diff options
Diffstat (limited to 'src/UndoHistory.h')
| -rw-r--r-- | src/UndoHistory.h | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/src/UndoHistory.h b/src/UndoHistory.h index 8975b4362..d9f4d37ce 100644 --- a/src/UndoHistory.h +++ b/src/UndoHistory.h @@ -10,6 +10,30 @@ namespace Scintilla::Internal { +// ScaledVector is a vector of unsigned integers that uses elements sized to hold the largest value. +// Thus, if an undo history only contains short insertions and deletions the lengths vector may +// only use 2 bytes or even 1 byte for each length. +// This saves much memory often reducing by 50% for 32-bit builds and 75% for 64-bit builds. + +class ScaledVector { + size_t elementSize = 1; + size_t elementMax = 255; + std::vector<uint8_t> bytes; +public: + [[nodiscard]] size_t Size() const noexcept; + [[nodiscard]] size_t ValueAt(size_t index) const noexcept; + [[nodiscard]] intptr_t SignedValueAt(size_t index) const noexcept; + void SetValueAt(size_t index, size_t value); + void ClearValueAt(size_t index) noexcept; + void Clear() noexcept; + void Truncate(size_t length) noexcept; + void ReSize(size_t length); + void PushBack(); + + // For testing + [[nodiscard]] size_t SizeInBytes() const noexcept; +}; + class UndoActionType { public: ActionType at : 4; @@ -19,12 +43,14 @@ public: struct UndoActions { std::vector<UndoActionType> types; - std::vector<Sci::Position> positions; - std::vector<Sci::Position> lengths; + ScaledVector positions; + ScaledVector lengths; + UndoActions() noexcept; void resize(size_t length); [[nodiscard]] size_t size() const noexcept; - void Create(size_t index, ActionType at_, Sci::Position position_ = 0, Sci::Position lenData_ = 0, bool mayCoalesce_ = true) noexcept; + void CreateStart(size_t index) noexcept; + void Create(size_t index, ActionType at_, Sci::Position position_=0, Sci::Position lenData_=0, bool mayCoalesce_=true); }; class ScrapStack { |