1 files changed, 86 insertions, 0 deletions
diff --git a/inputmethods/dasher/AlphabetMap.cpp b/inputmethods/dasher/AlphabetMap.cpp
new file mode 100644
index 0000000..09e2c72
--- a/dev/null
+++ b/inputmethods/dasher/AlphabetMap.cpp
@@ -0,0 +1,86 @@
+// AlphabetMap.cpp
+//
+/////////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2002 Iain Murray
+//
+/////////////////////////////////////////////////////////////////////////////
+
+#include "AlphabetMap.h"
+
+using namespace Dasher;
+using namespace std;
+
+alphabet_map::alphabet_map(unsigned int InitialTableSize)
+	: Undefined(0), HashTable(InitialTableSize<<1)
+{
+	Entries.reserve(InitialTableSize);
+}
+
+
+void alphabet_map::Add(const string& Key, symbol Value)
+{
+	RecursiveAdd(Key, Value, false);
+}
+
+
+void alphabet_map::RecursiveAdd(const string& Key, symbol Value, bool PrefixFlag)
+{
+	Entry*& HashEntry = HashTable[Hash(Key)];
+	
+	// Loop through Entries with the correct Hash value.
+	for (Entry* i = HashEntry; i; i=i->Next) {
+		if (i->Key==Key) {
+			if (PrefixFlag) {
+				// Just tagging - don't change symbol. Recurse if necessary
+				i->KeyIsPrefix = true;
+				if (Key.size()>1)
+					RecursiveAdd(Key.substr(Key.size()-1), Undefined, true);
+			} else {
+				// Add symbol and leave
+				i->Symbol = Value;
+			}
+			return;
+		}
+	}
+	
+	// When hash table gets 1/2 full...
+	// (no I haven't optimised when to resize)
+	if (Entries.size()<<1 >= HashTable.size()) {
+		// Double up all the storage
+		HashTable.clear();
+		HashTable.resize(Entries.size()<<2);
+		Entries.reserve(Entries.size()<<1);
+		
+		// Rehash as the pointers will all be mangled.
+		for (uint j=0; j<Entries.size(); j++) {
+			Entry*& HashEntry2 = HashTable[Hash(Entries[j].Key)];
+			Entries[j].Next = HashEntry2;
+			HashEntry2 = &Entries[j];
+		}
+		
+		// Have to recall this function as the key's hash needs recalculating
+		RecursiveAdd(Key, Value, PrefixFlag);
+		return;
+	}
+	
+	Entries.push_back(Entry(Key, Value, HashEntry));
+	HashEntry = &Entries.back();
+}
+
+
+symbol alphabet_map::Get(const string& Key, bool* KeyIsPrefix) const
+{
+	// Loop through Entries with the correct Hash value.
+	for (Entry* i = HashTable[Hash(Key)]; i; i=i->Next) {
+		if (i->Key==Key) {
+			if (KeyIsPrefix!=0)
+				*KeyIsPrefix = i->KeyIsPrefix;
+			return i->Symbol;
+		}
+	}
+	
+	if (KeyIsPrefix!=0)
+		*KeyIsPrefix = false;
+	return Undefined;
+}