changed the API of the client

client/alloc_runner.go

@@ -3,7 +3,6 @@ package client
 import (
 	"encoding/json"
 	"fmt"
-	"io"
 	"log"
 	"os"
 	"path/filepath"
@@ -426,14 +425,6 @@ func (r *AllocRunner) WaitCh() <-chan struct{} {
 	return r.waitCh
 }
 
-func (r *AllocRunner) FSList(path string) ([]*allocdir.AllocFileInfo, error) {
-	return r.ctx.AllocDir.List(path)
-}
-
-func (r *AllocRunner) FSStat(path string) (*allocdir.AllocFileInfo, error) {
-	return r.ctx.AllocDir.Stat(path)
-}
-
-func (r *AllocRunner) FSReadAt(allocID string, path string, offset int64, limit int64, w io.Writer) error {
-	return r.ctx.AllocDir.ReadAt(allocID, path, offset, limit, w)
+func (r *AllocRunner) GetAllocFS(allocID string) allocdir.AllocDirFS {
+	return r.ctx.AllocDir
 }

client/allocdir/alloc_dir.go

@@ -44,6 +44,12 @@ type AllocFileInfo struct {
 	Size  int64
 }
 
+type AllocDirFS interface {
+	List(path string) ([]*AllocFileInfo, error)
+	Stat(path string) (*AllocFileInfo, error)
+	ReadAt(path string, offset int64, limit int64) (io.ReadCloser, error)
+}
+
 func NewAllocDir(allocDir string) *AllocDir {
 	d := &AllocDir{AllocDir: allocDir, TaskDirs: make(map[string]string)}
 	d.SharedDir = filepath.Join(d.AllocDir, SharedAllocName)
@@ -254,15 +260,18 @@ func (d *AllocDir) Stat(path string) (*AllocFileInfo, error) {
 	}, nil
 }
 
-func (d *AllocDir) ReadAt(allocID string, path string, offset int64, limit int64, w io.Writer) error {
+func (d *AllocDir) ReadAt(path string, offset int64, limit int64) (io.ReadCloser, error) {
 	p := filepath.Join(d.AllocDir, path)
 	f, err := os.Open(p)
 	if err != nil {
-		return err
+		return nil, err
 	}
-	defer f.Close()
-	io.Copy(w, io.LimitReader(f, limit))
-	return nil
+	return &LimitReadCloser{Reader: io.LimitReader(f, limit), Closer: f}, nil
+}
+
+type LimitReadCloser struct {
+	io.Reader
+	io.Closer
 }
 
 func fileCopy(src, dst string, perm os.FileMode) error {

client/client.go

@@ -2,7 +2,6 @@ package client
 
 import (
 	"fmt"
-	"io"
 	"io/ioutil"
 	"log"
 	"net"
@@ -355,29 +354,13 @@ func (c *Client) Node() *structs.Node {
 	return c.config.Node
 }
 
-func (c *Client) FSList(allocID string, path string) ([]*allocdir.AllocFileInfo, error) {
-	ar, ok := c.allocs[allocID]
-	if !ok {
-		return nil, fmt.Errorf("alloc not present")
-	}
-
-	return ar.FSList(path)
-}
-
-func (c *Client) FSStat(allocID string, path string) (*allocdir.AllocFileInfo, error) {
+func (c *Client) GetAllocFS(allocID string) (allocdir.AllocDirFS, error) {
 	ar, ok := c.allocs[allocID]
 	if !ok {
 		return nil, fmt.Errorf("alloc not found")
 	}
-	return ar.FSStat(path)
-}
+	return ar.GetAllocFS(allocID), nil
 
-func (c *Client) FSReadAt(allocID string, path string, offset int64, limit int64, w io.Writer) error {
-	ar, ok := c.allocs[allocID]
-	if !ok {
-		return fmt.Errorf("alloc not found")
-	}
-	return ar.FSReadAt(allocID, path, offset, limit, w)
 }
 
 // restoreState is used to restore our state from the data dir

command/agent/fs_endpoint.go

@@ -2,6 +2,7 @@ package agent
 
 import (
 	"fmt"
+	"io"
 	"net/http"
 	"strconv"
 	"strings"
@@ -21,7 +22,11 @@ func (s *HTTPServer) DirectoryListRequest(resp http.ResponseWriter, req *http.Re
 	if path = req.URL.Query().Get("path"); path == "" {
 		path = "/"
 	}
-	return s.agent.client.FSList(allocID, path)
+	fs, err := s.agent.client.GetAllocFS(allocID)
+	if err != nil {
+		return nil, err
+	}
+	return fs.List(path)
 }
 
 func (s *HTTPServer) FileStatRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
@@ -32,7 +37,11 @@ func (s *HTTPServer) FileStatRequest(resp http.ResponseWriter, req *http.Request
 	if path = req.URL.Query().Get("path"); path == "" {
 		return nil, fileNameNotPresentErr
 	}
-	return s.agent.client.FSStat(allocID, path)
+	fs, err := s.agent.client.GetAllocFS(allocID)
+	if err != nil {
+		return nil, err
+	}
+	return fs.Stat(path)
 }
 
 func (s *HTTPServer) FileReadAtRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
@@ -55,8 +64,14 @@ func (s *HTTPServer) FileReadAtRequest(resp http.ResponseWriter, req *http.Reque
 	if limit, err = strconv.ParseInt(q.Get("limit"), 10, 64); err != nil {
 		return nil, fmt.Errorf("error parsing limit: %v", err)
 	}
-	if err = s.agent.client.FSReadAt(allocID, path, offset, limit, resp); err != nil {
+	fs, err := s.agent.client.GetAllocFS(allocID)
+	if err != nil {
 		return nil, err
 	}
+	r, err := fs.ReadAt(path, offset, limit)
+	if err != nil {
+		return nil, err
+	}
+	io.Copy(resp, r)
 	return nil, nil
 }