From f1a59e5373c844d34acbc1c7eabbc75b23a77e54 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Mon, 19 Jan 2015 14:57:24 -0500
Subject: [PATCH] new read tester for investigating read bandwidth issues

---
 tools/sfrtest.cc | 167 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 tools/sfrtest.cc

diff --git a/tools/sfrtest.cc b/tools/sfrtest.cc
new file mode 100644
index 0000000000..8a1d715007
--- /dev/null
+++ b/tools/sfrtest.cc
@@ -0,0 +1,167 @@
+/* g++ -o sfrtest sfrtest.cc `pkg-config --cflags --libs sndfile` `pkg-config --cflags --libs glibmm-2.4` */
+
+#include <vector>
+#include <iostream>
+#include <iomanip>
+#include <sstream>
+#include <cstdlib>
+#include <cerrno>
+
+#include <unistd.h>
+#include <sndfile.h>
+#include <stdint.h>
+#include <string.h>
+#include <getopt.h>
+#include <fcntl.h>
+
+#include <glibmm/miscutils.h>
+#include <glibmm/fileutils.h>
+
+using namespace std;
+
+SF_INFO format_info;
+float* data = 0;
+bool with_sync = false;
+
+int
+read_one (SNDFILE* sf, uint32_t nframes)
+{
+	if (sf_read_float (sf, (float*) data, nframes) != nframes) {
+		return -1;
+	}
+
+	if (with_sync) {
+		sf_write_sync (sf);
+	}
+
+	return 0;
+}
+
+void
+usage ()
+{
+	cout << "sfrtest [ -n NFILES ] [ -b BLOCKSIZE ] [ -s ] [ -D ] filename-template" << endl;
+}
+
+int
+main (int argc, char* argv[])
+{
+	vector<SNDFILE*> sndfiles;
+	uint32_t sample_size;
+	char optstring[] = "n:b:s";
+	uint32_t block_size = 64 * 1024;
+	uint32_t nfiles = 100;
+        bool direct = false;
+	const struct option longopts[] = {
+		{ "nfiles", 1, 0, 'n' },
+		{ "blocksize", 1, 0, 'b' },
+		{ "sync", 0, 0, 's' },
+		{ "direct", 0, 0, 'D' },
+		{ 0, 0, 0, 0 }
+	};
+
+	int option_index = 0;
+	int c = 0;
+	char const * name_template = 0;
+	int samplerate;
+	
+	while (1) {
+		if ((c = getopt_long (argc, argv, optstring, longopts, &option_index)) == -1) {
+			break;
+		}
+
+		switch (c) {
+		case 'n':
+			nfiles = atoi (optarg);
+			break;
+		case 'b':
+			block_size = atoi (optarg);
+			break;
+		case 's':
+			with_sync = true;
+			break;
+                case 'D':
+                        direct = true;
+                        break;
+		default:
+			usage ();
+			return 0;
+		}
+	}
+
+	if (optind < argc) {
+		name_template = argv[optind];
+	} else {
+		usage ();
+		return 1;
+	}
+	
+	for (uint32_t n = 1; n <= nfiles; ++n) {
+		SNDFILE* sf;
+		char path[PATH_MAX+1];
+
+		snprintf (path, sizeof (path), name_template, n);
+
+		if (!Glib::file_test (path, Glib::FILE_TEST_EXISTS|Glib::FILE_TEST_IS_REGULAR)) {
+			break;
+		}
+		
+                int flags = O_RDONLY;
+                int fd = open (path, flags, 0644);
+
+                if (fd < 0) {
+			cerr << "Could not open file #" << n << " @ " << path << " (" << strerror (errno) << ")" << endl;
+			return 1;
+                }
+
+#ifdef __APPLE__
+                if (direct) {
+                        /* Apple man pages say only that it returns "a value other than -1 on success",
+                           which probably means zero, but you just can't be too careful with
+                           those guys.
+                        */
+                        if (fcntl (fd, F_NOCACHE, 1) == -1) {
+                                cerr << "Cannot set F_NOCACHE on file # " << n << endl;
+                        }
+                }
+#endif
+
+		if ((sf = sf_open_fd (fd, SFM_READ, &format_info, true)) == 0) {
+			cerr << "Could not open SNDFILE #" << n << " @ " << path << " (" << sf_strerror (0) << ")" << endl;
+			return 1;
+		}
+
+		samplerate = format_info.samplerate;
+		
+		sndfiles.push_back (sf);
+	}
+
+	cout << "Discovered " << nfiles+1 << " files using " << name_template << endl;
+		
+	data = new float[block_size];
+	uint64_t read = 0;
+	
+	while (true) {
+		gint64 before;
+		before = g_get_monotonic_time();
+		for (vector<SNDFILE*>::iterator s = sndfiles.begin(); s != sndfiles.end(); ++s) {
+			if (read_one (*s, block_size)) {
+				cerr << "Read failed for file #" << distance (sndfiles.begin(), s) << endl;
+				return 1;
+			}
+		}
+		read += block_size;
+		gint64 elapsed = g_get_monotonic_time() - before;
+		double bandwidth = (sndfiles.size() * block_size * sample_size) / (elapsed/1000000.0);
+		double data_minutes = read / (double) (60.0 * 48000.0);
+		const double data_rate = sndfiles.size() * sample_size * samplerate;
+		stringstream ds;
+		ds << setprecision (1) << data_minutes;
+		
+		cout << "BW @ " << read << " frames (" << ds.str() << " minutes) = " << (bandwidth/1048576.0) <<  " MB/sec " << bandwidth / data_rate << " x faster than necessary " << endl;
+	}
+
+	return 0;
+}
+
+