Add proxying memfs files

cluster/cluster.go

@@ -3,7 +3,9 @@ package cluster
 import (
 	"context"
 	"fmt"
+	"path/filepath"
 	"sync"
+	"time"
 
 	"github.com/datarhei/core/v16/log"
 )
@@ -14,6 +16,7 @@ type Cluster interface {
 	ListNodes() []NodeReader
 	GetNode(id string) (NodeReader, error)
 	Stop()
+	GetFile(path string) (string, error)
 }
 
 type ClusterConfig struct {
@@ -21,9 +24,10 @@ type ClusterConfig struct {
 }
 
 type cluster struct {
-	nodes   map[string]*node
-	idfiles map[string][]string
-	fileid  map[string]string
+	nodes    map[string]*node
+	idfiles  map[string][]string
+	idupdate map[string]time.Time
+	fileid   map[string]string
 
 	updates chan NodeState
 
@@ -36,11 +40,12 @@ type cluster struct {
 
 func New(config ClusterConfig) (Cluster, error) {
 	c := &cluster{
-		nodes:   map[string]*node{},
-		idfiles: map[string][]string{},
-		fileid:  map[string]string{},
-		updates: make(chan NodeState, 64),
-		logger:  config.Logger,
+		nodes:    map[string]*node{},
+		idfiles:  map[string][]string{},
+		idupdate: map[string]time.Time{},
+		fileid:   map[string]string{},
+		updates:  make(chan NodeState, 64),
+		logger:   config.Logger,
 	}
 
 	if c.logger == nil {
@@ -56,7 +61,11 @@ func New(config ClusterConfig) (Cluster, error) {
 			case <-ctx.Done():
 				return
 			case state := <-c.updates:
-				c.logger.Info().WithField("node", state.ID).WithField("state", state.State).Log("got news from node")
+				c.logger.Debug().WithFields(log.Fields{
+					"node":  state.ID,
+					"state": state.State,
+					"files": len(state.Files),
+				}).Log("got update")
 
 				c.lock.Lock()
 
@@ -66,6 +75,7 @@ func New(config ClusterConfig) (Cluster, error) {
 					delete(c.fileid, file)
 				}
 				delete(c.idfiles, state.ID)
+				delete(c.idupdate, state.ID)
 
 				if state.State == "connected" {
 					// Add files
@@ -73,6 +83,7 @@ func New(config ClusterConfig) (Cluster, error) {
 						c.fileid[file] = state.ID
 					}
 					c.idfiles[state.ID] = files
+					c.idupdate[state.ID] = state.LastUpdate
 				}
 
 				c.lock.Unlock()
@@ -153,8 +164,44 @@ func (c *cluster) GetNode(id string) (NodeReader, error) {
 
 	node, ok := c.nodes[id]
 	if !ok {
-		return nil, fmt.Errorf("no such node")
+		return nil, fmt.Errorf("node not found")
 	}
 
 	return node, nil
 }
+
+func (c *cluster) GetFile(path string) (string, error) {
+	c.lock.RLock()
+	defer c.lock.RUnlock()
+
+	c.logger.Debug().WithField("path", path).Log("opening")
+
+	id, ok := c.fileid[path]
+	if !ok {
+		c.logger.Debug().WithField("path", path).Log("not found")
+		return "", fmt.Errorf("file not found")
+	}
+
+	ts, ok := c.idupdate[id]
+	if !ok {
+		c.logger.Debug().WithField("path", path).Log("no age information found")
+		return "", fmt.Errorf("file not found")
+	}
+
+	if time.Since(ts) > 2*time.Second {
+		c.logger.Debug().WithField("path", path).Log("file too old")
+		return "", fmt.Errorf("file not found")
+	}
+
+	node, ok := c.nodes[id]
+	if !ok {
+		c.logger.Debug().WithField("path", path).Log("unknown node")
+		return "", fmt.Errorf("file not found")
+	}
+
+	url := node.Address() + "/" + filepath.Join("memfs", path)
+
+	c.logger.Debug().WithField("url", url).Log("file cluster url")
+
+	return url, nil
+}