/// <summary>
/// Finds the EngineDatabase that matches a cache file from a stream, if available.
/// </summary>
/// <param name="reader">The stream to read from.</param>
/// <param name="engineDb">The engine database to use to process the cache file.</param>
/// <returns>The EngineDescription used to describe the cache file, otherwise null.</returns>
public static EngineDescription FindEngineDescription(IReader reader, EngineDatabase engineDb)
{
// Set the reader's endianness based upon the file's header magic
reader.SeekTo(0);
byte[] headerMagic = reader.ReadBlock(4);
reader.Endianness = DetermineCacheFileEndianness(headerMagic);
reader.SeekTo(0x4);
int fileVersion = reader.ReadInt32();
var matches = engineDb.FindEnginesByVersion(fileVersion, reader.Endianness);
Dictionary <int, string> offsetCache = new Dictionary <int, string>();
foreach (EngineDescription engine in matches)
{
if (offsetCache.ContainsKey(engine.BuildStringOffset))
{
if (offsetCache[engine.BuildStringOffset] == engine.BuildVersion)
{
return(engine);
}
else
{
continue;
}
}
reader.SeekTo(engine.BuildStringOffset);
string buildString = reader.ReadAscii();
if (buildString == engine.BuildVersion)
{
return(engine);
}
offsetCache[engine.BuildStringOffset] = buildString;
}
return(null);
}
/// <summary>
/// Finds any EngineDatabase that matches a cache file from a stream, if available.
/// List return is intended to be passed to the user to make the final choice in case of > 1 matches.
/// </summary>
/// <param name="reader">The stream to read from.</param>
/// <param name="engineDb">The engine database to use to process the cache file.</param>
/// <returns>List containing matching EngineDescriptions that could possibly describe the cache file, if any.</returns>
public static List <EngineDescription> FindEngineDescriptions(IReader reader, EngineDatabase engineDb)
{
// Set the reader's endianness based upon the file's header magic
reader.SeekTo(0);
byte[] headerMagic = reader.ReadBlock(4);
var endian = DetermineCacheFileEndianness(headerMagic);
int fileVersion;
if (endian != null)
{
reader.Endianness = endian.Value;
reader.SeekTo(0x4);
fileVersion = reader.ReadInt32();
}
else
{
//halo trial lol
reader.SeekTo(0x2C0);
headerMagic = reader.ReadBlock(4);
var trialendian = DetermineTrialCacheFileEndianness(headerMagic);
reader.Endianness = trialendian;
reader.SeekTo(0x588);
fileVersion = reader.ReadInt32();
}
var possibleEngines = engineDb.FindEnginesByVersion(fileVersion, reader.Endianness);
//reduce extra reads by caching the value at each offset
Dictionary <int, string> offsetCache = new Dictionary <int, string>();
List <EngineDescription> matches = new List <EngineDescription>();
foreach (EngineDescription engine in possibleEngines)
{
if (offsetCache.ContainsKey(engine.BuildStringOffset))
{
if (offsetCache[engine.BuildStringOffset] == engine.BuildVersion)
{
matches.Add(engine);
if (!string.IsNullOrEmpty(engine.BuildVersion))
{
break;
}
}
continue;
}
reader.SeekTo(engine.BuildStringOffset);
string buildString = reader.ReadAscii(0x20);
if (buildString == engine.BuildVersion)
{
matches.Add(engine);
if (!string.IsNullOrEmpty(engine.BuildVersion))
{
break;
}
}
offsetCache[engine.BuildStringOffset] = buildString;
}
return(matches);
}
