lib_unity_purchase/Runtime/Purchasing/TransactionLog.cs

90 lines
2.8 KiB
C#

using System;
using System.IO;
using System.Text;
namespace UnityEngine.Purchasing
{
/// <summary>
/// Records processed transactions on the file system
/// for de duplication purposes.
/// </summary>
internal class TransactionLog
{
private readonly ILogger logger;
private readonly string persistentDataPath;
public TransactionLog(ILogger logger, string persistentDataPath)
{
this.logger = logger;
if (!string.IsNullOrEmpty(persistentDataPath))
{
this.persistentDataPath = Path.Combine(Path.Combine(persistentDataPath, "Unity"), "UnityPurchasing");
}
}
/// <summary>
/// Removes all transactions from the log.
/// </summary>
public void Clear()
{
Directory.Delete(persistentDataPath, true);
}
public bool HasRecordOf(string transactionID)
{
if (string.IsNullOrEmpty(transactionID) || string.IsNullOrEmpty(persistentDataPath))
{
return false;
}
return Directory.Exists(GetRecordPath(transactionID));
}
public void Record(string transactionID)
{
// Consumables have additional de-duplication logic.
if (!(string.IsNullOrEmpty(transactionID) || string.IsNullOrEmpty(persistentDataPath)))
{
var path = GetRecordPath(transactionID);
try
{
Directory.CreateDirectory(path);
}
catch (Exception recordPathException)
{
// A wide variety of exceptions can occur, for all of which
// nothing is the best course of action.
logger.LogException(recordPathException);
}
}
}
private string GetRecordPath(string transactionID)
{
return Path.Combine(persistentDataPath, ComputeHash(transactionID));
}
/// <summary>
/// Compute a 64 bit Knuth hash of a transaction ID.
/// This should be more than sufficient for the few thousand maximum
/// products expected in an App.
/// </summary>
internal static string ComputeHash(string transactionID)
{
var hash = 3074457345618258791ul;
for (var i = 0; i < transactionID.Length; i++)
{
hash += transactionID[i];
hash *= 3074457345618258799ul;
}
var builder = new StringBuilder(16);
foreach (var b in BitConverter.GetBytes(hash))
{
builder.AppendFormat("{0:X2}", b);
}
return builder.ToString();
}
}
}