local: Sort devices, channels and attributes when adding them.

In this way, other iio utilities will output information in an easy to
read/compare way.

This has no functionality difference, except to add a small negative
performance, but it makes the output of iio_attr and iio_info, much
easier to track by hand.

Signed-off-by: Robin Getz <[email protected]>

CMakeLists.txt

@@ -99,7 +99,7 @@ if (ENABLE_IPV6)
 	endif()
 endif()
 
-set(LIBIIO_CFILES backend.c channel.c device.c context.c buffer.c utilities.c scan.c)
+set(LIBIIO_CFILES backend.c channel.c device.c context.c buffer.c utilities.c scan.c sort.c)
 set(LIBIIO_HEADERS iio.h)
 
 add_definitions(-D_POSIX_C_SOURCE=200809L -D__XSI_VISIBLE=500 -DLIBIIO_EXPORTS=1)

context.c

@@ -19,6 +19,7 @@
 #include "debug.h"
 #include "iio-config.h"
 #include "iio-private.h"
+#include "sort.h"
 
 #include <errno.h>
 #include <string.h>
@@ -201,30 +202,11 @@ struct iio_device * iio_context_find_device(const struct iio_context *ctx,
 
 static void reorder_channels(struct iio_device *dev)
 {
-	bool found;
 	unsigned int i;
 
 	/* Reorder channels by index */
-	do {
-		found = false;
-		for (i = 1; i < dev->nb_channels; i++) {
-			struct iio_channel **channels = dev->channels;
-			long ch1 = channels[i - 1]->index;
-			long ch2 = channels[i]->index;
-
-			if (ch1 == ch2 && ch1 >= 0) {
-				ch1 = channels[i - 1]->format.shift;
-				ch2 = channels[i]->format.shift;
-			}
-
-			if (ch2 >= 0 && ((ch1 > ch2) || ch1 < 0)) {
-				struct iio_channel *bak = channels[i];
-				channels[i] = channels[i - 1];
-				channels[i - 1] = bak;
-				found = true;
-			}
-		}
-	} while (found);
+	 qsort(dev->channels, dev->nb_channels, sizeof(struct iio_channel *),
+                qsort_iio_channel);
 
 	for (i = 0; i < dev->nb_channels; i++)
 		dev->channels[i]->number = i;

iio-private.h

@@ -138,6 +138,11 @@ struct iio_backend_ops {
 	int (*set_timeout)(struct iio_context *ctx, unsigned int timeout);
 };
 
+/*
+ * If these structures are updated, the qsort functions defined in sort.c
+ * may need to be updated.
+ */
+
 struct iio_context_pdata;
 struct iio_device_pdata;
 struct iio_channel_pdata;

local.c

@@ -18,6 +18,7 @@
 
 #include "debug.h"
 #include "iio-private.h"
+#include "sort.h"
 
 #include <dirent.h>
 #include <errno.h>
@@ -1359,7 +1360,9 @@ static int add_channel_to_device(struct iio_device *dev,
 
 	channels[dev->nb_channels++] = chn;
 	dev->channels = channels;
-	DEBUG("Added channel \'%s\' to device \'%s\'\n", chn->id, dev->id);
+	DEBUG("Added %s channel \'%s\' to device \'%s\'\n",
+		chn->is_output ? "output" : "input", chn->id, dev->id);
+
 	return 0;
 }
 
@@ -1708,6 +1711,9 @@ static int add_buffer_attributes(struct iio_device *dev, const char *devpath)
 		int ret = foreach_in_dir(dev, buf, false, add_buffer_attr);
 		if (ret < 0)
 			return ret;
+
+		qsort(dev->buffer_attrs, dev->nb_buffer_attrs, sizeof(char *),
+			qsort_iio_buffer_attr);
 	}
 
 	return 0;
@@ -1761,12 +1767,18 @@ static int create_device(void *d, const char *path)
 		free_protected_attrs(chn);
 		if (ret < 0)
 			goto err_free_scan_elements;
+
+		qsort(chn->attrs,  chn->nb_attrs, sizeof(struct iio_channel_attr),
+			qsort_iio_channel_attr);
 	}
 
 	ret = detect_and_move_global_attrs(dev);
 	if (ret < 0)
 		goto err_free_device;
 
+	qsort(dev->attrs,  dev->nb_attrs, sizeof(char *),
+		qsort_iio_device_attr);
+
 	dev->words = (dev->nb_channels + 31) / 32;
 	if (dev->words) {
 		mask = calloc(dev->words, sizeof(*mask));
@@ -1990,6 +2002,9 @@ struct iio_context * local_create_context(void)
 	if (ret < 0)
 		goto err_context_destroy;
 
+	qsort(ctx->devices, ctx->nb_devices, sizeof(struct iio_device *),
+		qsort_iio_device);
+
 	foreach_in_dir(ctx, "/sys/kernel/debug/iio", true, add_debug);
 
 	init_scan_elements(ctx);

sort.c

@@ -0,0 +1,87 @@
+/*
+ * libiio - Library for interfacing industrial I/O (IIO) devices
+ *
+ * Copyright (C) 2018 Analog Devices, Inc.
+ * Author: Robin Getz <[email protected]>
+ *
+ * This library 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.
+ *
+ * This library 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.
+ *
+ * */
+
+#include "iio-private.h"
+#include <string.h>
+
+/* These are a few functions to do sorting for various
+ * iio structures. For more info, see the qsort(3) man page.
+ * If the structures are updated, the sort functions may
+ * need to be updated.
+ *
+ * The actual arguments to these function are "pointers to
+ * pointers to char", but strcmp(3) arguments are "pointers
+ * to char", hence the cast plus dereference
+ */
+
+int qsort_iio_channel(const void *p1, const void *p2)
+{
+	const struct iio_channel *tmp1 = *(struct iio_channel **)p1;
+	const struct iio_channel *tmp2 = *(struct iio_channel **)p2;
+
+	/* make sure buffer enabled channels are first */
+	if (iio_channel_is_scan_element(tmp1) && !iio_channel_is_scan_element(tmp2))
+		return -1;
+	if (!iio_channel_is_scan_element(tmp1) && iio_channel_is_scan_element(tmp2))
+		return 1;
+	/* and sort them by index */
+	if (iio_channel_is_scan_element(tmp1) && iio_channel_is_scan_element(tmp2)){
+		if (iio_channel_get_index(tmp1) > iio_channel_get_index(tmp2))
+			return 1;
+		return -1;
+	}
+	/* otherwise, if the ID is the same, input channels first */
+	if (strcmp(tmp1->id, tmp2->id) == 0)
+		return !iio_channel_is_output(tmp1);
+
+	/* finally by ID */
+	return strcmp(tmp1->id, tmp2->id);
+}
+
+int qsort_iio_channel_attr(const void *p1, const void *p2)
+{
+	const struct iio_channel_attr *tmp1 = (struct iio_channel_attr *)p1;
+	const struct iio_channel_attr *tmp2 = (struct iio_channel_attr *)p2;
+	/* qsort channel attributes by name */
+	return strcmp(tmp1->name, tmp2->name);
+}
+
+int qsort_iio_device(const void *p1, const void *p2)
+{
+	const struct iio_device *tmp1 = *(struct iio_device **)p1;
+	const struct iio_device *tmp2 = *(struct iio_device **)p2;
+	/* qsort devices by ID */
+	return strcmp(tmp1->id, tmp2->id);
+}
+
+int qsort_iio_device_attr(const void *p1, const void *p2)
+{
+	const char *tmp1 = *(const char **)p1;
+	const char *tmp2 = *(const char **)p2;
+	/* qsort device attributes by name */
+	return strcmp(tmp1, tmp2);
+}
+
+int qsort_iio_buffer_attr(const void *p1, const void *p2)
+{
+	const char *tmp1 = *(const char **)p1;
+	const char *tmp2 = *(const char **)p2;
+	/* qsort buffer attributes by name */
+	return strcmp(tmp1, tmp2);
+}
+

sort.h

@@ -0,0 +1,28 @@
+/*
+ * libiio - Library for interfacing industrial I/O (IIO) devices
+ *
+ * Copyright (C) 2018 Analog Devices, Inc.
+ * Author: Robin Getz <[email protected]>
+ *
+ * This library 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.
+ *
+ * This library 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.
+ *
+ * */
+
+#ifndef __IIO_QSORT_H__
+#define __IIO_QSORT_H__
+
+int qsort_iio_channel(const void *p1, const void *p2);
+int qsort_iio_channel_attr(const void *p1, const void *p2);
+int qsort_iio_device(const void *p1, const void *p2);
+int qsort_iio_device_attr(const void *p1, const void *p2);
+int qsort_iio_buffer_attr(const void *p1, const void *p2);
+
+#endif /* __IIO_QSORT_H__ */