/// <summary>
/// Read all documents from current collection with NO index use - read direct from free lists
/// There is no document order
/// </summary>
public IEnumerable <BsonDocument> GetDocuments(string collection)
{
var colPage = this.ReadPage <CollectionPage>(_collections[collection]);
for (var slot = 0; slot < PAGE_FREE_LIST_SLOTS; slot++)
{
var next = colPage.FreeDataPageList[slot];
while (next != uint.MaxValue)
{
var page = this.ReadPage <DataPage>(next);
foreach (var block in page.GetBlocks(true))
{
using (var r = new BufferReader(this.ReadBlocks(block)))
{
var doc = r.ReadDocument(null);
yield return(doc);
}
}
next = page.NextPageID;
}
}
}
/// <summary>
/// Load page content based on page buffer
/// </summary>
public void LoadPage()
{
// check database file format
var info = _buffer.ReadString(P_HEADER_INFO, HEADER_INFO.Length);
var ver = _buffer[P_FILE_VERSION];
if (string.CompareOrdinal(info, HEADER_INFO) != 0 || ver != FILE_VERSION)
{
throw LiteException.InvalidDatabase();
}
// CreateTime is readonly
this.FreeEmptyPageList = _buffer.ReadUInt32(P_FREE_EMPTY_PAGE_ID);
this.LastPageID = _buffer.ReadUInt32(P_LAST_PAGE_ID);
// initialize engine pragmas
this.Pragmas = new EnginePragmas(_buffer, this);
// create new buffer area to store BsonDocument collections
var area = _buffer.Slice(P_COLLECTIONS, COLLECTIONS_SIZE);
using (var r = new BufferReader(new[] { area }, false))
{
_collections = r.ReadDocument();
}
_isCollectionsChanged = false;
}
public virtual BsonDocument Load(PageAddress rawId)
{
using (var reader = new BufferReader(_data.Read(rawId), _utcDate))
{
var doc = reader.ReadDocument(_fields);
doc.RawId = rawId;
return(doc);
}
}
/// <summary>
/// Check for all document and deserialize to test if ok (use PK index)
/// </summary>
public int VerifyDocuments()
{
return(this.AutoTransaction(transaction =>
{
var counter = 0;
foreach (var col in _header.GetCollections())
{
var snapshot = transaction.CreateSnapshot(LockMode.Read, col.Key, false);
var data = new DataService(snapshot);
for (var slot = 0; slot < CollectionPage.PAGE_FREE_LIST_SLOTS; slot++)
{
var next = snapshot.CollectionPage.FreeDataPageID[slot];
while (next != uint.MaxValue)
{
var page = snapshot.GetPage <DataPage>(next);
foreach (var block in page.GetBlocks(true))
{
using (var r = new BufferReader(data.Read(block)))
{
var doc = r.ReadDocument();
counter++;
}
}
next = page.NextPageID;
transaction.Safepoint();
}
}
}
return counter;
}));
}
/// <summary>
/// Read all documents from current collection with NO index use - read direct from free lists
/// There is no document order
/// </summary>
public IEnumerable <BsonDocument> ReadAll(HashSet <string> fields = null)
{
for (var slot = 0; slot < CollectionPage.PAGE_FREE_LIST_SLOTS; slot++)
{
var next = _snapshot.CollectionPage.FreeDataPageID[slot];
while (next != uint.MaxValue)
{
var page = _snapshot.GetPage <DataPage>(next);
foreach (var block in page.GetBlocks(true))
{
using (var r = new BufferReader(this.Read(block)))
{
var doc = r.ReadDocument(fields);
yield return(doc);
}
}
next = page.NextPageID;
}
}
}
/// <summary>
/// Create a new index (or do nothing if already exists) to a collection/field
/// </summary>
public bool EnsureIndex(string collection, string name, BsonExpression expression, bool unique)
{
if (collection.IsNullOrWhiteSpace())
{
throw new ArgumentNullException(nameof(collection));
}
if (name.IsNullOrWhiteSpace())
{
throw new ArgumentNullException(nameof(name));
}
if (expression == null)
{
throw new ArgumentNullException(nameof(expression));
}
if (expression.IsIndexable == false)
{
throw new ArgumentException("Index expressions must contains at least one document field. Used methods must be immutable. Parameters are not supported.", nameof(expression));
}
if (name.Length > INDEX_NAME_MAX_LENGTH)
{
throw LiteException.InvalidIndexName(name, collection, "MaxLength = " + INDEX_NAME_MAX_LENGTH);
}
if (!name.IsWord())
{
throw LiteException.InvalidIndexName(name, collection, "Use only [a-Z$_]");
}
if (name.StartsWith("$"))
{
throw LiteException.InvalidIndexName(name, collection, "Index name can't starts with `$`");
}
if (name == "_id")
{
return(false); // always exists
}
return(this.AutoTransaction(transaction =>
{
var snapshot = transaction.CreateSnapshot(LockMode.Write, collection, true);
var col = snapshot.CollectionPage;
var indexer = new IndexService(snapshot);
var data = new DataService(snapshot);
// check if index already exists
var current = col.GetCollectionIndex(name);
// if already exists, just exit
if (current != null)
{
// but if expression are different, throw error
if (current.Expression != expression.Source)
{
throw LiteException.IndexAlreadyExist(name);
}
return false;
}
LOG($"create index `{collection}.{name}`", "COMMAND");
// create index head
var index = indexer.CreateIndex(name, expression.Source, unique);
var count = 0u;
// read all objects (read from PK index)
foreach (var pkNode in new IndexAll("_id", LiteDB.Query.Ascending).Run(col, indexer))
{
using (var reader = new BufferReader(data.Read(pkNode.DataBlock)))
{
var doc = reader.ReadDocument(expression.Fields);
// first/last node in this document that will be added
IndexNode last = null;
IndexNode first = null;
// get values from expression in document
var keys = expression.Execute(doc);
// adding index node for each value
foreach (var key in keys)
{
// when index key is an array, get items inside array.
// valid only for first level (if this items are another array, this arrays will be indexed as array)
if (key.IsArray)
{
var arr = key.AsArray;
foreach (var itemKey in arr)
{
// insert new index node
var node = indexer.AddNode(index, itemKey, pkNode.DataBlock, last, _flipCoin);
if (first == null)
{
first = node;
}
last = node;
count++;
}
}
else
{
// insert new index node
var node = indexer.AddNode(index, key, pkNode.DataBlock, last, _flipCoin);
if (first == null)
{
first = node;
}
last = node;
count++;
}
}
// fix single linked-list in pkNode
if (first != null)
{
last.SetNextNode(pkNode.NextNode);
pkNode.SetNextNode(first.Position);
}
}
transaction.Safepoint();
}
index.KeyCount = count;
return true;
}));
}
