Initial checkin of gRPC to third_party/

third_party/grpc/test/core/support/histogram_test.c

Index: third_party/grpc/test/core/support/histogram_test.c
diff --git a/third_party/grpc/test/core/support/histogram_test.c b/third_party/grpc/test/core/support/histogram_test.c
new file mode 100644
index 0000000000000000000000000000000000000000..be935ede0933f60f873491920ae7465653d20196
--- /dev/null
+++ b/third_party/grpc/test/core/support/histogram_test.c
@@ -0,0 +1,178 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <grpc/support/histogram.h>
+#include <grpc/support/log.h>
+
+#define LOG_TEST(x) gpr_log(GPR_INFO, "%s", x);
+
+static void test_no_op(void) {
+  gpr_histogram_destroy(gpr_histogram_create(0.01, 60e9));
+}
+
+static void expect_percentile(gpr_histogram *h, double percentile,
+                              double min_expect, double max_expect) {
+  double got = gpr_histogram_percentile(h, percentile);
+  gpr_log(GPR_INFO, "@%f%%, expect %f <= %f <= %f", percentile, min_expect, got,
+          max_expect);
+  GPR_ASSERT(min_expect <= got);
+  GPR_ASSERT(got <= max_expect);
+}
+
+static void test_simple(void) {
+  gpr_histogram *h;
+
+  LOG_TEST("test_simple");
+
+  h = gpr_histogram_create(0.01, 60e9);
+  gpr_histogram_add(h, 10000);
+  gpr_histogram_add(h, 10000);
+  gpr_histogram_add(h, 11000);
+  gpr_histogram_add(h, 11000);
+
+  expect_percentile(h, 50, 10001, 10999);
+  GPR_ASSERT(gpr_histogram_mean(h) == 10500);
+
+  gpr_histogram_destroy(h);
+}
+
+static void test_percentile(void) {
+  gpr_histogram *h;
+  double last;
+  double i;
+  double cur;
+
+  LOG_TEST("test_percentile");
+
+  h = gpr_histogram_create(0.05, 1e9);
+  gpr_histogram_add(h, 2.5);
+  gpr_histogram_add(h, 2.5);
+  gpr_histogram_add(h, 8);
+  gpr_histogram_add(h, 4);
+
+  GPR_ASSERT(gpr_histogram_count(h) == 4);
+  GPR_ASSERT(gpr_histogram_minimum(h) == 2.5);
+  GPR_ASSERT(gpr_histogram_maximum(h) == 8);
+  GPR_ASSERT(gpr_histogram_sum(h) == 17);
+  GPR_ASSERT(gpr_histogram_sum_of_squares(h) == 92.5);
+  GPR_ASSERT(gpr_histogram_mean(h) == 4.25);
+  GPR_ASSERT(gpr_histogram_variance(h) == 5.0625);
+  GPR_ASSERT(gpr_histogram_stddev(h) == 2.25);
+
+  expect_percentile(h, -10, 2.5, 2.5);
+  expect_percentile(h, 0, 2.5, 2.5);
+  expect_percentile(h, 12.5, 2.5, 2.5);
+  expect_percentile(h, 25, 2.5, 2.5);
+  expect_percentile(h, 37.5, 2.5, 2.8);
+  expect_percentile(h, 50, 3.0, 3.5);
+  expect_percentile(h, 62.5, 3.5, 4.5);
+  expect_percentile(h, 75, 5, 7.9);
+  expect_percentile(h, 100, 8, 8);
+  expect_percentile(h, 110, 8, 8);
+
+  /* test monotonicity */
+  last = 0.0;
+  for (i = 0; i < 100.0; i += 0.01) {
+    cur = gpr_histogram_percentile(h, i);
+    GPR_ASSERT(cur >= last);
+    last = cur;
+  }
+
+  gpr_histogram_destroy(h);
+}
+
+static void test_merge(void) {
+  gpr_histogram *h1, *h2;
+  double last;
+  double i;
+  double cur;
+
+  LOG_TEST("test_merge");
+
+  h1 = gpr_histogram_create(0.05, 1e9);
+  gpr_histogram_add(h1, 2.5);
+  gpr_histogram_add(h1, 2.5);
+  gpr_histogram_add(h1, 8);
+  gpr_histogram_add(h1, 4);
+
+  h2 = gpr_histogram_create(0.01, 1e9);
+  GPR_ASSERT(gpr_histogram_merge(h1, h2) == 0);
+  gpr_histogram_destroy(h2);
+
+  h2 = gpr_histogram_create(0.05, 1e10);
+  GPR_ASSERT(gpr_histogram_merge(h1, h2) == 0);
+  gpr_histogram_destroy(h2);
+
+  h2 = gpr_histogram_create(0.05, 1e9);
+  GPR_ASSERT(gpr_histogram_merge(h1, h2) == 1);
+  GPR_ASSERT(gpr_histogram_count(h1) == 4);
+  GPR_ASSERT(gpr_histogram_minimum(h1) == 2.5);
+  GPR_ASSERT(gpr_histogram_maximum(h1) == 8);
+  GPR_ASSERT(gpr_histogram_sum(h1) == 17);
+  GPR_ASSERT(gpr_histogram_sum_of_squares(h1) == 92.5);
+  GPR_ASSERT(gpr_histogram_mean(h1) == 4.25);
+  GPR_ASSERT(gpr_histogram_variance(h1) == 5.0625);
+  GPR_ASSERT(gpr_histogram_stddev(h1) == 2.25);
+  gpr_histogram_destroy(h2);
+
+  h2 = gpr_histogram_create(0.05, 1e9);
+  gpr_histogram_add(h2, 7.0);
+  gpr_histogram_add(h2, 17.0);
+  gpr_histogram_add(h2, 1.0);
+  GPR_ASSERT(gpr_histogram_merge(h1, h2) == 1);
+  GPR_ASSERT(gpr_histogram_count(h1) == 7);
+  GPR_ASSERT(gpr_histogram_minimum(h1) == 1.0);
+  GPR_ASSERT(gpr_histogram_maximum(h1) == 17.0);
+  GPR_ASSERT(gpr_histogram_sum(h1) == 42.0);
+  GPR_ASSERT(gpr_histogram_sum_of_squares(h1) == 431.5);
+  GPR_ASSERT(gpr_histogram_mean(h1) == 6.0);
+
+  /* test monotonicity */
+  last = 0.0;
+  for (i = 0; i < 100.0; i += 0.01) {
+    cur = gpr_histogram_percentile(h1, i);
+    GPR_ASSERT(cur >= last);
+    last = cur;
+  }
+
+  gpr_histogram_destroy(h1);
+  gpr_histogram_destroy(h2);
+}
+
+int main(void) {
+  test_no_op();
+  test_simple();
+  test_percentile();
+  test_merge();
+  return 0;
+}