private static Metadata readMetadataTable(FileStream metadataStream, int offset)
{
MetadataTableInfo info = readMetadataTableInfo(metadataStream, offset);
List<Tuple<int, byte[]>> table = new List<Tuple<int, byte[]>>();
int offs_acc = info.tableOffset.value;
for(int i=0; i<info.numEntries; i++)
{
table.Add(readMetadataEntry(metadataStream, offs_acc));
offs_acc += metadataStream.ReadInt(offs_acc) + 4;
offs_acc = HexTools.align(offs_acc); //word align
}
Metadata ret = new Metadata();
ret.data = table;
ret.info = info;
return ret;
}
public void writeMetadata()
{
//metadataStream.Seek(0, SeekOrigin.Begin);
//TODO
//Load all tables into RAM, erase the file, rewrite all the tables.
mainTable.info.numEntries = tables.Count;
metadataStream = File.Open(metadataPath, FileMode.Open);
MetadataTableInfo[] tableInfo = new MetadataTableInfo[tables.Count];
var myData = new List<Metadata>();
foreach(var table in tables)
{
myData.Add(table.Value);
}
for(int i=0; i<tables.Count; i++)
{
tableInfo[i] = myData[i].info;
}
int [] tableInfoOffsets = new int[myData.Count];
int offs_acc = TABLE_INFO_SIZE;
for(int i=0; i<myData.Count; i++)
{
tableInfoOffsets[i] = offs_acc;
MetadataTableInfo curTable;
curTable = myData[i].info;
offs_acc += TABLE_INFO_SIZE;
}
mainTable.info.tableOffset = new Pointer(offs_acc); //start of main data
//mainTable.data = new List<Tuple<int, byte[]>>();
//now write the main table
for (int i = 0; i < myData.Count; i++)
{
metadataStream.WriteInt(4, offs_acc);
offs_acc += 4;
metadataStream.WriteInt(tableInfoOffsets[i], offs_acc);
offs_acc += 4;
//mainTable.data.Add(Tuple.Create(4, BitConverter.GetBytes(tableInfoOffsets[i])));
}
//now write all the other tables' data
for (int i=0; i<myData.Count; i++)
{
tableInfo[i].tableOffset = new Pointer(offs_acc);
for(int j=0; j<myData[i].data.Count; j++)
{
int len = myData[i].data[j].Item1;
metadataStream.WriteInt(len, offs_acc); //length
offs_acc += 4;
metadataStream.Seek(offs_acc, SeekOrigin.Begin);
metadataStream.Write(myData[i].data[j].Item2, 0, len);
offs_acc += len;
int align_diff = HexTools.align(offs_acc) - offs_acc;
if(align_diff!=0)
{
byte[] alignment = new byte[align_diff];
Array.Clear(alignment, 0, align_diff);
metadataStream.Write(alignment, 0, align_diff);
}
offs_acc += align_diff;
}
}
metadataStream.SetLength(offs_acc);
//now go back to the top and write all the table data
writeMetadataTableInfo(metadataStream, mainTable.info, 0);
offs_acc = TABLE_INFO_SIZE;
for (int i = 0; i < myData.Count; i++)
{
writeMetadataTableInfo(metadataStream, tableInfo[i], offs_acc);
offs_acc += TABLE_INFO_SIZE;
}
mainTable = readMetadataTable(metadataStream, 0);
metadataStream.Flush();
metadataStream.Close();
//And we're done.
//All headers, then all data
//TableData1, TableData2, TableData3, . . .
//length, dataaaaaaaaaaaa; length, dataaaaaaaaaaaaa, . . .
}
public void setMetadataTable(string identifier, byte[][] table)
{
Metadata toAdd = new Metadata();
toAdd.info = new MetadataTableInfo();
toAdd.data = new List<Tuple<int, byte[]>>();
toAdd.info.identifier = identifier;
toAdd.info.numEntries = table.Length;
toAdd.info.tableOffset = new Pointer(0); //Placeholder; determined upon write
int len = 0;
foreach(byte[] entry in table)
{
len += 4;
int entry_len = entry.Length;
len += entry_len;
toAdd.data.Add(Tuple.Create(entry_len, entry));
}
toAdd.info.totalLength = len;
if(tables.ContainsKey(identifier))
{
tables[identifier] = toAdd;
quickWrite(identifier);
}
else
{
tables[identifier] = toAdd;
writeMetadata();
}
//placeholder until metadata is written
//myData.Add(toAdd);
}
public void setMetadataTable(string identifier, Metadata meta)
{
if (tables.ContainsKey(identifier))
{
tables[identifier] = meta;
quickWrite(identifier);
}
else
{
tables[identifier] = meta;
writeMetadata();
}
}
//private List<Metadata> myData;
//List<MetadataTable> tables; //maybe in the works for more efficient refactoring
public MetadataManager(string filePath)
{
this.metadataPath = filePath;
if (!File.Exists(filePath))
{
metadataStream = File.Open(filePath, FileMode.CreateNew);
initializeMetadata(metadataStream);
}
else
{ metadataStream = File.Open(filePath, FileMode.Open); }
tables = new Dictionary<string, Metadata>();
//myData = new List<Metadata>();
mainTable = readMetadataTable(metadataStream, 0);//new Metadata();
//mainTable.info = readMetadataTableInfo(metadataStream, 0);
int numTables = mainTable.info.numEntries;
int offs = mainTable.info.tableOffset.value;
//int offs = 4;
for (int i = 0; i < numTables; i++)
{
offs += 4; //ignore length data; constant length
Pointer tableOffs = new Pointer(metadataStream.ReadData(offs,4)); //Get the pointer to the data table
Metadata temp = readMetadataTable(metadataStream, tableOffs.value);
offs += 4;
string identifier = metadataStream.ReadASCII(tableOffs.value, IDENTIFIER_LENGTH); //read the identifier of the data table
tables.Add(identifier, temp);
//myData.Add(temp);
}
metadataStream.Close();
}