Add strings udf C++ classes and functions for phase II

python/strings_udf/cpp/include/cudf/strings/udf/case.cuh

@@ -0,0 +1,209 @@
+/*
+ * Copyright (c) 2022, NVIDIA CORPORATION.
+ *
+ * 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.
+ */
+#pragma once
+
+#include "udf_string.cuh"
+
+#include <cudf/strings/detail/char_tables.hpp>
+#include <cudf/strings/detail/utf8.hpp>
+#include <cudf/strings/string_view.cuh>
+
+namespace cudf {
+namespace strings {
+namespace udf {
+
+/**
+ * @brief Global variables for character-type flags and case conversion
+ */
+struct chars_tables {
+  cudf::strings::detail::character_flags_table_type* flags_table;
+  cudf::strings::detail::character_cases_table_type* cases_table;
+  struct cudf::strings::detail::special_case_mapping* special_case_mapping_table;
+};
+
+namespace detail {
+
+/**
+ * @brief Utility for converting a single character
+ *
+ * There are special cases where the conversion may result in multiple characters.
+ *
+ * @param tables The char tables required for conversion
+ * @param result String to append the converted character
+ * @param code_point The code-point of the character to convert
+ * @param flag The char-type flag of the character to convert
+ */
+__device__ inline void convert_char(chars_tables const tables,
+                                    udf_string& result,
+                                    uint32_t code_point,
+                                    uint8_t flag)
+{
+  if (!cudf::strings::detail::IS_SPECIAL(flag)) {
+    result.append(cudf::strings::detail::codepoint_to_utf8(tables.cases_table[code_point]));
+    return;
+  }
+
+  // handle special case
+  auto const map =
+    tables
+      .special_case_mapping_table[cudf::strings::detail::get_special_case_hash_index(code_point)];
+  auto const output_count =
+    cudf::strings::detail::IS_LOWER(flag) ? map.num_upper_chars : map.num_lower_chars;
+  auto const* output_chars = cudf::strings::detail::IS_LOWER(flag) ? map.upper : map.lower;
+  for (uint16_t idx = 0; idx < output_count; idx++) {
+    result.append(cudf::strings::detail::codepoint_to_utf8(output_chars[idx]));
+  }
+}
+
+/**
+ * @brief Converts the given string to either upper or lower case
+ *
+ * @param tables The char tables required for conversion
+ * @param d_str Input string to convert
+ * @param case_flag Identifies upper/lower case conversion
+ * @return New string containing the converted characters
+ */
+__device__ inline udf_string convert_case(
+  chars_tables const tables,
+  string_view d_str,
+  cudf::strings::detail::character_flags_table_type case_flag)
+{
+  udf_string result;
+  for (auto const chr : d_str) {
+    auto const code_point = cudf::strings::detail::utf8_to_codepoint(chr);
+    auto const flag       = code_point <= 0x00FFFF ? tables.flags_table[code_point] : 0;
+
+    if ((flag & case_flag) || (cudf::strings::detail::IS_SPECIAL(flag) &&
+                               !cudf::strings::detail::IS_UPPER_OR_LOWER(flag))) {
+      convert_char(tables, result, code_point, flag);
+    } else {
+      result.append(chr);
+    }
+  }
+
+  return result;
+}
+
+/**
+ * @brief Utility for capitalize and title functions
+ *
+ * @tparam CaptializeNextFn returns true if the next candidate character should be capitalized
+ * @param tables The char tables required for conversion
+ * @param d_str Input string to convert
+ * @return New string containing the converted characters
+ */
+template <typename CapitalizeNextFn>
+__device__ inline udf_string capitalize(chars_tables const tables,
+                                        string_view d_str,
+                                        CapitalizeNextFn next_fn)
+{
+  udf_string result;
+  bool capitalize = true;
+  for (auto const chr : d_str) {
+    auto const code_point = cudf::strings::detail::utf8_to_codepoint(chr);
+    auto const flag       = code_point <= 0x00FFFF ? tables.flags_table[code_point] : 0;
+    auto const change_case =
+      capitalize ? cudf::strings::detail::IS_LOWER(flag) : cudf::strings::detail::IS_UPPER(flag);
+    if (change_case) {
+      detail::convert_char(tables, result, code_point, flag);
+    } else {
+      result.append(chr);
+    }
+    capitalize = next_fn(flag);
+  }
+  return result;
+}
+}  // namespace detail
+
+/**
+ * @brief Converts the given string to lower case
+ *
+ * @param tables The char tables required for conversion
+ * @param d_str Input string to convert
+ * @return New string containing the converted characters
+ */
+__device__ inline udf_string to_lower(chars_tables const tables, string_view d_str)
+{
+  cudf::strings::detail::character_flags_table_type case_flag =
+    cudf::strings::detail::IS_UPPER(0xFF);  // convert only upper case characters
+  return detail::convert_case(tables, d_str, case_flag);
+}
+
+/**
+ * @brief Converts the given string to upper case
+ *
+ * @param tables The char tables required for conversion
+ * @param d_str Input string to convert
+ * @return New string containing the converted characters
+ */
+__device__ inline udf_string to_upper(chars_tables const tables, string_view d_str)
+{
+  cudf::strings::detail::character_flags_table_type case_flag =
+    cudf::strings::detail::IS_LOWER(0xFF);  // convert only lower case characters
+  return detail::convert_case(tables, d_str, case_flag);
+}
+
+/**
+ * @brief Converts the given string to lower/upper case
+ *
+ * All lower case characters are converted to upper case and
+ * all upper case characters are converted to lower case.
+ *
+ * @param tables The char tables required for conversion
+ * @param d_str Input string to convert
+ * @return New string containing the converted characters
+ */
+__device__ inline udf_string swapcase(chars_tables const tables, string_view d_str)
+{
+  cudf::strings::detail::character_flags_table_type case_flag =
+    cudf::strings::detail::IS_LOWER(0xFF) | cudf::strings::detail::IS_UPPER(0xFF);
+  return detail::convert_case(tables, d_str, case_flag);
+}
+
+/**
+ * @brief Capitalize the first character of the given string
+ *
+ * @param tables The char tables required for conversion
+ * @param d_str Input string to convert
+ * @return New string containing the converted characters
+ */
+__device__ inline udf_string capitalize(chars_tables const tables, string_view d_str)
+{
+  auto next_fn = [](cudf::strings::detail::character_flags_table_type) -> bool { return false; };
+  return detail::capitalize(tables, d_str, next_fn);
+}
+
+/**
+ * @brief Converts the given string to title case
+ *
+ * The first character after a non-character is converted to upper case.
+ * All other characters are converted to lower case.
+ *
+ * @param tables The char tables required for conversion
+ * @param d_str Input string to convert
+ * @return New string containing the converted characters
+ */
+__device__ inline udf_string title(chars_tables const tables, string_view d_str)
+{
+  auto next_fn = [](cudf::strings::detail::character_flags_table_type flag) -> bool {
+    return !cudf::strings::detail::IS_ALPHA(flag);
+  };
+  return detail::capitalize(tables, d_str, next_fn);
+}
+
+}  // namespace udf
+}  // namespace strings
+}  // namespace cudf

python/strings_udf/cpp/include/cudf/strings/udf/char_types.cuh

@@ -25,7 +25,7 @@ namespace strings {
 namespace udf {
 
 /**
- * @brief Returns true if all characters in the string are of the type specified.
+ * @brief Returns true if all characters in the string are of the type specified
  *
  * The output will be false if the string is empty or has at least one character
  * not of the specified type. If all characters fit the type then true is returned.

python/strings_udf/cpp/include/cudf/strings/udf/numeric.cuh

@@ -0,0 +1,74 @@
+
+/*
+ * Copyright (c) 2022, NVIDIA CORPORATION.
+ *
+ * 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.
+ */
+#pragma once
+
+#include "udf_string.cuh"
+
+#include <cudf/strings/detail/convert/int_to_string.cuh>
+#include <cudf/strings/detail/convert/string_to_float.cuh>
+#include <cudf/strings/detail/convert/string_to_int.cuh>
+
+namespace cudf {
+namespace strings {
+namespace udf {
+
+/**
+ * @brief Converts a string into an integer
+ *
+ * The '+' and '-' are allowed but only at the beginning of the string.
+ * The string is expected to contain base-10 [0-9] characters only.
+ * Any other character will end the parse.
+ * Overflow of the int64 type is not detected.
+ */
+__device__ inline int64_t stoi(string_view const& d_str)
+{
+  return cudf::strings::detail::string_to_integer(d_str);
+}
+
+/**
+ * @brief Converts an integer into string
+ *
+ * @param value integer value to convert
+ */
+__device__ inline udf_string to_string(int64_t value)
+{
+  udf_string result;
+  if (value == 0) {
+    result.append("0");
+    return result;
+  }
+  auto const d_value = static_cast<double>(abs(value));
+  auto digits        = static_cast<int32_t>(log10(d_value)) + 1 + (value < 0);
+  result.resize(digits);
+  cudf::strings::detail::integer_to_string(value, result.data());
+  return result;
+}
+
+/**
+ * @brief Converts a string into a double
+ *
+ * Support scientific notation as well.
+ * Overflow goes to inf or -inf and underflow may go to 0.
+ */
+__device__ inline double stod(string_view const& d_str)
+{
+  return cudf::strings::detail::stod(d_str);
+}
+
+}  // namespace udf
+}  // namespace strings
+}  // namespace cudf

python/strings_udf/cpp/include/cudf/strings/udf/pad.cuh

@@ -0,0 +1,72 @@
+
+/*
+ * Copyright (c) 2022, NVIDIA CORPORATION.
+ *
+ * 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.
+ */
+#pragma once
+
+#include "udf_string.cuh"
+
+#include <cudf/strings/detail/pad_impl.cuh>
+
+namespace cudf {
+namespace strings {
+namespace udf {
+
+/**
+ * @brief Pad beginning and/or end of a string with the given fill character
+ *
+ * The side_type::BOTH will attempt to center the text using the `fill_char`.
+ * If the `width` is smaller than the length of `d_str` no change occurs.
+ *
+ * @tparam side Specify where the padding should occur
+ * @param d_str String to pad
+ * @param width Minimum length in characters of the output string
+ * @param fill_char Character used for padding
+ */
+template <side_type side = side_type::RIGHT>
+__device__ udf_string pad(cudf::string_view const d_str,
+                          cudf::size_type width,
+                          cudf::string_view fill_char = cudf::string_view{" ", 1})
+{
+  if (fill_char.empty()) { return udf_string{d_str}; }
+
+  udf_string result;
+  result.resize(cudf::strings::detail::compute_padded_size(d_str, width, fill_char.size_bytes()));
+  cudf::strings::detail::pad_impl<side>(d_str, width, *fill_char.begin(), result.data());
+  return result;
+}
+
+/**
+ * @brief Pad beginning of a string with zero '0'
+ *
+ * If the `width` is smaller than the length of `d_str` no change occurs.
+ *
+ * If d_str starts with a sign character ('-' or '+') then '0' padding
+ * starts after the sign.
+ *
+ * @param d_str String to fill
+ * @param width Minimum length in characters of the output string
+ */
+__device__ udf_string zfill(cudf::string_view const d_str, cudf::size_type width)
+{
+  udf_string result;
+  result.resize(cudf::strings::detail::compute_padded_size(d_str, width, 1));
+  cudf::strings::detail::zfill_impl(d_str, width, result.data());
+  return result;
+}
+
+}  // namespace udf
+}  // namespace strings
+}  // namespace cudf

python/strings_udf/cpp/include/cudf/strings/udf/search.cuh

@@ -23,7 +23,7 @@ namespace udf {
 
 /**
  * @brief Returns the number of times that the target string appears
- * in the source string.
+ * in the source string
  *
  * If `start <= 0` the search begins at the beginning of the `source` string.
  * If `end <=0` or `end` is greater the length of the `source` string,