public PlateFile2(string filename, int filecount)
{
fileStream = File.Open(filename, FileMode.Create);
//Initialize the header
header.Signature = 0x17914242;
header.HashBuckets = NextPowerOfTwo(filecount);
header.HashTableLocation = Marshal.SizeOf(header);
header.FirstDirectoryEntry = header.HashTableLocation + header.HashBuckets * 8;
header.NextFreeDirectoryEntry = header.FirstDirectoryEntry + Marshal.SizeOf(entry);
header.FileCount = 0;
header.FreeEntries = header.HashBuckets - 1;
//Write the header and the empty Hash area. O/S will zero the data
Byte[] headerData = GetHeaderBytes();
fileStream.Write(headerData, 0, headerData.Length);
fileStream.Seek(header.NextFreeDirectoryEntry + Marshal.SizeOf(entry) * header.HashBuckets, SeekOrigin.Begin);
fileStream.WriteByte(42);
fileStream.Seek(header.FirstDirectoryEntry, SeekOrigin.Begin);
entry = new DirectoryEntry();
entry.size = (uint)header.FreeEntries * (uint)Marshal.SizeOf(entry);
entry.location = header.FirstDirectoryEntry;
byte[] entryData = GetEntryBytes();
fileStream.Write(entryData, 0, entryData.Length);
fileStream.Seek(0, SeekOrigin.Begin);
}
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.
}
}
private void SetEntryBytes(byte[] data)
{
GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned);
entry = (DirectoryEntry)Marshal.PtrToStructure(handle.AddrOfPinnedObject(), typeof(DirectoryEntry));
handle.Free();
}
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 int GetTotalFiles()
{
DirectoryEntry de = new DirectoryEntry(0, 0, 0, 0, 0, 0);
int total = 0;
for (UInt32 i = 0; i < header.HashBuckets; i++)
{
long hep = GetHashEntryPosition(i);
while (hep != 0)
{
total++;
de = GetDirectoryEntry(hep);
hep = de.NextEntryInChain;
}
}
return total;
}
public string GetLongestChainID()
{
DirectoryEntry de = new DirectoryEntry(0, 0, 0, 0, 0, 0);
int longest = 0;
int current = 0;
string id = "";
for (UInt32 i = 0; i < header.HashBuckets; i++)
{
long hep = GetHashEntryPosition(i);
current = 0;
while (hep != 0)
{
current++;
de = GetDirectoryEntry(hep);
hep = de.NextEntryInChain;
}
if (current > longest)
{
longest = current;
id = i.ToString();
}
}
return id;
}
public int GetLongestChain()
{
DirectoryEntry de = new DirectoryEntry(0, 0, 0, 0, 0, 0);
int longest = 0;
int current = 0;
for (UInt32 i = 0; i < header.HashBuckets; i++)
{
long hep = GetHashEntryPosition(i);
current = 0;
while (hep != 0)
{
current++;
de = GetDirectoryEntry(hep);
hep = de.NextEntryInChain;
}
if (current > longest)
{
longest = current;
}
}
return longest;
}
public IEnumerable<DirectoryEntry> GetDirectoryEntries()
{
DirectoryEntry de = new DirectoryEntry(0, 0, 0, 0, 0, 0);
long hep = header.FirstDirectoryEntry;
while (hep != 0)
{
de = GetDirectoryEntry(hep);
de.location = hep;
if (de.size != 0)
{
yield return de;
}
hep = de.NextEntryInChain;
}
}
public IEnumerable<DirectoryEntry> GetEntries()
{
DirectoryEntry de = new DirectoryEntry(0, 0, 0, 0, 0, 0);
for (UInt32 i = 0; i < header.HashBuckets; i++)
{
long hep = GetHashEntryPosition(i);
while (hep != 0)
{
de = GetDirectoryEntry(hep);
yield return de;
hep = de.NextEntryInChain;
}
}
}
public void Optimize()
{
DirectoryEntry de = new DirectoryEntry(0, 0, 0, 0, 0, 0);
// preload the directory & hashtable here to make sure reads are serial and in system cache
List<List<DirectoryEntry>> list = new List<List<DirectoryEntry>>();
byte[] buf = new byte[header.HashBuckets * 8];
fileStream.Read(buf, 0, (int)buf.Length);
de = GetDirectoryEntry(header.FirstDirectoryEntry);
buf = new byte[de.size];
fileStream.Read(buf, 0, (int)de.size);
for (UInt32 i = 0; i < header.HashBuckets; i++)
{
List<DirectoryEntry> dirList = new List<DirectoryEntry>();
long hep = GetHashEntryPosition(i);
while (hep != 0)
{
de = GetDirectoryEntry(hep);
dirList.Add(de);
hep = de.NextEntryInChain;
}
dirList.Sort();
list.Add(dirList);
}
long curPos = header.FirstDirectoryEntry + Marshal.SizeOf(entry);
long[] hashTable = new long[header.HashBuckets];
for (int i = 0; i < header.HashBuckets; i++)
{
List<DirectoryEntry> dir = list[i];
if (dir.Count > 0)
{
hashTable[i] = curPos;
for (int j = 0; j < dir.Count; j++)
{
de = dir[j];
if (j == dir.Count - 1)
{
de.NextEntryInChain = 0;
}
else
{
de.NextEntryInChain = curPos + Marshal.SizeOf(entry);
}
fileStream.Seek(curPos, SeekOrigin.Begin);
de.Write(fileStream);
curPos += Marshal.SizeOf(entry);
}
}
}
// Write table seperately to sequence writes
for (int i = 0; i < header.HashBuckets; i++)
{
WriteHashEntryPosition((uint)i, hashTable[i]);
}
}
