private static Context_Compress produceW(Context_Compress context)
{
if (context.dictionaryToCreate.ContainsKey(context.w))
{
if (context.w[0] < 256)
{
context.data = writeBits(context.numBits, 0, context.data);
context.data = writeBits(8, context.w[0], context.data);
}
else
{
context.data = writeBits(context.numBits, 1, context.data);
context.data = writeBits(16, context.w[0], context.data);
}
context = decrementEnlargeIn(context);
context.dictionaryToCreate.Remove(context.w);
}
else
{
context.data = writeBits(context.numBits, context.dictionary[context.w], context.data);
}
return(context);
}
private static Context_Compress produceW(Context_Compress context)
{
if (context.dictionaryToCreate.ContainsKey(context.w))
{
if (context.w[0] < 256)
{
context.data = writeBits(context.numBits, 0, context.data);
context.data = writeBits(8, context.w[0], context.data);
}
else
{
context.data = writeBits(context.numBits, 1, context.data);
context.data = writeBits(16, context.w[0], context.data);
}
context = decrementEnlargeIn(context);
context.dictionaryToCreate.Remove(context.w);
}
else
{
context.data = writeBits(context.numBits, context.dictionary[context.w], context.data);
}
return context;
}
private static Context_Compress decrementEnlargeIn(Context_Compress context)
{
context.enlargeIn--;
if (context.enlargeIn == 0)
{
context.enlargeIn = (int)Math.Pow(2, context.numBits);
context.numBits++;
}
return(context);
}
public static string compress(string uncompressed)
{
Context_Compress context = new Context_Compress();
Context_Compress_Data data = new Context_Compress_Data();
context.dictionary = new Dictionary <string, int>();
context.dictionaryToCreate = new Dictionary <string, bool>();
context.c = "";
context.wc = "";
context.w = "";
context.enlargeIn = 2;
context.dictSize = 3;
context.numBits = 2;
data.str = "";
data.val = 0;
data.position = 0;
context.data = data;
try
{
for (int i = 0; i < uncompressed.Length; i++)
{
context.c = uncompressed[i].ToString();
if (!context.dictionary.ContainsKey(context.c))
{
context.dictionary[context.c] = context.dictSize++;
context.dictionaryToCreate[context.c] = true;
}
;
context.wc = context.w + context.c;
if (context.dictionary.ContainsKey(context.wc))
{
context.w = context.wc;
}
else
{
context = produceW(context);
context = decrementEnlargeIn(context);
context.dictionary[context.wc] = context.dictSize++;
context.w = context.c;
}
}
if (context.w != "")
{
context = produceW(context);
}
// Mark the end of the stream
context.data = writeBits(context.numBits, 2, context.data);
// Flush the last char
while (true)
{
context.data.val = (context.data.val << 1);
if (context.data.position == 15)
{
context.data.str += (char)context.data.val;
break;
}
else
{
context.data.position++;
}
}
}
catch (Exception ex)
{
return(ex.Message);
}
return(context.data.str);
}
private static Context_Compress decrementEnlargeIn(Context_Compress context)
{
context.enlargeIn--;
if (context.enlargeIn == 0)
{
context.enlargeIn = (int)Math.Pow(2, context.numBits);
context.numBits++;
}
return context;
}
public static string compress(string uncompressed)
{
Context_Compress context = new Context_Compress();
Context_Compress_Data data = new Context_Compress_Data();
context.dictionary = new Dictionary<string, int>();
context.dictionaryToCreate = new Dictionary<string, bool>();
context.c = "";
context.wc = "";
context.w = "";
context.enlargeIn = 2;
context.dictSize = 3;
context.numBits = 2;
data.str = "";
data.val = 0;
data.position = 0;
context.data = data;
try
{
for (int i = 0; i < uncompressed.Length; i++)
{
context.c = uncompressed[i].ToString();
if (!context.dictionary.ContainsKey(context.c))
{
context.dictionary[context.c] = context.dictSize++;
context.dictionaryToCreate[context.c] = true;
};
context.wc = context.w + context.c;
if (context.dictionary.ContainsKey(context.wc))
{
context.w = context.wc;
}
else
{
context = produceW(context);
context = decrementEnlargeIn(context);
context.dictionary[context.wc] = context.dictSize++;
context.w = context.c;
}
}
if (context.w != "")
{
context = produceW(context);
}
// Mark the end of the stream
context.data = writeBits(context.numBits, 2, context.data);
// Flush the last char
while (true)
{
context.data.val = (context.data.val << 1);
if (context.data.position == 15)
{
context.data.str += (char)context.data.val;
break;
}
else
context.data.position++;
}
}
catch (Exception ex)
{
return ex.Message;
}
return context.data.str;
}
