/// <summary>
/// Find the items containing *any word* starting with the word passed
/// and add the union of all of them to the result set passed.
/// </summary>
/// <param name="prefix">Prefix to find</param>
/// <param name="result">Result to which to add matches</param>
public void WhereMatches(ByteBlock prefix, ShortSet result)
{
if (result == null)
{
throw new ArgumentNullException("result");
}
// Split each word in the input value
RangeSet prefixWords = _splitter.Split(prefix);
// Shortcut: If only one word, add directly to result set
if (prefixWords.Count == 1 && prefixWords.Ranges[0].Length == prefix.Length)
{
// Add matches for words starting with this prefix in every block
foreach (WordIndexBlock block in _blocks)
{
block.WhereMatches(prefix, result);
}
}
else
{
// We need to add (OR) the items which match all words (AND) in the split prefix
ShortSet matchesForAllWords = null;
ShortSet matchesForWord = new ShortSet(result.Capacity);
// For each found word, add all matches
for (int i = 0; i < prefixWords.Count; ++i)
{
Range word = prefixWords.Ranges[i];
ByteBlock wordBlock = new ByteBlock(prefix.Array, word.Index, word.Length);
matchesForWord.Clear();
// Add matches for words starting with this prefix in every block
foreach (WordIndexBlock block in _blocks)
{
block.WhereMatches(wordBlock, matchesForWord);
}
// AND matches for this word with each other word in the prefix
if (matchesForAllWords == null)
{
matchesForAllWords = new ShortSet(result.Capacity);
matchesForAllWords.Or(matchesForWord);
}
else
{
matchesForAllWords.And(matchesForWord);
}
}
// OR matches for ALL words with the final result
if (matchesForAllWords != null)
{
result.Or(matchesForAllWords);
}
}
}
public void Index(ushort id, ByteBlock oldValue, ByteBlock newValue)
{
RangeSet oldValueWords = _splitter.Split(oldValue);
RangeSet newValueWords = _splitter.Split(newValue);
for (int i = 0; i < oldValueWords.Count; ++i)
{
Range word = oldValueWords.Ranges[i];
ByteBlock wordBlock = new ByteBlock(oldValue.Array, word.Index, word.Length);
RemoveWord(id, wordBlock);
}
for (int i = 0; i < newValueWords.Count; ++i)
{
Range word = newValueWords.Ranges[i];
ByteBlock wordBlock = new ByteBlock(newValue.Array, word.Index, word.Length);
AddWord(id, wordBlock);
}
}