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);
}
public static void AddETagToCache( string url, string etag, EntryList tags )
{
if( etag == null ) return;
byte[] utf8 = Encoding.UTF8.GetBytes( url );
string crc32 = CRC32( utf8 ).ToString();
for( int i = 0; i < tags.Entries.Count; i++ ) {
if( !tags.Entries[i].StartsWith( crc32 ) ) continue;
tags.Entries[i] = crc32 + " " + etag;
tags.Save(); return;
}
tags.AddEntry( crc32 + " " + etag );
}
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));
}
public static void AddETagToCache(string url, string etag, EntryList tags)
{
if (etag == null)
{
return;
}
byte[] utf8 = Encoding.UTF8.GetBytes(url);
string crc32 = CRC32(utf8).ToString();
for (int i = 0; i < tags.Entries.Count; i++)
{
if (!tags.Entries[i].StartsWith(crc32))
{
continue;
}
tags.Entries[i] = crc32 + " " + etag;
tags.Save(); return;
}
tags.AddEntry(crc32 + " " + etag);
}
public static string GetETagFromCache(string url, EntryList tags)
{
byte[] utf8 = Encoding.UTF8.GetBytes(url);
string crc32 = CRC32(utf8).ToString();
foreach (string entry in tags.Entries)
{
if (!entry.StartsWith(crc32))
{
continue;
}
string[] parts = entry.Split(trimChars, 2);
if (parts.Length == 1)
{
continue;
}
return(parts[1]);
}
return(null);
}
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));
}
public static string GetETagFromCache( string url, EntryList tags )
{
byte[] utf8 = Encoding.UTF8.GetBytes( url );
string crc32 = CRC32( utf8 ).ToString();
foreach( string entry in tags.Entries ) {
if( !entry.StartsWith( crc32 ) ) continue;
string[] parts = entry.Split( trimChars, 2 );
if( parts.Length == 1 ) continue;
return parts[1];
}
return null;
}
