Refactor MD5 implementation.

cpp/include/cudf/detail/utilities/hash_functions.cuh

@@ -21,110 +21,27 @@
 #include <cudf/fixed_point/fixed_point.hpp>
 #include <cudf/strings/string_view.cuh>
 #include <cudf/types.hpp>
-#include <hash/hash_constants.hpp>
 
 using hash_value_type = uint32_t;
 
 namespace cudf {
 namespace detail {
-namespace {
-/**
- * @brief Core MD5 algorithm implementation. Processes a single 512-bit chunk,
- * updating the hash value so far. Does not zero out the buffer contents.
- */
-void CUDA_DEVICE_CALLABLE md5_hash_step(md5_intermediate_data* hash_state)
-{
-  uint32_t A = hash_state->hash_value[0];
-  uint32_t B = hash_state->hash_value[1];
-  uint32_t C = hash_state->hash_value[2];
-  uint32_t D = hash_state->hash_value[3];
-
-  for (unsigned int j = 0; j < 64; j++) {
-    uint32_t F;
-    uint32_t g;
-    switch (j / 16) {
-      case 0:
-        F = (B & C) | ((~B) & D);
-        g = j;
-        break;
-      case 1:
-        F = (D & B) | ((~D) & C);
-        g = (5 * j + 1) % 16;
-        break;
-      case 2:
-        F = B ^ C ^ D;
-        g = (3 * j + 5) % 16;
-        break;
-      case 3:
-        F = C ^ (B | (~D));
-        g = (7 * j) % 16;
-        break;
-    }
-
-    uint32_t buffer_element_as_int;
-    std::memcpy(&buffer_element_as_int, hash_state->buffer + g * 4, 4);
-    F = F + A + md5_hash_constants[j] + buffer_element_as_int;
-    A = D;
-    D = C;
-    C = B;
-    B = B + __funnelshift_l(F, F, md5_shift_constants[((j / 16) * 4) + (j % 4)]);
-  }
-
-  hash_state->hash_value[0] += A;
-  hash_state->hash_value[1] += B;
-  hash_state->hash_value[2] += C;
-  hash_state->hash_value[3] += D;
-
-  hash_state->buffer_length = 0;
-}
 
 /**
- * @brief Core MD5 element processing function
+ * Normalization of floating point NaNs and zeros, passthrough for all other values.
  */
-template <typename TKey>
-void CUDA_DEVICE_CALLABLE md5_process(TKey const& key, md5_intermediate_data* hash_state)
+template <typename T>
+T CUDA_DEVICE_CALLABLE normalize_nans_and_zeros(T const& key)
 {
-  uint32_t const len  = sizeof(TKey);
-  uint8_t const* data = reinterpret_cast<uint8_t const*>(&key);
-  hash_state->message_length += len;
-
-  // 64 bytes for the number of byt es processed in a given step
-  constexpr int md5_chunk_size = 64;
-  if (hash_state->buffer_length + len < md5_chunk_size) {
-    std::memcpy(hash_state->buffer + hash_state->buffer_length, data, len);
-    hash_state->buffer_length += len;
-  } else {
-    uint32_t copylen = md5_chunk_size - hash_state->buffer_length;
-
-    std::memcpy(hash_state->buffer + hash_state->buffer_length, data, copylen);
-    md5_hash_step(hash_state);
-
-    while (len > md5_chunk_size + copylen) {
-      std::memcpy(hash_state->buffer, data + copylen, md5_chunk_size);
-      md5_hash_step(hash_state);
-      copylen += md5_chunk_size;
+  if constexpr (is_floating_point<T>()) {
+    if (isnan(key)) {
+      return std::numeric_limits<T>::quiet_NaN();
+    } else if (key == T{0.0}) {
+      return T{0.0};
     }
-
-    std::memcpy(hash_state->buffer, data + copylen, len - copylen);
-    hash_state->buffer_length = len - copylen;
-  }
-}
-
-/**
- * Normalization of floating point NANs and zeros helper
- */
-template <typename T, std::enable_if_t<std::is_floating_point<T>::value>* = nullptr>
-T CUDA_DEVICE_CALLABLE normalize_nans_and_zeros_helper(T key)
-{
-  if (isnan(key)) {
-    return std::numeric_limits<T>::quiet_NaN();
-  } else if (key == T{0.0}) {
-    return T{0.0};
-  } else {
-    return key;
   }
+  return key;
 }
-}  // namespace
 
 /**
  * Modified GPU implementation of
@@ -149,217 +66,6 @@ void CUDA_DEVICE_CALLABLE uint32ToLowercaseHexString(uint32_t num, char* destina
   std::memcpy(destination, reinterpret_cast<uint8_t*>(&x), 8);
 }
 
-struct MD5ListHasher {
-  template <typename T, std::enable_if_t<is_chrono<T>()>* = nullptr>
-  void __device__ operator()(column_device_view data_col,
-                             size_type offset_begin,
-                             size_type offset_end,
-                             md5_intermediate_data* hash_state) const
-  {
-    cudf_assert(false && "MD5 Unsupported chrono type column");
-  }
-
-  template <typename T, std::enable_if_t<!is_fixed_width<T>()>* = nullptr>
-  void __device__ operator()(column_device_view data_col,
-                             size_type offset_begin,
-                             size_type offset_end,
-                             md5_intermediate_data* hash_state) const
-  {
-    cudf_assert(false && "MD5 Unsupported non-fixed-width type column");
-  }
-
-  template <typename T, std::enable_if_t<is_floating_point<T>()>* = nullptr>
-  void __device__ operator()(column_device_view data_col,
-                             size_type offset_begin,
-                             size_type offset_end,
-                             md5_intermediate_data* hash_state) const
-  {
-    for (int i = offset_begin; i < offset_end; i++) {
-      if (!data_col.is_null(i)) {
-        md5_process(normalize_nans_and_zeros_helper<T>(data_col.element<T>(i)), hash_state);
-      }
-    }
-  }
-
-  template <
-    typename T,
-    std::enable_if_t<is_fixed_width<T>() && !is_floating_point<T>() && !is_chrono<T>()>* = nullptr>
-  void CUDA_DEVICE_CALLABLE operator()(column_device_view data_col,
-                                       size_type offset_begin,
-                                       size_type offset_end,
-                                       md5_intermediate_data* hash_state) const
-  {
-    for (int i = offset_begin; i < offset_end; i++) {
-      if (!data_col.is_null(i)) md5_process(data_col.element<T>(i), hash_state);
-    }
-  }
-};
-
-template <>
-void CUDA_DEVICE_CALLABLE
-MD5ListHasher::operator()<string_view>(column_device_view data_col,
-                                       size_type offset_begin,
-                                       size_type offset_end,
-                                       md5_intermediate_data* hash_state) const
-{
-  for (int i = offset_begin; i < offset_end; i++) {
-    if (!data_col.is_null(i)) {
-      string_view key     = data_col.element<string_view>(i);
-      uint32_t const len  = static_cast<uint32_t>(key.size_bytes());
-      uint8_t const* data = reinterpret_cast<uint8_t const*>(key.data());
-
-      hash_state->message_length += len;
-
-      if (hash_state->buffer_length + len < 64) {
-        std::memcpy(hash_state->buffer + hash_state->buffer_length, data, len);
-        hash_state->buffer_length += len;
-      } else {
-        uint32_t copylen = 64 - hash_state->buffer_length;
-        std::memcpy(hash_state->buffer + hash_state->buffer_length, data, copylen);
-        md5_hash_step(hash_state);
-
-        while (len > 64 + copylen) {
-          std::memcpy(hash_state->buffer, data + copylen, 64);
-          md5_hash_step(hash_state);
-          copylen += 64;
-        }
-
-        std::memcpy(hash_state->buffer, data + copylen, len - copylen);
-        hash_state->buffer_length = len - copylen;
-      }
-    }
-  }
-}
-
-struct MD5Hash {
-  MD5Hash() = default;
-  constexpr MD5Hash(uint32_t seed) : m_seed(seed) {}
-
-  void __device__ finalize(md5_intermediate_data* hash_state, char* result_location) const
-  {
-    auto const full_length = (static_cast<uint64_t>(hash_state->message_length)) << 3;
-    thrust::fill_n(thrust::seq, hash_state->buffer + hash_state->buffer_length, 1, 0x80);
-
-    // 64 bytes for the number of bytes processed in a given step
-    constexpr int md5_chunk_size = 64;
-    // 8 bytes for the total message length, appended to the end of the last chunk processed
-    constexpr int message_length_size = 8;
-    // 1 byte for the end of the message flag
-    constexpr int end_of_message_size = 1;
-    if (hash_state->buffer_length + message_length_size + end_of_message_size <= md5_chunk_size) {
-      thrust::fill_n(
-        thrust::seq,
-        hash_state->buffer + hash_state->buffer_length + 1,
-        (md5_chunk_size - message_length_size - end_of_message_size - hash_state->buffer_length),
-        0x00);
-    } else {
-      thrust::fill_n(thrust::seq,
-                     hash_state->buffer + hash_state->buffer_length + 1,
-                     (md5_chunk_size - hash_state->buffer_length),
-                     0x00);
-      md5_hash_step(hash_state);
-
-      thrust::fill_n(thrust::seq, hash_state->buffer, md5_chunk_size - message_length_size, 0x00);
-    }
-
-    std::memcpy(hash_state->buffer + md5_chunk_size - message_length_size,
-                reinterpret_cast<uint8_t const*>(&full_length),
-                message_length_size);
-    md5_hash_step(hash_state);
-
-#pragma unroll
-    for (int i = 0; i < 4; ++i)
-      uint32ToLowercaseHexString(hash_state->hash_value[i], result_location + (8 * i));
-  }
-
-  template <typename T, std::enable_if_t<is_chrono<T>()>* = nullptr>
-  void __device__ operator()(column_device_view col,
-                             size_type row_index,
-                             md5_intermediate_data* hash_state) const
-  {
-    cudf_assert(false && "MD5 Unsupported chrono type column");
-  }
-
-  template <typename T, std::enable_if_t<!is_fixed_width<T>()>* = nullptr>
-  void __device__ operator()(column_device_view col,
-                             size_type row_index,
-                             md5_intermediate_data* hash_state) const
-  {
-    cudf_assert(false && "MD5 Unsupported non-fixed-width type column");
-  }
-
-  template <typename T, std::enable_if_t<is_floating_point<T>()>* = nullptr>
-  void __device__ operator()(column_device_view col,
-                             size_type row_index,
-                             md5_intermediate_data* hash_state) const
-  {
-    md5_process(normalize_nans_and_zeros_helper<T>(col.element<T>(row_index)), hash_state);
-  }
-
-  template <
-    typename T,
-    std::enable_if_t<is_fixed_width<T>() && !is_floating_point<T>() && !is_chrono<T>()>* = nullptr>
-  void CUDA_DEVICE_CALLABLE operator()(column_device_view col,
-                                       size_type row_index,
-                                       md5_intermediate_data* hash_state) const
-  {
-    md5_process(col.element<T>(row_index), hash_state);
-  }
-
- private:
-  uint32_t m_seed{cudf::DEFAULT_HASH_SEED};
-};
-
-template <>
-void CUDA_DEVICE_CALLABLE MD5Hash::operator()<string_view>(column_device_view col,
-                                                           size_type row_index,
-                                                           md5_intermediate_data* hash_state) const
-{
-  string_view key     = col.element<string_view>(row_index);
-  uint32_t const len  = static_cast<uint32_t>(key.size_bytes());
-  uint8_t const* data = reinterpret_cast<uint8_t const*>(key.data());
-
-  hash_state->message_length += len;
-
-  if (hash_state->buffer_length + len < 64) {
-    std::memcpy(hash_state->buffer + hash_state->buffer_length, data, len);
-    hash_state->buffer_length += len;
-  } else {
-    uint32_t copylen = 64 - hash_state->buffer_length;
-    std::memcpy(hash_state->buffer + hash_state->buffer_length, data, copylen);
-    md5_hash_step(hash_state);
-
-    while (len > 64 + copylen) {
-      std::memcpy(hash_state->buffer, data + copylen, 64);
-      md5_hash_step(hash_state);
-      copylen += 64;
-    }
-
-    std::memcpy(hash_state->buffer, data + copylen, len - copylen);
-    hash_state->buffer_length = len - copylen;
-  }
-}
-
-template <>
-void CUDA_DEVICE_CALLABLE MD5Hash::operator()<list_view>(column_device_view col,
-                                                         size_type row_index,
-                                                         md5_intermediate_data* hash_state) const
-{
-  static constexpr size_type offsets_column_index{0};
-  static constexpr size_type data_column_index{1};
-
-  column_device_view offsets = col.child(offsets_column_index);
-  column_device_view data    = col.child(data_column_index);
-
-  if (data.type().id() == type_id::LIST) cudf_assert(false && "Nested list unsupported");
-
-  cudf::type_dispatcher(data.type(),
-                        MD5ListHasher{},
-                        data,
-                        offsets.element<size_type>(row_index),
-                        offsets.element<size_type>(row_index + 1),
-                        hash_state);
-}
 }  // namespace detail
 }  // namespace cudf