C++ change return types of NumericalMechanism::AddNoise

We are changing the return type of NumericalMechanism::AddNoise from
T to double or int64_t.  This reduces confusion when T is an unsigned
type.  This is *not* a breaking change, since there is an implicit
conversion and when using T, which was in the library, and is now in
control of the user.

Additionally, this commit contains minor clean-ups and an absl
dependency update.

PiperOrigin-RevId: 634249123
Change-Id: I8423326fb6056e944fbc4d9ceae2c8918edcfedc
GitOrigin-RevId: b9193e7d7621855b41d1b430ec01d4534b73f407

cc/algorithms/internal/BUILD

@@ -24,6 +24,7 @@ cc_library(
     deps = [
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/status",
+        "@com_google_absl//absl/strings",
         "@com_google_cc_differential_privacy//base:status_macros",
         "@com_google_differential_privacy//proto:summary_cc_proto",
     ],
@@ -36,6 +37,7 @@ cc_test(
         ":count-tree",
         "//base/testing:proto_matchers",
         "//base/testing:status_matchers",
+        "@com_google_absl//absl/status",
         "@com_google_googletest//:gtest_main",
     ],
 )

cc/algorithms/internal/count-tree.cc

@@ -16,9 +16,12 @@
 
 #include "algorithms/internal/count-tree.h"
 
-#include <unordered_map>
+#include <cmath>
+#include <cstdint>
+#include <utility>
 
 #include "absl/status/status.h"
+#include "absl/strings/str_cat.h"
 #include "proto/summary.pb.h"
 #include "base/status_macros.h"
 

cc/algorithms/internal/count-tree_test.cc

@@ -20,6 +20,7 @@
 #include "base/testing/status_matchers.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include "absl/status/status.h"
 
 namespace differential_privacy {
 namespace internal {

cc/algorithms/numerical-mechanisms.h

@@ -54,13 +54,13 @@ class NumericalMechanism {
   virtual ~NumericalMechanism() = default;
 
   template <typename T, std::enable_if_t<std::is_integral<T>::value>* = nullptr>
-  T AddNoise(T result) {
+  int64_t AddNoise(T result) {
     return AddInt64Noise(result);
   }
 
   template <typename T,
             std::enable_if_t<std::is_floating_point<T>::value>* = nullptr>
-  T AddNoise(T result) {
+  double AddNoise(T result) {
     return AddDoubleNoise(result);
   }
 

cc/algorithms/numerical-mechanisms_test.cc

@@ -17,7 +17,10 @@
 #include "algorithms/numerical-mechanisms.h"
 
 #include <cmath>
+#include <cstdint>
 #include <cstdlib>
+#include <memory>
+#include <vector>
 
 #include "base/testing/status_matchers.h"
 #include "gmock/gmock.h"
@@ -29,11 +32,13 @@ namespace differential_privacy {
 namespace {
 
 using ::testing::_;
+using ::testing::Contains;
 using ::testing::DoubleNear;
 using ::testing::Eq;
 using ::testing::Ge;
 using ::testing::HasSubstr;
 using ::testing::IsNull;
+using ::testing::Lt;
 using ::testing::MatchesRegex;
 using ::testing::Not;
 using ::testing::Return;
@@ -1284,5 +1289,23 @@ TEST(NumericalMechanismTest, MinVarianceMechanismBuilderFailsWithoutEpsilon) {
   EXPECT_THAT(fails.status().message(), HasSubstr("Epsilon must be set"));
 }
 
+TEST(NumericalMechanismTest, AddNoiseReturnsNegativeValuesForUnsignedInt) {
+  // Flakiness of this test is approximately 1 / 2**50 ~= 8e-16
+  absl::StatusOr<std::unique_ptr<NumericalMechanism>> mechanism =
+      LaplaceMechanism::Builder()
+          .SetEpsilon(0.001)  // low epsilon for more variance
+          .SetL0Sensitivity(20)
+          .SetLInfSensitivity(100)
+          .Build();
+  ASSERT_OK(mechanism);
+
+  std::vector<int64_t> results;
+  for (int i = 0; i < 50; ++i) {
+    results.push_back(mechanism.value()->AddNoise<uint8_t>(0));
+  }
+
+  EXPECT_THAT(results, Contains(Lt(0)));
+}
+
 }  // namespace
 }  // namespace differential_privacy

cc/cc_differential_privacy_deps.bzl

@@ -26,9 +26,9 @@ def cc_differential_privacy_deps():
     # Abseil
     http_archive(
         name = "com_google_absl",
-        url = "https://github.com/abseil/abseil-cpp/archive/refs/tags/20230802.1.tar.gz",
-        sha256 = "987ce98f02eefbaf930d6e38ab16aa05737234d7afbab2d5c4ea7adbe50c28ed",
-        strip_prefix = "abseil-cpp-20230802.1",
+        url = "https://github.com/abseil/abseil-cpp/archive/refs/tags/20240116.2.tar.gz",
+        sha256 = "733726b8c3a6d39a4120d7e45ea8b41a434cdacde401cba500f14236c49b39dc",
+        strip_prefix = "abseil-cpp-20240116.2",
     )
 
     # Common bazel rules.  Also required for Abseil.

examples/zetasql/WORKSPACE

@@ -22,8 +22,9 @@ load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 http_archive(
     name = "com_google_zetasql",
-    strip_prefix = "zetasql-2023.11.1",
-    url = "https://github.com/google/zetasql/archive/refs/tags/2023.11.1.tar.gz",
+    sha256 = "58510f44dc815648039fd4e45fc40da3d9f0a746cf483e6bbc5171e984eb7e79",
+    strip_prefix = "zetasql-2024.03.1",
+    url = "https://github.com/google/zetasql/archive/refs/tags/2024.03.1.tar.gz",
 )
 
 # Transitive dependencies from the ZetaSQL WORKSPACE file:

python/dp_auditorium/README.md

@@ -7,18 +7,18 @@ guarantees as described in the introductory paper
 The root directory is structured as follows. It contains four main folders and a
 runner module described below:
 
-*   [Testers](testers/): Contains modules introducing `PropertyTesters` that
+*   [Testers](dp_auditorium/testers/): Contains modules introducing `PropertyTesters` that
     check if there is evidence to reject the hypothesis that a privacy guarantee
     holds on a fixed pair of datasets.
-*   [Generators](generators/): Contains modules introducing `DatasetGenerators`
+*   [Generators](dp_auditorium/generators/): Contains modules introducing `DatasetGenerators`
     that output pairs of neighboring datasets, for example under the add/remove
     neighboring relation.
-*   [Mechanisms](mechanims/): Contains examples of private and non-private
+*   [Mechanisms](dp_auditorium/mechanisms/): Contains examples of private and non-private
     mechanisms used to exemplify testers.
 *   `privacy_test_runner.py`: Module with runner that specializes to a tester
     and generator and instantiates the `PropertyTester` on several datasets'
     trials generated by the `DatasetGenerator`.
-*   [Examples](examples/): Folder containing examples on how to combine the
+*   [Examples](dp_auditorium/examples/): Folder containing examples on how to combine the
     above tools.
 
 Details on the signature of the above objects, can be found in the