Fix benchmark C++11 code

PiperOrigin-RevId: 913030038

.bazelrc

@@ -1,2 +1,4 @@
 # googletest requires C++14 or above
 build --cxxopt='-std=c++17'
+# Enable Bzlmod for every Bazel command
+common --enable_bzlmod

.github/workflows/riscv64-qemu-test.yaml

@@ -0,0 +1,43 @@
+name: riscv64-qemu-test
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    env: 
+      RISCV_CROSSCOMPILE: "ON"
+      riscv_gnu_toolchain_download_path: https://github.com/riscv-collab/riscv-gnu-toolchain/releases/download/2025.07.03/riscv64-glibc-ubuntu-24.04-gcc-nightly-2025.07.03-nightly.tar.xz
+      RISCV_PATH: /opt/riscv
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: recursive
+    
+    - name: Install dependencies
+      run: |
+        sudo apt update
+        sudo apt install -y --no-install-recommends \
+          qemu-user qemu-user-static \
+          build-essential \
+          cmake \
+          git
+        sudo mkdir -p $RISCV_PATH
+        wget ${riscv_gnu_toolchain_download_path} -O riscv-toolchain.tar.xz
+        sudo tar -xvf riscv-toolchain.tar.xz -C $RISCV_PATH --strip-components=1
+        sudo sed -i "s|libdir='/mnt/riscv/riscv64-unknown-linux-gnu/lib'|libdir='$RISCV_PATH/riscv64-unknown-linux-gnu/lib'|g" $RISCV_PATH/riscv64-unknown-linux-gnu/lib/libatomic.la
+
+    - name: Build and Run Unit Tests
+      run: |
+        export PATH=$RISCV_PATH/bin:$PATH
+        export LD_LIBRARY_PATH="/opt/riscv/lib:$LD_LIBRARY_PATH"
+        export QEMU_LD_PREFIX=$RISCV_PATH/sysroot
+        mkdir build && cd build
+        cmake -DCMAKE_BUILD_TYPE=Release ../
+        make -j$(nproc)
+        make test
+
+    - name: Run Benchmark
+      run: ./build/snappy_benchmark
+      working-directory: ./

.gitignore

@@ -6,4 +6,5 @@
 # Build directory.
 build/
 /bazel-*
+MODULE.bazel.lock
 out/

BUILD.bazel

@@ -26,11 +26,21 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+load("@bazel_skylib//rules:expand_template.bzl", "expand_template")
+load("@bazel_skylib//rules:write_file.bzl", "write_file")
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+
 package(default_visibility = ["//visibility:public"])
 
 licenses(["notice"])
 
-SNAPPY_VERSION = (1, 1, 10)
+exports_files([
+    "COPYING",
+    "COPYING.notestdata",
+])
+
+SNAPPY_VERSION = (1, 2, 2)
 
 config_setting(
     name = "windows",
@@ -40,7 +50,7 @@ config_setting(
 cc_library(
     name = "config",
     hdrs = ["config.h"],
-    defines = ["HAVE_CONFIG_H"]
+    defines = ["HAVE_CONFIG_H"],
 )
 
 cc_library(
@@ -52,8 +62,10 @@ cc_library(
     name = "snappy-stubs-internal",
     srcs = ["snappy-stubs-internal.cc"],
     hdrs = ["snappy-stubs-internal.h"],
-    deps = [
+    implementation_deps = [
         ":config",
+    ],
+    deps = [
         ":snappy-stubs-public",
     ],
 )
@@ -70,12 +82,15 @@ cc_library(
         "snappy-sinksource.h",
     ],
     copts = select({
-      ":windows": [],
+        ":windows": [],
-      "//conditions:default": [
+        "//conditions:default": [
-        "-Wno-sign-compare",
+            "-Wno-sign-compare",
-    ]}),
+        ],
-    deps = [
+    }),
+    implementation_deps = [
         ":config",
+    ],
+    deps = [
         ":snappy-stubs-internal",
         ":snappy-stubs-public",
     ],
@@ -114,7 +129,7 @@ cc_test(
     deps = [
         ":snappy",
         ":snappy-test",
-        "//third_party/benchmark:benchmark_main",
+        "@com_google_benchmark//:benchmark_main",
     ],
 )
 
@@ -127,15 +142,15 @@ cc_test(
     deps = [
         ":snappy",
         ":snappy-test",
-        "//third_party/googletest:gtest_main",
+        "@com_google_googletest//:gtest_main",
     ],
 )
 
 # Generate a config.h similar to what cmake would produce.
-genrule(
+write_file(
     name = "config_h",
-    outs = ["config.h"],
+    out = "config.h",
-    cmd = """cat <<EOF >$@
+    content = """\
 #define HAVE_STDDEF_H 1
 #define HAVE_STDINT_H 1
 #ifdef __has_builtin
@@ -192,19 +207,17 @@ genrule(
 #    define SNAPPY_IS_BIG_ENDIAN 1
 #  endif
 #endif
-EOF
+""".splitlines(),
-""",
 )
 
-genrule(
+expand_template(
     name = "snappy_stubs_public_h",
-    srcs = ["snappy-stubs-public.h.in"],
+    out = "snappy-stubs-public.h",
-    outs = ["snappy-stubs-public.h"],
+    substitutions = {
-    # Assume sys/uio.h is available on non-Windows.
+        "${HAVE_SYS_UIO_H_01}": "!_WIN32",
-    # Set the version numbers.
+        "${PROJECT_VERSION_MAJOR}": str(SNAPPY_VERSION[0]),
-    cmd = ("""sed -e 's/$${HAVE_SYS_UIO_H_01}/!_WIN32/g' \
+        "${PROJECT_VERSION_MINOR}": str(SNAPPY_VERSION[1]),
-           -e 's/$${PROJECT_VERSION_MAJOR}/%d/g' \
+        "${PROJECT_VERSION_PATCH}": str(SNAPPY_VERSION[2]),
-           -e 's/$${PROJECT_VERSION_MINOR}/%d/g' \
+    },
-           -e 's/$${PROJECT_VERSION_PATCH}/%d/g' \
+    template = "snappy-stubs-public.h.in",
-    $< >$@""" % SNAPPY_VERSION),
 )

CMakeLists.txt

@@ -26,8 +26,8 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.10)
-project(Snappy VERSION 1.1.10 LANGUAGES C CXX)
+project(Snappy VERSION 1.2.2 LANGUAGES C CXX)
 
 # C++ standard can be overridden when this is used as a sub-project.
 if(NOT CMAKE_CXX_STANDARD)
@@ -38,7 +38,7 @@ if(NOT CMAKE_CXX_STANDARD)
 endif(NOT CMAKE_CXX_STANDARD)
 
 # https://github.com/izenecloud/cmake/blob/master/SetCompilerWarningAll.cmake
-if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+if(MSVC)
   # Use the highest warning level for Visual Studio.
   set(CMAKE_CXX_WARNING_LEVEL 4)
   if(CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
@@ -55,7 +55,7 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
   # Disable RTTI.
   string(REGEX REPLACE "/GR" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /GR-")
-else(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+else(MSVC)
   # Use -Wall for clang and gcc.
   if(NOT CMAKE_CXX_FLAGS MATCHES "-Wall")
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
@@ -85,7 +85,7 @@ else(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
   # Disable RTTI.
   string(REGEX REPLACE "-frtti" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti")
-endif(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+endif(MSVC)
 
 # BUILD_SHARED_LIBS is a standard CMake variable, but we declare it here to make
 # it prominent in the GUI.
@@ -155,10 +155,20 @@ int main() {
   return __builtin_expect(0, 1);
 }" HAVE_BUILTIN_EXPECT)
 
+# Check if the built-in __builtin_ctz (count trailing zeros) is available.
+# Require either a non-RISC-V target, or a RISC-V core that implements
+# the Zbb bit-manipulation extension where ctz is guaranteed.
 check_cxx_source_compiles("
-int main() {
+#ifdef __riscv
-  return __builtin_ctzll(0);
+  #ifdef __riscv_zbb
-}" HAVE_BUILTIN_CTZ)
+    int main() { return __builtin_ctzll(0); }
+  #else
+    #error \"ZBB not enabled in current config\"
+  #endif
+#else
+  int main() { return __builtin_ctzll(0); }
+#endif
+" HAVE_BUILTIN_CTZ)
 
 check_cxx_source_compiles("
 int main() {
@@ -206,13 +216,41 @@ int main() {
 
 check_cxx_source_compiles("
 #include <arm_neon.h>
+#include <stdint.h>
 int main() {
   uint8_t val = 3, dup[8];
-  uint8x16_t v = vld1q_dup_u8(&val);
+  uint8x16_t v1 = vld1q_dup_u8(&val);
-  vst1q_u8(dup, v);
+  uint8x16_t v2 = vqtbl1q_u8(v1, v1);
+  vst1q_u8(dup, v1);
+  vst1q_u8(dup, v2);
   return 0;
 }" SNAPPY_HAVE_NEON)
 
+#check RVV 1.0 need __riscv_ prefix
+check_cxx_source_compiles("
+  #include <riscv_vector.h>
+  #include <stdint.h>
+  #include <stddef.h>
+  int main() {
+    uint8_t val = 3, dup[8];
+    size_t vl = __riscv_vsetvl_e8m1(8);
+    vuint8m1_t v = __riscv_vmv_v_x_u8m1(val, vl);
+    return 0;
+  }" SNAPPY_RVV_1)
+
+
+#check RVV 0.7.1 not  __riscv_ prefix
+check_cxx_source_compiles("
+  #include <riscv_vector.h>
+  #include <stdint.h>
+  #include <stddef.h>
+  int main() {
+    uint8_t val = 3, dup[8];
+    size_t vl = vsetvl_e8m1(8);
+    vuint8m1_t v = vmv_v_x_u8m1(val, vl);
+    return 0;
+  }" SNAPPY_RVV_0_7)
+
 include(CheckSymbolExists)
 check_symbol_exists("mmap" "sys/mman.h" HAVE_FUNC_MMAP)
 check_symbol_exists("sysconf" "unistd.h" HAVE_FUNC_SYSCONF)
@@ -258,9 +296,7 @@ target_sources(snappy
     "snappy-stubs-internal.cc"
     "snappy.cc"
     "${PROJECT_BINARY_DIR}/config.h"
-
+  PUBLIC
-  # Only CMake 3.3+ supports PUBLIC sources in targets exported by "install".
-  $<$<VERSION_GREATER:CMAKE_VERSION,3.2>:PUBLIC>
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/snappy-c.h>
     $<INSTALL_INTERFACE:include/snappy-c.h>
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/snappy-sinksource.h>
@@ -297,6 +333,9 @@ if(SNAPPY_BUILD_TESTS OR SNAPPY_BUILD_BENCHMARKS)
 
   # Test files include snappy-test.h, HAVE_CONFIG_H must be defined.
   target_compile_definitions(snappy_test_support PUBLIC -DHAVE_CONFIG_H)
+  if(BUILD_SHARED_LIBS)
+    set_target_properties(snappy_test_support PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS ON)
+  endif(BUILD_SHARED_LIBS)
 
   target_link_libraries(snappy_test_support snappy)
 

COPYING.notestdata

@@ -0,0 +1,28 @@
+Copyright 2011, 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.

MODULE.bazel

@@ -0,0 +1,26 @@
+module(
+    name = "snappy",
+    version = "1.2.2",
+    compatibility_level = 1,
+)
+
+bazel_dep(name = "rules_cc", version = "0.2.4")
+bazel_dep(name = "bazel_skylib", version = "1.8.2")
+
+bazel_dep(
+    name = "googletest",
+    version = "1.17.0.bcr.2",
+    dev_dependency = True,
+    repo_name = "com_google_googletest",
+)
+bazel_dep(
+    name = "google_benchmark",
+    version = "1.9.5",
+    dev_dependency = True,
+    repo_name = "com_google_benchmark",
+)
+
+bazel_dep(
+    name = "platforms",
+    version = "1.0.0",
+)

NEWS

@@ -1,3 +1,18 @@
+Snappy v1.2.2, Mar 26th 2025:
+
+  * We added a new compression level in v1.2.1 which compresses a bit
+    denser but slower. Decompression speed should be even faster with it.
+
+  * We fixed a very old issue of data corruption when compressed size
+    exceeds 4GB. This can happen when you compress data close to 4GB
+    and it's incompressible, for example, random data.
+
+  * Started to use minimum CMake 3.10 because older ones are not
+    planned to be supported.
+
+  * Various other small fixes and performance improvements (especially
+    for clang).
+
 Snappy v1.1.10, Mar 8th 2023:
 
   * Performance improvements

README.md

@@ -140,10 +140,10 @@ explicitly supports the following:
 1. C++11
 2. Clang (gcc and MSVC are best-effort).
 3. Low level optimizations (e.g. assembly or equivalent intrinsics) for:
-  1. [x86](https://en.wikipedia.org/wiki/X86)
+      - [x86](https://en.wikipedia.org/wiki/X86)
-  2. [x86-64](https://en.wikipedia.org/wiki/X86-64)
+      - [x86-64](https://en.wikipedia.org/wiki/X86-64)
-  3. ARMv7 (32-bit)
+      - ARMv7 (32-bit)
-  4. ARMv8 (AArch64)
+      - ARMv8 (AArch64)
 4. Supports only the Snappy compression scheme as described in
   [format_description.txt](format_description.txt).
 5. CMake for building

cmake/config.h.in

@@ -58,6 +58,12 @@
 /* Define to 1 if you target processors with NEON and have <arm_neon.h>. */
 #cmakedefine01 SNAPPY_HAVE_NEON
 
+/* Define to 1 if you target processors with RVV1.0 and have <riscv_vector.h>. */
+#cmakedefine01 SNAPPY_RVV_1
+
+/* Define to 1 if you target processors with RVV0.7 and have <riscv_vector.h>. */
+#cmakedefine01 SNAPPY_RVV_0_7
+
 /* Define to 1 if you have <arm_neon.h> and <arm_acle.h> and want to optimize
    compression speed by using __crc32cw from <arm_acle.h>. */
 #cmakedefine01 SNAPPY_HAVE_NEON_CRC32

snappy-internal.h

@@ -46,6 +46,23 @@
 #include <arm_neon.h>
 #endif
 
+#if SNAPPY_RVV_1 || SNAPPY_RVV_0_7
+#define SNAPPY_HAVE_RVV 1
+#include <riscv_vector.h>
+#else
+#define SNAPPY_HAVE_RVV 0
+#endif
+
+#ifdef SNAPPY_RVV_1
+#define VSETVL_E8M2 __riscv_vsetvl_e8m2
+#define VLE8_V_U8M2 __riscv_vle8_v_u8m2
+#define VSE8_V_U8M2 __riscv_vse8_v_u8m2
+#elif SNAPPY_RVV_0_7
+#define VSETVL_E8M2 vsetvl_e8m2
+#define VLE8_V_U8M2 vle8_v_u8m2
+#define VSE8_V_U8M2 vse8_v_u8m2
+#endif
+
 #if SNAPPY_HAVE_SSSE3 || SNAPPY_HAVE_NEON
 #define SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE 1
 #else
@@ -110,6 +127,8 @@ inline V128 V128_Shuffle(V128 input, V128 shuffle_mask) {
 }
 
 inline V128 V128_DupChar(char c) { return vdupq_n_u8(c); }
+
+
 #endif
 #endif  // SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE
 
@@ -172,9 +191,10 @@ char* CompressFragment(const char* input,
 // loading from s2 + n.
 //
 // Separate implementation for 64-bit, little-endian cpus.
+// riscv and little-endian cpu choose this routinue can be done faster too.
 #if !SNAPPY_IS_BIG_ENDIAN && \
     (defined(__x86_64__) || defined(_M_X64) || defined(ARCH_PPC) || \
-     defined(ARCH_ARM))
+     defined(__aarch64__) || (defined(__riscv) && (__riscv_xlen == 64)))
 static inline std::pair<size_t, bool> FindMatchLength(const char* s1,
                                                       const char* s2,
                                                       const char* s2_limit,

snappy-stubs-internal.h

@@ -304,6 +304,7 @@ class Bits {
   void operator=(const Bits&);
 };
 
+// In RISC-V,  CLZ  is supported by instructions from the ZBB bit-manipulation extension.
 #if HAVE_BUILTIN_CTZ
 
 inline int Bits::Log2FloorNonZero(uint32_t n) {
@@ -393,6 +394,7 @@ inline int Bits::FindLSBSetNonZero(uint32_t n) {
 
 #endif  // End portable versions.
 
+// In RISC-V,  CLZ  is supported by instructions from the ZBB bit-manipulation extension.
 #if HAVE_BUILTIN_CTZ
 
 inline int Bits::FindLSBSetNonZero64(uint64_t n) {

snappy.cc

@@ -280,6 +280,8 @@ inline char* IncrementalCopySlow(const char* src, char* op,
 // 4, 5, 0, 1, 2, 3, 4, 5, 0, 1}. These byte index sequences are generated by
 // calling MakePatternMaskBytes(0, 6, index_sequence<16>()) and
 // MakePatternMaskBytes(16, 6, index_sequence<16>()) respectively.
+
+
 template <size_t... indexes>
 inline constexpr std::array<char, sizeof...(indexes)> MakePatternMaskBytes(
     int index_offset, int pattern_size, index_sequence<indexes...>) {
@@ -297,7 +299,6 @@ MakePatternMaskBytesTable(int index_offset,
       MakePatternMaskBytes(index_offset, pattern_sizes_minus_one + 1,
                            make_index_sequence</*indexes=*/sizeof(V128)>())...};
 }
-
 // This is an array of shuffle control masks that can be used as the source
 // operand for PSHUFB to permute the contents of the destination XMM register
 // into a repeating byte pattern.
@@ -493,7 +494,6 @@ inline char* IncrementalCopy(const char* src, char* op, char* const op_limit,
           LoadPatternAndReshuffleMask(src, pattern_size);
       V128 pattern = pattern_and_reshuffle_mask.first;
       V128 reshuffle_mask = pattern_and_reshuffle_mask.second;
-
       // There is at least one, and at most four 16-byte blocks. Writing four
       // conditionals instead of a loop allows FDO to layout the code with
       // respect to the actual probabilities of each length.
@@ -520,7 +520,6 @@ inline char* IncrementalCopy(const char* src, char* op, char* const op_limit,
           LoadPatternAndReshuffleMask(src, pattern_size);
       V128 pattern = pattern_and_reshuffle_mask.first;
       V128 reshuffle_mask = pattern_and_reshuffle_mask.second;
-
       // This code path is relatively cold however so we save code size
       // by avoiding unrolling and vectorizing.
       //
@@ -959,6 +958,8 @@ emit_remainder:
 char* CompressFragmentDoubleHash(const char* input, size_t input_size, char* op,
                                  uint16_t* table, const int table_size,
                                  uint16_t* table2, const int table_size2) {
+  (void)table_size2;
+  assert(table_size == table_size2);
   // "ip" is the input pointer, and "op" is the output pointer.
   const char* ip = input;
   assert(input_size <= kBlockSize);
@@ -1224,7 +1225,7 @@ inline bool Copy64BytesWithPatternExtension(ptrdiff_t dst, size_t offset) {
 void MemCopy64(char* dst, const void* src, size_t size) {
   // Always copy this many bytes.  If that's below size then copy the full 64.
   constexpr int kShortMemCopy = 32;
-
+  (void)kShortMemCopy;
   assert(size <= 64);
   assert(std::less_equal<const void*>()(static_cast<const char*>(src) + size,
                                         dst) ||
@@ -1243,6 +1244,27 @@ void MemCopy64(char* dst, const void* src, size_t size) {
     data = _mm256_lddqu_si256(static_cast<const __m256i *>(src) + 1);
     _mm256_storeu_si256(reinterpret_cast<__m256i *>(dst) + 1, data);
   }
+  // RVV acceleration available on RISC-V when compiled with -march=rv64gcv
+#elif defined(__riscv) && SNAPPY_HAVE_RVV
+  // Cast pointers to the type we will operate on.
+  unsigned char* dst_ptr = reinterpret_cast<unsigned char*>(dst);
+  const unsigned char* src_ptr = reinterpret_cast<const unsigned char*>(src);
+  size_t remaining_bytes = size;
+  // Loop as long as there are bytes remaining to be copied.
+  while (remaining_bytes > 0) {
+    // Set vector configuration: e8 (8-bit elements), m2 (LMUL=2).
+    // Use e8m2 configuration to maximize throughput.
+    size_t vl = VSETVL_E8M2(remaining_bytes);
+    // Load data from the current source pointer.
+    vuint8m2_t vec = VLE8_V_U8M2(src_ptr, vl);
+    // Store data to the current destination pointer.
+    VSE8_V_U8M2(dst_ptr, vec, vl);
+    // Update pointers and the remaining count.
+    src_ptr += vl;
+    dst_ptr += vl;
+    remaining_bytes -= vl;
+  }
+
 #else
   std::memmove(dst, src, kShortMemCopy);
   // Profiling shows that nearly all copies are short.
@@ -1342,19 +1364,51 @@ inline size_t AdvanceToNextTagX86Optimized(const uint8_t** ip_p, size_t* tag) {
   return tag_type;
 }
 
+SNAPPY_ATTRIBUTE_ALWAYS_INLINE
+inline size_t AdvanceToNextTagRVOptimized(const uint8_t** ip_p, size_t* tag) {
+  const uint8_t*& ip = *ip_p;
+  // This section is crucial for the throughput of the decompression loop.
+  // The latency of an iteration is fundamentally constrained by the data chain on ip:
+  // ip -> c = *tag -> literal_len = c >> 2, tag_type = c & 3
+  //      -> literal_advance = literal_len + 2, copy_advance = tag_type + 1
+  //      -> next_ip = ip + literal_advance  OR  ip + copy_advance (literal vs copy)
+  //      -> *tag = byte at (next_ip - 1); ip = next_ip
+  //
+  // Base RISC-V has no x86-style cmov and no AArch64 csinc on the same shape; this
+  // computes both candidate advances and both load offsets, then selects with
+  // (is_literal ? ... : ...). With the Zicond extension (czero.eqz / czero.nez), those
+  // selections typically lower to branchless conditional-zero ops instead of a
+  // hard-to-predict literal/copy branch, which is why this form tends to win there.
+  const size_t literal_len = *tag >> 2;
+  const size_t tag_type = *tag & 3;
+  const bool is_literal = (tag_type == 0);
+  const size_t copy_advance = tag_type + 1;
+  const size_t literal_advance = literal_len + 2;
+  const uint8_t* next_ip = is_literal ? (ip + literal_advance) : (ip + copy_advance);
+  *tag = is_literal ? ip[literal_advance - 1] : ip[copy_advance - 1];
+  ip = next_ip;
+  return tag_type;
+}
+
 // Extract the offset for copy-1 and copy-2 returns 0 for literals or copy-4.
 inline uint32_t ExtractOffset(uint32_t val, size_t tag_type) {
-  // For x86 non-static storage works better. For ARM static storage is better.
+  // For Arm non-static storage works better. For x86 static storage is better.
   // TODO: Once the array is recognized as a register, improve the
   // readability for x86.
 #if defined(__x86_64__)
-  constexpr uint64_t kExtractMasksCombined = 0x0000FFFF00FF0000ull;
+  static constexpr uint64_t kExtractMasksCombined = 0x0000FFFF00FF0000ull;
   uint16_t result;
   memcpy(&result,
          reinterpret_cast<const char*>(&kExtractMasksCombined) + 2 * tag_type,
          sizeof(result));
   return val & result;
-#elif defined(__aarch64__)
+  // For AArch64 and RISC-V, use a bit-twiddling trick to extract the mask from a
+  // single combined constant instead of a lookup table. The constant packs multiple
+  // 16-bit masks based on tag_type (see implementation below). The code calculates
+  // the shift amount from tag_type, right-shifts the constant to move the desired
+  // mask to the LSB position, then extracts it with & 0xFFFF. This branchless
+  // approach is often more performant on modern CPUs.
+#elif defined(__aarch64__) || (defined(__riscv) && (__riscv_xlen == 64))
   constexpr uint64_t kExtractMasksCombined = 0x0000FFFF00FF0000ull;
   return val & static_cast<uint32_t>(
       (kExtractMasksCombined >> (tag_type * 16)) & 0xFFFF);
@@ -1418,6 +1472,11 @@ std::pair<const uint8_t*, ptrdiff_t> DecompressBranchless(
         // We never need more than 16 bits. Doing a Load16 allows the compiler
         // to elide the masking operation in ExtractOffset.
         next = LittleEndian::Load16(old_ip);
+#elif defined(__riscv)
+        size_t tag_type = AdvanceToNextTagRVOptimized(&ip, &tag);
+        // We never need more than 16 bits. Doing a Load16 allows the compiler
+        // to elide the masking operation in ExtractOffset.
+        next = LittleEndian::Load16(old_ip);
 #else
         size_t tag_type = AdvanceToNextTagX86Optimized(&ip, &tag);
         next = LittleEndian::Load32(old_ip);
@@ -1496,7 +1555,7 @@ class SnappyDecompressor {
   // If ip < ip_limit_min_maxtaglen_ it's safe to read kMaxTagLength from
   // buffer.
   const char* ip_limit_min_maxtaglen_;
-  uint32_t peeked_;                  // Bytes peeked from reader (need to skip)
+  uint64_t peeked_;                  // Bytes peeked from reader (need to skip)
   bool eof_;                         // Hit end of input without an error?
   char scratch_[kMaximumTagLength];  // See RefillTag().
 
@@ -1687,7 +1746,8 @@ constexpr uint32_t CalculateNeeded(uint8_t tag) {
 #if __cplusplus >= 201402L
 constexpr bool VerifyCalculateNeeded() {
   for (int i = 0; i < 1; i++) {
-    if (CalculateNeeded(i) != (char_table[i] >> 11) + 1) return false;
+    if (CalculateNeeded(i) != static_cast<uint32_t>((char_table[i] >> 11)) + 1)
+      return false;
   }
   return true;
 }
@@ -1723,7 +1783,7 @@ bool SnappyDecompressor::RefillTag() {
   assert(needed <= sizeof(scratch_));
 
   // Read more bytes from reader if needed
-  uint32_t nbuf = ip_limit_ - ip;
+  uint64_t nbuf = ip_limit_ - ip;
   if (nbuf < needed) {
     // Stitch together bytes from ip and reader to form the word
     // contents.  We store the needed bytes in "scratch_".  They
@@ -1736,7 +1796,7 @@ bool SnappyDecompressor::RefillTag() {
       size_t length;
       const char* src = reader_->Peek(&length);
       if (length == 0) return false;
-      uint32_t to_add = std::min<uint32_t>(needed - nbuf, length);
+      uint64_t to_add = std::min<uint64_t>(needed - nbuf, length);
       std::memcpy(scratch_ + nbuf, src, to_add);
       nbuf += to_add;
       reader_->Skip(to_add);
@@ -1775,13 +1835,13 @@ static bool InternalUncompressAllTags(SnappyDecompressor* decompressor,
                                       Writer* writer, uint32_t compressed_len,
                                       uint32_t uncompressed_len) {
     int token = 0;
-  Report(token, "snappy_uncompress", compressed_len, uncompressed_len);
 
   writer->SetExpectedLength(uncompressed_len);
 
   // Process the entire input
   decompressor->DecompressAllTags(writer);
   writer->Flush();
+  Report(token, "snappy_uncompress", compressed_len, uncompressed_len);
   return (decompressor->eof() && writer->CheckLength());
 }
 
@@ -1790,12 +1850,15 @@ bool GetUncompressedLength(Source* source, uint32_t* result) {
   return decompressor.ReadUncompressedLength(result);
 }
 
+size_t Compress(Source* reader, Sink* writer) {
+  return Compress(reader, writer, CompressionOptions{});
+}
+
 size_t Compress(Source* reader, Sink* writer, CompressionOptions options) {
   assert(options.level == 1 || options.level == 2);
-  int token = 0;
   size_t written = 0;
   size_t N = reader->Available();
-  const size_t uncompressed_size = N;
+  assert(N <= 0xFFFFFFFFu);
   char ulength[Varint::kMax32];
   char* p = Varint::Encode32(ulength, N);
   writer->Append(ulength, p - ulength);
@@ -1848,22 +1911,21 @@ size_t Compress(Source* reader, Sink* writer, CompressionOptions options) {
     // have room for us directly.
     char* dest = writer->GetAppendBuffer(max_output, wmem.GetScratchOutput());
     char* end = nullptr;
-    if (options.level == 1) {
+      if (options.level == 1) {
-      end = internal::CompressFragment(fragment, fragment_size, dest, table,
+        end = internal::CompressFragment(fragment, fragment_size, dest, table,
-                                       table_size);
+                                         table_size);
-    } else if (options.level == 2) {
+      } else if (options.level == 2) {
-      end = internal::CompressFragmentDoubleHash(
+        end = internal::CompressFragmentDoubleHash(
-          fragment, fragment_size, dest, table, table_size >> 1,
+            fragment, fragment_size, dest, table, table_size >> 1,
-          table + (table_size >> 1), table_size >> 1);
+            table + (table_size >> 1), table_size >> 1);
-    }
+      }
+
     writer->Append(dest, end - dest);
     written += (end - dest);
 
     N -= num_to_read;
     reader->Skip(pending_advance);
   }
-
-  Report(token, "snappy_compress", written, uncompressed_size);
   return written;
 }
 
@@ -1886,16 +1948,16 @@ class SnappyIOVecReader : public Source {
     if (total_size > 0 && curr_size_remaining_ == 0) Advance();
   }
 
-  ~SnappyIOVecReader() = default;
+  ~SnappyIOVecReader() override = default;
 
-  size_t Available() const { return total_size_remaining_; }
+  size_t Available() const override { return total_size_remaining_; }
 
-  const char* Peek(size_t* len) {
+  const char* Peek(size_t* len) override {
     *len = curr_size_remaining_;
     return curr_pos_;
   }
 
-  void Skip(size_t n) {
+  void Skip(size_t n) override {
     while (n >= curr_size_remaining_ && n > 0) {
       n -= curr_size_remaining_;
       Advance();
@@ -2296,6 +2358,12 @@ bool IsValidCompressed(Source* compressed) {
   return InternalUncompress(compressed, &writer);
 }
 
+void RawCompress(const char* input, size_t input_length, char* compressed,
+                 size_t* compressed_length) {
+  RawCompress(input, input_length, compressed, compressed_length,
+              CompressionOptions{});
+}
+
 void RawCompress(const char* input, size_t input_length, char* compressed,
                  size_t* compressed_length, CompressionOptions options) {
   ByteArraySource reader(input, input_length);
@@ -2306,6 +2374,12 @@ void RawCompress(const char* input, size_t input_length, char* compressed,
   *compressed_length = (writer.CurrentDestination() - compressed);
 }
 
+void RawCompressFromIOVec(const struct iovec* iov, size_t uncompressed_length,
+                          char* compressed, size_t* compressed_length) {
+  RawCompressFromIOVec(iov, uncompressed_length, compressed, compressed_length,
+                       CompressionOptions{});
+}
+
 void RawCompressFromIOVec(const struct iovec* iov, size_t uncompressed_length,
                           char* compressed, size_t* compressed_length,
                           CompressionOptions options) {
@@ -2317,6 +2391,11 @@ void RawCompressFromIOVec(const struct iovec* iov, size_t uncompressed_length,
   *compressed_length = writer.CurrentDestination() - compressed;
 }
 
+size_t Compress(const char* input, size_t input_length,
+                std::string* compressed) {
+  return Compress(input, input_length, compressed, CompressionOptions{});
+}
+
 size_t Compress(const char* input, size_t input_length, std::string* compressed,
                 CompressionOptions options) {
   // Pre-grow the buffer to the max length of the compressed output
@@ -2329,6 +2408,11 @@ size_t Compress(const char* input, size_t input_length, std::string* compressed,
   return compressed_length;
 }
 
+size_t CompressFromIOVec(const struct iovec* iov, size_t iov_cnt,
+                         std::string* compressed) {
+  return CompressFromIOVec(iov, iov_cnt, compressed, CompressionOptions{});
+}
+
 size_t CompressFromIOVec(const struct iovec* iov, size_t iov_cnt,
                          std::string* compressed, CompressionOptions options) {
   // Compute the number of bytes to be compressed.
@@ -2533,7 +2617,6 @@ bool SnappyScatteredWriter<Allocator>::SlowAppendFromSelf(size_t offset,
 class SnappySinkAllocator {
  public:
   explicit SnappySinkAllocator(Sink* dest) : dest_(dest) {}
-  ~SnappySinkAllocator() {}
 
   char* Allocate(int size) {
     Datablock block(new char[size], size);

snappy.h

@@ -64,6 +64,10 @@ namespace snappy {
     // faster decompression speeds than snappy:1 and zstd:-3.
     int level = DefaultCompressionLevel();
 
+      constexpr CompressionOptions() = default;
+      constexpr CompressionOptions(int compression_level)
+          : level(compression_level) {}
+
     static constexpr int MinCompressionLevel() { return 1; }
     static constexpr int MaxCompressionLevel() { return 2; }
     static constexpr int DefaultCompressionLevel() { return 1; }
@@ -75,8 +79,10 @@ namespace snappy {
 
   // Compress the bytes read from "*reader" and append to "*writer". Return the
   // number of bytes written.
+  // First version is to preserve ABI.
+  size_t Compress(Source* reader, Sink* writer);
   size_t Compress(Source* reader, Sink* writer,
-                  CompressionOptions options = {});
+                  CompressionOptions options);
 
   // Find the uncompressed length of the given stream, as given by the header.
   // Note that the true length could deviate from this; the stream could e.g.
@@ -95,16 +101,22 @@ namespace snappy {
   // Original contents of *compressed are lost.
   //
   // REQUIRES: "input[]" is not an alias of "*compressed".
+  // First version is to preserve ABI.
   size_t Compress(const char* input, size_t input_length,
-                  std::string* compressed, CompressionOptions options = {});
+                  std::string* compressed);
+  size_t Compress(const char* input, size_t input_length,
+                  std::string* compressed, CompressionOptions options);
 
   // Same as `Compress` above but taking an `iovec` array as input. Note that
   // this function preprocesses the inputs to compute the sum of
   // `iov[0..iov_cnt-1].iov_len` before reading. To avoid this, use
   // `RawCompressFromIOVec` below.
+  // First version is to preserve ABI.
+  size_t CompressFromIOVec(const struct iovec* iov, size_t iov_cnt,
+                           std::string* compressed);
   size_t CompressFromIOVec(const struct iovec* iov, size_t iov_cnt,
                            std::string* compressed,
-                           CompressionOptions options = {});
+                           CompressionOptions options);
 
   // Decompresses "compressed[0..compressed_length-1]" to "*uncompressed".
   // Original contents of "*uncompressed" are lost.
@@ -147,15 +159,21 @@ namespace snappy {
   //    RawCompress(input, input_length, output, &output_length);
   //    ... Process(output, output_length) ...
   //    delete [] output;
+  // First version is to preserve ABI.
   void RawCompress(const char* input, size_t input_length, char* compressed,
-                   size_t* compressed_length, CompressionOptions options = {});
+                   size_t* compressed_length);
+  void RawCompress(const char* input, size_t input_length, char* compressed,
+                   size_t* compressed_length, CompressionOptions options);
 
   // Same as `RawCompress` above but taking an `iovec` array as input. Note that
   // `uncompressed_length` is the total number of bytes to be read from the
   // elements of `iov` (_not_ the number of elements in `iov`).
+  // First version is to preserve ABI.
+  void RawCompressFromIOVec(const struct iovec* iov, size_t uncompressed_length,
+                            char* compressed, size_t* compressed_length);
   void RawCompressFromIOVec(const struct iovec* iov, size_t uncompressed_length,
                             char* compressed, size_t* compressed_length,
-                            CompressionOptions options = {});
+                            CompressionOptions options);
 
   // Given data in "compressed[0..compressed_length-1]" generated by
   // calling the Snappy::Compress routine, this routine

snappy_benchmark.cc

@@ -31,12 +31,10 @@
 #include <string>
 #include <vector>
 
-#include "snappy-test.h"
-
 #include "benchmark/benchmark.h"
-
 #include "snappy-internal.h"
 #include "snappy-sinksource.h"
+#include "snappy-test.h"
 #include "snappy.h"
 #include "snappy_test_data.h"
 
@@ -44,7 +42,7 @@ namespace snappy {
 
 namespace {
 
-void FilesAndLevels(::testing::Benchmark* benchmark) {
+void FilesAndLevels(benchmark::internal::Benchmark* benchmark) {
   for (int i = 0; i < ARRAYSIZE(kTestDataFiles); ++i) {
     for (int level = snappy::CompressionOptions::MinCompressionLevel();
          level <= snappy::CompressionOptions::MaxCompressionLevel(); ++level) {
@@ -64,8 +62,9 @@ void BM_UFlat(benchmark::State& state) {
                        kTestDataFiles[file_index].size_limit);
 
   std::string zcontents;
-  snappy::Compress(contents.data(), contents.size(), &zcontents,
+  snappy::Compress(
-                   snappy::CompressionOptions{.level = state.range(1)});
+      contents.data(), contents.size(), &zcontents,
+      snappy::CompressionOptions{/*level=*/static_cast<int>(state.range(1))});
   char* dst = new char[contents.size()];
 
   for (auto s : state) {
@@ -129,8 +128,9 @@ void BM_UValidate(benchmark::State& state) {
                        kTestDataFiles[file_index].size_limit);
 
   std::string zcontents;
-  snappy::Compress(contents.data(), contents.size(), &zcontents,
+  snappy::Compress(
-                   snappy::CompressionOptions{.level = state.range(1)});
+      contents.data(), contents.size(), &zcontents,
+      snappy::CompressionOptions{/*level=*/static_cast<int>(state.range(1))});
 
   for (auto s : state) {
     CHECK(snappy::IsValidCompressedBuffer(zcontents.data(), zcontents.size()));
@@ -193,7 +193,7 @@ void BM_UIOVecSource(benchmark::State& state) {
   size_t zsize = 0;
   for (auto s : state) {
     snappy::RawCompressFromIOVec(iov, contents.size(), dst, &zsize,
-                                 snappy::CompressionOptions{.level = level});
+                                 snappy::CompressionOptions{/*level=*/level});
     benchmark::DoNotOptimize(iov);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
@@ -226,7 +226,7 @@ void BM_UIOVecSink(benchmark::State& state) {
   // Uncompress into an iovec containing ten entries.
   const int kNumEntries = 10;
   struct iovec iov[kNumEntries];
-  char *dst = new char[contents.size()];
+  char* dst = new char[contents.size()];
   size_t used_so_far = 0;
   for (int i = 0; i < kNumEntries; ++i) {
     iov[i].iov_base = dst + used_so_far;
@@ -267,8 +267,9 @@ void BM_UFlatSink(benchmark::State& state) {
                        kTestDataFiles[file_index].size_limit);
 
   std::string zcontents;
-  snappy::Compress(contents.data(), contents.size(), &zcontents,
+  snappy::Compress(
-                   snappy::CompressionOptions{.level = state.range(1)});
+      contents.data(), contents.size(), &zcontents,
+      snappy::CompressionOptions{/*level=*/static_cast<int>(state.range(1))});
   char* dst = new char[contents.size()];
 
   for (auto s : state) {
@@ -304,7 +305,7 @@ void BM_ZFlat(benchmark::State& state) {
   size_t zsize = 0;
   for (auto s : state) {
     snappy::RawCompress(contents.data(), contents.size(), dst, &zsize,
-                        snappy::CompressionOptions{.level = level});
+                        snappy::CompressionOptions{/*level=*/level});
     benchmark::DoNotOptimize(dst);
   }
   state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) *
@@ -340,7 +341,7 @@ void BM_ZFlatAll(benchmark::State& state) {
   for (auto s : state) {
     for (int i = 0; i < num_files; ++i) {
       snappy::RawCompress(contents[i].data(), contents[i].size(), dst[i],
-                          &zsize, snappy::CompressionOptions{.level = level});
+                          &zsize, snappy::CompressionOptions{/*level=*/level});
       benchmark::DoNotOptimize(dst);
     }
   }
@@ -377,7 +378,7 @@ void BM_ZFlatIncreasingTableSize(benchmark::State& state) {
   for (auto s : state) {
     for (size_t i = 0; i < contents.size(); ++i) {
       snappy::RawCompress(contents[i].data(), contents[i].size(), dst[i],
-                          &zsize, snappy::CompressionOptions{.level = level});
+                          &zsize, snappy::CompressionOptions{/*level=*/level});
       benchmark::DoNotOptimize(dst);
     }
   }

snappy_compress_fuzzer.cc

@@ -44,7 +44,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
     std::string compressed;
     size_t compressed_size =
         snappy::Compress(input.data(), input.size(), &compressed,
-                         snappy::CompressionOptions{.level = level});
+                         snappy::CompressionOptions{/*level=*/level});
 
     (void)compressed_size;  // Variable only used in debug builds.
     assert(compressed_size == compressed.size());

snappy_unittest.cc

@@ -27,6 +27,7 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <algorithm>
+#include <cinttypes>
 #include <cmath>
 #include <cstdlib>
 #include <random>
@@ -484,6 +485,18 @@ TEST(Snappy, MaxBlowup) {
   Verify(input);
 }
 
+// Issue #201, when output is more than 4GB, we had a data corruption bug.
+// We cannot run this test always because of CI constraints.
+TEST(Snappy, DISABLED_MoreThan4GB) {
+  std::mt19937 rng;
+  std::uniform_int_distribution<int> uniform_byte(0, 255);
+  std::string input;
+  input.resize((1ull << 32) - 1);
+  for (uint64_t i = 0; i < ((1ull << 32) - 1); ++i)
+    input[i] = static_cast<char>(uniform_byte(rng));
+  Verify(input);
+}
+
 TEST(Snappy, RandomData) {
   std::minstd_rand0 rng(snappy::GetFlag(FLAGS_test_random_seed));
   std::uniform_int_distribution<int> uniform_0_to_3(0, 3);