Add YPIR algorithm implementation

.bazelrc

@@ -46,10 +46,17 @@ build:linux-release --action_env=BAZEL_LINKLIBS=-l%:libstdc++.a:-l%:libgcc.a
 # platform specific config
 # Bazel will automatic pick platform config since we have enable_platform_specific_config set
 build:macos --copt=-Wno-unused-command-line-argument
+build:macos --copt=-Wno-vla-cxx-extension
 build:macos --features=-supports_dynamic_linker
 build:macos --macos_minimum_os=12.0
 build:macos --host_macos_minimum_os=12.0
 
+# Fix yacl VLA warning on macOS Clang (Xcode 16.4+)
+build --per_file_copt=external/yacl.*openssl.*@-Wno-vla-cxx-extension
+# Fix brpc deprecated protobuf API warning
+build --per_file_copt=external/yacl.*brpc.*@-Wno-deprecated-declarations
+build --per_file_copt=external/brpc.*@-Wno-deprecated-declarations
+
 # NOTE: fix build on linux_aarch64, since `build:linux_aarch64` works only if `--config linux_aarch64` option included.
 build:linux --cxxopt=-Wno-mismatched-new-delete
 

.circleci/test.yml

@@ -37,6 +37,12 @@ commands:
       - run:
           name: Setup BuildBuddy Cache
           command: ../devtools/bazel_cache_setup.py
+      - run:
+          name: Install Intel HEXL
+          command: |
+            export HEXL_ROOT="${HOME}/.local/hexl"
+            ./bazel/install_hexl.sh "${HEXL_ROOT}"
+            echo "export HEXL_ROOT=${HEXL_ROOT}" >> "${BASH_ENV}"
       - run:
           name: "build"
           command: bazel build //... -c opt --ui_event_filters=-info,-debug,-warning --jobs 20
@@ -76,8 +82,8 @@ jobs:
      - build_and_test
   macos_ut:
     macos:
-      xcode: 16.2.0
-    resource_class: macos.m1.large.gen1
+      xcode: 16.4.0
+    resource_class: m4pro.medium
     steps:
       - checkout
       - run:

.gitignore

@@ -48,3 +48,4 @@ ossutil_output/
 
 psi/apps/pir/docker/linux/
 psi/apps/pir/docker/version.txt
+.vscode/

CONTRIBUTING.md

@@ -13,6 +13,8 @@ part of the project.
 
 In general, please use clang-format to format code, and follow clang-tidy tips.
 
+For Bazel files (`MODULE.bazel`, `*.bzl`, `BUILD`, `BUILD.bazel`), please use `buildifier`.
+
 Most of the code style is derived from the
 [Google C++ style guidelines](https://google.github.io/styleguide/cppguide.html), except:
 
@@ -57,6 +59,10 @@ docker exec -it psi-dev-$(whoami) bash
 
 ```sh
 Install gcc>=11.2, cmake>=3.26, ninja, nasm>=2.15, python>=3.10, bazelisk, xxd, lld
+
+# Install Intel HEXL, or set HEXL_ROOT to an existing install prefix.
+./bazel/install_hexl.sh "$HOME/.local/hexl"
+export HEXL_ROOT="$HOME/.local/hexl"
 ```
 
 #### macOS
@@ -80,6 +86,10 @@ brew install bazelisk cmake ninja libomp wget
 
 # For Intel mac only
 brew install nasm
+
+# Install Intel HEXL, or set HEXL_ROOT to an existing install prefix.
+./bazel/install_hexl.sh "$HOME/.local/hexl"
+export HEXL_ROOT="$HOME/.local/hexl"
 ```
 
 ### Build & UnitTest

MODULE.bazel

@@ -58,6 +58,8 @@ use_repo(
 
 new_local_repository = use_repo_rule("@bazel_tools//tools/build_defs/repo:local.bzl", "new_local_repository")
 
+hexl_repository = use_repo_rule("//bazel:hexl_repo.bzl", "hexl_repository")
+
 new_local_repository(
     name = "macos_omp_x64",
     build_file = "@yacl//bazel:local_openmp_macos.BUILD",
@@ -70,6 +72,8 @@ new_local_repository(
     path = "/opt/homebrew/opt/libomp/",
 )
 
+hexl_repository(name = "hexl")
+
 bazel_dep(name = "kuscia", version = "0.14.0b0")
 bazel_dep(name = "perfetto", version = "41.0")
 

README.md

@@ -218,3 +218,4 @@ Please refer to [PSI V2 Benchmark](docs/user_guide/psi_v2_benchmark.md)
 ## APSI Benchmark
 
 Please refer to [APSI Benchmark](docs/user_guide/apsi_benchmark.md)
+

bazel/hexl.BUILD

@@ -0,0 +1,15 @@
+load("@rules_cc//cc:defs.bzl", "cc_import", "cc_library")
+
+package(default_visibility = ["//visibility:public"])
+
+cc_import(
+    name = "hexl_lib",
+    static_library = "lib/libhexl.a",
+)
+
+cc_library(
+    name = "hexl",
+    hdrs = glob(["include/hexl/**/*.h", "include/hexl/**/*.hpp"]),
+    includes = ["include"],
+    deps = [":hexl_lib"],
+)

bazel/hexl_repo.bzl

@@ -0,0 +1,65 @@
+_HEXL_BUILD = """load("@rules_cc//cc:defs.bzl", "cc_import", "cc_library")
+
+package(default_visibility = ["//visibility:public"])
+
+cc_import(
+    name = "hexl_lib",
+    static_library = "lib/libhexl.a",
+)
+
+cc_library(
+    name = "hexl",
+    hdrs = glob(["include/hexl/**/*.h", "include/hexl/**/*.hpp"]),
+    includes = ["include"],
+    deps = [":hexl_lib"],
+)
+"""
+
+_HEXL_STUB_BUILD = """load("@rules_cc//cc:defs.bzl", "cc_library")
+
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "hexl",
+)
+"""
+
+def _hexl_repository_impl(repository_ctx):
+    roots = []
+    env_root = repository_ctx.os.environ.get("HEXL_ROOT", "")
+    if env_root:
+        roots.append(env_root)
+
+    roots.extend([
+        "/usr/local/opt/intel-hexl",
+        "/usr/local",
+        "/opt/homebrew/opt/intel-hexl",
+        "/opt/homebrew",
+        "/usr",
+    ])
+
+    for root in roots:
+        include_dir = repository_ctx.path(root + "/include")
+        header_dir = repository_ctx.path(root + "/include/hexl")
+        for lib_dir_name in ["lib", "lib64"]:
+            lib_dir = repository_ctx.path(root + "/" + lib_dir_name)
+            static_lib = repository_ctx.path(root + "/" + lib_dir_name + "/libhexl.a")
+            if header_dir.exists and static_lib.exists:
+                repository_ctx.symlink(include_dir, "include")
+                repository_ctx.symlink(lib_dir, "lib")
+                repository_ctx.file("BUILD.bazel", _HEXL_BUILD)
+                repository_ctx.file("WORKSPACE.bazel", "workspace(name = \"hexl\")\n")
+                return
+
+    # HEXL not found — create a stub so the workspace resolves on non-x86
+    # platforms.  Targets that actually depend on @hexl are gated by
+    # target_compatible_with = ["@platforms//cpu:x86_64"] and will never be
+    # built on ARM / macOS Apple Silicon.
+    repository_ctx.file("BUILD.bazel", _HEXL_STUB_BUILD)
+    repository_ctx.file("WORKSPACE.bazel", "workspace(name = \"hexl\")\n")
+
+hexl_repository = repository_rule(
+    implementation = _hexl_repository_impl,
+    environ = ["HEXL_ROOT"],
+    local = True,
+)

bazel/install_hexl.sh

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+hexl_version="${HEXL_VERSION:-v1.2.6}"
+install_prefix="${1:-${HEXL_ROOT:-${HOME}/.local/hexl}}"
+arch="$(uname -m)"
+
+case "${arch}" in
+  x86_64|amd64)
+    ;;
+  *)
+    printf 'Skipping Intel HEXL installation on unsupported architecture %s\n' \
+      "${arch}"
+    exit 0
+    ;;
+esac
+
+if [[ -f "${install_prefix}/lib/libhexl.a" && -d "${install_prefix}/include/hexl" ]]; then
+  printf 'Intel HEXL already installed at %s\n' "${install_prefix}"
+  exit 0
+fi
+
+parallelism="$(getconf _NPROCESSORS_ONLN 2>/dev/null || echo 4)"
+workdir="$(mktemp -d)"
+repo_dir="${workdir}/hexl"
+build_dir="${workdir}/build"
+
+cleanup() {
+  rm -rf "${workdir}"
+}
+
+trap cleanup EXIT
+
+printf 'Installing Intel HEXL %s into %s\n' "${hexl_version}" "${install_prefix}"
+
+git clone --depth 1 --branch "${hexl_version}"   https://github.com/IntelLabs/hexl.git "${repo_dir}"
+
+cmake -S "${repo_dir}" -B "${build_dir}"   -DCMAKE_BUILD_TYPE=Release   -DCMAKE_INSTALL_PREFIX="${install_prefix}"   -DHEXL_BENCHMARK=OFF   -DHEXL_COVERAGE=OFF   -DHEXL_DOCS=OFF   -DHEXL_SHARED_LIB=OFF   -DHEXL_TESTING=OFF   -DHEXL_TREAT_WARNING_AS_ERROR=OFF
+
+cmake --build "${build_dir}" --parallel "${parallelism}"
+cmake --install "${build_dir}"

bazel/psi.bzl

@@ -26,7 +26,7 @@ WARNING_FLAGS = [
 ]
 DEBUG_FLAGS = ["-O0", "-g", "-DSPDLOG_ACTIVE_LEVEL=1"]
 RELEASE_FLAGS = ["-O2"]
-FAST_FLAGS = ["-O1"]
+FAST_FLAGS = ["-O3"]
 
 def _psi_copts():
     return select({

docs/user_guide/pir.rst

@@ -13,6 +13,8 @@ Supported Protocols
 +----------------+-------------+---------------+
 | APSI           | Keyword PIR | Single Server |
 +----------------+-------------+---------------+
+| YPIR           | Index PIR   | Single Server |
++----------------+-------------+---------------+
 
 At this moment, SealPIR is under development.
 

psi/algorithm/pir_interface/pir_type.proto

@@ -21,6 +21,7 @@ enum PirType {
   INVALID = 0;
   SEAL_PIR = 1;
   SPIRAL_PIR = 2;
+  YPIR_PIR = 3;
 }
 
 message PirTypeProto {