From ef4c0f141301b6c4ea0bf2d02a39095d89d7eb78 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Mon, 29 Jan 2018 18:18:08 +1100
Subject: [PATCH] Add Torrent.Stats.ConnectedSeeders

Fixes #231
---
 connection.go    | 24 +++++++++++++++++-------
 torrent.go       |  6 ++++++
 torrent_stats.go | 10 ++++++----
 3 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/connection.go b/connection.go
index 753bc64f..40d02aba 100644
--- a/connection.go
+++ b/connection.go
@@ -82,7 +82,7 @@ type connection struct {
 	peerPieces bitmap.Bitmap
 	// The peer has everything. This can occur due to a special message, when
 	// we may not even know the number of pieces in the torrent yet.
-	peerHasAll bool
+	peerSentHaveAll bool
 	// The highest possible number of pieces the torrent could have based on
 	// communication with the peer. Generally only useful until we have the
 	// torrent info.
@@ -102,6 +102,16 @@ type connection struct {
 	writerCond   sync.Cond
 }
 
+func (cn *connection) peerHasAllPieces() (all bool, known bool) {
+	if cn.peerSentHaveAll {
+		return true, true
+	}
+	if !cn.t.haveInfo() {
+		return false, false
+	}
+	return bitmap.Flip(cn.peerPieces, 0, cn.t.numPieces()).IsEmpty(), true
+}
+
 func (cn *connection) mu() sync.Locker {
 	return &cn.t.cl.mu
 }
@@ -234,7 +244,7 @@ func (cn *connection) Close() {
 }
 
 func (cn *connection) PeerHasPiece(piece int) bool {
-	return cn.peerHasAll || cn.peerPieces.Contains(piece)
+	return cn.peerSentHaveAll || cn.peerPieces.Contains(piece)
 }
 
 func (cn *connection) Post(msg pp.Message) {
@@ -695,7 +705,7 @@ func (cn *connection) peerSentHave(piece int) error {
 }
 
 func (cn *connection) peerSentBitfield(bf []bool) error {
-	cn.peerHasAll = false
+	cn.peerSentHaveAll = false
 	if len(bf)%8 != 0 {
 		panic("expected bitfield length divisible by 8")
 	}
@@ -716,8 +726,8 @@ func (cn *connection) peerSentBitfield(bf []bool) error {
 	return nil
 }
 
-func (cn *connection) peerSentHaveAll() error {
-	cn.peerHasAll = true
+func (cn *connection) onPeerSentHaveAll() error {
+	cn.peerSentHaveAll = true
 	cn.peerPieces.Clear()
 	cn.peerPiecesChanged()
 	return nil
@@ -725,7 +735,7 @@ func (cn *connection) peerSentHaveAll() error {
 
 func (cn *connection) peerSentHaveNone() error {
 	cn.peerPieces.Clear()
-	cn.peerHasAll = false
+	cn.peerSentHaveAll = false
 	cn.peerPiecesChanged()
 	return nil
 }
@@ -883,7 +893,7 @@ func (c *connection) mainReadLoop() error {
 		case pp.Bitfield:
 			err = c.peerSentBitfield(msg.Bitfield)
 		case pp.HaveAll:
-			err = c.peerSentHaveAll()
+			err = c.onPeerSentHaveAll()
 		case pp.HaveNone:
 			err = c.peerSentHaveNone()
 		case pp.Piece:
diff --git a/torrent.go b/torrent.go
index a215859d..f5d3b2a6 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1354,6 +1354,12 @@ func (t *Torrent) statsLocked() TorrentStats {
 	t.stats.HalfOpenPeers = len(t.halfOpen)
 	t.stats.PendingPeers = len(t.peers)
 	t.stats.TotalPeers = t.numTotalPeers()
+	t.stats.ConnectedSeeders = 0
+	for c := range t.conns {
+		if all, ok := c.peerHasAllPieces(); all && ok {
+			t.stats.ConnectedSeeders++
+		}
+	}
 	return t.stats
 }
 
diff --git a/torrent_stats.go b/torrent_stats.go
index 3dd2716a..f155a0d8 100644
--- a/torrent_stats.go
+++ b/torrent_stats.go
@@ -3,8 +3,10 @@ package torrent
 type TorrentStats struct {
 	ConnStats // Aggregates stats over all connections past and present.
 
-	ActivePeers   int
-	HalfOpenPeers int
-	PendingPeers  int
-	TotalPeers    int
+	// Ordered by expected descending quantities (if all is well).
+	TotalPeers       int
+	PendingPeers     int
+	ActivePeers      int
+	ConnectedSeeders int
+	HalfOpenPeers    int
 }
-- 
2.48.1