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Diffstat (limited to 'chromium/third_party/brotli/src/brotli/enc/static_dict.h')
-rw-r--r-- | chromium/third_party/brotli/src/brotli/enc/static_dict.h | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/chromium/third_party/brotli/src/brotli/enc/static_dict.h b/chromium/third_party/brotli/src/brotli/enc/static_dict.h new file mode 100644 index 00000000000..1b5a77fe504 --- /dev/null +++ b/chromium/third_party/brotli/src/brotli/enc/static_dict.h @@ -0,0 +1,68 @@ +// Copyright 2013 Google Inc. All Rights Reserved. +// +// 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. +// +// Class to model the static dictionary. + +#ifndef BROTLI_ENC_STATIC_DICT_H_ +#define BROTLI_ENC_STATIC_DICT_H_ + +#include <algorithm> +#include <unordered_map> +#include <string> + +namespace brotli { + +class StaticDictionary { + public: + StaticDictionary() {} + void Insert(const std::string &str, int len, int dist) { + int ix = (dist << 6) + len; + std::unordered_map<std::string, int>::const_iterator it = map_.find(str); + if (it != map_.end() && ix >= it->second) { + return; + } + map_[str] = ix; + int v = 0; + for (int i = 0; i < 4 && i < str.size(); ++i) { + v += str[i] << (8 * i); + } + if (prefix_map_[v] < str.size()) { + prefix_map_[v] = str.size(); + } + } + int GetLength(int v) const { + std::unordered_map<int, int>::const_iterator it = prefix_map_.find(v); + if (it == prefix_map_.end()) { + return 0; + } + return it->second; + } + bool Get(const std::string &str, int *len, int *dist) const { + std::unordered_map<std::string, int>::const_iterator it = map_.find(str); + if (it == map_.end()) { + return false; + } + int v = it->second; + *len = v & 63; + *dist = v >> 6; + return true; + } + private: + std::unordered_map<std::string, int> map_; + std::unordered_map<int, int> prefix_map_; +}; + +} // namespace brotli + +#endif // BROTLI_ENC_STATIC_DICT_H_ |