/// <summary>
/// Given a string, it hashes said string and if <paramref name="addIdentifiableCharacters"/> is true appends identifiable characters to make the root of the cache more human readable
/// </summary>
/// <param name="value"></param>
/// <param name="addIdentifiableCharacters">whether to addIdentifiableCharacters. The default is true</param>
/// <returns>hash</returns>
public static string ComputeHash(string value, bool addIdentifiableCharacters = true)
{
var trailing = value.Length > 32 ? value.Substring(value.Length - 32) : value;
byte[] hash;
using (var sha = SHA256.Create())
{
hash = sha.ComputeHash(Encoding.UTF8.GetBytes(value));
}
return(EncodingUtility.ToHex(hash, HashLength) + (addIdentifiableCharacters ? "$" + trailing : string.Empty));
}
private static string FilePathToLockName(string filePath)
{
// If we use a file path directly as the name of a semaphore,
// the ctor of semaphore looks for the file and throws an IOException
// when the file doesn't exist. So we need a conversion from a file path
// to a unique lock name.
using (var sha = SHA256.Create())
{
// To avoid conflicts on package id casing a case-insensitive lock is used.
var fullPath = Path.IsPathRooted(filePath) ? Path.GetFullPath(filePath) : filePath;
var normalizedPath = fullPath.ToUpperInvariant();
var hash = sha.ComputeHash(Encoding.UTF32.GetBytes(normalizedPath));
return(EncodingUtility.ToHex(hash, HashLength));
}
}
