From cfb23e271f1f509cc39e59484c9bfe3e0075990d Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Sat, 18 Sep 2021 18:57:50 +1000
Subject: [PATCH] Export request_strategy.GetRequestablePieces

---
 request-strategy/order.go   | 23 +++++++++++++----------
 request-strategy/torrent.go |  3 ++-
 requesting.go               | 10 +++++++---
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/request-strategy/order.go b/request-strategy/order.go
index 8b4b6799..0a32ae9a 100644
--- a/request-strategy/order.go
+++ b/request-strategy/order.go
@@ -89,13 +89,13 @@ type filterPiece struct {
 	*Piece
 }
 
-func getRequestablePieces(input Input) (ret []requestablePiece) {
+// Calls f with requestable pieces in order.
+func GetRequestablePieces(input Input, f func(t *Torrent, p *Piece, pieceIndex int)) {
 	maxPieces := 0
 	for i := range input.Torrents {
 		maxPieces += len(input.Torrents[i].Pieces)
 	}
 	pieces := make([]filterPiece, 0, maxPieces)
-	ret = make([]requestablePiece, 0, maxPieces)
 	// Storage capacity left for this run, keyed by the storage capacity pointer on the storage
 	// TorrentImpl. A nil value means no capacity limit.
 	storageLeft := make(map[storage.TorrentCapacity]*int64)
@@ -147,13 +147,7 @@ func getRequestablePieces(input Input) (ret []requestablePiece) {
 		}
 		piece.t.unverifiedBytes += piece.Length
 		allTorrentsUnverifiedBytes += piece.Length
-		ret = append(ret, requestablePiece{
-			index:             piece.index,
-			t:                 piece.t.Torrent,
-			NumPendingChunks:  piece.NumPendingChunks,
-			IterPendingChunks: piece.iterPendingChunksWrapper,
-			alwaysReallocate:  piece.Priority >= types.PiecePriorityNext,
-		})
+		f(piece.t.Torrent, piece.Piece, piece.index)
 	}
 	return
 }
@@ -165,7 +159,16 @@ type Input struct {
 
 // TODO: We could do metainfo requests here.
 func Run(input Input) map[PeerId]PeerNextRequestState {
-	requestPieces := getRequestablePieces(input)
+	var requestPieces []requestablePiece
+	GetRequestablePieces(input, func(t *Torrent, piece *Piece, pieceIndex int) {
+		requestPieces = append(requestPieces, requestablePiece{
+			index:             pieceIndex,
+			t:                 t,
+			NumPendingChunks:  piece.NumPendingChunks,
+			IterPendingChunks: piece.iterPendingChunksWrapper,
+			alwaysReallocate:  piece.Priority >= types.PiecePriorityNext,
+		})
+	})
 	torrents := input.Torrents
 	allPeers := make(map[uintptr][]*requestsPeer, len(torrents))
 	for _, t := range torrents {
diff --git a/request-strategy/torrent.go b/request-strategy/torrent.go
index c7ed3c60..a31ec772 100644
--- a/request-strategy/torrent.go
+++ b/request-strategy/torrent.go
@@ -7,7 +7,8 @@ import (
 type Torrent struct {
 	Pieces   []Piece
 	Capacity storage.TorrentCapacity
-	Peers    []Peer // not closed.
+	// Unclosed Peers. Not necessary for getting requestable piece ordering.
+	Peers []Peer
 	// Some value that's unique and stable between runs. Could even use the infohash?
 	StableId uintptr
 
diff --git a/requesting.go b/requesting.go
index ea1fb8e8..7e42baba 100644
--- a/requesting.go
+++ b/requesting.go
@@ -39,7 +39,7 @@ func (cl *Client) tickleRequester() {
 	cl.updateRequests.Broadcast()
 }
 
-func (cl *Client) doRequests() {
+func (cl *Client) getRequestStrategyInput() request_strategy.Input {
 	ts := make([]request_strategy.Torrent, 0, len(cl.torrents))
 	for _, t := range cl.torrents {
 		rst := request_strategy.Torrent{
@@ -90,10 +90,14 @@ func (cl *Client) doRequests() {
 		})
 		ts = append(ts, rst)
 	}
-	nextPeerStates := request_strategy.Run(request_strategy.Input{
+	return request_strategy.Input{
 		Torrents:           ts,
 		MaxUnverifiedBytes: cl.config.MaxUnverifiedBytes,
-	})
+	}
+}
+
+func (cl *Client) doRequests() {
+	nextPeerStates := request_strategy.Run(cl.getRequestStrategyInput())
 	for p, state := range nextPeerStates {
 		setPeerNextRequestState(p, state)
 	}
-- 
2.48.1