private async Task loadRegisterFromDiskAsync()
{
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:Loading cache register: {0}",
CacheRegister);
if (!Directory.Exists(CachePath))
{
_trace.TraceEvent(TraceEventType.Warning, 0, "EveLibFileCache:Cache directory not found: {0}",
CachePath);
return;
}
if (!File.Exists(CacheRegister))
{
_trace.TraceEvent(TraceEventType.Warning, 0, "EveLibFileCache:Cache register not found: {0}",
CacheRegister);
return;
}
try {
// read all lines
string[] data = await
AsyncFileUtilities.ReadAllLinesAsync(CacheRegister).ConfigureAwait(false);
foreach (string entry in data)
{
string[] split = entry.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
DateTime cacheValidUntil = DateTime.Parse(split[1], CultureInfo.InvariantCulture);
string fileName = split[0];
// if cache is still valid we register it
if (cacheValidUntil > DateTime.UtcNow)
{
_register[fileName] = cacheValidUntil;
}
else
{
// if cache is out of date we delete the data
if (File.Exists(CachePath + Config.Separator + fileName))
{
File.Delete(CachePath + Config.Separator + fileName);
}
}
}
// delete all files that aren't listed in the register file
IEnumerable <string> files = Directory.EnumerateFiles(CachePath);
foreach (
string file in
files.Where(
file =>
!_register.ContainsKey(file.Replace(CachePath + Config.Separator, "")) &&
!file.Equals(CacheRegister)))
{
File.Delete(file);
}
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:CacheRegisterLoaded");
}
catch (Exception) {
_trace.TraceEvent(TraceEventType.Error, 0, "EveLibFileCache:Could not load cache register");
}
}
private async Task writeRegisterToDiskAsync()
{
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:Writing cache register to disk");
var lockTask = await _registerLock.WriterLockAsync();
try {
await AsyncFileUtilities.WriteAllLinesAsync(CacheRegister,
_register.Select(x => x.Key + "," + x.Value.ToString(CultureInfo.InvariantCulture)))
.ConfigureAwait(false);
}
finally {
lockTask.Dispose();
}
}
/// <summary>
/// Loads data from cache
/// </summary>
/// <param name="uri">The uri to load cache for</param>
/// <returns>The cached data</returns>
public async Task <string> LoadAsync(Uri uri)
{
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache.LoadAsync:Start");
await initAsync().ConfigureAwait(false);
string data = null;
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:CacheRegisterLookupUri: {0}", uri);
string hash = getHash(uri);
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:CacheRegisterLookupHash: {0}", hash);
DateTime cacheExpirationTime;
bool found = _register.TryGetValue(hash, out cacheExpirationTime);
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:CacheRegisterHit: {0}", found);
if (found)
{
bool validCache = DateTime.UtcNow < cacheExpirationTime;
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:CacheIsValid: {0} ({1})", validCache,
cacheExpirationTime);
if (validCache)
{
string filePath = CachePath + Config.Separator + hash;
bool fileExist = File.Exists(filePath);
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:CacheDataFound: {0}", fileExist);
if (File.Exists(filePath))
{
try {
data =
await
AsyncFileUtilities.ReadAllTextAsync(CachePath + Config.Separator +
getHash(uri))
.ConfigureAwait(false);
_trace.TraceEvent(TraceEventType.Verbose, 0,
"EveLibFileCache:Data successfully loaded from cache: {0}",
filePath);
}
catch (Exception) {
_trace.TraceEvent(TraceEventType.Error, 0,
"EveLibFileCache:Cache data could not be loaded: {0}", filePath);
}
}
}
}
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache.LoadAsync:Complete");
return(data);
}
private Task writeCacheDataToDiskAsync(Uri uri, string data)
{
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:Writing cache data to disk: {0}", uri);
return(AsyncFileUtilities.WriteAllTextAsync(Path.Combine(CachePath, getHash(uri)),
data));
}
private Task writeRegisterToDiskAsync()
{
_trace.TraceEvent(TraceEventType.Verbose, 0, "EveLibFileCache:Writing cache register to disk");
return(AsyncFileUtilities.WriteAllLinesAsync(CacheRegister,
_register.Select(x => x.Key + "," + x.Value.ToString(CultureInfo.InvariantCulture))));
}
