using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Collections;
using System.Linq.Expressions;
using System.Threading.Tasks;
using System.Reflection;
namespace RaptorDB.Views
{
// FEATURE : background save indexes to disk on timer
internal class ViewHandler
{
private ILog _log = LogManager.GetLogger(typeof(ViewHandler));
public ViewHandler(string path, ViewManager manager)
{
_Path = path;
_viewmanager = manager;
}
private string _Path = "";
private ViewManager _viewmanager;
internal ViewBase _view;
private SafeDictionary<string, IIndex> _indexes = new SafeDictionary<string, IIndex>();
private StorageFile<Guid> _viewData;
private BoolIndex _deletedRows;
private string _docid = "docid";
private List<string> _colnames = new List<string>();
internal void SetView<T>(View<T> view, KeyStoreGuid docs)
{
bool rebuild = false;
_view = view;
// generate schemacolumns from schema
GenerateSchemaColumns(_view);
if (_Path.EndsWith("\\") == false) _Path += "\\";
_Path += view.Name + "\\";
if (Directory.Exists(_Path) == false)
{
Directory.CreateDirectory(_Path);
rebuild = true;
}
else
{
// read version file and check with view
int version = 0;
if (File.Exists(_Path + "version_.dat"))
{
version = Helper.ToInt32(File.ReadAllBytes(_Path + "version_.dat"), 0);
if (version < view.Version)
{
_log.Debug("Newer view version detected");
_log.Debug("Deleting view = " + view.Name);
Directory.Delete(_Path, true);
Directory.CreateDirectory(_Path);
rebuild = true;
}
}
}
// load indexes here
CreateLoadIndexes(_view.SchemaColumns);
LoadDeletedRowsBitmap();
_viewData = new StorageFile<Guid>(_Path + view.Name + ".mgdat");
_viewData.SkipDateTime = true;
if(rebuild)
RebuildFromScratch(docs);
}
internal void FreeMemory()
{
foreach (var i in _indexes)
i.Value.FreeMemory();
_deletedRows.FreeMemory();
}
internal void Insert<T>(Guid guid, T doc)
{
apimapper api = new apimapper(_viewmanager);
View<T> view = (View<T>)_view;
if (view.Mapper != null)
view.Mapper(api, guid, doc);
// FEATURE : ELSE -> call map dll
foreach (var d in api.emit)
{
// delete any items with docid in view
if (_view.DeleteBeforeInsert)
DeleteRowsWith(d.Key);
// insert new items into view
InsertRowsWithIndexUpdate(guid, d.Value);
}
}
internal Result Query(string filter)
{
DateTime dt = FastDateTime.Now;
_log.Debug("query : " + filter);
// FEATURE : add query caching here
Result ret = new Result();
WAHBitArray ba = new WAHBitArray();
List<object[]> rows = new List<object[]>();
var e = System.Linq.Dynamic.DynamicExpression.ParseLambda(_view.Schema, typeof(bool), filter, null);
QueryVisitor qv = new QueryVisitor(QueryColumnExpression);
qv.Visit(e.Body);
ba = ((WAHBitArray)qv._bitmap.Pop()).AndNot(_deletedRows.GetBits());
_log.Debug("query bitmap done (ms) : " + FastDateTime.Now.Subtract(dt).TotalMilliseconds);
dt = FastDateTime.Now;
// exec query return rows
return RetrunRows(ba);
}
internal Result Query<T>(Expression<Predicate<T>> filter)
{
DateTime dt = FastDateTime.Now;
// FEATURE : add query caching here
Result ret = new Result();
WAHBitArray ba = new WAHBitArray();
List<object[]> rows = new List<object[]>();
QueryVisitor qv = new QueryVisitor(QueryColumnExpression);
qv.Visit(filter);
ba = ((WAHBitArray)qv._bitmap.Pop()).AndNot(_deletedRows.GetBits());
_log.Debug("query bitmap done (ms) : " + FastDateTime.Now.Subtract(dt).TotalMilliseconds);
dt = FastDateTime.Now;
// exec query return rows
return RetrunRows(ba);
}
internal Result Query()
{
// no filter query -> just show all the data
DateTime dt = FastDateTime.Now;
int count = _viewData.Count();
List<object[]> rows = new List<object[]>();
Result ret = new Result();
WAHBitArray del = _deletedRows.GetBits();
for (int i = 0; i < count; i++)
{
if (del.Get(i) == true)
continue;
byte[] b = _viewData.ReadData(i);
if (b == null) continue;
rows.Add(
((ArrayList)fastBinaryJSON.BJSON.Instance.ToObject(b)).ToArray()
);
}
_log.Debug("query rows fetched (ms) : " + FastDateTime.Now.Subtract(dt).TotalMilliseconds);
_log.Debug("query rows count : " + rows.Count);
ret.OK = true;
ret.Count = rows.Count;
ret.TotalCount = rows.Count;
ret.Rows = rows;
List<string> cols = new List<string>();
cols.Add("docid");
cols.AddRange(_colnames);
ret.Columns = cols;
return ret;
}
internal void Shutdown()
{
_log.Debug("Shutting down Viewhandler");
// shutdown indexes
foreach (var v in _indexes)
{
_log.Debug("Shutting down view index : " + v.Key);
v.Value.Shutdown();
}
// save deletedbitmap
_deletedRows.Shutdown();
_viewData.Shutdown();
// write view version
File.WriteAllBytes(_Path + "version_.dat", Helper.GetBytes(_view.Version, false));
}
#region [ private methods ]
private Result RetrunRows(WAHBitArray ba)
{
DateTime dt = FastDateTime.Now;
List<object[]> rows = new List<object[]>();
Result ret = new Result();
foreach (int i in ba.GetBitIndexes())
{
byte[] b = _viewData.ReadData(i);
if (b == null) continue;
rows.Add(
((ArrayList)fastBinaryJSON.BJSON.Instance.ToObject(b)).ToArray()
);
}
_log.Debug("query rows fetched (ms) : " + FastDateTime.Now.Subtract(dt).TotalMilliseconds);
_log.Debug("query rows count : " + rows.Count);
ret.OK = true;
ret.Count = rows.Count;
ret.TotalCount = rows.Count;
ret.Rows = rows;
List<string> cols = new List<string>();
cols.Add("docid");
cols.AddRange(_colnames);
ret.Columns = cols;
return ret;
}
MethodInfo view = null;
private void RebuildFromScratch(KeyStoreGuid docs)
{
view = this.GetType().GetMethod("Insert", BindingFlags.Instance | BindingFlags.Public);
_log.Debug("Rebuilding view from scratch...");
_log.Debug("View = " + _view.Name);
DateTime dt = FastDateTime.Now;
int c = docs.RecordCount();
for (int i = 0; i < c; i++)
{
Guid docid = Guid.Empty;
byte[] b = docs.Get(i, out docid);
if (b != null)
{
// FEATURE : optimize this by not creating the object if not in FireOnTypes
object obj = CreateObject(b);
Type t = obj.GetType();
if (_view.FireOnTypes.Contains(t.AssemblyQualifiedName))
{
var m = view.MakeGenericMethod(new Type[] { obj.GetType() });
m.Invoke(this, new object[] { docid, obj });
}
}
else
_log.Error("Doc is null : " + docid);
}
_log.Debug("rebuild done (s) = " + FastDateTime.Now.Subtract(dt).TotalSeconds);
}
private object CreateObject(byte[] b)
{
if (b[0] < 32)
return fastBinaryJSON.BJSON.Instance.ToObject(b);
else
return fastJSON.JSON.Instance.ToObject(Encoding.ASCII.GetString(b));
}
private void CreateLoadIndexes(ViewRowDefinition viewRowDefinition)
{
int i = 0;
_indexes.Add(_docid, new TypeIndexes<Guid>(_Path, _docid, 16));
// load indexes
foreach (var c in viewRowDefinition.Columns)
{
_indexes.Add(_view.SchemaColumns.Columns[i].Key,
CreateIndex(
_view.SchemaColumns.Columns[i].Key,
_view.SchemaColumns.Columns[i].Value));
i++;
}
}
private void GenerateSchemaColumns(ViewBase _view)
{
// generate schema columns from schema
_view.SchemaColumns = new ViewRowDefinition();
_view.SchemaColumns.Name = _view.Name;
foreach (var p in _view.Schema.GetProperties())
{
Type t = p.PropertyType;
if (p.GetCustomAttributes(typeof(FullTextAttribute), true).Length > 0)
t = typeof(FullTextString);
_view.SchemaColumns.Add(p.Name, t);
}
foreach (var f in _view.Schema.GetFields())
{
Type t = f.FieldType;
if (f.GetCustomAttributes(typeof(FullTextAttribute), true).Length > 0)
t = typeof(FullTextString);
_view.SchemaColumns.Add(f.Name, t);
}
foreach (var s in _view.SchemaColumns.Columns)
_colnames.Add(s.Key);
}
private void LoadDeletedRowsBitmap()
{
_deletedRows = new BoolIndex(_Path, "deleted_.idx");
}
private void InsertRowsWithIndexUpdate(Guid guid, List<object[]> rows)
{
foreach (var row in rows)
{
object[] r = new object[row.Length + 1];
r[0] = guid;
Array.Copy(row, 0, r, 1, row.Length);
byte[] b = fastBinaryJSON.BJSON.Instance.ToBJSON(r);
int rownum = _viewData.WriteData(guid, b, false);
IndexRow(guid, row, rownum);
}
}
private void IndexRow(Guid docid, object[] row, int rownum)
{
//return;
int i = 0;
_indexes[_docid].Set(docid, rownum);
// index the row
foreach (var d in row)
_indexes[_colnames[i++]].Set(d, rownum);
}
private IIndex CreateIndex(string name, Type type)
{
if (type == typeof(FullTextString))
return new FullTextIndex(_Path, name);
else if (type == typeof(string))
return new TypeIndexes<string>(_Path, name, Global.DefaultStringKeySize);
else if (type == typeof(bool))
return new BoolIndex(_Path, name);
else
return (IIndex)Activator.CreateInstance(
typeof(TypeIndexes<>).MakeGenericType(type),
new object[] { _Path, name, Global.DefaultStringKeySize });
}
private void DeleteRowsWith(Guid guid)
{
// find bitmap for guid column
WAHBitArray gc = QueryColumnExpression(_docid, RDBExpression.Equal, guid);
_deletedRows.InPlaceOR(gc);
}
private WAHBitArray QueryColumnExpression(string colname, RDBExpression exp, object from)
{
return _indexes[colname].Query(exp, from);
}
#endregion
}
}
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