wip

include/libtorrent/aux_/disk_cache.hpp

@@ -85,6 +85,11 @@ struct cached_piece_entry
 		, ph(hasher())
 	{}
 
+	span<cached_block_entry> get_blocks() const
+	{
+		return {blocks.get(), blocks_in_piece};
+	}
+
 	piece_location piece;
 
 	// this is set to true when the piece has been populated with all blocks
@@ -107,8 +112,6 @@ struct cached_piece_entry
 	// hashes as well
 	bool v2_hashes = false;
 
-//#error we need a field indicating whether some blocks were flushed and removed from the cache before hashed, since otherwise we may hang the hash job on the piece but it never completes
-
 	int blocks_in_piece = 0;
 
 	// the number of blocks that have been hashed so far. Specifically for the
@@ -156,6 +159,13 @@ struct compare_storage
 	}
 };
 
+bool have_buffers(span<const cached_block_entry> blocks)
+{
+	for (auto const& b : blocks)
+		if (b.buf == nullptr) return false;
+	return true;
+}
+
 struct disk_cache
 {
 	using piece_container = mi::multi_index_container<
@@ -336,8 +346,21 @@ struct disk_cache
 		// we should only ask for the hash once
 		TORRENT_ASSERT(!i->piece_hash_returned);
 
+		if (!i->hashing && i->hasher_cursor == i->blocks_in_piece)
+		{
+			view.modify(i, [&](cached_piece_entry& e) {
+				e.piece_hash_returned = true;
+
+				job::hash& job = std::get<aux::job::hash>(hash_job->action);
+				job.piece_hash = e.ph.final();
+			});
+			return hash_result::job_completed;
+		}
+
 		if (i->hashing
-			|| i->hasher_cursor < i->blocks_in_piece)
+			&& i->hasher_cursor < i->blocks_in_piece
+			&& have_buffers(i->get_blocks().subspan(i->hasher_cursor))
+			)
 		{
 			// We're not done hashing yet, let the hashing thread post the
 			// completion once it's done
@@ -349,12 +372,6 @@ struct disk_cache
 			return hash_result::job_queued;
 		}
 
-		view.modify(i, [&](cached_piece_entry& e) {
-			e.piece_hash_returned = true;
-
-			job::hash& job = std::get<aux::job::hash>(hash_job->action);
-			job.piece_hash = e.ph.final();
-		});
 		return hash_result::post_job;
 	}
 
@@ -521,7 +538,6 @@ struct disk_cache
 			if (count < piece_iter->blocks_in_piece)
 				return;
 
-// #error this is not thread safe!
 			if (piece_iter->piece_hash_returned)
 				piece_iter = view.erase(piece_iter);
 			else
@@ -751,7 +767,6 @@ struct disk_cache
 				return;
 			}
 
-// #error this is not thread safe!
 			if (piece_iter->piece_hash_returned)
 				piece_iter = view.erase(piece_iter);
 			else