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[Net] Simplify IP resolution code, fix caching.

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First, we should not insert into cache if the hostname resolution has
failed (as it might be a temporary internet issue), second, the async
resolver should also properly insert into cache.

Took the chance to remove some duplicate code with critical section in
it at the cost of little performance when calling the blocking
resolve_hostname function.
This commit is contained in:
Fabio Alessandrelli 2022-01-29 01:33:29 +01:00
parent 252ec22ff9
commit 49297d937c
2 changed files with 13 additions and 31 deletions
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42
core/io/ip.cpp
View file

@ -98,6 +98,11 @@ struct _IP_ResolverPrivate {
if (queue[i].status.get() != IP::RESOLVER_STATUS_WAITING) { if (queue[i].status.get() != IP::RESOLVER_STATUS_WAITING) {
continue; continue;
} }
// We might be overriding another result, but we don't care as long as the result is valid.
if (response.size()) {
String key = get_cache_key(hostname, type);
cache[key] = response;
}
queue[i].response = response; queue[i].response = response;
queue[i].status.set(response.is_empty() ? IP::RESOLVER_STATUS_ERROR : IP::RESOLVER_STATUS_DONE); queue[i].status.set(response.is_empty() ? IP::RESOLVER_STATUS_ERROR : IP::RESOLVER_STATUS_DONE);
} }
@ -120,30 +125,8 @@ struct _IP_ResolverPrivate {
}; };
IPAddress IP::resolve_hostname(const String &p_hostname, IP::Type p_type) { IPAddress IP::resolve_hostname(const String &p_hostname, IP::Type p_type) {
List<IPAddress> res; const Array addresses = resolve_hostname_addresses(p_hostname, p_type);
String key = _IP_ResolverPrivate::get_cache_key(p_hostname, p_type); return addresses.size() ? addresses[0].operator IPAddress() : IPAddress();
resolver->mutex.lock();
if (resolver->cache.has(key)) {
res = resolver->cache[key];
} else {
// This should be run unlocked so the resolver thread can keep
// resolving other requests.
resolver->mutex.unlock();
_resolve_hostname(res, p_hostname, p_type);
resolver->mutex.lock();
// We might be overriding another result, but we don't care (they are the
// same hostname).
resolver->cache[key] = res;
}
resolver->mutex.unlock();
for (int i = 0; i < res.size(); ++i) {
if (res[i].is_valid()) {
return res[i];
}
}
return IPAddress();
} }
Array IP::resolve_hostname_addresses(const String &p_hostname, Type p_type) { Array IP::resolve_hostname_addresses(const String &p_hostname, Type p_type) {
@ -159,17 +142,16 @@ Array IP::resolve_hostname_addresses(const String &p_hostname, Type p_type) {
resolver->mutex.unlock(); resolver->mutex.unlock();
_resolve_hostname(res, p_hostname, p_type); _resolve_hostname(res, p_hostname, p_type);
resolver->mutex.lock(); resolver->mutex.lock();
// We might be overriding another result, but we don't care (they are the // We might be overriding another result, but we don't care as long as the result is valid.
// same hostname). if (res.size()) {
resolver->cache[key] = res; resolver->cache[key] = res;
}
} }
resolver->mutex.unlock(); resolver->mutex.unlock();
Array result; Array result;
for (int i = 0; i < res.size(); ++i) { for (int i = 0; i < res.size(); ++i) {
if (res[i].is_valid()) { result.push_back(String(res[i]));
result.push_back(String(res[i]));
}
} }
return result; return result;
} }

2
drivers/unix/ip_unix.cpp
View file

@ -115,7 +115,7 @@ void IPUnix::_resolve_hostname(List<IPAddress> &r_addresses, const String &p_hos
continue; continue;
} }
IPAddress ip = _sockaddr2ip(next->ai_addr); IPAddress ip = _sockaddr2ip(next->ai_addr);
if (!r_addresses.find(ip)) { if (ip.is_valid() && !r_addresses.find(ip)) {
r_addresses.push_back(ip); r_addresses.push_back(ip);
} }
next = next->ai_next; next = next->ai_next;