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Diffstat (limited to 'third_party/abseil_cpp/absl/strings/str_split.cc')
-rw-r--r-- | third_party/abseil_cpp/absl/strings/str_split.cc | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/strings/str_split.cc b/third_party/abseil_cpp/absl/strings/str_split.cc new file mode 100644 index 000000000000..e08c26b6bbbe --- /dev/null +++ b/third_party/abseil_cpp/absl/strings/str_split.cc @@ -0,0 +1,139 @@ +// Copyright 2017 The Abseil Authors. +// +// 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 +// +// https://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. + +#include "absl/strings/str_split.h" + +#include <algorithm> +#include <cassert> +#include <cstdint> +#include <cstdlib> +#include <cstring> +#include <iterator> +#include <limits> +#include <memory> + +#include "absl/base/internal/raw_logging.h" +#include "absl/strings/ascii.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN + +namespace { + +// This GenericFind() template function encapsulates the finding algorithm +// shared between the ByString and ByAnyChar delimiters. The FindPolicy +// template parameter allows each delimiter to customize the actual find +// function to use and the length of the found delimiter. For example, the +// Literal delimiter will ultimately use absl::string_view::find(), and the +// AnyOf delimiter will use absl::string_view::find_first_of(). +template <typename FindPolicy> +absl::string_view GenericFind(absl::string_view text, + absl::string_view delimiter, size_t pos, + FindPolicy find_policy) { + if (delimiter.empty() && text.length() > 0) { + // Special case for empty string delimiters: always return a zero-length + // absl::string_view referring to the item at position 1 past pos. + return absl::string_view(text.data() + pos + 1, 0); + } + size_t found_pos = absl::string_view::npos; + absl::string_view found(text.data() + text.size(), + 0); // By default, not found + found_pos = find_policy.Find(text, delimiter, pos); + if (found_pos != absl::string_view::npos) { + found = absl::string_view(text.data() + found_pos, + find_policy.Length(delimiter)); + } + return found; +} + +// Finds using absl::string_view::find(), therefore the length of the found +// delimiter is delimiter.length(). +struct LiteralPolicy { + size_t Find(absl::string_view text, absl::string_view delimiter, size_t pos) { + return text.find(delimiter, pos); + } + size_t Length(absl::string_view delimiter) { return delimiter.length(); } +}; + +// Finds using absl::string_view::find_first_of(), therefore the length of the +// found delimiter is 1. +struct AnyOfPolicy { + size_t Find(absl::string_view text, absl::string_view delimiter, size_t pos) { + return text.find_first_of(delimiter, pos); + } + size_t Length(absl::string_view /* delimiter */) { return 1; } +}; + +} // namespace + +// +// ByString +// + +ByString::ByString(absl::string_view sp) : delimiter_(sp) {} + +absl::string_view ByString::Find(absl::string_view text, size_t pos) const { + if (delimiter_.length() == 1) { + // Much faster to call find on a single character than on an + // absl::string_view. + size_t found_pos = text.find(delimiter_[0], pos); + if (found_pos == absl::string_view::npos) + return absl::string_view(text.data() + text.size(), 0); + return text.substr(found_pos, 1); + } + return GenericFind(text, delimiter_, pos, LiteralPolicy()); +} + +// +// ByChar +// + +absl::string_view ByChar::Find(absl::string_view text, size_t pos) const { + size_t found_pos = text.find(c_, pos); + if (found_pos == absl::string_view::npos) + return absl::string_view(text.data() + text.size(), 0); + return text.substr(found_pos, 1); +} + +// +// ByAnyChar +// + +ByAnyChar::ByAnyChar(absl::string_view sp) : delimiters_(sp) {} + +absl::string_view ByAnyChar::Find(absl::string_view text, size_t pos) const { + return GenericFind(text, delimiters_, pos, AnyOfPolicy()); +} + +// +// ByLength +// +ByLength::ByLength(ptrdiff_t length) : length_(length) { + ABSL_RAW_CHECK(length > 0, ""); +} + +absl::string_view ByLength::Find(absl::string_view text, + size_t pos) const { + pos = std::min(pos, text.size()); // truncate `pos` + absl::string_view substr = text.substr(pos); + // If the string is shorter than the chunk size we say we + // "can't find the delimiter" so this will be the last chunk. + if (substr.length() <= static_cast<size_t>(length_)) + return absl::string_view(text.data() + text.size(), 0); + + return absl::string_view(substr.data() + length_, 0); +} + +ABSL_NAMESPACE_END +} // namespace absl |