From: Matt Joiner <anacrolix@gmail.com>
Date: Sat, 20 Feb 2016 16:32:59 +0000 (+1100)
Subject: Move dataReadAt to torrent.readAt, and do the waitNoPendingWrites check there
X-Git-Tag: v1.0.0~874
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=e20858a1e86fb27623030400a5e5e5f8ad284dc1;p=btrtrc.git

Move dataReadAt to torrent.readAt, and do the waitNoPendingWrites check there
---

diff --git a/client.go b/client.go
index 9b3c870b..612152ef 100644
--- a/client.go
+++ b/client.go
@@ -253,17 +253,6 @@ func (cl *Client) WriteStatus(_w io.Writer) {
 	}
 }
 
-// TODO: Make this non-blocking Read on Torrent.
-func dataReadAt(d Data, b []byte, off int64) (n int, err error) {
-	// defer func() {
-	// 	if err == io.ErrUnexpectedEOF && n != 0 {
-	// 		err = nil
-	// 	}
-	// }()
-	// log.Println("data read at", len(b), off)
-	return d.ReadAt(b, off)
-}
-
 // Calculates the number of pieces to set to Readahead priority, after the
 // Now, and Next pieces.
 func readaheadPieces(readahead, pieceLength int64) (ret int) {
@@ -1357,10 +1346,8 @@ func (me *Client) sendChunk(t *torrent, c *connection, r request) error {
 	// Count the chunk being sent, even if it isn't.
 	c.chunksSent++
 	b := make([]byte, r.Length)
-	tp := &t.Pieces[r.Index]
-	tp.waitNoPendingWrites()
 	p := t.Info.Piece(int(r.Index))
-	n, err := dataReadAt(t.data, b, p.Offset()+int64(r.Begin))
+	n, err := t.readAt(b, p.Offset()+int64(r.Begin))
 	if n != len(b) {
 		if err == nil {
 			panic("expected error")
diff --git a/reader.go b/reader.go
index 571ce4f2..12caf4ca 100644
--- a/reader.go
+++ b/reader.go
@@ -125,14 +125,12 @@ func (r *Reader) readOnceAt(b []byte, pos int64) (n int, err error) {
 		}
 		b1 := b[:avail]
 		pi := int(pos / r.t.Info().PieceLength)
-		tp := &r.t.torrent.Pieces[pi]
 		ip := r.t.Info().Piece(pi)
 		po := pos % ip.Length()
 		if int64(len(b1)) > ip.Length()-po {
 			b1 = b1[:ip.Length()-po]
 		}
-		tp.waitNoPendingWrites()
-		n, err = dataReadAt(r.t.torrent.data, b1, pos)
+		n, err = r.t.torrent.readAt(b1, pos)
 		if n != 0 {
 			return
 		}
diff --git a/torrent.go b/torrent.go
index 0fffe67f..daca65c0 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1039,3 +1039,14 @@ func (t *torrent) putPieceInclination(pi []int) {
 func (t *torrent) updatePieceCompletion(piece int) {
 	t.completedPieces.Set(piece, t.pieceCompleteUncached(piece))
 }
+
+// Non-blocking read. Client lock is not required.
+func (t *torrent) readAt(b []byte, off int64) (n int, err error) {
+	if off+int64(len(b)) > t.length {
+		b = b[:t.length-off]
+	}
+	for pi := off / t.Info.PieceLength; pi*t.Info.PieceLength < off+int64(len(b)); pi++ {
+		t.Pieces[pi].waitNoPendingWrites()
+	}
+	return t.data.ReadAt(b, off)
+}