public async Task <T> GetAsync(string key)
{
Clean();
ItemLock <T> progressLock = null;
ItemLock <T> ownProgressLock = null;
T res = null;
lock (instanceLock)
{
if (items.ContainsKey(key))
{
progressLock = items[key];
}
else
{
ownProgressLock = new ItemLock <T>();
items[key] = ownProgressLock;
}
}
if (ownProgressLock != null)
{
try
{
res = await cacheMissedHandlerAsync(key);
}
catch
{
res = null;
}
// dont keep in cache loading failures
if (!allowNullCaching && res == null)
{
lock (instanceLock)
{
items.Remove(key);
}
}
lock (ownProgressLock)
{
ownProgressLock.Data = res;
ownProgressLock.Done = true;
Monitor.PulseAll(ownProgressLock);
}
}
if (progressLock != null)
{
lock (progressLock)
{
if (!progressLock.Done)
{
Monitor.Wait(progressLock);
}
}
res = progressLock.Data;
}
return(res);
}
public string GetItem(string key)
{
//Random rand = new Random();
//bool clean = (rand.Next(100) == 1);
//if(clean)
Clean();
ItemLock itemLock = null;
lock (lockInstance) {
if (inprogress.ContainsKey(key))
{
itemLock = inprogress[key];
}
else
{
itemLock = new ItemLock();
inprogress[key] = itemLock;
}
}
long id = -1;
try {
lock (itemLock) {
if (!itemLock.Done)
{
string connectionString = "URI=file:" + basePath + "cache.db";
using (IDbConnection dbcon = (IDbConnection) new SqliteConnection(connectionString)) {
dbcon.Open();
// get the item
using (IDbCommand dbcmd = dbcon.CreateCommand()) {
dbcmd.CommandText = "SELECT id FROM item WHERE key='" + key.Replace("'", "''") + "' AND last > DATETIME('now', '-" + timeout + " seconds')";
object res = dbcmd.ExecuteScalar();
if (res != null)
{
id = Convert.ToInt64(res);
}
}
// if not found, get a new version
if (id == -1)
{
string validity;
string file = handler(key, out validity);
if (file != null)
{
using (IDbCommand dbcmd = dbcon.CreateCommand()) {
dbcmd.CommandText = "INSERT INTO item (key,validity,last) VALUES ('" + key.Replace("'", "''") + "','" + validity.Replace("'", "''") + "',DATETIME('now'))";
dbcmd.ExecuteNonQuery();
}
// get the insert id
using (IDbCommand dbcmd = dbcon.CreateCommand()) {
dbcmd.CommandText = "SELECT last_insert_rowid()";
id = Convert.ToInt64(dbcmd.ExecuteScalar());
}
File.Move(file, basePath + "/data/" + id.ToString());
}
}
dbcon.Close();
}
if (id != -1)
{
itemLock.File = basePath + "/data/" + id.ToString();
}
else
{
itemLock.File = null;
}
}
}
}
catch (Exception) {
}
finally {
lock (lockInstance) {
if (inprogress.ContainsKey(key))
{
inprogress.Remove(key);
}
}
}
return(itemLock.File);
}
