private static int readBits(int numBits, Decompress_Data data)
{
int res = 0;
int maxpower = (int)Math.Pow(2, numBits);
int power = 1;
while (power != maxpower)
{
res |= readBit(data) * power;
power <<= 1;
}
return(res);
}
private static int readBit(Decompress_Data data)
{
var res = data.val & data.position;
data.position >>= 1;
if (data.position == 0)
{
data.position = 32768;
// This 'if' check doesn't appear in the orginal lz-string javascript code.
// Added as a check to make sure we don't exceed the length of data.str
// The javascript charCodeAt will return a NaN if it exceeds the index but will not error out
if (data.index < data.str.Length)
{
data.val = data.str[data.index++]; // data.val = data.string.charCodeAt(data.index++); <---javascript equivilant
}
}
return(res > 0 ? 1 : 0);
}
public static string decompress(string compressed)
{
Decompress_Data data = new Decompress_Data();
List <string> dictionary = new List <string>();
int next = 0;
int enlargeIn = 4;
int numBits = 3;
string entry = "";
string result = "";
int i = 0;
dynamic w = "";
dynamic c = "";
int errorCount = 0;
data.str = compressed;
data.val = (int)compressed[0];
data.position = 32768;
data.index = 1;
try
{
for (i = 0; i < 3; i++)
{
dictionary.Add(i.ToString());
}
next = readBits(2, data);
switch (next)
{
case 0:
c = Convert.ToChar(readBits(8, data)).ToString();
break;
case 1:
c = Convert.ToChar(readBits(16, data)).ToString();
break;
case 2:
return("");
}
dictionary.Add(c);
w = result = c;
while (true)
{
c = readBits(numBits, data);
int cc = (int)(c);
switch (cc)
{
case 0:
if (errorCount++ > 10000)
{
throw new Exception("To many errors");
}
c = Convert.ToChar(readBits(8, data)).ToString();
dictionary.Add(c);
c = dictionary.Count - 1;
enlargeIn--;
break;
case 1:
c = Convert.ToChar(readBits(16, data)).ToString();
dictionary.Add(c);
c = dictionary.Count - 1;
enlargeIn--;
break;
case 2:
return(result);
}
if (enlargeIn == 0)
{
enlargeIn = (int)Math.Pow(2, numBits);
numBits++;
}
if (dictionary.ElementAtOrDefault((int)c) != null) // if (dictionary[c] ) <------- original Javascript Equivalant
{
entry = dictionary[c];
}
else
{
if (c == dictionary.Count)
{
entry = w + w[0];
}
else
{
return(null);
}
}
result += entry;
dictionary.Add(w + entry[0]);
enlargeIn--;
w = entry;
if (enlargeIn == 0)
{
enlargeIn = (int)Math.Pow(2, numBits);
numBits++;
}
}
}
catch (Exception ex)
{
return(ex.Message);
}
}
public static string decompress(string compressed)
{
Decompress_Data data = new Decompress_Data();
List<string> dictionary = new List<string>();
int next = 0;
int enlargeIn = 4;
int numBits = 3;
string entry = "";
string result = "";
int i = 0;
dynamic w = "";
dynamic c = "";
int errorCount = 0;
data.str = compressed;
data.val = (int)compressed[0];
data.position = 32768;
data.index = 1;
try
{
for (i = 0; i < 3; i++)
{
dictionary.Add(i.ToString());
}
next = readBits(2, data);
switch (next)
{
case 0:
c = Convert.ToChar(readBits(8, data)).ToString();
break;
case 1:
c = Convert.ToChar(readBits(16, data)).ToString();
break;
case 2:
return "";
}
dictionary.Add(c);
w = result = c;
while (true)
{
c = readBits(numBits, data);
int cc = (int)(c);
switch (cc)
{
case 0:
if (errorCount++ > 10000)
throw new Exception("To many errors");
c = Convert.ToChar(readBits(8, data)).ToString();
dictionary.Add(c);
c = dictionary.Count - 1;
enlargeIn--;
break;
case 1:
c = Convert.ToChar(readBits(16, data)).ToString();
dictionary.Add(c);
c = dictionary.Count - 1;
enlargeIn--;
break;
case 2:
return result;
}
if (enlargeIn == 0)
{
enlargeIn = (int)Math.Pow(2, numBits);
numBits++;
}
if (dictionary.ElementAtOrDefault((int)c) != null) // if (dictionary[c] ) <------- original Javascript Equivalant
{
entry = dictionary[c];
}
else
{
if (c == dictionary.Count)
{
entry = w + w[0];
}
else
{
return null;
}
}
result += entry;
dictionary.Add(w + entry[0]);
enlargeIn--;
w = entry;
if (enlargeIn == 0)
{
enlargeIn = (int)Math.Pow(2, numBits);
numBits++;
}
}
}
catch (Exception ex)
{
return ex.Message;
}
}
private static int readBits(int numBits, Decompress_Data data)
{
int res = 0;
int maxpower = (int)Math.Pow(2, numBits);
int power = 1;
while (power != maxpower)
{
res |= readBit(data) * power;
power <<= 1;
}
return res;
}
private static int readBit(Decompress_Data data)
{
var res = data.val & data.position;
data.position >>= 1;
if (data.position == 0)
{
data.position = 32768;
// This 'if' check doesn't appear in the orginal lz-string javascript code.
// Added as a check to make sure we don't exceed the length of data.str
// The javascript charCodeAt will return a NaN if it exceeds the index but will not error out
if (data.index < data.str.Length)
{
data.val = data.str[data.index++]; // data.val = data.string.charCodeAt(data.index++); <---javascript equivilant
}
}
return res > 0 ? 1 : 0;
}
