public static void AdddLastModified(string url, DateTime lastModified, EntryList tags)
{
if (lastModified == DateTime.MinValue)
{
return;
}
string data = lastModified.ToUniversalTime().Ticks.ToString();
AddToTags(url, data, tags);
}
/// <summary> Gets the time the data associated with the url from the cache was last modified,
/// returning DateTime.MinValue if data for the url was not found in the cache. </summary>
public static DateTime GetLastModified(string url, string path, EntryList tags)
{
string entry = GetFromTags(url, tags);
long ticks = 0;
if (entry != null && long.TryParse(entry, out ticks))
{
return(new DateTime(ticks, DateTimeKind.Utc));
}
else
{
return(File.GetLastWriteTimeUtc(path));
}
}
static void AddToTags(string url, string data, EntryList tags)
{
string crc32 = CRC32(url);
for (int i = 0; i < tags.Entries.Count; i++)
{
if (!tags.Entries[i].StartsWith(crc32))
{
continue;
}
tags.Entries[i] = crc32 + " " + data;
tags.Save(); return;
}
tags.AddEntry(crc32 + " " + data);
}
/// <summary> Gets the time the data associated with the url from the cache was last modified,
/// returning DateTime.MinValue if data for the url was not found in the cache. </summary>
public static DateTime GetLastModified(string url, EntryList tags)
{
string entry = GetFromTags(url, tags);
long ticks = 0;
if (entry != null && long.TryParse(entry, out ticks))
{
return(new DateTime(ticks, DateTimeKind.Utc));
}
string path = MakePath(url);
if (!File.Exists(path))
{
return(DateTime.MinValue);
}
return(File.GetLastWriteTimeUtc(path));
}
static string GetFromTags(string url, EntryList tags)
{
string crc32 = CRC32(url);
for (int i = 0; i < tags.Entries.Count; i++)
{
string entry = tags.Entries[i];
if (!entry.StartsWith(crc32))
{
continue;
}
int sepIndex = entry.IndexOf(' ');
if (sepIndex == -1)
{
continue;
}
return(entry.Substring(sepIndex + 1));
}
return(null);
}
public static string GetETag(string url, EntryList tags)
{
return(GetFromTags(url, tags));
}
