/// <summary>
/// Internal private hashing method.
///
/// This is the new hashing algorithm from other clients.
/// Found to be fast and have very good distribution.
///
/// UPDATE: this is dog slow under java. Maybe under .NET?
/// </summary>
/// <param name="key">string to hash</param>
/// <returns>hashcode for this string using memcached's hashing algorithm</returns>
private static int NewHashingAlgorithm(string key)
{
CRCTool checksum = new CRCTool();
checksum.Init(CRCTool.CRCCode.CRC32);
int crc = (int)checksum.crctablefast(UTF8Encoding.UTF8.GetBytes(key));
return((crc >> 16) & 0x7fff);
}
protected override Variant fixupImpl()
{
var elem = elements["ref"];
byte[] data = elem.Value.Value;
CRCTool crcTool = new CRCTool();
crcTool.Init(type);
return(new Variant((uint)crcTool.crctablefast(data)));
}
protected override Variant fixupImpl()
{
var elem = elements["ref"];
var data = elem.Value;
data.Seek(0, System.IO.SeekOrigin.Begin);
CRCTool crcTool = new CRCTool();
crcTool.Init(type);
return(new Variant((uint)crcTool.crctablefast(data)));
}
protected override Variant fixupImpl()
{
var ref1 = elements["ref1"];
var ref2 = elements["ref2"];
byte[] data1 = ref1.Value.Value;
byte[] data2 = ref2.Value.Value;
byte[] data3 = new byte[data1.Length + data2.Length];
Buffer.BlockCopy(data1, 0, data3, 0, data1.Length);
Buffer.BlockCopy(data2, 0, data3, data1.Length, data2.Length);
CRCTool crcTool = new CRCTool();
crcTool.Init(type);
return(new Variant((uint)crcTool.crctablefast(data3)));
}
protected override Variant fixupImpl()
{
var ref1 = elements["ref1"];
var ref2 = elements["ref2"];
var data = new BitStreamList();
data.Add(ref1.Value);
data.Add(ref2.Value);
data.Seek(0, System.IO.SeekOrigin.Begin);
CRCTool crcTool = new CRCTool();
crcTool.Init(type);
return(new Variant((uint)crcTool.crctablefast(data)));
}
public void TestFixupBefore()
{
// Verify that in a DOM with Fixups before Relations, the fixup runs
// after the relation has.
// In this case the data model is:
// CRC, 4 byte number whose value is the CRC of the data model
// Len, 4 byte number whose value is the size of the data model
// Data, 5 byte string.
// The CRC should include the computed size relation.
string xml = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n" +
"<Peach>" +
" <DataModel name=\"TheDataModel\">" +
" <Block>" +
" <Number name=\"CRC\" size=\"32\" signed=\"false\">" +
" <Fixup class=\"Crc32Fixup\">" +
" <Param name=\"ref\" value=\"TheDataModel\"/>" +
" </Fixup>" +
" </Number>" +
" </Block>" +
" <Number name=\"len\" size=\"32\" signed=\"false\">" +
" <Relation type=\"size\" of=\"TheDataModel\" />" +
" </Number>" +
" <Blob name=\"Data\" value=\"Hello\">" +
" <Hint name=\"BlobMutator-How\" value=\"ExpandAllRandom\"/>" +
" </Blob>" +
" </DataModel>" +
" <StateModel name=\"TheState\" initialState=\"Initial\">" +
" <State name=\"Initial\">" +
" <Action type=\"output\">" +
" <DataModel ref=\"TheDataModel\"/>" +
" </Action>" +
" </State>" +
" </StateModel>" +
" <Test name=\"Default\">" +
" <StateModel ref=\"TheState\"/>" +
" <Publisher class=\"Null\"/>" +
" <Strategy class=\"RandomDeterministic\"/>" +
" </Test>" +
"</Peach>";
PitParser parser = new PitParser();
Dom.Dom dom = parser.asParser(null, new MemoryStream(ASCIIEncoding.ASCII.GetBytes(xml)));
dom.tests[0].includedMutators = new List <string>();
dom.tests[0].includedMutators.Add("BlobMutator");
RunConfiguration config = new RunConfiguration();
Engine e = new Engine(null);
e.startFuzzing(dom, config);
Assert.AreEqual(2, dataModels.Count);
byte[] dm1 = dataModels[0].Value.ToArray();
byte[] dm2 = dataModels[1].Value.ToArray();
Assert.AreEqual(4 + 4 + 5, dm1.Length);
Assert.Greater(dm2.Length, dm1.Length);
var data = Bits.Fmt("{0:L32}{1:L32}{2}", 0, 13, "Hello");
var crc = new CRCTool();
crc.Init(CRCTool.CRCCode.CRC32);
data.Seek(0, SeekOrigin.Begin);
data.WriteBits(Endian.Little.GetBits((uint)crc.crctablefast(data.ToArray()), 32), 32);
byte[] final = data.ToArray();
Assert.AreEqual(final, dm1);
}
/// <summary>
/// Internal private hashing method.
///
/// This is the new hashing algorithm from other clients.
/// Found to be fast and have very good distribution.
///
/// UPDATE: this is dog slow under java. Maybe under .NET?
/// </summary>
/// <param name="key">string to hash</param>
/// <returns>hashcode for this string using memcached's hashing algorithm</returns>
private static int NewHashingAlgorithm(string key)
{
CRCTool checksum = new CRCTool();
checksum.Init(CRCTool.CRCCode.CRC32);
int crc = (int)checksum.crctablefast(UTF8Encoding.UTF8.GetBytes(key));
return (crc >> 16) & 0x7fff;
}
