Start writing tests for 10169.

Now we cover more chunk allocation functions.

src/or/buffers.c

@@ -423,9 +423,10 @@ struct buf_t {
  *
  * If <b>nulterminate</b> is true, ensure that there is a 0 byte in
  * buf->head->mem right after all the data. */
-static void
+STATIC void
 buf_pullup(buf_t *buf, size_t bytes, int nulterminate)
 {
+  /* XXXX nothing uses nulterminate; remove it. */
   chunk_t *dest, *src;
   size_t capacity;
   if (!buf->head)
@@ -497,6 +498,20 @@ buf_pullup(buf_t *buf, size_t bytes, int nulterminate)
   check();
 }
 
+#ifdef TOR_UNIT_TESTS
+void
+buf_get_first_chunk_data(const buf_t *buf, const char **cp, size_t *sz)
+{
+  if (!buf || !buf->head) {
+    *cp = NULL;
+    *sz = 0;
+  } else {
+    *cp = buf->head->data;
+    *sz = buf->head->datalen;
+  }
+}
+#endif
+
 /** Resize buf so it won't hold extra memory that we haven't been
  * using lately.
  */
@@ -551,6 +566,12 @@ buf_new(void)
   return buf;
 }
 
+size_t
+buf_get_default_chunk_size(const buf_t *buf)
+{
+  return buf->default_chunk_size;
+}
+
 /** Remove all data from <b>buf</b>. */
 void
 buf_clear(buf_t *buf)

src/or/buffers.h

@@ -16,6 +16,7 @@
 
 buf_t *buf_new(void);
 buf_t *buf_new_with_capacity(size_t size);
+size_t buf_get_default_chunk_size(const buf_t *buf);
 void buf_free(buf_t *buf);
 void buf_clear(buf_t *buf);
 buf_t *buf_copy(const buf_t *buf);
@@ -103,6 +104,8 @@ void assert_buf_ok(buf_t *buf);
 
 #ifdef BUFFERS_PRIVATE
 STATIC int buf_find_string_offset(const buf_t *buf, const char *s, size_t n);
+STATIC void buf_pullup(buf_t *buf, size_t bytes, int nulterminate);
+void buf_get_first_chunk_data(const buf_t *buf, const char **cp, size_t *sz);
 #endif
 
 #endif

src/test/test_buffers.c

@@ -193,7 +193,120 @@ test_buffers_basic(void *arg)
     buf_free(buf);
   if (buf2)
     buf_free(buf2);
+  buf_shrink_freelists(1);
 }
+
+static void
+test_buffer_pullup(void *arg)
+{
+  buf_t *buf;
+  char *stuff, *tmp;
+  const char *cp;
+  size_t sz;
+  (void)arg;
+  stuff = tor_malloc(16384);
+  tmp = tor_malloc(16384);
+
+  /* Note: this test doesn't check the nulterminate argument to buf_pullup,
+     since nothing actually uses it.  We should remove it some time. */
+
+  buf = buf_new_with_capacity(3000); /* rounds up to next power of 2. */
+
+  tt_assert(buf);
+  tt_int_op(buf_get_default_chunk_size(buf), ==, 4096);
+
+  tt_int_op(buf_get_total_allocation(), ==, 0);
+
+  /* There are a bunch of cases for pullup.  One is the trivial case. Let's
+     mess around with an empty buffer. */
+  buf_pullup(buf, 16, 1);
+  buf_get_first_chunk_data(buf, &cp, &sz);
+  tt_ptr_op(cp, ==, NULL);
+  tt_ptr_op(sz, ==, 0);
+
+  /* Let's make sure nothing got allocated */
+  tt_int_op(buf_get_total_allocation(), ==, 0);
+
+  /* Case 1: everything puts into the first chunk with some moving. */
+
+  /* Let's add some data. */
+  crypto_rand(stuff, 16384);
+  write_to_buf(stuff, 3000, buf);
+  write_to_buf(stuff+3000, 3000, buf);
+  buf_get_first_chunk_data(buf, &cp, &sz);
+  tt_ptr_op(cp, !=, NULL);
+  tt_int_op(sz, <=, 4096);
+
+  /* Make room for 3000 bytes in the first chunk, so that the pullup-move code
+   * can get tested. */
+  tt_int_op(fetch_from_buf(tmp, 3000, buf), ==, 3000);
+  test_memeq(tmp, stuff, 3000);
+  buf_pullup(buf, 2048, 0);
+  assert_buf_ok(buf);
+  buf_get_first_chunk_data(buf, &cp, &sz);
+  tt_ptr_op(cp, !=, NULL);
+  tt_int_op(sz, >=, 2048);
+  test_memeq(cp, stuff+3000, 2048);
+  tt_int_op(3000, ==, buf_datalen(buf));
+  tt_int_op(fetch_from_buf(tmp, 3000, buf), ==, 0);
+  test_memeq(tmp, stuff+3000, 2048);
+
+  buf_free(buf);
+
+  /* Now try the large-chunk case. */
+  buf = buf_new_with_capacity(3000); /* rounds up to next power of 2. */
+  write_to_buf(stuff, 4000, buf);
+  write_to_buf(stuff+4000, 4000, buf);
+  write_to_buf(stuff+8000, 4000, buf);
+  write_to_buf(stuff+12000, 4000, buf);
+  tt_int_op(buf_datalen(buf), ==, 16000);
+  buf_get_first_chunk_data(buf, &cp, &sz);
+  tt_ptr_op(cp, !=, NULL);
+  tt_int_op(sz, <=, 4096);
+
+  buf_pullup(buf, 12500, 0);
+  assert_buf_ok(buf);
+  buf_get_first_chunk_data(buf, &cp, &sz);
+  tt_ptr_op(cp, !=, NULL);
+  tt_int_op(sz, >=, 12500);
+  test_memeq(cp, stuff, 12500);
+  tt_int_op(buf_datalen(buf), ==, 16000);
+
+  fetch_from_buf(tmp, 12400, buf);
+  test_memeq(tmp, stuff, 12400);
+  tt_int_op(buf_datalen(buf), ==, 3600);
+  fetch_from_buf(tmp, 3500, buf);
+  test_memeq(tmp, stuff+12400, 3500);
+  fetch_from_buf(tmp, 100, buf);
+  test_memeq(tmp, stuff+15900, 10);
+
+  buf_free(buf);
+
+  /* Make sure that the pull-up-whole-buffer case works */
+  buf = buf_new_with_capacity(3000); /* rounds up to next power of 2. */
+  write_to_buf(stuff, 4000, buf);
+  write_to_buf(stuff+4000, 4000, buf);
+  fetch_from_buf(tmp, 100, buf); /* dump 100 bytes from first chunk */
+  buf_pullup(buf, 16000, 0); /* Way too much. */
+  assert_buf_ok(buf);
+  buf_get_first_chunk_data(buf, &cp, &sz);
+  tt_ptr_op(cp, !=, NULL);
+  tt_int_op(sz, ==, 7900);
+  test_memeq(cp, stuff+100, 7900);
+
+  buf_free(buf);
+  buf = NULL;
+
+  buf_shrink_freelists(1);
+
+  tt_int_op(buf_get_total_allocation(), ==, 0);
+ done:
+  buf_free(buf);
+  buf_shrink_freelists(1);
+  tor_free(stuff);
+  tor_free(tmp);
+}
+
 static void
 test_buffer_copy(void *arg)
 {
@@ -257,6 +370,7 @@ test_buffer_copy(void *arg)
     generic_buffer_free(buf);
   if (buf2)
     generic_buffer_free(buf2);
+  buf_shrink_freelists(1);
 }
 
 static void
@@ -331,12 +445,40 @@ test_buffer_ext_or_cmd(void *arg)
   ext_or_cmd_free(cmd);
   generic_buffer_free(buf);
   tor_free(tmp);
+  buf_shrink_freelists(1);
+}
+
+static void
+test_buffer_allocation_tracking(void *arg)
+{
+  buf_t *buf1 = NULL, *buf2 = NULL;
+
+  (void)arg;
+
+  tt_int_op(buf_get_total_allocation(), ==, 0);
+
+  buf1 = buf_new();
+  tt_assert(buf1);
+  buf2 = buf_new();
+  tt_assert(buf2);
+
+  //xXXXXXX buf_add
+
+  tt_int_op(buf_get_total_allocation(), ==, 0);
+
+ done:
+  buf_free(buf1);
+  buf_free(buf2);
+  buf_shrink_freelists(1);
 }
 
 struct testcase_t buffer_tests[] = {
-  { "basic", test_buffers_basic, 0, NULL, NULL },
-  { "copy", test_buffer_copy, 0, NULL, NULL },
-  { "ext_or_cmd", test_buffer_ext_or_cmd, 0, NULL, NULL },
+  { "basic", test_buffers_basic, TT_FORK, NULL, NULL },
+  { "copy", test_buffer_copy, TT_FORK, NULL, NULL },
+  { "pullup", test_buffer_pullup, TT_FORK, NULL, NULL },
+  { "ext_or_cmd", test_buffer_ext_or_cmd, TT_FORK, NULL, NULL },
+  { "allocation_tracking", test_buffer_allocation_tracking, TT_FORK,
+    NULL, NULL },
   END_OF_TESTCASES
 };