Begin extracting 'squirrel' from storage/sqlite

diff --git a/storage/sqlite/direct.go b/storage/sqlite/direct.go
index 5e6b52ddb23d85600ec3879742b7914ce76b9f83..d687f64f0b75c8a38608f963f84c3b60025bf1a4 100644 (file)
--- a/storage/sqlite/direct.go
+++ b/storage/sqlite/direct.go
@@ -26,15 +26,13 @@ type NewDirectStorageOpts struct {
        BlobFlushInterval time.Duration
 }
 
-// A convenience function that creates a connection pool, resource provider, and a pieces storage
-// ClientImpl and returns them all with a Close attached.
-func NewDirectStorage(opts NewDirectStorageOpts) (_ storage.ClientImplCloser, err error) {
+func NewSquirrelCache(opts NewDirectStorageOpts) (_ *SquirrelCache, err error) {
        conn, err := newConn(opts.NewConnOpts)
        if err != nil {
                return
        }
        if opts.PageSize == 0 {
-               // The largest size sqlite supports. I think we want this to be the smallest piece size we
+               // The largest size sqlite supports. I think we want this to be the smallest SquirrelBlob size we
                // can expect, which is probably 1<<17.
                opts.PageSize = 1 << 16
        }
@@ -53,7 +51,7 @@ func NewDirectStorage(opts NewDirectStorageOpts) (_ storage.ClientImplCloser, er
                // a few chances at getting a transaction through.
                opts.BlobFlushInterval = time.Second
        }
-       cl := &client{
+       cl := &SquirrelCache{
                conn:  conn,
                blobs: make(map[string]*sqlite.Blob),
                opts:  opts,
@@ -68,7 +66,17 @@ func NewDirectStorage(opts NewDirectStorageOpts) (_ storage.ClientImplCloser, er
        return cl, nil
 }
 
-func (cl *client) getCapacity() (ret *int64) {
+// A convenience function that creates a connection pool, resource provider, and a pieces storage
+// ClientImpl and returns them all with a Close attached.
+func NewDirectStorage(opts NewDirectStorageOpts) (_ storage.ClientImplCloser, err error) {
+       cache, err := NewSquirrelCache(opts)
+       if err != nil {
+               return
+       }
+       return &client{cache}, nil
+}
+
+func (cl *SquirrelCache) getCapacity() (ret *int64) {
        cl.l.Lock()
        defer cl.l.Unlock()
        err := sqlitex.Exec(cl.conn, "select value from setting where name='capacity'", func(stmt *sqlite.Stmt) error {
@@ -82,7 +90,7 @@ func (cl *client) getCapacity() (ret *int64) {
        return
 }
 
-type client struct {
+type SquirrelCache struct {
        l           sync.Mutex
        conn        conn
        blobs       map[string]*sqlite.Blob
@@ -92,7 +100,11 @@ type client struct {
        capacity    func() *int64
 }
 
-func (c *client) blobFlusherFunc() {
+type client struct {
+       *SquirrelCache
+}
+
+func (c *SquirrelCache) blobFlusherFunc() {
        c.l.Lock()
        defer c.l.Unlock()
        c.flushBlobs()
@@ -101,7 +113,7 @@ func (c *client) blobFlusherFunc() {
        }
 }
 
-func (c *client) flushBlobs() {
+func (c *SquirrelCache) flushBlobs() {
        for key, b := range c.blobs {
                // Need the lock to prevent racing with the GC finalizers.
                b.Close()
@@ -109,12 +121,12 @@ func (c *client) flushBlobs() {
        }
 }
 
-func (c *client) OpenTorrent(info *metainfo.Info, infoHash metainfo.Hash) (storage.TorrentImpl, error) {
+func (c *SquirrelCache) OpenTorrent(info *metainfo.Info, infoHash metainfo.Hash) (storage.TorrentImpl, error) {
        t := torrent{c}
        return storage.TorrentImpl{Piece: t.Piece, Close: t.Close, Capacity: &c.capacity}, nil
 }
 
-func (c *client) Close() (err error) {
+func (c *SquirrelCache) Close() (err error) {
        c.l.Lock()
        defer c.l.Unlock()
        c.flushBlobs()
@@ -130,7 +142,7 @@ func (c *client) Close() (err error) {
 }
 
 type torrent struct {
-       c *client
+       c *SquirrelCache
 }
 
 func rowidForBlob(c conn, name string, length int64, create bool) (rowid int64, err error) {
@@ -163,27 +175,29 @@ func rowidForBlob(c conn, name string, length int64, create bool) (rowid int64,
 }
 
 func (t torrent) Piece(p metainfo.Piece) storage.PieceImpl {
-       t.c.l.Lock()
-       defer t.c.l.Unlock()
        name := p.Hash().HexString()
-       return piece{
+       return piece{SquirrelBlob{
                name,
                p.Length(),
                t.c,
-       }
+       }}
 }
 
 func (t torrent) Close() error {
        return nil
 }
 
-type piece struct {
+type SquirrelBlob struct {
        name   string
        length int64
-       *client
+       *SquirrelCache
+}
+
+type piece struct {
+       SquirrelBlob
 }
 
-func (p piece) doAtIoWithBlob(
+func (p SquirrelBlob) doAtIoWithBlob(
        atIo func(*sqlite.Blob) func([]byte, int64) (int, error),
        b []byte,
        off int64,
@@ -224,13 +238,13 @@ func (p piece) doAtIoWithBlob(
        return atIo(blob)(b, off)
 }
 
-func (p piece) ReadAt(b []byte, off int64) (n int, err error) {
+func (p SquirrelBlob) ReadAt(b []byte, off int64) (n int, err error) {
        return p.doAtIoWithBlob(func(blob *sqlite.Blob) func([]byte, int64) (int, error) {
                return blob.ReadAt
        }, b, off, false)
 }
 
-func (p piece) WriteAt(b []byte, off int64) (n int, err error) {
+func (p SquirrelBlob) WriteAt(b []byte, off int64) (n int, err error) {
        return p.doAtIoWithBlob(func(blob *sqlite.Blob) func([]byte, int64) (int, error) {
                return blob.WriteAt
        }, b, off, true)
@@ -250,7 +264,7 @@ func (p piece) MarkComplete() error {
        return nil
 }
 
-func (p piece) forgetBlob() {
+func (p SquirrelBlob) forgetBlob() {
        blob, ok := p.blobs[p.name]
        if !ok {
                return
@@ -279,7 +293,7 @@ func (p piece) Completion() (ret storage.Completion) {
        return
 }
 
-func (p piece) getBlob(create bool) (*sqlite.Blob, error) {
+func (p SquirrelBlob) getBlob(create bool) (*sqlite.Blob, error) {
        blob, ok := p.blobs[p.name]
        if !ok {
                rowid, err := rowidForBlob(p.conn, p.name, p.length, create)