provided code

src/tests/filesys/base/random.inc

@@ -0,0 +1,59 @@
+/* -*- c -*- */
+
+#include <random.h>
+#include <stdio.h>
+#include <string.h>
+#include <syscall.h>
+#include "tests/lib.h"
+#include "tests/main.h"
+
+#if TEST_SIZE % BLOCK_SIZE != 0
+#error TEST_SIZE must be a multiple of BLOCK_SIZE
+#endif
+
+#define BLOCK_CNT (TEST_SIZE / BLOCK_SIZE)
+
+char buf[TEST_SIZE];
+int order[BLOCK_CNT];
+
+void
+test_main (void) 
+{
+  const char *file_name = "bazzle";
+  int fd;
+  size_t i;
+
+  random_init (57);
+  random_bytes (buf, sizeof buf);
+
+  for (i = 0; i < BLOCK_CNT; i++)
+    order[i] = (int) i;
+
+  CHECK (create (file_name, TEST_SIZE), "create \"%s\"", file_name);
+  CHECK ((fd = open (file_name)) > 1, "open \"%s\"", file_name);
+
+  msg ("write \"%s\" in random order", file_name);
+  shuffle (order, BLOCK_CNT, sizeof *order);
+  for (i = 0; i < BLOCK_CNT; i++) 
+    {
+      size_t ofs = BLOCK_SIZE * (unsigned) order[i];
+      seek (fd, ofs);
+      if (write (fd, buf + ofs, BLOCK_SIZE) != BLOCK_SIZE)
+        fail ("write %d bytes at offset %zu failed", (int) BLOCK_SIZE, ofs);
+    }
+
+  msg ("read \"%s\" in random order", file_name);
+  shuffle (order, BLOCK_CNT, sizeof *order);
+  for (i = 0; i < BLOCK_CNT; i++) 
+    {
+      char block[BLOCK_SIZE];
+      size_t ofs = BLOCK_SIZE * (unsigned) order[i];
+      seek (fd, ofs);
+      if (read (fd, block, BLOCK_SIZE) != BLOCK_SIZE)
+        fail ("read %d bytes at offset %zu failed", (int) BLOCK_SIZE, ofs);
+      compare_bytes (block, buf + ofs, BLOCK_SIZE, ofs, file_name);
+    }
+
+  msg ("close \"%s\"", file_name);
+  close (fd);
+}