analog_old *analog, void *info);
 
+/*--- sw_limits.c -----------------------------------------------------------*/
+
+struct sr_sw_limits {
+	uint64_t limit_samples;
+	uint64_t limit_msec;
+	uint64_t samples_read;
+	uint64_t start_time;
+};
+
+SR_PRIV int sr_sw_limits_config_get(struct sr_sw_limits *limits, uint32_t key,
+	GVariant **data);
+SR_PRIV int sr_sw_limits_config_set(struct sr_sw_limits *limits, uint32_t key,
+	GVariant *data);
+SR_PRIV void sr_sw_limits_acquisition_start(struct sr_sw_limits *limits);
+SR_PRIV gboolean sr_sw_limits_check(struct sr_sw_limits *limits);
+SR_PRIV void sr_sw_limits_update_samples_read(struct sr_sw_limits *limits,
+	uint64_t samples_read);
+SR_PRIV void sr_sw_limits_init(struct sr_sw_limits *limits);
+
 #endif

src/sw_limits.c

@@ -0,0 +1,96 @@
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2016 Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <ctype.h>
+#include <libsigrok/libsigrok.h>
+#include "libsigrok-internal.h"
+
+SR_PRIV void sr_sw_limits_init(struct sr_sw_limits *limits)
+{
+	limits->limit_samples = 0;
+	limits->limit_msec = 0;
+}
+
+SR_PRIV int sr_sw_limits_config_get(struct sr_sw_limits *limits, uint32_t key,
+	GVariant **data)
+{
+	switch (key) {
+	case SR_CONF_LIMIT_SAMPLES:
+		*data = g_variant_new_uint64(limits->limit_samples);
+		break;
+	case SR_CONF_LIMIT_MSEC:
+		*data = g_variant_new_uint64(limits->limit_msec / 1000);
+		break;
+	default:
+		return SR_ERR_NA;
+	}
+
+	return SR_OK;
+}
+
+SR_PRIV int sr_sw_limits_config_set(struct sr_sw_limits *limits, uint32_t key,
+	GVariant *data)
+{
+	switch (key) {
+	case SR_CONF_LIMIT_SAMPLES:
+		limits->limit_samples = g_variant_get_uint64(data);
+		break;
+	case SR_CONF_LIMIT_MSEC:
+		limits->limit_msec = g_variant_get_uint64(data) * 1000;
+		break;
+	default:
+		return SR_ERR_NA;
+	}
+
+	return SR_OK;
+}
+
+SR_PRIV void sr_sw_limits_acquisition_start(struct sr_sw_limits *limits)
+{
+	limits->samples_read = 0;
+	limits->start_time = g_get_monotonic_time();
+}
+
+SR_PRIV gboolean sr_sw_limits_check(struct sr_sw_limits *limits)
+{
+	if (limits->limit_samples) {
+		if (limits->samples_read >= limits->limit_samples)
+			return TRUE;
+	}
+
+	if (limits->limit_msec) {
+		guint64 now;
+		now = g_get_monotonic_time();
+		if (now > limits->start_time &&
+			now - limits->start_time > limits->limit_msec)
+			return TRUE;
+	}
+
+	return FALSE;
+}
+
+SR_PRIV void sr_sw_limits_update_samples_read(struct sr_sw_limits *limits,
+	uint64_t samples_read)
+{
+	limits->samples_read += samples_read;
+}