extras/vpp_stats_fs/stats_fs.go - fdio/vpp - Gitiles

 /*
  * Copyright (c) 2021 Cisco Systems and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 /*Go-FUSE allows us to define the behaviour of our filesystem by recoding any primitive function we need.
  *The structure of the filesystem is constructed as a tree.
  *Each type of nodes (root, directory, file) follows its own prmitives.
  */
 package main

 import (
 	"context"
 	"fmt"
 	"path"
 	"path/filepath"
 	"strings"
 	"syscall"
 	"time"

 	"github.com/hanwen/go-fuse/v2/fs"
 	"github.com/hanwen/go-fuse/v2/fuse"

 	"git.fd.io/govpp.git/adapter"
 	"git.fd.io/govpp.git/adapter/statsclient"
 )

 func updateDir(ctx context.Context, n *fs.Inode, cl *statsclient.StatsClient, dirPath string) syscall.Errno {
 	stats, err := cl.PrepareDir(dirPath)
 	if err != nil {
 		LogMsg(fmt.Sprintf("Listing stats index failed: %v\n", err))
 		return syscall.EAGAIN
 	}

 	n.Operations().(*dirNode).epoch = stats.Epoch

 	n.RmAllChildren()

 	for _, entry := range stats.Entries {
 		localPath := strings.TrimPrefix(string(entry.Name), dirPath)
 		dirPath, base := filepath.Split(localPath)

 		parent := n
 		for _, component := range strings.Split(dirPath, "/") {
 			if len(component) == 0 {
 				continue
 			}
 			child := parent.GetChild(component)
 			if child == nil {
 				child = parent.NewInode(ctx, &dirNode{client: cl, epoch: stats.Epoch},
 					fs.StableAttr{Mode: fuse.S_IFDIR})
 				parent.AddChild(component, child, true)
 			} else {
 				child.Operations().(*dirNode).epoch = stats.Epoch
 			}

 			parent = child
 		}

 		filename := strings.Replace(base, " ", "_", -1)
 		child := parent.GetChild(filename)
 		if child == nil {
 			child := parent.NewPersistentInode(ctx, &statNode{client: cl, index: entry.Index}, fs.StableAttr{})
 			parent.AddChild(filename, child, true)
 		}
 	}
 	return 0
 }

 func getCounterContent(index uint32, client *statsclient.StatsClient) (content string, status syscall.Errno) {
 	content = ""
 	statsDir, err := client.PrepareDirOnIndex(index)
 	if err != nil {
 		LogMsg(fmt.Sprintf("Dumping stats on index failed: %v\n", err))
 		return content, syscall.EAGAIN
 	}
 	if len(statsDir.Entries) != 1 {
 		return content, syscall.ENOENT
 	}
 	result := statsDir.Entries[0]
 	if result.Data == nil {
 		return content, 0
 	}

 	switch result.Type {
 	case adapter.ScalarIndex:
 		stats := result.Data.(adapter.ScalarStat)
 		content = fmt.Sprintf("%.2f\n", stats)
 	case adapter.ErrorIndex:
 		stats := result.Data.(adapter.ErrorStat)
 		content = fmt.Sprintf("%-16s%s\n", "Index", "Count")
 		for i, value := range stats {
 			content += fmt.Sprintf("%-16d%d\n", i, value)
 		}
 	case adapter.SimpleCounterVector:
 		stats := result.Data.(adapter.SimpleCounterStat)
 		content = fmt.Sprintf("%-16s%-16s%s\n", "Thread", "Index", "Packets")
 		for i, vector := range stats {
 			for j, value := range vector {
 				content += fmt.Sprintf("%-16d%-16d%d\n", i, j, value)
 			}
 		}
 	case adapter.CombinedCounterVector:
 		stats := result.Data.(adapter.CombinedCounterStat)
 		content = fmt.Sprintf("%-16s%-16s%-16s%s\n", "Thread", "Index", "Packets", "Bytes")
 		for i, vector := range stats {
 			for j, value := range vector {
 				content += fmt.Sprintf("%-16d%-16d%-16d%d\n", i, j, value[0], value[1])
 			}
 		}
 	case adapter.NameVector:
 		stats := result.Data.(adapter.NameStat)
 		content = fmt.Sprintf("%-16s%s\n", "Index", "Name")
 		for i, value := range stats {
 			content += fmt.Sprintf("%-16d%s\n", i, string(value))
 		}
 	default:
 		content = fmt.Sprintf("Unknown stat type: %d\n", result.Type)
 		//For now, the empty type (file deleted) is not implemented in GoVPP
 		return content, syscall.ENOENT
 	}
 	return content, fs.OK
 }

 //The dirNode structure represents directories
 type dirNode struct {
 	fs.Inode
 	client *statsclient.StatsClient
 	epoch  int64
 }

 var _ = (fs.NodeOpendirer)((*dirNode)(nil))
 var _ = (fs.NodeGetattrer)((*dirNode)(nil))
 var _ = (fs.NodeOnAdder)((*dirNode)(nil))

 func (dn *dirNode) OnAdd(ctx context.Context) {
 	if dn.Inode.IsRoot() {
 		updateDir(ctx, &dn.Inode, dn.client, "/")
 	}
 }

 func (dn *dirNode) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) syscall.Errno {
 	out.Mtime = uint64(time.Now().Unix())
 	out.Atime = out.Mtime
 	out.Ctime = out.Mtime
 	return 0
 }

 func (dn *dirNode) Opendir(ctx context.Context) syscall.Errno {
 	var status syscall.Errno = syscall.F_OK
 	var sleepTime time.Duration = 10 * time.Millisecond
 	newEpoch, inProgress := dn.client.GetEpoch()
 	for inProgress {
 		newEpoch, inProgress = dn.client.GetEpoch()
 		time.Sleep(sleepTime)
 		sleepTime = sleepTime * 2
 	}

 	//We check that the directory epoch is up to date
 	if dn.epoch != newEpoch {
 		//directoryPath is the path to the current directory from root
 		directoryPath := path.Clean("/" + dn.Inode.Path(nil) + "/")
 		status = updateDir(ctx, &dn.Inode, dn.client, directoryPath)
 	}
 	return status
 }

 //The statNode structure represents counters
 type statNode struct {
 	fs.Inode
 	client *statsclient.StatsClient
 	index  uint32
 }

 var _ = (fs.NodeOpener)((*statNode)(nil))
 var _ = (fs.NodeGetattrer)((*statNode)(nil))

 func (fh *statNode) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) syscall.Errno {
 	out.Mtime = uint64(time.Now().Unix())
 	out.Atime = out.Mtime
 	out.Ctime = out.Mtime
 	return 0
 }

 //When a file is opened, the correpsonding counter value is dumped and a file handle is created
 func (sn *statNode) Open(ctx context.Context, flags uint32) (fs.FileHandle, uint32, syscall.Errno) {
 	content, status := getCounterContent(sn.index, sn.client)
 	if status == syscall.ENOENT {
 		_, parent := sn.Inode.Parent()
 		parent.RmChild(sn.Inode.Path(parent))

 	}
 	return &statFH{data: []byte(content)}, fuse.FOPEN_DIRECT_IO, status
 }

 /* The statFH structure aims at dislaying the counters dynamically.
  * It allows the Kernel to read data as I/O without having to specify files sizes, as they may evolve dynamically.
  */
 type statFH struct {
 	data []byte
 }

 var _ = (fs.FileReader)((*statFH)(nil))

 func (fh *statFH) Read(ctx context.Context, data []byte, off int64) (fuse.ReadResult, syscall.Errno) {
 	end := int(off) + len(data)
 	if end > len(fh.data) {
 		end = len(fh.data)
 	}
 	return fuse.ReadResultData(fh.data[off:end]), fs.OK
 }

 //NewStatsFileSystem creates the fs for the stat segment.
 func NewStatsFileSystem(sc *statsclient.StatsClient) (root fs.InodeEmbedder, err error) {
 	return &dirNode{client: sc}, nil
 }
	/*
	* Copyright (c) 2021 Cisco Systems and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	/*Go-FUSE allows us to define the behaviour of our filesystem by recoding any primitive function we need.
	*The structure of the filesystem is constructed as a tree.
	*Each type of nodes (root, directory, file) follows its own prmitives.
	*/
	package main

	import (
	"context"
	"fmt"
	"path"
	"path/filepath"
	"strings"
	"syscall"
	"time"

	"github.com/hanwen/go-fuse/v2/fs"
	"github.com/hanwen/go-fuse/v2/fuse"

	"git.fd.io/govpp.git/adapter"
	"git.fd.io/govpp.git/adapter/statsclient"
	)

	func updateDir(ctx context.Context, n fs.Inode, cl statsclient.StatsClient, dirPath string) syscall.Errno {
	stats, err := cl.PrepareDir(dirPath)
	if err != nil {
	LogMsg(fmt.Sprintf("Listing stats index failed: %v\n", err))
	return syscall.EAGAIN
	}

	n.Operations().(*dirNode).epoch = stats.Epoch

	n.RmAllChildren()

	for _, entry := range stats.Entries {
	localPath := strings.TrimPrefix(string(entry.Name), dirPath)
	dirPath, base := filepath.Split(localPath)

	parent := n
	for _, component := range strings.Split(dirPath, "/") {
	if len(component) == 0 {
	continue
	}
	child := parent.GetChild(component)
	if child == nil {
	child = parent.NewInode(ctx, &dirNode{client: cl, epoch: stats.Epoch},
	fs.StableAttr{Mode: fuse.S_IFDIR})
	parent.AddChild(component, child, true)
	} else {
	child.Operations().(*dirNode).epoch = stats.Epoch
	}

	parent = child
	}

	filename := strings.Replace(base, " ", "_", -1)
	child := parent.GetChild(filename)
	if child == nil {
	child := parent.NewPersistentInode(ctx, &statNode{client: cl, index: entry.Index}, fs.StableAttr{})
	parent.AddChild(filename, child, true)
	}
	}
	return 0
	}

	func getCounterContent(index uint32, client *statsclient.StatsClient) (content string, status syscall.Errno) {
	content = ""
	statsDir, err := client.PrepareDirOnIndex(index)
	if err != nil {
	LogMsg(fmt.Sprintf("Dumping stats on index failed: %v\n", err))
	return content, syscall.EAGAIN
	}
	if len(statsDir.Entries) != 1 {
	return content, syscall.ENOENT
	}
	result := statsDir.Entries[0]
	if result.Data == nil {
	return content, 0
	}

	switch result.Type {
	case adapter.ScalarIndex:
	stats := result.Data.(adapter.ScalarStat)
	content = fmt.Sprintf("%.2f\n", stats)
	case adapter.ErrorIndex:
	stats := result.Data.(adapter.ErrorStat)
	content = fmt.Sprintf("%-16s%s\n", "Index", "Count")
	for i, value := range stats {
	content += fmt.Sprintf("%-16d%d\n", i, value)
	}
	case adapter.SimpleCounterVector:
	stats := result.Data.(adapter.SimpleCounterStat)
	content = fmt.Sprintf("%-16s%-16s%s\n", "Thread", "Index", "Packets")
	for i, vector := range stats {
	for j, value := range vector {
	content += fmt.Sprintf("%-16d%-16d%d\n", i, j, value)
	}
	}
	case adapter.CombinedCounterVector:
	stats := result.Data.(adapter.CombinedCounterStat)
	content = fmt.Sprintf("%-16s%-16s%-16s%s\n", "Thread", "Index", "Packets", "Bytes")
	for i, vector := range stats {
	for j, value := range vector {
	content += fmt.Sprintf("%-16d%-16d%-16d%d\n", i, j, value[0], value[1])
	}
	}
	case adapter.NameVector:
	stats := result.Data.(adapter.NameStat)
	content = fmt.Sprintf("%-16s%s\n", "Index", "Name")
	for i, value := range stats {
	content += fmt.Sprintf("%-16d%s\n", i, string(value))
	}
	default:
	content = fmt.Sprintf("Unknown stat type: %d\n", result.Type)
	//For now, the empty type (file deleted) is not implemented in GoVPP
	return content, syscall.ENOENT
	}
	return content, fs.OK
	}

	//The dirNode structure represents directories
	type dirNode struct {
	fs.Inode
	client *statsclient.StatsClient
	epoch int64
	}

	var _ = (fs.NodeOpendirer)((*dirNode)(nil))
	var _ = (fs.NodeGetattrer)((*dirNode)(nil))
	var _ = (fs.NodeOnAdder)((*dirNode)(nil))

	func (dn *dirNode) OnAdd(ctx context.Context) {
	if dn.Inode.IsRoot() {
	updateDir(ctx, &dn.Inode, dn.client, "/")
	}
	}

	func (dn dirNode) Getattr(ctx context.Context, f fs.FileHandle, out fuse.AttrOut) syscall.Errno {
	out.Mtime = uint64(time.Now().Unix())
	out.Atime = out.Mtime
	out.Ctime = out.Mtime
	return 0
	}

	func (dn *dirNode) Opendir(ctx context.Context) syscall.Errno {
	var status syscall.Errno = syscall.F_OK
	var sleepTime time.Duration = 10 * time.Millisecond
	newEpoch, inProgress := dn.client.GetEpoch()
	for inProgress {
	newEpoch, inProgress = dn.client.GetEpoch()
	time.Sleep(sleepTime)
	sleepTime = sleepTime * 2
	}

	//We check that the directory epoch is up to date
	if dn.epoch != newEpoch {
	//directoryPath is the path to the current directory from root
	directoryPath := path.Clean("/" + dn.Inode.Path(nil) + "/")
	status = updateDir(ctx, &dn.Inode, dn.client, directoryPath)
	}
	return status
	}

	//The statNode structure represents counters
	type statNode struct {
	fs.Inode
	client *statsclient.StatsClient
	index uint32
	}

	var _ = (fs.NodeOpener)((*statNode)(nil))
	var _ = (fs.NodeGetattrer)((*statNode)(nil))

	func (fh statNode) Getattr(ctx context.Context, f fs.FileHandle, out fuse.AttrOut) syscall.Errno {
	out.Mtime = uint64(time.Now().Unix())
	out.Atime = out.Mtime
	out.Ctime = out.Mtime
	return 0
	}

	//When a file is opened, the correpsonding counter value is dumped and a file handle is created
	func (sn *statNode) Open(ctx context.Context, flags uint32) (fs.FileHandle, uint32, syscall.Errno) {
	content, status := getCounterContent(sn.index, sn.client)
	if status == syscall.ENOENT {
	_, parent := sn.Inode.Parent()
	parent.RmChild(sn.Inode.Path(parent))

	}
	return &statFH{data: []byte(content)}, fuse.FOPEN_DIRECT_IO, status
	}

	/* The statFH structure aims at dislaying the counters dynamically.
	* It allows the Kernel to read data as I/O without having to specify files sizes, as they may evolve dynamically.
	*/
	type statFH struct {
	data []byte
	}

	var _ = (fs.FileReader)((*statFH)(nil))

	func (fh *statFH) Read(ctx context.Context, data []byte, off int64) (fuse.ReadResult, syscall.Errno) {
	end := int(off) + len(data)
	if end > len(fh.data) {
	end = len(fh.data)
	}
	return fuse.ReadResultData(fh.data[off:end]), fs.OK
	}

	//NewStatsFileSystem creates the fs for the stat segment.
	func NewStatsFileSystem(sc *statsclient.StatsClient) (root fs.InodeEmbedder, err error) {
	return &dirNode{client: sc}, nil
	}