_ Git - ldk-java/blob - src/main/java/org/ldk/structs/BackgroundProcessor.java

   1 package org.ldk.structs;
   2
   3 import org.ldk.impl.bindings;
   4 import org.ldk.enums.*;
   5 import org.ldk.util.*;
   6 import java.util.Arrays;
   7 import javax.annotation.Nullable;
   8
   9
  10 /**
  11  * BackgroundProcessor takes care of tasks that (1) need to happen periodically to keep
  12  * Rust-Lightning running properly, and (2) either can or should be run in the background. Its
  13  * responsibilities are:
  14  * Monitoring whether the ChannelManager needs to be re-persisted to disk, and if so,
  15  * writing it to disk/backups by invoking the callback given to it at startup.
  16  * ChannelManager persistence should be done in the background.
  17  * Calling `ChannelManager::timer_tick_occurred()` and
  18  * `PeerManager::timer_tick_occurred()` every minute (can be done in the
  19  * background).
  20  *
  21  * Note that if ChannelManager persistence fails and the persisted manager becomes out-of-date,
  22  * then there is a risk of channels force-closing on startup when the manager realizes it's
  23  * outdated. However, as long as `ChannelMonitor` backups are sound, no funds besides those used
  24  * for unilateral chain closure fees are at risk.
  25  */
  26 @SuppressWarnings("unchecked") // We correctly assign various generic arrays
  27 public class BackgroundProcessor extends CommonBase {
  28         BackgroundProcessor(Object _dummy, long ptr) { super(ptr); }
  29         @Override @SuppressWarnings("deprecation")
  30         protected void finalize() throws Throwable {
  31                 super.finalize();
  32                 if (ptr != 0) { bindings.BackgroundProcessor_free(ptr); }
  33         }
  34
  35         /**
  36          * Start a background thread that takes care of responsibilities enumerated in the top-level
  37          * documentation.
  38          *
  39          * If `persist_manager` returns an error, then this thread will return said error (and
  40          * `start()` will need to be called again to restart the `BackgroundProcessor`). Users should
  41          * wait on [`thread_handle`]'s `join()` method to be able to tell if and when an error is
  42          * returned, or implement `persist_manager` such that an error is never returned to the
  43          * `BackgroundProcessor`
  44          *
  45          * `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
  46          * uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
  47          * [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
  48          * provided implementation.
  49          *
  50          * [`thread_handle`]: BackgroundProcessor::thread_handle
  51          * [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
  52          * [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
  53          * [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
  54          */
  55         public static BackgroundProcessor start(ChannelManagerPersister persister, EventHandler event_handler, ChainMonitor chain_monitor, ChannelManager channel_manager, PeerManager peer_manager, Logger logger) {
  56                 long ret = bindings.BackgroundProcessor_start(persister == null ? 0 : persister.ptr, event_handler == null ? 0 : event_handler.ptr, chain_monitor == null ? 0 : chain_monitor.ptr & ~1, channel_manager == null ? 0 : channel_manager.ptr & ~1, peer_manager == null ? 0 : peer_manager.ptr & ~1, logger == null ? 0 : logger.ptr);
  57                 if (ret < 1024) { return null; }
  58                 BackgroundProcessor ret_hu_conv = new BackgroundProcessor(null, ret);
  59                 ret_hu_conv.ptrs_to.add(ret_hu_conv);
  60                 ret_hu_conv.ptrs_to.add(persister);
  61                 ret_hu_conv.ptrs_to.add(event_handler);
  62                 ret_hu_conv.ptrs_to.add(chain_monitor);
  63                 ret_hu_conv.ptrs_to.add(channel_manager);
  64                 ret_hu_conv.ptrs_to.add(peer_manager);
  65                 ret_hu_conv.ptrs_to.add(logger);
  66                 return ret_hu_conv;
  67         }
  68
  69         /**
  70          * Stop `BackgroundProcessor`'s thread.
  71          */
  72         public Result_NoneErrorZ stop() {
  73                 long ret = bindings.BackgroundProcessor_stop(this.ptr);
  74                 if (ret < 1024) { return null; }
  75                 Result_NoneErrorZ ret_hu_conv = Result_NoneErrorZ.constr_from_ptr(ret);
  76                 this.ptrs_to.add(this);
  77                 // Due to rust's strict-ownership memory model, in some cases we need to "move"
  78                 // an object to pass exclusive ownership to the function being called.
  79                 // In most cases, we avoid this being visible in GC'd languages by cloning the object
  80                 // at the FFI layer, creating a new object which Rust can claim ownership of
  81                 // However, in some cases (eg here), there is no way to clone an object, and thus
  82                 // we actually have to pass full ownership to Rust.
  83                 // Thus, after this call, this is reset to null and is now a dummy object.
  84                 this.ptr = 0;
  85                 return ret_hu_conv;
  86         }
  87
  88 }