public Stream GetFileStream(int tag, int level, int x, int y)
{
entry = new DirectoryEntry(tag, level, x, y, 0, 0);
UInt32 index = entry.ComputeHash() % (UInt32)(header.HashBuckets);
long hep = GetHashEntryPosition(index);
DirectoryEntry de;
while (hep != 0)
{
de = GetDirectoryEntry(hep);
if ((de.x == x) && (de.y == y) && ((de.tag == tag) || (tag == -1)) && (de.level == level))
{
return(StreamSlice.Create(dataStream, de.location, de.size));
}
else
{
hep = de.NextEntryInChain;
}
}
return(null);
}
public Stream GetFileStream(int tag, int level, int x, int y)
{
entry = new DirectoryEntry(tag, level, x, y, 0, 0);
UInt32 index = entry.ComputeHash() % (UInt32)(header.HashBuckets);
long hep = GetHashEntryPosition(index);
DirectoryEntry de;
while (hep != 0)
{
de = GetDirectoryEntry(hep);
if ((de.x == x) && (de.y == y) && ((de.tag == tag) || (tag == -1)) && (de.level == level))
{
MemoryStream ms = null;
byte[] buffer = new byte[de.size];
dataStream.Seek(de.location, SeekOrigin.Begin);
dataStream.Read(buffer, 0, (int)de.size);
ms = new MemoryStream(buffer);
return(ms);
}
else
{
hep = de.NextEntryInChain;
}
}
return(null);
}
public void AddFile(string inputFilename, int tag, int level, int x, int y)
{
FileInfo fi = new FileInfo(inputFilename);
if (fi.Exists)
{
Byte[] entryData = null;
// Check for empty directory and add new Directory Block
if (header.FreeEntries == 0)
{
// Write Directory Header Block
entry = new DirectoryEntry();
entry.size = 8192 * (uint)Marshal.SizeOf(entry);
entry.NextEntryInChain = header.FirstDirectoryEntry;
entryData = GetEntryBytes();
header.FirstDirectoryEntry = fileStream.Seek(0, SeekOrigin.End);
fileStream.Write(entryData, 0, entryData.Length);
// Allocate a new 8k entries
header.FreeEntries = 8192;
header.NextFreeDirectoryEntry = fileStream.Seek(0, SeekOrigin.End);
fileStream.Seek(8192 * Marshal.SizeOf(entry), SeekOrigin.End);
fileStream.WriteByte(42);
}
long position = fileStream.Seek(0, SeekOrigin.End);
entry = new DirectoryEntry(tag, level, x, y, position, (UInt32)fi.Length);
UInt32 index = entry.ComputeHash() % (UInt32)header.HashBuckets;
byte[] buf = null;
// Copy the input file stream to the end of the file
using (FileStream ifs = File.Open(inputFilename, FileMode.Open, FileAccess.Read, FileShare.Read))
{
int len = (int)fi.Length;
buf = new byte[fi.Length];
ifs.Read(buf, 0, len);
fileStream.Write(buf, 0, len);
ifs.Close();
}
long hep = GetHashEntryPosition(index);
entry.NextEntryInChain = hep;
// Update the Hash Table
WriteHashEntryPosition(index, header.NextFreeDirectoryEntry);
// Write the directory entry
fileStream.Seek(header.NextFreeDirectoryEntry, SeekOrigin.Begin);
entryData = GetEntryBytes();
fileStream.Write(entryData, 0, entryData.Length);
// Update Header
header.FileCount++;
header.NextFreeDirectoryEntry += Marshal.SizeOf(entry);
header.FreeEntries--;
// Write it back to file
Byte[] headerData = GetHeaderBytes();
fileStream.Seek(0, SeekOrigin.Begin);
fileStream.Write(headerData, 0, headerData.Length);
//todo check for file count and extend file when we get to end.
}
}
public Stream GetFileStreamFullSearch(int tag, int level, int x, int y)
{
entry = new DirectoryEntry(tag, level, x, y, 0, 0);
UInt32 index = entry.ComputeHash() % (UInt32)(header.HashBuckets);
long hep = GetHashEntryPosition(index);
DirectoryEntry de;
DirectoryEntry den = new DirectoryEntry();
while (hep != 0)
{
de = GetDirectoryEntry(hep);
if ((de.x == x) && (de.y == y) && ((de.tag == tag) || (tag == -1)) && (de.level == level))
{
if (den.tag < de.tag)
{
den = de;
if (tag != -1)
{
break;
}
}
}
hep = de.NextEntryInChain;
}
if (den.location != 0)
{
MemoryStream ms = null;
byte[] buffer = new byte[den.size];
fileStream.Seek(den.location, SeekOrigin.Begin);
fileStream.Read(buffer, 0, (int)den.size);
ms = new MemoryStream(buffer);
return ms;
}
return null;
}
public void AddFile(string inputFilename, int tag, int level, int x, int y)
{
FileInfo fi = new FileInfo(inputFilename);
if (fi.Exists)
{
Byte[] entryData = null;
// Check for empty directory and add new Directory Block
if (header.FreeEntries == 0)
{
// Write Directory Header Block
entry = new DirectoryEntry();
entry.size = 8192 * (uint)Marshal.SizeOf(entry);
entry.NextEntryInChain = header.FirstDirectoryEntry;
entryData = GetEntryBytes();
header.FirstDirectoryEntry = dataStream.Seek(0, SeekOrigin.End);
dataStream.Write(entryData, 0, entryData.Length);
// Allocate a new 8k entries
header.FreeEntries = 8192;
header.NextFreeDirectoryEntry = dataStream.Seek(0, SeekOrigin.End);
dataStream.Seek(8192 * Marshal.SizeOf(entry), SeekOrigin.End);
dataStream.WriteByte(42);
}
long position = dataStream.Seek(0, SeekOrigin.End);
entry = new DirectoryEntry(tag, level, x, y, position, (UInt32)fi.Length);
UInt32 index = entry.ComputeHash() % (UInt32)header.HashBuckets;
byte[] buf = null;
// Copy the input file stream to the end of the file
using (FileStream ifs = File.Open(inputFilename, FileMode.Open, FileAccess.Read, FileShare.Read))
{
int len = (int)fi.Length;
buf = new byte[fi.Length];
ifs.Read(buf, 0, len);
dataStream.Write(buf, 0, len);
ifs.Close();
}
long hep = GetHashEntryPosition(index);
entry.NextEntryInChain = hep;
// Update the Hash Table
WriteHashEntryPosition(index, header.NextFreeDirectoryEntry);
// Write the directory entry
dataStream.Seek(header.NextFreeDirectoryEntry, SeekOrigin.Begin);
entryData = GetEntryBytes();
dataStream.Write(entryData, 0, entryData.Length);
// Update Header
header.FileCount++;
header.NextFreeDirectoryEntry += Marshal.SizeOf(entry);
header.FreeEntries--;
// Write it back to file
Byte[] headerData = GetHeaderBytes();
dataStream.Seek(0, SeekOrigin.Begin);
dataStream.Write(headerData, 0, headerData.Length);
//todo check for file count and extend file when we get to end.
}
}
