111 lines
4.1 KiB
C++
111 lines
4.1 KiB
C++
// Copyright 2013 Google Inc. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// Author: dsites@google.com (Dick Sites)
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//
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#ifndef I18N_ENCODINGS_CLD2_INTERNAL_GETONESCRIPTSPAN_H_
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#define I18N_ENCODINGS_CLD2_INTERNAL_GETONESCRIPTSPAN_H_
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#include "integral_types.h"
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#include "langspan.h"
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#include "offsetmap.h"
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namespace CLD2 {
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static const int kMaxScriptBuffer = 40960;
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static const int kMaxScriptLowerBuffer = (kMaxScriptBuffer * 3) / 2;
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static const int kMaxScriptBytes = kMaxScriptBuffer - 32; // Leave some room
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static const int kWithinScriptTail = 32; // Stop at word space in last
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// N bytes of script buffer
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static inline bool IsContinuationByte(char c) {
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return static_cast<signed char>(c) < -64;
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}
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// Gets lscript number for letters; always returns
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// 0 (common script) for non-letters
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int GetUTF8LetterScriptNum(const char* src);
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// Update src pointer to point to next quadgram, +2..+5
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// Looks at src[0..4]
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const char* AdvanceQuad(const char* src);
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class ScriptScanner {
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public:
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ScriptScanner(const char* buffer, int buffer_length, bool is_plain_text);
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ScriptScanner(const char* buffer, int buffer_length, bool is_plain_text,
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bool any_text, bool any_script);
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~ScriptScanner();
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// Copy next run of same-script non-tag letters to buffer [NUL terminated]
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bool GetOneScriptSpan(LangSpan* span);
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// Force Latin and Cyrillic scripts to be lowercase
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void LowerScriptSpan(LangSpan* span);
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// Copy next run of same-script non-tag letters to buffer [NUL terminated]
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// Force Latin and Cyrillic scripts to be lowercase
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bool GetOneScriptSpanLower(LangSpan* span);
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// Copy next run of non-tag characters to buffer [NUL terminated]
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// This just removes tags and removes entities
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// Buffer has leading space
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bool GetOneTextSpan(LangSpan* span);
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// Maps byte offset in most recent GetOneScriptSpan/Lower
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// span->text [0..text_bytes] into an additional byte offset from
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// span->offset, to get back to corresponding text in the original
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// input buffer.
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// text_offset must be the first byte
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// of a UTF-8 character, or just beyond the last character. Normally this
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// routine is called with the first byte of an interesting range and
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// again with the first byte of the following range.
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int MapBack(int text_offset);
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const char* GetBufferStart() {return start_byte_;};
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private:
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// Skip over tags and non-letters
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int SkipToFrontOfSpan(const char* src, int len, int* script);
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const char* start_byte_; // Starting byte of buffer to scan
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const char* next_byte_; // First unscanned byte
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const char* next_byte_limit_; // Last byte + 1
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int byte_length_; // Bytes left: next_byte_limit_ - next_byte_
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bool is_plain_text_; // true fo text, false for HTML
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char* script_buffer_; // Holds text with expanded entities
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char* script_buffer_lower_; // Holds lowercased text
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bool letters_marks_only_; // To distinguish scriptspan of one
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// letters/marks vs. any mixture of text
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bool one_script_only_; // To distinguish scriptspan of one
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// script vs. any mixture of scripts
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int exit_state_; // For tag parser kTagParseTbl_0, based
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// on letters_marks_only_
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public :
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// Expose for debugging
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OffsetMap map2original_; // map from script_buffer_ to buffer
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OffsetMap map2uplow_; // map from script_buffer_lower_ to script_buffer_
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};
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} // namespace CLD2
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#endif // I18N_ENCODINGS_CLD2_INTERNAL_GETONESCRIPTSPAN_H_
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