class Gio::Resolver

Overview

#GResolver provides cancellable synchronous and asynchronous DNS resolution, for hostnames (g_resolver_lookup_by_address(), g_resolver_lookup_by_name() and their async variants) and SRV (service) records (g_resolver_lookup_service()).

#GNetworkAddress and #GNetworkService provide wrappers around #GResolver functionality that also implement #GSocketConnectable, making it easy to connect to a remote host/service.

Defined in:

lib/gi-crystal/src/auto/gio-2.0/resolver.cr

Constructors

Class Method Summary

Instance Method Summary

Instance methods inherited from class GObject::Object

bind_property(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags) : GObject::Binding bind_property, bind_property_full(source_property : String, target : GObject::Object, target_property : String, flags : GObject::BindingFlags, transform_to : GObject::Closure, transform_from : GObject::Closure) : GObject::Binding bind_property_full, data(key : String) : Pointer(Void)? data, finalize finalize, freeze_notify : Nil freeze_notify, getv(names : Enumerable(String), values : Enumerable(_)) : Nil getv, notify(property_name : String) : Nil notify, notify_by_pspec(pspec : GObject::ParamSpec) : Nil notify_by_pspec, notify_signal notify_signal, property(property_name : String, value : _) : Nil property, qdata(quark : UInt32) : Pointer(Void)? qdata, ref_count : UInt32 ref_count, run_dispose : Nil run_dispose, set_data(key : String, data : Pointer(Void)?) : Nil set_data, set_property(property_name : String, value : _) : Nil set_property, steal_data(key : String) : Pointer(Void)? steal_data, steal_qdata(quark : UInt32) : Pointer(Void)? steal_qdata, thaw_notify : Nil thaw_notify, to_unsafe : Pointer(Void) to_unsafe, watch_closure(closure : GObject::Closure) : Nil watch_closure

Constructor methods inherited from class GObject::Object

cast(obj : GObject::Object) : self cast, cast?(obj : GObject::Object) : self? cast?, new(pointer : Pointer(Void), transfer : GICrystal::Transfer)
new new, newv(object_type : UInt64, parameters : Enumerable(GObject::Parameter)) : self newv

Class methods inherited from class GObject::Object

compat_control(what : UInt64, data : Pointer(Void)?) : UInt64 compat_control, g_type : UInt64 g_type, interface_find_property(g_iface : GObject::TypeInterface, property_name : String) : GObject::ParamSpec interface_find_property, interface_list_properties(g_iface : GObject::TypeInterface) : Enumerable(GObject::ParamSpec) interface_list_properties

Constructor Detail

def self.new #

Initialize a new Resolver.


Class Method Detail

def self.default : Gio::Resolver #

Gets the default #GResolver. You should unref it when you are done with it. #GResolver may use its reference count as a hint about how many threads it should allocate for concurrent DNS resolutions.


def self.g_type : UInt64 #

Returns the type id (GType) registered in GLib type system.


Instance Method Detail

def lookup_by_address(address : Gio::InetAddress, cancellable : Gio::Cancellable?) : String #

Synchronously reverse-resolves @address to determine its associated hostname.

If the DNS resolution fails, @error (if non-nil) will be set to a value from #GResolverError.

If @cancellable is non-nil, it can be used to cancel the operation, in which case @error (if non-nil) will be set to %G_IO_ERROR_CANCELLED.


def lookup_by_address_async(address : Gio::InetAddress, cancellable : Gio::Cancellable?, callback : Gio::AsyncReadyCallback?, user_data : Pointer(Void)?) : Nil #

Begins asynchronously reverse-resolving @address to determine its associated hostname, and eventually calls @callback, which must call g_resolver_lookup_by_address_finish() to get the final result.


def lookup_by_address_finish(result : Gio::AsyncResult) : String #

Retrieves the result of a previous call to g_resolver_lookup_by_address_async().

If the DNS resolution failed, @error (if non-nil) will be set to a value from #GResolverError. If the operation was cancelled, @error will be set to %G_IO_ERROR_CANCELLED.


def lookup_by_name(hostname : String, cancellable : Gio::Cancellable?) : GLib::List #

Synchronously resolves @hostname to determine its associated IP address(es). @hostname may be an ASCII-only or UTF-8 hostname, or the textual form of an IP address (in which case this just becomes a wrapper around g_inet_address_new_from_string()).

On success, g_resolver_lookup_by_name() will return a non-empty #GList of #GInetAddress, sorted in order of preference and guaranteed to not contain duplicates. That is, if using the result to connect to @hostname, you should attempt to connect to the first address first, then the second if the first fails, etc. If you are using the result to listen on a socket, it is appropriate to add each result using e.g. g_socket_listener_add_address().

If the DNS resolution fails, @error (if non-nil) will be set to a value from #GResolverError and nil will be returned.

If @cancellable is non-nil, it can be used to cancel the operation, in which case @error (if non-nil) will be set to %G_IO_ERROR_CANCELLED.

If you are planning to connect to a socket on the resolved IP address, it may be easier to create a #GNetworkAddress and use its #GSocketConnectable interface.


def lookup_by_name_async(hostname : String, cancellable : Gio::Cancellable?, callback : Gio::AsyncReadyCallback?, user_data : Pointer(Void)?) : Nil #

Begins asynchronously resolving @hostname to determine its associated IP address(es), and eventually calls @callback, which must call g_resolver_lookup_by_name_finish() to get the result. See g_resolver_lookup_by_name() for more details.


def lookup_by_name_finish(result : Gio::AsyncResult) : GLib::List #

Retrieves the result of a call to g_resolver_lookup_by_name_async().

If the DNS resolution failed, @error (if non-nil) will be set to a value from #GResolverError. If the operation was cancelled, @error will be set to %G_IO_ERROR_CANCELLED.


def lookup_by_name_with_flags(hostname : String, flags : Gio::ResolverNameLookupFlags, cancellable : Gio::Cancellable?) : GLib::List #

This differs from g_resolver_lookup_by_name() in that you can modify the lookup behavior with @flags. For example this can be used to limit results with %G_RESOLVER_NAME_LOOKUP_FLAGS_IPV4_ONLY.


def lookup_by_name_with_flags_async(hostname : String, flags : Gio::ResolverNameLookupFlags, cancellable : Gio::Cancellable?, callback : Gio::AsyncReadyCallback?, user_data : Pointer(Void)?) : Nil #

Begins asynchronously resolving @hostname to determine its associated IP address(es), and eventually calls @callback, which must call g_resolver_lookup_by_name_with_flags_finish() to get the result. See g_resolver_lookup_by_name() for more details.


def lookup_by_name_with_flags_finish(result : Gio::AsyncResult) : GLib::List #

Retrieves the result of a call to g_resolver_lookup_by_name_with_flags_async().

If the DNS resolution failed, @error (if non-nil) will be set to a value from #GResolverError. If the operation was cancelled, @error will be set to %G_IO_ERROR_CANCELLED.


def lookup_records(rrname : String, record_type : Gio::ResolverRecordType, cancellable : Gio::Cancellable?) : GLib::List #

Synchronously performs a DNS record lookup for the given @rrname and returns a list of records as #GVariant tuples. See #GResolverRecordType for information on what the records contain for each @record_type.

If the DNS resolution fails, @error (if non-nil) will be set to a value from #GResolverError and nil will be returned.

If @cancellable is non-nil, it can be used to cancel the operation, in which case @error (if non-nil) will be set to %G_IO_ERROR_CANCELLED.


def lookup_records_async(rrname : String, record_type : Gio::ResolverRecordType, cancellable : Gio::Cancellable?, callback : Gio::AsyncReadyCallback?, user_data : Pointer(Void)?) : Nil #

Begins asynchronously performing a DNS lookup for the given @rrname, and eventually calls @callback, which must call g_resolver_lookup_records_finish() to get the final result. See g_resolver_lookup_records() for more details.


def lookup_records_finish(result : Gio::AsyncResult) : GLib::List #

Retrieves the result of a previous call to g_resolver_lookup_records_async(). Returns a non-empty list of records as #GVariant tuples. See #GResolverRecordType for information on what the records contain.

If the DNS resolution failed, @error (if non-nil) will be set to a value from #GResolverError. If the operation was cancelled, @error will be set to %G_IO_ERROR_CANCELLED.


def lookup_service(service : String, protocol : String, domain : String, cancellable : Gio::Cancellable?) : GLib::List #

Synchronously performs a DNS SRV lookup for the given @service and @protocol in the given @domain and returns an array of #GSrvTarget. @domain may be an ASCII-only or UTF-8 hostname. Note also that the @service and @protocol arguments do not include the leading underscore that appears in the actual DNS entry.

On success, g_resolver_lookup_service() will return a non-empty #GList of #GSrvTarget, sorted in order of preference. (That is, you should attempt to connect to the first target first, then the second if the first fails, etc.)

If the DNS resolution fails, @error (if non-nil) will be set to a value from #GResolverError and nil will be returned.

If @cancellable is non-nil, it can be used to cancel the operation, in which case @error (if non-nil) will be set to %G_IO_ERROR_CANCELLED.

If you are planning to connect to the service, it is usually easier to create a #GNetworkService and use its #GSocketConnectable interface.


def lookup_service_async(service : String, protocol : String, domain : String, cancellable : Gio::Cancellable?, callback : Gio::AsyncReadyCallback?, user_data : Pointer(Void)?) : Nil #

Begins asynchronously performing a DNS SRV lookup for the given @service and @protocol in the given @domain, and eventually calls @callback, which must call g_resolver_lookup_service_finish() to get the final result. See g_resolver_lookup_service() for more details.


def lookup_service_finish(result : Gio::AsyncResult) : GLib::List #

Retrieves the result of a previous call to g_resolver_lookup_service_async().

If the DNS resolution failed, @error (if non-nil) will be set to a value from #GResolverError. If the operation was cancelled, @error will be set to %G_IO_ERROR_CANCELLED.


def reload_signal #

def set_default : Nil #

Sets @resolver to be the application's default resolver (reffing @resolver, and unreffing the previous default resolver, if any). Future calls to g_resolver_get_default() will return this resolver.

This can be used if an application wants to perform any sort of DNS caching or "pinning"; it can implement its own #GResolver that calls the original default resolver for DNS operations, and implements its own cache policies on top of that, and then set itself as the default resolver for all later code to use.