/// <summary>
/// Analyze collection indexes to update UniqueKey counter. If collections parameter are null, analyze all collections
/// </summary>
public int Analyze(string[] collections)
{
// collection analyze is possible only in exclusive transaction for this
if (_locker.IsInTransaction)
{
throw LiteException.AlreadyExistsTransaction();
}
var cols = collections == null || collections.Length == 0 ? _header.GetCollections().Select(x => x.Key).ToArray() : collections;
var count = 0;
foreach (var collection in cols)
{
// counters for indexes
var keyCount = new Dictionary <string, uint>();
var keyUniqueCount = new Dictionary <string, uint>();
// create one transaction per colection to avoid lock all database
this.AutoTransaction(transaction =>
{
// first, get read-only snapshot
var snapshot = transaction.CreateSnapshot(LockMode.Read, collection, false);
// do not use "col" local variable because `WriteMode()` clear _collectionPage instance
if (snapshot.CollectionPage == null)
{
return(0);
}
var indexer = new IndexService(snapshot);
var indexes = snapshot.CollectionPage.GetCollectionIndexes().ToArray();
foreach (var index in indexes)
{
var last = BsonValue.MinValue;
var counter = 0u;
var uniqueCounter = 0u;
foreach (var node in indexer.FindAll(index, LiteDB.Query.Ascending))
{
counter++;
uniqueCounter += node.Key == last ? 0u : 1u;
last = node.Key;
}
keyCount[index.Name] = counter;
keyUniqueCount[index.Name] = uniqueCounter;
}
// after do all analyze, update snapshot to write mode
snapshot = transaction.CreateSnapshot(LockMode.Write, collection, false);
foreach (var name in indexes.Select(x => x.Name))
{
// will get index and set as dirty
var index = snapshot.CollectionPage.UpdateCollectionIndex(name);
index.KeyCount = keyCount[index.Name];
index.UniqueKeyCount = keyUniqueCount[index.Name];
}
snapshot.CollectionPage.LastAnalyzed = DateTime.Now;
snapshot.CollectionPage.IsDirty = true;
return(++count);
});
}
return(count);
}
/// <summary>
/// Delete current collection and all pages - this snapshot can't be used after this
/// </summary>
public void DropCollection(Action safePoint)
{
var indexer = new IndexService(this, _header.Pragmas.Collation);
// CollectionPage will be last deleted page (there is no NextPageID from CollectionPage)
_transPages.FirstDeletedPageID = _collectionPage.PageID;
_transPages.LastDeletedPageID = _collectionPage.PageID;
// mark collection page as empty
_collectionPage.MarkAsEmtpy();
_transPages.DeletedPages = 1;
var indexPages = new HashSet <uint>();
// getting all indexes pages from all indexes
foreach (var index in _collectionPage.GetCollectionIndexes())
{
// add head/tail (same page) to be deleted
indexPages.Add(index.Head.PageID);
foreach (var node in indexer.FindAll(index, Query.Ascending))
{
indexPages.Add(node.Page.PageID);
safePoint();
}
}
// now, mark all pages as deleted
foreach (var pageID in indexPages)
{
var page = this.GetPage <IndexPage>(pageID);
// mark page as delete and fix deleted page list
page.MarkAsEmtpy();
page.NextPageID = _transPages.FirstDeletedPageID;
_transPages.FirstDeletedPageID = page.PageID;
_transPages.DeletedPages++;
safePoint();
}
// adding all data pages
foreach (var startPageID in _collectionPage.FreeDataPageList)
{
var next = startPageID;
while (next != uint.MaxValue)
{
var page = this.GetPage <DataPage>(next);
next = page.NextPageID;
// mark page as delete and fix deleted page list
page.MarkAsEmtpy();
page.NextPageID = _transPages.FirstDeletedPageID;
_transPages.FirstDeletedPageID = page.PageID;
_transPages.DeletedPages++;
safePoint();
}
}
// remove collection name (in header) at commit time
_transPages.Commit += (h) => h.DeleteCollection(_collectionName);
}
private IEnumerable <IndexNode> ExecuteLike(IndexService indexer, CollectionIndex index)
{
return(indexer
.FindAll(index, this.Order)
.Where(x => x.Key.IsString && x.Key.AsString.SqlLike(_pattern, indexer.Collation)));
}