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Diffstat (limited to 'browser/components/translation/cld2/internal/offsetmap.h')
| -rw-r--r-- | browser/components/translation/cld2/internal/offsetmap.h | 175 |
1 files changed, 0 insertions, 175 deletions
diff --git a/browser/components/translation/cld2/internal/offsetmap.h b/browser/components/translation/cld2/internal/offsetmap.h deleted file mode 100644 index 632555400..000000000 --- a/browser/components/translation/cld2/internal/offsetmap.h +++ /dev/null @@ -1,175 +0,0 @@ -// 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. - -// -// Author: dsites@google.com (Dick Sites) -// - -#ifndef UTIL_UTF8_OFFSETMAP_H_ -#define UTIL_UTF8_OFFSETMAP_H_ - -#include <string> // for string -#include "integral_types.h" // for uint32 - -// ***************************** OffsetMap ************************** -// -// An OffsetMap object is a container for a mapping from offsets in one text -// buffer A' to offsets in another text buffer A. It is most useful when A' is -// built from A via substitutions that occasionally do not preserve byte length. -// -// A series of operators are used to build the correspondence map, then -// calls can be made to map an offset in A' to an offset in A, or vice versa. -// The map starts with offset 0 in A corresponding to offset 0 in A'. -// The mapping is then built sequentially, adding on byte ranges that are -// identical in A and A', byte ranges that are inserted in A', and byte ranges -// that are deleted from A. All bytes beyond those specified when building the -// map are assumed to correspond, i.e. a Copy(infinity) is assumed at the -// end of the map. -// -// The internal data structure records positions at which bytes are added or -// deleted. Using the map is O(1) when increasing the A' or A offset -// monotonically, and O(n) when accessing random offsets, where n is the -// number of differences. -// - -namespace CLD2 { - -class OffsetMap { - public: - // Constructor, destructor - OffsetMap(); - ~OffsetMap(); - - // Clear the map - void Clear(); - - // Add to mapping from A to A', specifying how many next bytes correspond - // in A and A' - void Copy(int bytes); - - // Add to mapping from A to A', specifying how many next bytes are - // inserted in A' while not advancing in A at all - void Insert(int bytes); - - // Add to mapping from A to A', specifying how many next bytes are - // deleted from A while not advancing in A' at all - void Delete(int bytes); - - // Print map to file, for debugging - void Printmap(const char* filename); - - // [Finish building map,] Re-position to offset 0 - // This call is optional; MapForward and MapBack finish building the map - // if necessary - void Reset(); - - // Map an offset in A' to the corresponding offset in A - int MapBack(int aprimeoffset); - - // Map an offset in A to the corresponding offset in A' - int MapForward(int aoffset); - - // h = ComposeOffsetMap(g, f), where f is a map from A to A', g is - // from A' to A'' and h is from A to A''. - // - // Note that g->MoveForward(f->MoveForward(aoffset)) always equals - // to h->MoveForward(aoffset), while - // f->MoveBack(g->MoveBack(aprimeprimeoffset)) doesn't always equals - // to h->MoveBack(aprimeprimeoffset). This happens when deletion in - // f and insertion in g are at the same place. For example, - // - // A 1 2 3 4 - // ^ | ^ ^ - // | | / | f - // v vv v - // A' 1' 2' 3' - // ^ ^^ ^ - // | | \ | g - // v | v v - // A'' 1'' 2'' 3'' 4'' - // - // results in: - // - // A 1 2 3 4 - // ^ ^\ ^ ^ - // | | \ | | h - // v | vv v - // A'' 1'' 2'' 3'' 4'' - // - // 2'' is mapped 3 in the former figure, while 2'' is mapped to 2 in - // the latter figure. - static void ComposeOffsetMap(OffsetMap* g, OffsetMap* f, OffsetMap* h); - - // For debugging only; writes to stderr - void DumpWindow(); - - // For testing only -- force a mapping - void StuffIt(const std::string& diffs, int max_aoffset, int max_aprimeoffset); - - private: - enum MapOp {PREFIX_OP, COPY_OP, INSERT_OP, DELETE_OP}; - - void Flush(); - void FlushAll(); - void MaybeFlushAll(); - void Emit(MapOp op, int len); - - void SetLeft(); - void SetRight(); - - // Back up over previous range, 1..5 bytes - // Return subscript at the beginning of that. Pins at 0 - int Backup(int sub); - - // Parse next range, 1..5 bytes - // Return subscript just off the end of that - int ParseNext(int sub, MapOp* op, int* length); - - // Parse previous range, 1..5 bytes - // Return current subscript - int ParsePrevious(int sub, MapOp* op, int* length); - - void PrintPosition(const char* str); - - bool MoveRight(); // Returns true if OK - bool MoveLeft(); // Returns true if OK - void DumpString(); - - // Copies insert operations from source to dest. Returns true if no - // other operations are found. - static bool CopyInserts(OffsetMap* source, OffsetMap* dest); - - // Copies delete operations from source to dest. Returns true if no other - // operations are found. - static bool CopyDeletes(OffsetMap* source, OffsetMap* dest); - - std::string diffs_; - MapOp pending_op_; - uint32 pending_length_; - - // Offsets in the ranges below correspond to each other, with A' = A + diff - int next_diff_sub_; - int current_lo_aoffset_; - int current_hi_aoffset_; - int current_lo_aprimeoffset_; - int current_hi_aprimeoffset_; - int current_diff_; - int max_aoffset_; - int max_aprimeoffset_; -}; - -} // namespace CLD2 - -#endif // UTIL_UTF8_OFFSETMAP_H_ - |