From 861d07a58c4b5c9f07f57077e5c9ffd1f7ab937e Mon Sep 17 00:00:00 2001
From: Rameshkumar Shihora <rameshshihora@fb.com>
Date: Wed, 21 Oct 2015 11:31:52 -0700
Subject: [PATCH] Move FingerprintBenchmark to Folly

Summary: FingerprintBenchmark was in an internal directory before, but it belongs alongside the Fingerprint code.

Reviewed By: yfeldblum

Differential Revision: D2534646

fb-gh-sync-id: d8ded3a5a9d33f60e9674ea71dc87a2d8d19a51b
---
 folly/test/FingerprintBenchmark.cpp | 148 ++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 folly/test/FingerprintBenchmark.cpp

diff --git a/folly/test/FingerprintBenchmark.cpp b/folly/test/FingerprintBenchmark.cpp
new file mode 100644
index 00000000..61709b67
--- /dev/null
+++ b/folly/test/FingerprintBenchmark.cpp
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2015 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <random>
+#include <folly/Benchmark.h>
+#include <folly/Format.h>
+#include <folly/detail/SlowFingerprint.h>
+#include <folly/Fingerprint.h>
+
+using namespace std;
+using namespace folly;
+using folly::detail::SlowFingerprint;
+
+namespace {
+constexpr int kMaxIds = 64 << 10;  // 64Ki
+constexpr int kMaxTerms = 64 << 10;
+
+// Globals are generally bad, but this is a benchmark, so there.
+uint64_t ids[kMaxIds];
+
+std::string terms[kMaxTerms];
+
+void initialize() {
+  std::mt19937 rng;
+  for (int i = 0; i < kMaxIds; i++) {
+    ids[i] = (((uint64_t)rng()) << 32) | rng();
+  }
+  // Use randomly generated words.  These numbers are out of my hat and
+  // probably wrong.
+  // word length = uniformly distributed between 1 and 10
+  // charset = 0x20 - 0x7f
+  std::uniform_int_distribution<size_t> term_len(1, 10);
+  std::uniform_int_distribution<uint8_t> term_char(0x20, 0x7f);
+  for (int i = 0; i < kMaxTerms; i++) {
+    std::string& term = terms[i];
+    int len = term_len(rng);
+    term.reserve(len);
+    for (int j = 0; j < len; j++) {
+      term.append(1, (char)term_char(rng));
+    }
+  }
+}
+
+template <class FP>
+void fingerprintIds(int num_iterations, int num_ids) {
+  for (int iter = 0; iter < num_iterations; iter++) {
+    FP fp;
+    for (int i = 0; i < num_ids; i++) {
+      fp.update64(ids[i]);
+    }
+    // GOTCHA: if we don't actually call write(), compiler optimizes
+    // away the inner loop!
+    uint64_t out;
+    fp.write(&out);
+    VLOG(1) << out;
+  }
+}
+
+template <class FP>
+void fingerprintTerms(int num_iterations, int num_terms) {
+  for (int iter = 0; iter < num_iterations; iter++) {
+    FP fp;
+    for (int i = 0; i < num_terms; i++) {
+      fp.update(terms[i]);
+    }
+    // GOTCHA: if we don't actually call write(), compiler optimizes
+    // away the inner loop!
+    uint64_t out;
+    fp.write(&out);
+    VLOG(1) << out;
+  }
+}
+
+void fastFingerprintIds64(int num_iterations, int num_ids) {
+  fingerprintIds<Fingerprint<64> >(num_iterations, num_ids);
+}
+
+void slowFingerprintIds64(int num_iterations, int num_ids) {
+  fingerprintIds<SlowFingerprint<64> >(num_iterations, num_ids);
+}
+
+void fastFingerprintIds96(int num_iterations, int num_ids) {
+  fingerprintIds<Fingerprint<96> >(num_iterations, num_ids);
+}
+
+void fastFingerprintIds128(int num_iterations, int num_ids) {
+  fingerprintIds<Fingerprint<128> >(num_iterations, num_ids);
+}
+
+void fastFingerprintTerms64(int num_iterations, int num_ids) {
+  fingerprintTerms<Fingerprint<64> >(num_iterations, num_ids);
+}
+
+void slowFingerprintTerms64(int num_iterations, int num_ids) {
+  fingerprintTerms<SlowFingerprint<64> >(num_iterations, num_ids);
+}
+
+void fastFingerprintTerms96(int num_iterations, int num_ids) {
+  fingerprintTerms<Fingerprint<96> >(num_iterations, num_ids);
+}
+
+void fastFingerprintTerms128(int num_iterations, int num_ids) {
+  fingerprintTerms<Fingerprint<128> >(num_iterations, num_ids);
+}
+
+
+}  // namespace
+
+// Only benchmark one size of slowFingerprint; it's significantly slower
+// than fastFingeprint (as you can see for 64 bits) and it just slows down
+// the benchmark without providing any useful data.
+
+int main(int argc, char** argv) {
+  initialize();
+    # define BM(name, min, max) \
+    for (size_t i = min; i <= max; i *= 2) { \
+      addBenchmark( \
+          __FILE__, \
+          sformat("{}_{}", #name, i).c_str(), \
+          [=](int iters) { name(iters, i); return iters; }); \
+    }
+
+      BM(fastFingerprintIds64, 1, kMaxIds)
+      BM(slowFingerprintIds64, 1, kMaxIds)
+      BM(fastFingerprintIds96, 1, kMaxIds)
+      BM(fastFingerprintIds128, 1, kMaxIds)
+      BM(fastFingerprintTerms64, 1, kMaxTerms)
+      BM(slowFingerprintTerms64, 1, kMaxTerms)
+      BM(fastFingerprintTerms96, 1, kMaxTerms)
+      BM(fastFingerprintTerms128, 1, kMaxTerms)
+      # undef BM
+
+    runBenchmarks();
+    return 0;
+}
-- 
2.34.1