Addition of PositionCache module which adds cacing of string

to position information and segments long pieces of text so they
can be handled more efficiently.

1 files changed, 154 insertions, 0 deletions

diff --git a/src/PositionCache.h b/src/PositionCache.h
new file mode 100644
index 000000000..fc261fbbc
--- /dev/null
+++ b/src/PositionCache.h
@@ -0,0 +1,154 @@
+// Scintilla source code edit control
+/** @file PositionCache.h
+ ** Classes for caching layout information.
+ **/
+// Copyright 1998-2007 by Neil Hodgson <neilh@scintilla.org>
+// The License.txt file describes the conditions under which this software may be distributed.
+
+#ifndef POSITIONCACHE_H
+#define POSITIONCACHE_H
+
+static inline bool IsEOLChar(char ch) {
+	return (ch == '\r') || (ch == '\n');
+}
+
+/**
+ */
+class LineLayout {
+private:
+	friend class LineLayoutCache;
+	int *lineStarts;
+	int lenLineStarts;
+	/// Drawing is only performed for @a maxLineLength characters on each line.
+	int lineNumber;
+	bool inCache;
+public:
+	enum { wrapWidthInfinite = 0x7ffffff };
+	int maxLineLength;
+	int numCharsInLine;
+	enum validLevel { llInvalid, llCheckTextAndStyle, llPositions, llLines } validity;
+	int xHighlightGuide;
+	bool highlightColumn;
+	int selStart;
+	int selEnd;
+	bool containsCaret;
+	int edgeColumn;
+	char *chars;
+	unsigned char *styles;
+	int styleBitsSet;
+	char *indicators;
+	int *positions;
+	char bracePreviousStyles[2];
+
+	// Hotspot support
+	int hsStart;
+	int hsEnd;
+
+	// Wrapped line support
+	int widthLine;
+	int lines;
+
+	LineLayout(int maxLineLength_);
+	virtual ~LineLayout();
+	void Resize(int maxLineLength_);
+	void Free();
+	void Invalidate(validLevel validity_);
+	int LineStart(int line) const;
+	int LineLastVisible(int line) const;
+	void SetLineStart(int line, int start);
+	void SetBracesHighlight(Range rangeLine, Position braces[],
+		char bracesMatchStyle, int xHighlight);
+	void RestoreBracesHighlight(Range rangeLine, Position braces[]);
+	int FindBefore(int x, int lower, int upper) const;
+};
+
+/**
+ */
+class LineLayoutCache {
+	int level;
+	int length;
+	int size;
+	LineLayout **cache;
+	bool allInvalidated;
+	int styleClock;
+	int useCount;
+	void Allocate(int length_);
+	void AllocateForLevel(int linesOnScreen, int linesInDoc);
+public:
+	LineLayoutCache();
+	virtual ~LineLayoutCache();
+	void Deallocate();
+	enum {
+		llcNone=SC_CACHE_NONE,
+		llcCaret=SC_CACHE_CARET,
+		llcPage=SC_CACHE_PAGE,
+		llcDocument=SC_CACHE_DOCUMENT
+	};
+	void Invalidate(LineLayout::validLevel validity_);
+	void SetLevel(int level_);
+	int GetLevel() { return level; }
+	LineLayout *Retrieve(int lineNumber, int lineCaret, int maxChars, int styleClock_,
+		int linesOnScreen, int linesInDoc);
+	void Dispose(LineLayout *ll);
+};
+
+class PositionCacheEntry {
+	unsigned int styleNumber:8;
+	unsigned int len:8;
+	unsigned int clock:16;
+	short *positions;
+public:
+	PositionCacheEntry();
+	~PositionCacheEntry();
+	void Set(unsigned int styleNumber_, const char *s_, unsigned int len_, int *positions_, unsigned int clock);
+	void Clear();
+	bool Retrieve(unsigned int styleNumber_, const char *s_, unsigned int len_, int *positions_) const;
+	static int Hash(unsigned int styleNumber, const char *s, unsigned int len);
+	bool NewerThan(const PositionCacheEntry &other);
+	void ResetClock();
+};
+
+// Class to break a line of text into shorter runs at sensible places.
+class BreakFinder {
+	// If a whole run is longer than lengthStartSubdivision then subdivide
+	// into smaller runs at spaces or punctuation.
+	enum { lengthStartSubdivision = 10 };
+	// Try to make each subdivided run lengthEachSubdivision or shorter.
+	enum { lengthEachSubdivision = 5 };
+	LineLayout *ll;
+	int lineStart;
+	int lineEnd;
+	int posLineStart;
+	int nextBreak;
+	int selAndEdge[5];
+	unsigned int saeLen;
+	unsigned int saeCurrentPos;
+	int saeNext;
+	int subBreak;
+	void Insert(int val);
+public:
+	BreakFinder(LineLayout *ll_, int lineStart_, int lineEnd_, int posLineStart_, int xStart);
+	int First();
+	int Next();
+};
+
+class PositionCache {
+	PositionCacheEntry *pces;
+	size_t size;
+	unsigned int clock;
+	bool allClear;
+public:
+	PositionCache();
+	~PositionCache();
+	void Clear();
+	void SetSize(size_t size_);
+	int GetSize() { return size; }
+	void MeasureWidths(Surface *surface, ViewStyle &vstyle, unsigned int styleNumber,
+		const char *s, unsigned int len, int *positions);
+};
+
+inline bool IsSpaceOrTab(int ch) {
+	return ch == ' ' || ch == '\t';
+}
+
+#endif