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BitTorrent Client Library (Core)
package bt.runtime;
import bt.BtException;
import bt.module.BtModuleProvider;
import bt.module.ProtocolModule;
import bt.module.ServiceModule;
import com.google.inject.Guice;
import com.google.inject.Injector;
import com.google.inject.Module;
import com.google.inject.util.Modules;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.ServiceLoader;
import java.util.stream.Collectors;
/**
* Runtime builder.
*
* @since 1.0
*/
public class BtRuntimeBuilder {
private static final Logger LOGGER = LoggerFactory.getLogger(BtRuntimeBuilder.class);
private Config config;
private Collection customProviders;
private boolean shouldDisableAutomaticShutdown;
private boolean shouldAutoLoadModules;
/**
* Create runtime builder with default config.
*
* @since 1.4
*/
public BtRuntimeBuilder() {
this.config = new Config();
}
/**
* Create runtime builder with provided config.
*
* @param config Runtime config
* @since 1.0
*/
public BtRuntimeBuilder(Config config) {
this.config = Objects.requireNonNull(config, "Missing runtime config");
}
/**
* Set runtime config.
*
* @since 1.4
*/
public BtRuntimeBuilder config(Config config) {
this.config = Objects.requireNonNull(config, "Missing runtime config");
return this;
}
/**
* Get this builder's config.
*
* @return Runtime config
* @since 1.0
*/
public Config getConfig() {
return config;
}
/**
* Contribute an extra module into the runtime.
*
* @since 1.0
*/
public BtRuntimeBuilder module(Module adapter) {
Objects.requireNonNull(adapter);
if (customProviders == null) {
customProviders = new ArrayList<>();
}
customProviders.add(() -> adapter);
return this;
}
/**
* Contribute an extra module into the runtime.
*
* @since 1.1
*/
public BtRuntimeBuilder module(Class adapterType) {
Objects.requireNonNull(adapterType);
if (customProviders == null) {
customProviders = new ArrayList<>();
}
customProviders.add(() -> {
try {
return adapterType.newInstance();
} catch (Exception e) {
throw new BtException("Failed to instantiate custom module: " + adapterType.getName(), e);
}
});
return this;
}
/**
* Disable automatic runtime shutdown, when all clients have been stopped.
*
* @since 1.0
*/
public BtRuntimeBuilder disableAutomaticShutdown() {
this.shouldDisableAutomaticShutdown = true;
return this;
}
/**
* If this option is set, Bt will use the service loading mechanism
* to load any modules that are available on application's classpath.
*
* To support auto-loading a module should expose {@link BtModuleProvider} provider.
* Auto-loaded modules will be used in default configuration.
*
* @since 1.1
*/
public BtRuntimeBuilder autoLoadModules() {
this.shouldAutoLoadModules = true;
return this;
}
/**
* @since 1.0
*/
public BtRuntime build() {
BtRuntime runtime = new BtRuntime(createInjector(), config);
if (shouldDisableAutomaticShutdown) {
runtime.disableAutomaticShutdown();
}
return runtime;
}
@SuppressWarnings("unchecked")
private Injector createInjector() {
Collection standardModules = collectModules(standardProviders());
Collection customModules;
if (shouldAutoLoadModules) {
Map, Module> autoLoadedProviders = mapByClass(collectModules(autoLoadedProviders()));
Map, Module> customProviders = mapByClass(collectModules(customProviders()));
autoLoadedProviders.forEach((k, v) -> {
if (!customProviders.containsKey(k)) {
LOGGER.info("Auto-loading module {} with default configuration", k.getName());
}
});
customProviders.forEach((k, v) -> {
if (autoLoadedProviders.containsKey(k)) {
LOGGER.info("Overriding auto-loaded module {}", k.getName());
} else {
LOGGER.info("Loading module {}", k.getName());
}
});
autoLoadedProviders.putAll(customProviders);
customModules = autoLoadedProviders.values();
} else {
customModules = collectModules(customProviders());
}
Injector injector;
if (customModules.size() > 0) {
Module customModule = Modules.override(standardModules).with(customModules);
injector = Guice.createInjector(customModule);
} else {
injector = Guice.createInjector(standardModules);
}
return injector;
}
@SuppressWarnings("unchecked")
private Collection collectModules(Collection... providers) {
return Arrays.asList(providers).stream()
.flatMap(Collection::stream)
.map(BtModuleProvider::module)
.collect(Collectors.toList());
}
@SuppressWarnings("unchecked")
private Map, T> mapByClass(Collection collection) {
return collection.stream().collect(HashMap::new, (m, o) -> m.put((Class)o.getClass(), o), Map::putAll);
}
private Collection standardProviders() {
Collection standardProviders = new ArrayList<>();
standardProviders.add(() -> new ServiceModule(config));
standardProviders.add(ProtocolModule::new);
return standardProviders;
}
private Collection customProviders() {
if (customProviders == null) {
return Collections.emptyList();
} else {
return customProviders.stream()
.map(BtRuntimeBuilder::nullCheckingProvider)
.collect(Collectors.toList());
}
}
private Collection autoLoadedProviders() {
Collection autoLoadedProviders = new ArrayList<>();
ServiceLoader.load(BtModuleProvider.class).forEach(p -> {
autoLoadedProviders.add(nullCheckingProvider(p));
});
return autoLoadedProviders;
}
private static BtModuleProvider nullCheckingProvider(BtModuleProvider provider) {
return () -> Objects.requireNonNull(provider.module(), "Missing module in provider:" + provider.getClass().getName());
}
}