1 files changed, 76 insertions, 0 deletions
diff --git a/contrib/replxx/src/killring.hxx b/contrib/replxx/src/killring.hxx
new file mode 100644
index 000000000..9eca23a8e
--- /dev/null
+++ b/contrib/replxx/src/killring.hxx
@@ -0,0 +1,76 @@
+#ifndef REPLXX_KILLRING_HXX_INCLUDED
+#define REPLXX_KILLRING_HXX_INCLUDED 1
+
+#include <vector>
+
+#include "unicodestring.hxx"
+
+namespace replxx {
+
+class KillRing {
+	static const int capacity = 10;
+	int size;
+	int index;
+	char indexToSlot[10];
+	std::vector<UnicodeString> theRing;
+
+public:
+	enum action { actionOther, actionKill, actionYank };
+	action lastAction;
+	size_t lastYankSize;
+
+	KillRing() : size(0), index(0), lastAction(actionOther) {
+		theRing.reserve(capacity);
+	}
+
+	void kill(const char32_t* text, int textLen, bool forward) {
+		if (textLen == 0) {
+			return;
+		}
+		UnicodeString killedText(text, textLen);
+		if (lastAction == actionKill && size > 0) {
+			int slot = indexToSlot[0];
+			int currentLen = static_cast<int>(theRing[slot].length());
+			UnicodeString temp;
+			if ( forward ) {
+				temp.append( theRing[slot].get(), currentLen ).append( killedText.get(), textLen );
+			} else {
+				temp.append( killedText.get(), textLen ).append( theRing[slot].get(), currentLen );
+			}
+			theRing[slot] = temp;
+		} else {
+			if (size < capacity) {
+				if (size > 0) {
+					memmove(&indexToSlot[1], &indexToSlot[0], size);
+				}
+				indexToSlot[0] = size;
+				size++;
+				theRing.push_back(killedText);
+			} else {
+				int slot = indexToSlot[capacity - 1];
+				theRing[slot] = killedText;
+				memmove(&indexToSlot[1], &indexToSlot[0], capacity - 1);
+				indexToSlot[0] = slot;
+			}
+			index = 0;
+		}
+	}
+
+	UnicodeString* yank() { return (size > 0) ? &theRing[indexToSlot[index]] : 0; }
+
+	UnicodeString* yankPop() {
+		if (size == 0) {
+			return 0;
+		}
+		++index;
+		if (index == size) {
+			index = 0;
+		}
+		return &theRing[indexToSlot[index]];
+	}
+};
+
+}
+
+#endif
+