Add direct support for double conversion and change double to string …

…conversions.cpp.

CMake/resolve_dependency_modules/README.md

@@ -27,7 +27,7 @@ by Velox. See details on bundling below.
 | flex              | 2.5.13          | No       |
 | bison             | 3.0.4           | No       |
 | cmake             | 3.14            | No       |
-| double-conversion | 3.1.5           | No       |
+| double-conversion | 3.3.0           | No       |
 | xsimd             | 10.0.0          | Yes      |
 | re2               | 2021-04-01      | Yes      |
 | fmt               | 10.1.1          | Yes      |

CMakeLists.txt

@@ -532,6 +532,7 @@ if(CMAKE_HOST_SYSTEM_NAME MATCHES "Darwin")
 endif()
 find_package(BISON 3.0.4 REQUIRED)
 find_package(FLEX 2.5.13 REQUIRED)
+find_package(double-conversion REQUIRED)
 
 include_directories(SYSTEM velox)
 include_directories(SYSTEM velox/external)

scripts/setup-macos.sh

@@ -112,7 +112,7 @@ function install_fbthrift {
 }
 
 function install_double_conversion {
-  github_checkout google/double-conversion v3.1.5
+  github_checkout google/double-conversion v3.3.0
   cmake_install -DBUILD_TESTING=OFF
 }
 

velox/expression/tests/CastExprTest.cpp

@@ -1033,6 +1033,10 @@ TEST_F(CastExprTest, primitiveInvalidCornerCases) {
   }
 }
 
+TEST_F(CastExprTest, primitivedtos) {
+  testCast<double, std::string>("varchar", {-0.000416}, {"-4.16E-4"});
+}
+
 TEST_F(CastExprTest, primitiveValidCornerCases) {
   // To integer.
   {

velox/functions/prestosql/fuzzer/CMakeLists.txt

@@ -37,3 +37,14 @@ target_link_libraries(
   velox_functions_prestosql
   gtest
   gtest_main)
+
+add_executable(velox_cast_fuzzer_test CastFuzzerTest.cpp)
+
+target_link_libraries(
+  velox_cast_fuzzer_test
+  velox_fuzzer_util
+  velox_aggregation_fuzzer_base
+  velox_expression_test_utility
+  velox_functions_prestosql
+  gtest
+  gtest_main)

velox/functions/prestosql/fuzzer/CastFuzzerTest.cpp

@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * 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 <folly/init/Init.h>
+#include <gflags/gflags.h>
+#include <gtest/gtest.h>
+
+#include "velox/dwio/dwrf/writer/Writer.h"
+#include "velox/exec/fuzzer/AggregationFuzzerRunner.h"
+#include "velox/exec/fuzzer/PrestoQueryRunner.h"
+#include "velox/exec/tests/utils/PlanBuilder.h"
+#include "velox/expression/Expr.h"
+#include "velox/expression/RegisterSpecialForm.h"
+#include "velox/functions/prestosql/aggregates/RegisterAggregateFunctions.h"
+
+DEFINE_int64(
+    seed,
+    0,
+    "Initial seed for random number generator used to reproduce previous "
+    "results (0 means start with random seed).");
+
+DEFINE_string(
+    presto_url,
+    "http://127.0.0.1:8080",
+    "Presto coordinator URI along with port. If set, we use Presto "
+    "source of truth."
+    "--presto_url=http://127.0.0.1:8080");
+
+DEFINE_uint32(
+    req_timeout_ms,
+    5000,
+    "Timeout in milliseconds for HTTP requests made to reference DB, "
+    "such as Presto. Example: --req_timeout_ms=2000");
+
+namespace facebook::velox::exec::test {
+
+auto constexpr batchSize = 1000;
+auto constexpr kColName = "c0";
+
+class CastFuzzer {
+ public:
+  CastFuzzer(
+      size_t initialSeed,
+      std::unique_ptr<PrestoQueryRunner> referenceQueryRunner)
+      : referenceQueryRunner_{std::move(referenceQueryRunner)} {
+    seed(initialSeed);
+    parse::registerTypeResolver();
+    exec::registerFunctionCallToSpecialForms();
+    facebook::velox::aggregate::prestosql::registerAllAggregateFunctions(
+        "", false, true);
+  }
+
+  void go() {
+    VELOX_CHECK(
+        FLAGS_steps > 0 || FLAGS_duration_sec > 0,
+        "Either --steps or --duration_sec needs to be greater than zero.")
+
+    auto startTime = std::chrono::system_clock::now();
+    size_t iteration = 0;
+
+    while (!isDone(iteration, startTime)) {
+      LOG(INFO) << "==============================> Started iteration "
+                << iteration << " (seed: " << currentSeed_ << ")";
+
+      TypePtr floatingType = vectorFuzzer_.coinToss(0.5)
+          ? static_cast<TypePtr>(DOUBLE())
+          : static_cast<TypePtr>(REAL());
+
+      LOG(INFO) << "Choosing type:" << floatingType->toString();
+      VELOX_CHECK_NOT_NULL(pool_.get());
+      auto input = makeRowVector(floatingType, batchSize);
+      auto castInput =
+          std::make_shared<facebook::velox::core::FieldAccessTypedExpr>(
+              floatingType, std::string(kColName));
+      std::vector<facebook::velox::core::TypedExprPtr> expr{
+          std::make_shared<facebook::velox::core::CastTypedExpr>(
+              VARCHAR(), castInput, false)};
+
+      exec::ExprSet exprSet(expr, &execCtx_, false);
+      SelectivityVector rows(input->size());
+      VectorPtr veloxResults;
+
+      // Evaluate Velox results.
+      evaluate(exprSet, input, rows, veloxResults);
+
+      // Evaluate same results on Presto.
+      std::string sql = "SELECT cast (c0 as varchar)  FROM tmp";
+      auto prestoResults = referenceQueryRunner_->executeVector(
+          sql, {input}, ROW({kColName}, {VARCHAR()}));
+      VELOX_CHECK_GT(prestoResults.size(), 0);
+
+      // Compare results, we are using a custom way of comparing results,
+      // since results obtained from Java can be off in the least significant
+      // digit.
+      auto veloxCastVector = veloxResults->asFlatVector<StringView>();
+      auto prestoCastVector =
+          prestoResults[0]->childAt(0)->asFlatVector<StringView>();
+
+      auto exactMatch = 0;
+      auto leastSignificantDigitOff = 0;
+
+      VELOX_CHECK_EQ(veloxCastVector->size(), prestoCastVector->size());
+
+      for (auto i = 0; i < veloxCastVector->size(); i++) {
+        auto matchType = compareVarchars(prestoCastVector, veloxCastVector, i);
+
+        if (matchType == MatchType::EXACT_MATCH) {
+          exactMatch++;
+        } else if (matchType == MatchType::LEAST_SIGNIFICANT_DIGIT_OFF) {
+          leastSignificantDigitOff++;
+        } else {
+          VELOX_FAIL(fmt::format(
+              "Cast conversion not matching for: {} to {}",
+              prestoCastVector->valueAt(i),
+              veloxCastVector->valueAt(i)));
+        }
+      }
+
+      LOG(INFO) << fmt::format(
+          "Results EXACT : {}, LEAST SIGNIFICANT: {}",
+          exactMatch,
+          leastSignificantDigitOff);
+
+      seed(rng_());
+      ++iteration;
+    }
+  };
+
+ private:
+  enum class MatchType {
+    EXACT_MATCH = 1,
+    LEAST_SIGNIFICANT_DIGIT_OFF,
+    NOT_A_MATCH
+  };
+
+  /// Compare's two StringView vectors at index i. The StringView vectors are
+  /// results of conversion of a floating point type to string. Returns
+  /// EXACT_MATCH if both the strings are eactly matching.
+  /// LEAST_SIGNIFICANT_DIGIT_OFF if they are off in the least siginficant digit
+  /// NOT_A_MATCH if exponents or any other part of mantissa doesnt match.
+  MatchType compareVarchars(
+      const FlatVector<StringView>* expected,
+      const FlatVector<StringView>* actual,
+      size_t i) {
+    VELOX_CHECK_EQ(expected->size(), actual->size());
+    VELOX_CHECK_LT(i, expected->size());
+
+    if (expected->isNullAt(i) && actual->isNullAt(i)) {
+      return MatchType::EXACT_MATCH;
+    } else if (expected->isNullAt(i) || actual->isNullAt(i)) {
+      return MatchType::NOT_A_MATCH;
+    }
+
+    auto expectedString = expected->valueAt(i).getString();
+    auto actualString = actual->valueAt(i).getString();
+
+    if (expectedString == actualString) {
+      return MatchType::EXACT_MATCH;
+    }
+
+    auto splitIntoMantissaExponent = [](std::string& val) {
+      auto pos = val.find('E');
+      return std::tuple(val.substr(0, pos - 1), val.substr(pos + 1));
+    };
+
+    auto [expectedMantissa, expectedExponent] =
+        splitIntoMantissaExponent(expectedString);
+    auto [actualMantissa, actualExponent] =
+        splitIntoMantissaExponent(actualString);
+
+    // Exponents should always be equal
+    VELOX_CHECK_EQ(actualExponent, expectedExponent);
+
+    if (expectedMantissa == actualMantissa) {
+      return MatchType::EXACT_MATCH;
+    }
+
+    // Handle case when the last significant digit is off or missing
+    auto smallestLength = expectedMantissa.length() < actualMantissa.length()
+        ? expectedMantissa.length()
+        : actualMantissa.length();
+
+    if (expectedMantissa.substr(0, smallestLength) ==
+        actualMantissa.substr(0, smallestLength)) {
+      return MatchType::LEAST_SIGNIFICANT_DIGIT_OFF;
+    }
+
+    // Note we dont handle cases like ..5999 and ..6000 where last n digits get
+    // rounded off
+    return MatchType::NOT_A_MATCH;
+  }
+
+  void evaluate(
+      exec::ExprSet& exprSet,
+      const RowVectorPtr& data,
+      const SelectivityVector& rows,
+      VectorPtr& result) {
+    exec::EvalCtx evalCtx(&execCtx_, &exprSet, data.get());
+    std::vector<VectorPtr> results{result};
+    exprSet.eval(rows, evalCtx, results);
+
+    if (!result) {
+      result = results[0];
+    }
+  }
+
+  RowVectorPtr makeRowVector(const TypePtr& type, vector_size_t size) {
+    VectorFuzzer::Options opts;
+    opts.vectorSize = size;
+    opts.nullRatio = 0;
+    VectorPtr input = vectorFuzzer_.fuzzFlat(type);
+    return vectorMaker_.rowVector(
+        std::vector<std::string>{std::string(kColName)},
+        std::vector<VectorPtr>{std::move(input)});
+  }
+
+  void seed(size_t seed) {
+    currentSeed_ = seed;
+    vectorFuzzer_.reSeed(seed);
+    rng_.seed(currentSeed_);
+  }
+
+  FuzzerGenerator rng_;
+  size_t currentSeed_{0};
+  std::unique_ptr<PrestoQueryRunner> referenceQueryRunner_;
+
+  std::shared_ptr<memory::MemoryPool> rootPool_{
+      memory::memoryManager()->addRootPool()};
+  std::shared_ptr<memory::MemoryPool> pool_{rootPool_->addLeafChild("leaf")};
+  std::shared_ptr<core::QueryCtx> queryCtx_{std::make_shared<core::QueryCtx>()};
+  core::ExecCtx execCtx_{pool_.get(), queryCtx_.get()};
+  facebook::velox::test::VectorMaker vectorMaker_{pool_.get()};
+  VectorFuzzer vectorFuzzer_{{}, pool_.get()};
+};
+
+} // namespace facebook::velox::exec::test
+
+int main(int argc, char** argv) {
+  using namespace facebook::velox;
+
+  ::testing::InitGoogleTest(&argc, argv);
+  folly::Init init(&argc, &argv);
+
+  memory::MemoryManager::initialize({});
+  dwrf::registerDwrfWriterFactory();
+
+  auto referenceQueryRunner = std::make_unique<exec::test::PrestoQueryRunner>(
+      FLAGS_presto_url,
+      "aggregation_fuzzer",
+      static_cast<std::chrono::milliseconds>(FLAGS_req_timeout_ms));
+
+  size_t initialSeed = FLAGS_seed == 0 ? std::time(nullptr) : FLAGS_seed;
+  auto castFuzzer = facebook::velox::exec::test::CastFuzzer(
+      initialSeed, std::move(referenceQueryRunner));
+
+  castFuzzer.go();
+  return RUN_ALL_TESTS();
+}

velox/type/CMakeLists.txt

@@ -46,4 +46,5 @@ target_link_libraries(
   velox_status
   Boost::headers
   Folly::folly
-  re2::re2)
+  re2::re2
+  double-conversion::double-conversion)