/// <summary>
/// Write the MFORTH hash table to the given writer.
/// </summary>
/// <param name="writer">The writer where the hash table should be
/// written.</param>
/// <param name="hashTable">MFORTH hash table.</param>
/// <param name="symbolTable">TASM symbol table for the MFORTH
/// ROM.</param>
private static void WriteHashTable(TextWriter writer, CuckooHashTable <Word> hashTable, IDictionary <int, string> symbolTable)
{
// Write out every possible entry in the hash table; not all
// hash locations will be filled.
for (int i = 0; i < HashTableSize; i++)
{
// Try to retrieve the word at this hash location; write
// out a zero value if no word is stored at this
// location.
Word word;
if (!hashTable.TryGetValue(i, out word))
{
writer.WriteLine(" .WORD 0");
continue;
}
// There is a word stored at this hash location. Find
// symbol associated with this word. Symbols point to
// the CFA of each word, so we need to offset the word
// address by the NFATOCFASZ. That value is different
// between standard MFORTH builds and profiled MFORTH
// builds. We try the standard value first and then
// fall back to the profile value.
string label;
if (!symbolTable.TryGetValue(word.NFA + 3, out label))
{
label = symbolTable[word.NFA + 5];
}
// Write out the hash entry, which must point to the NFA
// of the word and not the CFA.
writer.WriteLine(" .WORD {0}-NFATOCFASZ", label);
}
}
public static void DoTest()
{
var cuckooTable = new CuckooHashTable<string, int>();
cuckooTable.Add("Ahmad", 10);
cuckooTable.Add("Oliver", 11);
cuckooTable.Add("Konstantinos", 12);
cuckooTable.Add("Olympos", 13);
cuckooTable.Add("Bic", 14);
cuckooTable.Add("Carter", 15);
cuckooTable.Add("Sameeros", 16);
var Ahmad = cuckooTable["Ahmad"];
Debug.Assert(Ahmad == 10);
var Oliver = cuckooTable["Oliver"];
Debug.Assert(Oliver == 11);
var Konstantinos = cuckooTable["Konstantinos"];
Debug.Assert(Konstantinos == 12);
var Olympos = cuckooTable["Olympos"];
Debug.Assert(Olympos == 13);
var Bic = cuckooTable["Bic"];
Debug.Assert(Bic == 14);
var Carter = cuckooTable["Carter"];
Debug.Assert(Carter == 15);
var Sameeros = cuckooTable["Sameeros"];
Debug.Assert(Sameeros == 16);
cuckooTable.Clear();
}
public static void DoTest()
{
var cuckooTable = new CuckooHashTable <string, int>();
cuckooTable.Add("Ahmad", 10);
cuckooTable.Add("Oliver", 11);
cuckooTable.Add("Konstantinos", 12);
cuckooTable.Add("Olympos", 13);
cuckooTable.Add("Bic", 14);
cuckooTable.Add("Carter", 15);
cuckooTable.Add("Sameeros", 16);
var Ahmad = cuckooTable["Ahmad"];
Assert.True(Ahmad == 10);
var Oliver = cuckooTable["Oliver"];
Assert.True(Oliver == 11);
var Konstantinos = cuckooTable["Konstantinos"];
Assert.True(Konstantinos == 12);
var Olympos = cuckooTable["Olympos"];
Assert.True(Olympos == 13);
var Bic = cuckooTable["Bic"];
Assert.True(Bic == 14);
var Carter = cuckooTable["Carter"];
Assert.True(Carter == 15);
var Sameeros = cuckooTable["Sameeros"];
Assert.True(Sameeros == 16);
cuckooTable.Clear();
}
/// <summary>
/// Write the MFORTH hash table to the given writer.
/// </summary>
/// <param name="writer">The writer where the hash table should be
/// written.</param>
/// <param name="hashTable">MFORTH hash table.</param>
/// <param name="symbolTable">TASM symbol table for the MFORTH
/// ROM.</param>
private static void WriteHashTable(TextWriter writer, CuckooHashTable<Word> hashTable, IDictionary<int, string> symbolTable)
{
// Write out every possible entry in the hash table; not all
// hash locations will be filled.
for (int i = 0; i < HashTableSize; i++)
{
// Try to retrieve the word at this hash location; write
// out a zero value if no word is stored at this
// location.
Word word;
if (!hashTable.TryGetValue(i, out word))
{
writer.WriteLine(" .WORD 0");
continue;
}
// There is a word stored at this hash location. Find
// symbol associated with this word. Symbols point to
// the CFA of each word, so we need to offset the word
// address by the NFATOCFASZ. That value is different
// between standard MFORTH builds and profiled MFORTH
// builds. We try the standard value first and then
// fall back to the profile value.
string label;
if (!symbolTable.TryGetValue(word.NFA + 3, out label))
{
label = symbolTable[word.NFA + 5];
}
// Write out the hash entry, which must point to the NFA
// of the word and not the CFA.
writer.WriteLine(" .WORD {0}-NFATOCFASZ", label);
}
}
/// <summary>
/// Generate the MFORTH hash table.
/// </summary>
/// <param name="rom">MFORTH ROM.</param>
/// <param name="phf1">Upon return, will contain the first
/// PearsonHashFunction used by the hash table.</param>
/// <param name="phf2">Upon return, will contain the second
/// PearsonHashFunction used by the hash table.</param>
/// <returns>The MFORTH hash table.</returns>
private static CuckooHashTable<Word> GenerateHashTable(ROM rom, out PearsonHashFunction phf1, out PearsonHashFunction phf2)
{
// Initialize our random number generator.
var random = new Random(HashTableRandomSeed);
// Initialize our hash functions and the hash table.
var hashFunc1 = phf1 = new PearsonHashFunction(random);
var hashFunc2 = phf2 = new PearsonHashFunction(random);
var hashTable = new CuckooHashTable<Word>(
(w) => HashName(w.Name, hashFunc1, hashFunc2, HashMask),
(w) => HashName(w.Name, hashFunc2, hashFunc1, HashMask));
// Generate the hash table.
#if FINDING_OPTIMAL_HASH_SEED
int minValuesAtSecondLocation = int.MaxValue;
#endif
for (;;)
{
#if !FINDING_OPTIMAL_HASH_SEED
// Display a progress dot.
Console.Write(".");
#endif
// Add all of the words to our hash table; assume that
// we will be successful.
bool haveCompleteTable = true;
foreach (var word in rom.Words)
{
if (!hashTable.TryAddValue(word))
{
haveCompleteTable = false;
break;
}
}
#if !FINDING_OPTIMAL_HASH_SEED
// We're done if all of the words were added to the
// table.
if (haveCompleteTable)
{
break;
}
// We failed to generate a complete hash table; shuffle
// the hash functions, clear the table, and try again.
phf1.ShuffleAuxilliaryTable(random);
phf2.ShuffleAuxilliaryTable(random);
hashTable.Clear();
#else
// Print out the results if this seed produced better
// results than the previous best seed.
if (haveCompleteTable
&& hashTable.NumValuesStoredAtSecondHash < minValuesAtSecondLocation)
{
Console.WriteLine(
"Seed: {0}; 1st: {1}; 2nd: {2}",
HashTableRandomSeed,
hashTable.NumValuesStoredAtFirstHash,
hashTable.NumValuesStoredAtSecondHash);
minValuesAtSecondLocation = hashTable.NumValuesStoredAtSecondHash;
}
// Generate a new seed and re-create all of the hash
// functions and tables.
random = new Random(++HashTableRandomSeed);
hashFunc1 = phf1 = new PearsonHashFunction(random);
hashFunc2 = phf2 = new PearsonHashFunction(random);
hashTable = new CuckooHashTable<Word>(
(w) => HashName(w.Name, hashFunc1, hashFunc2, HashMask),
(w) => HashName(w.Name, hashFunc2, hashFunc1, HashMask));
#endif
}
// Ensure that all of the words in the ROM were added to the
// hash table.
if (rom.NumWords != hashTable.Count)
{
throw new InvalidDataException(
string.Format(
"Hash table only has {0} words; expected {1} words.",
hashTable.Count,
rom.NumWords));
}
// Return the hash table.
return hashTable;
}
/// <summary>
/// Generate the MFORTH hash table.
/// </summary>
/// <param name="rom">MFORTH ROM.</param>
/// <param name="phf1">Upon return, will contain the first
/// PearsonHashFunction used by the hash table.</param>
/// <param name="phf2">Upon return, will contain the second
/// PearsonHashFunction used by the hash table.</param>
/// <returns>The MFORTH hash table.</returns>
private static CuckooHashTable <Word> GenerateHashTable(ROM rom, out PearsonHashFunction phf1, out PearsonHashFunction phf2)
{
// Initialize our random number generator.
var random = new Random(HashTableRandomSeed);
// Initialize our hash functions and the hash table.
var hashFunc1 = phf1 = new PearsonHashFunction(random);
var hashFunc2 = phf2 = new PearsonHashFunction(random);
var hashTable = new CuckooHashTable <Word>(
(w) => HashName(w.Name, hashFunc1, hashFunc2, HashMask),
(w) => HashName(w.Name, hashFunc2, hashFunc1, HashMask));
// Generate the hash table.
#if FINDING_OPTIMAL_HASH_SEED
int minValuesAtSecondLocation = int.MaxValue;
#endif
for (;;)
{
#if !FINDING_OPTIMAL_HASH_SEED
// Display a progress dot.
Console.Write(".");
#endif
// Add all of the words to our hash table; assume that
// we will be successful.
bool haveCompleteTable = true;
foreach (var word in rom.Words)
{
if (!hashTable.TryAddValue(word))
{
haveCompleteTable = false;
break;
}
}
#if !FINDING_OPTIMAL_HASH_SEED
// We're done if all of the words were added to the
// table.
if (haveCompleteTable)
{
break;
}
// We failed to generate a complete hash table; shuffle
// the hash functions, clear the table, and try again.
phf1.ShuffleAuxilliaryTable(random);
phf2.ShuffleAuxilliaryTable(random);
hashTable.Clear();
#else
// Print out the results if this seed produced better
// results than the previous best seed.
if (haveCompleteTable &&
hashTable.NumValuesStoredAtSecondHash < minValuesAtSecondLocation)
{
Console.WriteLine(
"Seed: {0}; 1st: {1}; 2nd: {2}",
HashTableRandomSeed,
hashTable.NumValuesStoredAtFirstHash,
hashTable.NumValuesStoredAtSecondHash);
minValuesAtSecondLocation = hashTable.NumValuesStoredAtSecondHash;
}
// Generate a new seed and re-create all of the hash
// functions and tables.
random = new Random(++HashTableRandomSeed);
hashFunc1 = phf1 = new PearsonHashFunction(random);
hashFunc2 = phf2 = new PearsonHashFunction(random);
hashTable = new CuckooHashTable <Word>(
(w) => HashName(w.Name, hashFunc1, hashFunc2, HashMask),
(w) => HashName(w.Name, hashFunc2, hashFunc1, HashMask));
#endif
}
// Ensure that all of the words in the ROM were added to the
// hash table.
if (rom.NumWords != hashTable.Count)
{
throw new InvalidDataException(
string.Format(
"Hash table only has {0} words; expected {1} words.",
hashTable.Count,
rom.NumWords));
}
// Return the hash table.
return(hashTable);
}
