/// <summary>
/// Handles the <see cref="IInMemoryIndex.IndexChanged" /> events.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="e">The event arguments.</param>
protected void IndexChangedHandler(object sender, IndexChangedEventArgs e)
{
lock (this) {
if (disposed)
{
return;
}
switch (e.Change)
{
case IndexChangeType.IndexCleared:
InitDataStore(e.State);
break;
case IndexChangeType.DocumentAdded:
if (!dataCorrupted)
{
IndexStorerResult result = SaveData(e.ChangeData, e.State);
e.Result = result;
}
break;
case IndexChangeType.DocumentRemoved:
if (!dataCorrupted)
{
DeleteData(e.ChangeData, e.State);
}
break;
default:
throw new NotSupportedException("Invalid Change Type");
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="IndexChangedEventArgs" /> class.
/// </summary>
/// <param name="document">The affected document.</param>
/// <param name="change">The change performed.</param>
/// <param name="changeData">The dumped change data.</param>
/// <param name="state">A state object that is passed to the IndexStorer SaveDate/DeleteData function.</param>
/// <param name="result">The storer result, if any.</param>
/// <exception cref="ArgumentNullException">
/// If <paramref name="change" /> is not
/// <see cref="IndexChangeType.IndexCleared" /> and <paramref name="document" /> or <paramref name="changeData" /> are
/// <c>null</c>.
/// </exception>
public IndexChangedEventArgs(IDocument document, IndexChangeType change, DumpedChange changeData, object state,
IndexStorerResult result)
: this(document, change, changeData, state)
{
Result = result;
}
/// <summary>
/// Initializes a new instance of the <see cref="IndexChangedEventArgs" /> class.
/// </summary>
/// <param name="document">The affected document.</param>
/// <param name="change">The change performed.</param>
/// <param name="changeData">The dumped change data.</param>
/// <param name="state">A state object that is passed to the IndexStorer SaveDate/DeleteData function.</param>
/// <param name="result">The storer result, if any.</param>
/// <exception cref="ArgumentNullException">If <paramref name="change"/> is not <see cref="IndexChangeType.IndexCleared"/> and <paramref name="document"/> or <paramref name="changeData"/> are <c>null</c>.</exception>
public IndexChangedEventArgs(IDocument document, IndexChangeType change, DumpedChange changeData, object state, IndexStorerResult result)
: this(document, change, changeData, state)
{
this.result = result;
}
/// <summary>
/// Stores new data into the data storage.
/// </summary>
/// <param name="data">The data to store.</param>
/// <param name="state">A state object passed from the index.</param>
/// <returns>The storer result, if any.</returns>
/// <remarks>When saving a new document, the document ID in data.Mappings must be
/// replaced with the currect document ID, generated by the concrete implementation of
/// this method. data.Words should have IDs numbered from uint.MaxValue downwards.
/// The method re-numbers the words appropriately.</remarks>
protected override IndexStorerResult SaveData(DumpedChange data, object state)
{
IndexStorerResult result = new IndexStorerResult(null, null);
// 1. Save Document
using(FileStream fs = new FileStream(documentsFile, FileMode.Open, FileAccess.ReadWrite, FileShare.None)) {
int count = ReadCount(fs);
// Update count and append document
BinaryWriter writer = new BinaryWriter(fs, Encoding.UTF8);
fs.Seek(-4, SeekOrigin.Current);
writer.Write(count + 1);
writer.Seek(0, SeekOrigin.End);
data.Document.ID = firstFreeDocumentId;
WriteDumpedDocument(writer, data.Document);
result.DocumentID = firstFreeDocumentId;
firstFreeDocumentId++;
}
// 2. Save Words
Dictionary<uint, WordId> wordIds = null;
using(FileStream fs = new FileStream(wordsFile, FileMode.Open, FileAccess.ReadWrite, FileShare.None)) {
int count = ReadCount(fs);
// Update count and append words
BinaryWriter writer = new BinaryWriter(fs, Encoding.UTF8);
fs.Seek(-4, SeekOrigin.Current);
writer.Write(count + data.Words.Count);
fs.Seek(0, SeekOrigin.End);
wordIds = new Dictionary<uint, WordId>(data.Words.Count);
foreach(DumpedWord dw in data.Words) {
wordIds.Add(dw.ID, new WordId(dw.Text, firstFreeWordId));
dw.ID = firstFreeWordId;
WriteDumpedWord(writer, dw);
firstFreeWordId++;
}
result.WordIDs = new List<WordId>(wordIds.Values);
}
// 3. Save Mappings
using(FileStream fs = new FileStream(mappingsFile, FileMode.Open, FileAccess.ReadWrite, FileShare.None)) {
int count = ReadCount(fs);
// Update count and append mappings
BinaryWriter writer = new BinaryWriter(fs, Encoding.UTF8);
fs.Seek(-4, SeekOrigin.Current);
writer.Write(count + data.Mappings.Count);
fs.Seek(0, SeekOrigin.End);
foreach(DumpedWordMapping map in data.Mappings) {
// Words are autonumbered from uint.MaxValue downwards by IndexBase so that
// IndexStorer can identify the DumpedWordMappings easily and
// fix the IDs with the ones actually stored
WordId newMappingWordId;
if(wordIds != null && wordIds.TryGetValue(map.WordID, out newMappingWordId)) {
map.WordID = newMappingWordId.ID;
}
WriteDumpedWordMapping(writer,
new DumpedWordMapping(map.WordID, result.DocumentID.Value,
map.FirstCharIndex, map.WordIndex, map.Location));
}
}
return result;
}
/// <summary>
/// Stores a document in the index.
/// </summary>
/// <param name="document">The document.</param>
/// <param name="keywords">The document keywords, if any, an empty array or <c>null</c> otherwise.</param>
/// <param name="content">The content of the document.</param>
/// <param name="state">A state object that is passed to the IndexStorer SaveDate/DeleteData function.</param>
/// <returns>The number of indexed words (including duplicates) in the document title and content.</returns>
/// <remarks>Indexing the content of the document is <b>O(n)</b>,
/// where <b>n</b> is the total number of words in the document.
/// If the specified document was already in the index, all the old occurrences
/// are deleted from the index.</remarks>
/// <exception cref="ArgumentNullException">If <paramref name="document"/> or <paramref name="content"/> are <c>null</c>.</exception>
public int StoreDocument(IDocument document, string[] keywords, string content, object state)
{
if (document == null)
{
throw new ArgumentNullException("document");
}
if (keywords == null)
{
keywords = new string[0];
}
if (content == null)
{
throw new ArgumentNullException("content");
}
lock (this) {
DumpedChange removeChange = RemoveDocumentInternal(document);
if (removeChange != null)
{
OnIndexChange(document, IndexChangeType.DocumentRemoved, removeChange, state);
}
}
keywords = Tools.CleanupKeywords(keywords);
// When the IndexStorer handles the IndexChanged event and a document is added, the storer generates a new ID and returns it
// via the event handler, then the in-memory index is updated (the document instance is shared across all words) - the final ID
// is generated by the actual IndexStorer implementation (SaveData properly populates the Result field in the args)
List <DumpedWord> dw = new List <DumpedWord>(content.Length / 5);
List <DumpedWordMapping> dm = new List <DumpedWordMapping>(content.Length / 5);
Word tempWord = null;
List <Word> newWords = new List <Word>(50);
DumpedWord tempDumpedWord = null;
int count = 0;
uint sequentialWordId = uint.MaxValue;
// Store content words
WordInfo[] words = document.Tokenize(content);
words = Tools.RemoveStopWords(words, stopWords);
foreach (WordInfo info in words)
{
dm.Add(StoreWord(info.Text, document, info.FirstCharIndex, info.WordIndex, WordLocation.Content, out tempWord, out tempDumpedWord));
if (tempDumpedWord != null && tempWord != null)
{
dm[dm.Count - 1].WordID = sequentialWordId;
tempDumpedWord.ID = sequentialWordId;
dw.Add(tempDumpedWord);
tempWord.ID = sequentialWordId;
newWords.Add(tempWord);
sequentialWordId--;
}
}
count += words.Length;
// Store title words
words = document.Tokenize(document.Title);
words = Tools.RemoveStopWords(words, stopWords);
foreach (WordInfo info in words)
{
dm.Add(StoreWord(info.Text, document, info.FirstCharIndex, info.WordIndex, WordLocation.Title, out tempWord, out tempDumpedWord));
if (tempDumpedWord != null && tempWord != null)
{
dm[dm.Count - 1].WordID = sequentialWordId;
tempDumpedWord.ID = sequentialWordId;
dw.Add(tempDumpedWord);
tempWord.ID = sequentialWordId;
newWords.Add(tempWord);
sequentialWordId--;
}
}
count += words.Length;
ushort tempCount = 0;
// Store keywords
for (ushort i = 0; i < (ushort)keywords.Length; i++)
{
dm.Add(StoreWord(keywords[i], document, tempCount, i, WordLocation.Keywords, out tempWord, out tempDumpedWord));
if (tempDumpedWord != null && tempWord != null)
{
dm[dm.Count - 1].WordID = sequentialWordId;
tempDumpedWord.ID = sequentialWordId;
dw.Add(tempDumpedWord);
tempWord.ID = sequentialWordId;
newWords.Add(tempWord);
sequentialWordId--;
}
tempCount += (ushort)(1 + keywords[i].Length);
}
count += keywords.Length;
IndexStorerResult result = OnIndexChange(document, IndexChangeType.DocumentAdded,
new DumpedChange(new DumpedDocument(document), dw, dm), state);
// Update document ID
if (result != null && result.DocumentID.HasValue)
{
document.ID = result.DocumentID.Value;
}
else
{
// HACK: result is null -> index is corrupted, silently return
return(0);
}
// Update word IDs in newWords
bool wordIdUpdated = false;
foreach (Word word in newWords)
{
wordIdUpdated = false;
foreach (WordId id in result.WordIDs)
{
if (id.Text == word.Text)
{
word.ID = id.ID;
wordIdUpdated = true;
break;
}
}
if (!wordIdUpdated)
{
throw new InvalidOperationException("No ID for new word");
}
}
return(count);
}
