public static void AddProxy(string ip, int port, string proxySite)
{
try {
ProxyMutex.WaitOne();
var count = _connection.ExecuteScalar <int>(
"select count(*) from Proxy where Ip = @Ip and Port = @Port",
new { Ip = ip, Port = port }
);
if (count != 0)
{
return;
}
count = _connection.Execute(
"insert into Proxy(IP, Port, IsUsing, CrawledFrom) values(@Ip, @Port, 0, @CrawledFrom)",
new { Ip = ip, Port = port, CrawledFrom = proxySite }
);
if (count != 1)
{
throw new ProxyCacheException("Proxy cache: add proxy failed!");
}
} finally {
ProxyMutex.ReleaseMutex();
}
}
public static void RemoveProxy(string ip, int port)
{
try {
ProxyMutex.WaitOne();
var count = _connection.ExecuteScalar <int>(
"select count(*) from Proxy where Ip = @Ip and Port = @Port",
new { Ip = ip, Port = port }
);
if (count == 0)
{
return;
}
count = _connection.Execute(
"delete from Proxy where Ip = @Ip and Port = @Port",
new { Ip = ip, Port = port }
);
if (count != 1)
{
throw new ProxyCacheException("Proxy cache: remove proxy failed!");
}
} finally {
ProxyMutex.ReleaseMutex();
}
}
public static void Clear()
{
try {
ProxyMutex.WaitOne();
_connection.Execute("delete from Proxy");
} finally {
ProxyMutex.ReleaseMutex();
}
}
public static WebProxy GetRandomProxy()
{
try {
ProxyMutex.WaitOne();
var proxyList = _connection.Query("select Ip, Port from Proxy");
if (proxyList.Count() == 0)
{
return(null);
}
int i = new Random().Next(0, proxyList.Count());
var proxy = proxyList.ElementAt(i);
return(new WebProxy(string.Format("http://{0}:{1}", proxy.Ip, proxy.Port)));
} finally {
ProxyMutex.ReleaseMutex();
}
}
public static WebProxy GetProxy()
{
try {
ProxyMutex.WaitOne();
var proxyList = _connection.Query("select Ip, Port from Proxy where IsUsing = 0");
if (proxyList.Count() == 0)
{
return(null);
}
var proxy = proxyList.First();
var count = _connection.Execute("update Proxy Set IsUsing = 1 where Ip = @Ip and Port = @Port",
new { Ip = proxy.Ip, Port = proxy.Port });
if (count != 1)
{
throw new ProxyCacheException("Proxy cache: get proxy failed!");
}
return(new WebProxy(string.Format("http://{0}:{1}", proxy.Ip, proxy.Port)));
} finally {
ProxyMutex.ReleaseMutex();
}
}