/// <summary>
/// Removing an index from index.dw and AllIndexes
/// </summary>
/// <param name="idx">Index</param>
public void RemoveIndex( Index idx )
{
if ( idx != null )
RemoveIndex( idx.DwarfHashCode );
}
/// <summary>
/// Finds a chunk with index space,
/// that can contain an Index "idx"
/// </summary>
/// <param name="idx">Index</param>
/// <returns>filepath to chunk</returns>
private List<string> FindChunkFilesForRecord( Index idx )
{
return FindChunkFilesForRecord( idx.DwarfHashCode );
}
/// <summary>
/// Searching a Data Container by index
/// </summary>
/// <param name="dc_index">DC index</param>
/// <returns></returns>
public DataContainer GetDataContainer( Index dc_index )
{
// TODO: search for data container in file chunks
return null;
}
/// <summary>
/// Searching a Record by index
/// </summary>
/// <param name="dc_index">Record index</param>
/// <returns></returns>
public Record GetRecord( Index rec_index )
{
// Let's find our record in chunk files...
foreach (var convenient_chunk in FindChunkFilesForRecord( rec_index )) {
var item = ChunkFormat.GetItem( convenient_chunk, rec_index );
if ( item != null )
return (Record)item;
}
return null;
}
/// <summary>
/// Getting an item from a chunk file in a multithread mode
/// </summary>
/// <param name="json_reader">JSON text reader/param>
/// <param name="idx">item index</param>
private static IStructure GetItemInfile( JsonTextReader json_reader, Index idx )
{
InnerChunkElement inner = FindItem( json_reader, idx );
if ( inner != null ) {
if ( inner.NeedToRemove == 0 ) { // If we neeed not remove this element
var obj_json = inner.Contents;
if ( inner.ElementType == InnerChunkElement.ElemType.DATACONTAINER ) {
var ret_dc = JsonConvert.DeserializeObject<DataContainer>( obj_json );
return ret_dc;
} else {
var ret_rec = JsonConvert.DeserializeObject<Record>( obj_json );
return ret_rec;
}
} else
return null;
}
return null;
}
/// <summary>
/// Receiving records a record with given index
/// </summary>
/// <param name="ind"></param>
/// <returns></returns>
public IStructure GetStructure(Index ind)
{
try
{
if (items_dict.ContainsKey(ind.DwarfHashCode))
return items_dict[ind.DwarfHashCode];
else
return null;
}
catch (Exception ex)
{
Errors.Messages.DisplayError("FAILED TO GET STRUCTURE: " + ex.Message + ":" + ex.StackTrace,
"", "", DateTime.Now);
}
return null;
}
private static InnerChunkElement FindItem( JsonTextReader jr, Index idx )
{
return FindItem( jr, idx.DwarfHashCode );
}
/// <summary>
/// Removing an item to a chunk file in multithread mode
/// </summary>
/// <param name="filepath">path to file</param>
/// <param name="idx">datastructure index</param>
public static void RemoveItem( string filepath, Index idx )
{
var buffer = new byte[MaxChunkSize];
int offset = 0;
int needed_idx_pos = -1;
int needed_elem_type_pos = -1;
// let's use a direct method to find our element by hash index
using ( var fs = File.Open( filepath, FileMode.Open )) {
if ( fs.Read( buffer, offset, MaxChunkSize ) > 0 ) {
string buf = System.Text.Encoding.UTF8.GetString(buffer);
const string tmp_el_type ="\"ElementType\":";
string tmp_el_hash ="\"ElementHash\": \""+idx.DwarfHashCode+"\"";
int str_elem_type_pos = buf.IndexOf(tmp_el_type, StringComparison.InvariantCultureIgnoreCase);
int str_hash_pos = buf.IndexOf(tmp_el_hash, StringComparison.InvariantCultureIgnoreCase);
if ( str_hash_pos > -1 )
needed_idx_pos = str_hash_pos+15;
if ( str_elem_type_pos > -1 )
needed_elem_type_pos = str_elem_type_pos + 15;
}
}
// let's delete a hash index for object, that we should remove
if ( needed_idx_pos > -1 ) {
using ( var fs = File.Open( filepath, FileMode.Open )) {
var replacement = new byte[34];
fs.Position = needed_elem_type_pos;
fs.Write( System.Text.Encoding.UTF8.GetBytes( 3.ToString() /* REMOVED */ ), 0, 1);
fs.Position = needed_idx_pos;
fs.Write( replacement, 0, 34);
fs.Position -= 34;
fs.Write( System.Text.Encoding.UTF8.GetBytes( "null" ), 0, 4);
}
}
}
/// <summary>
/// Getting several elements from a chunk file in multithread mode
/// </summary>
/// <param name="filepath">path to file</param>
/// <param name="idx_arr">indexes array</param>
public static IStructure[] GetItemRange( string filepath, Index[] idx_arr )
{
var ret_arr = new IStructure[0];
var tmp_path = CreateTemporaryFile( filepath );
using (var json_reader = new JsonTextReader(new StreamReader(File.Open( tmp_path, FileMode.Open )))) {
json_reader.SupportMultipleContent = true;
foreach ( var index in idx_arr ) {
var elem = GetItemInfile( json_reader, index );
if ( elem != null ) {
Array.Resize( ref ret_arr, ret_arr.Length + 1 );
ret_arr[ret_arr.Length-1] = elem;
}
}
}
DeleteTemporaryFile( tmp_path );
return ret_arr;
}
/// <summary>
/// Getting an item from a chunk file in multithread mode
/// </summary>
/// <param name="filepath">path to a chunk file</param>
/// <param name="idx">item index</param>
public static IStructure GetItem( string filepath, Index idx )
{
return GetItem( filepath, idx.DwarfHashCode );
}
/// <summary>
/// Creating an index from hashcode
/// </summary>
/// <param name="hash"></param>
/// <returns></returns>
public static Index CreateFromDwarfHashCode( string hash )
{
var new_idx = new Index();
new_idx.DwarfHashCode = hash;
return new_idx;
}
