Add a very basic test of direct disk writing speed.

diff --git a/hacks/direct_disk_speed_test.cc b/hacks/direct_disk_speed_test.cc
new file mode 100644 (file)
index 0000000..0e20e2f
--- /dev/null
+++ b/hacks/direct_disk_speed_test.cc
@@ -0,0 +1,114 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+int test_posix(int block_size, int blocks, int gap, int rdisk, int nocache)
+{
+       struct timeval start;
+       gettimeofday(&start, NULL);
+
+       int f = -1;
+       if (rdisk) {
+               f = open("/dev/rdisk3", O_RDWR);
+       } else {
+               f = open("/dev/disk3", O_RDWR);
+       }
+        if (f == -1) {
+               printf("open failed.\n");
+               return -1;
+       }
+
+       fcntl(f, F_NOCACHE, nocache);
+
+       void* buffer = malloc(block_size);
+       if (!buffer) {
+               printf("malloc failed.\n");
+               return -1;
+       }
+
+       for (int i = 0; i < blocks; ++i) {
+               write(f, buffer, block_size);
+               if (gap > 0) {
+                       lseek(f, gap, SEEK_CUR);
+               }
+       }
+
+       close(f);
+
+       struct timeval end;
+       gettimeofday(&end, NULL);
+       float duration = ((end.tv_sec + end.tv_usec / 1e6) - (start.tv_sec + start.tv_usec / 1e6));
+       printf("POSIX: block_size=%d blocks=%d gap=%d rdisk=%d nocache=%d time=%f\n", block_size, blocks, gap, rdisk, nocache, duration);
+       return 0;
+}
+
+
+int test_stdio(int block_size, int blocks, int gap, int rdisk)
+{
+       struct timeval start;
+       gettimeofday(&start, NULL);
+
+       FILE* f = NULL;
+       if (rdisk) {
+               f = fopen("/dev/rdisk3", "r+b");
+       } else {
+               f = fopen("/dev/disk3", "r+b");
+       }
+        if (!f) {
+               printf("fopen failed.\n");
+               return -1;
+       }
+
+       setbuf(f, 0);
+
+       void* buffer = malloc(block_size);
+       if (!buffer) {
+               printf("malloc failed.\n");
+               return -1;
+       }
+
+       for (int i = 0; i < blocks; ++i) {
+               fwrite(buffer, block_size, 1, f);
+               if (gap > 0) {
+                       fseek(f, gap, SEEK_CUR);
+               }
+       }
+
+       fclose(f);
+
+       struct timeval end;
+       gettimeofday(&end, NULL);
+       float duration = ((end.tv_sec + end.tv_usec / 1e6) - (start.tv_sec + start.tv_usec / 1e6));
+       printf("STDIO: block_size=%d blocks=%d gap=%d rdisk=%d time=%f\n", block_size, blocks, gap, rdisk, duration);
+       return 0;
+}
+
+
+int main()
+{
+       for (int i = 0; i < 2; i++) {
+/*
+               test_posix(4096, 4096, 0, i);
+               test_posix(4096, 4096, 0, i);
+               test_posix(8192, 2048, 0, i);
+               test_posix(4096, 4096, 4096, i);
+               test_posix(4096, 4096, 65536, i);
+               test_posix(8192, 2048, 65536, i);
+               test_posix(16384, 1024, 65536, i);
+*/
+               for (int j = 0; j < 2; j++) {
+                       // test_posix(4096, 262144, 0, i, j);
+                       // test_posix(8192, 131072, 0, i, j);
+                       // test_posix(16384, 65536, 0, i, j);
+                       test_posix(32768, 32768, 0, i, j);
+                       test_posix(65536, 16384, 0, i, j);
+                       test_posix(131072, 8192, 0, i, j);
+                       test_posix(262144, 4096, 0, i, j);
+                       test_posix(524288, 2048, 0, i, j);
+               }
+       }
+}
+