cmd, ethdb, vendor: integrate leveldb iostats (#16277)

* cmd, dashboard, ethdb, vendor: send iostats to dashboard

* ethdb: change names

* ethdb: handle parsing errors

* ethdb: handle iostats syntax error

* ethdb: r -> w

vendor/github.com/syndtr/goleveldb/leveldb/db.go

@@ -906,6 +906,8 @@ func (db *DB) GetSnapshot() (*Snapshot, error) {
 //		Returns the number of files at level 'n'.
 //	leveldb.stats
 //		Returns statistics of the underlying DB.
+//	leveldb.iostats
+//		Returns statistics of effective disk read and write.
 //	leveldb.writedelay
 //		Returns cumulative write delay caused by compaction.
 //	leveldb.sstables
@@ -959,6 +961,10 @@ func (db *DB) GetProperty(name string) (value string, err error) {
 				level, len(tables), float64(tables.size())/1048576.0, duration.Seconds(),
 				float64(read)/1048576.0, float64(write)/1048576.0)
 		}
+	case p == "iostats":
+		value = fmt.Sprintf("Read(MB):%.5f Write(MB):%.5f",
+			float64(db.s.stor.reads())/1048576.0,
+			float64(db.s.stor.writes())/1048576.0)
 	case p == "writedelay":
 		writeDelayN, writeDelay := atomic.LoadInt32(&db.cWriteDelayN), time.Duration(atomic.LoadInt64(&db.cWriteDelay))
 		value = fmt.Sprintf("DelayN:%d Delay:%s", writeDelayN, writeDelay)

vendor/github.com/syndtr/goleveldb/leveldb/iterator/iter.go

@@ -88,7 +88,7 @@ type Iterator interface {
 	// its contents may change on the next call to any 'seeks method'.
 	Key() []byte
 
-	// Value returns the key of the current key/value pair, or nil if done.
+	// Value returns the value of the current key/value pair, or nil if done.
 	// The caller should not modify the contents of the returned slice, and
 	// its contents may change on the next call to any 'seeks method'.
 	Value() []byte

vendor/github.com/syndtr/goleveldb/leveldb/memdb/memdb.go

@@ -329,7 +329,7 @@ func (p *DB) Delete(key []byte) error {
 
 	h := p.nodeData[node+nHeight]
 	for i, n := range p.prevNode[:h] {
-		m := n + 4 + i
+		m := n + nNext + i
 		p.nodeData[m] = p.nodeData[p.nodeData[m]+nNext+i]
 	}
 

vendor/github.com/syndtr/goleveldb/leveldb/session.go

@@ -42,7 +42,7 @@ type session struct {
 	stTempFileNum    int64
 	stSeqNum         uint64 // last mem compacted seq; need external synchronization
 
-	stor     storage.Storage
+	stor     *iStorage
 	storLock storage.Locker
 	o        *cachedOptions
 	icmp     *iComparer
@@ -68,7 +68,7 @@ func newSession(stor storage.Storage, o *opt.Options) (s *session, err error) {
 		return
 	}
 	s = &session{
-		stor:     stor,
+		stor:     newIStorage(stor),
 		storLock: storLock,
 		fileRef:  make(map[int64]int),
 	}

vendor/github.com/syndtr/goleveldb/leveldb/storage.go

@@ -0,0 +1,63 @@
+package leveldb
+
+import (
+	"github.com/syndtr/goleveldb/leveldb/storage"
+	"sync/atomic"
+)
+
+type iStorage struct {
+	storage.Storage
+	read  uint64
+	write uint64
+}
+
+func (c *iStorage) Open(fd storage.FileDesc) (storage.Reader, error) {
+	r, err := c.Storage.Open(fd)
+	return &iStorageReader{r, c}, err
+}
+
+func (c *iStorage) Create(fd storage.FileDesc) (storage.Writer, error) {
+	w, err := c.Storage.Create(fd)
+	return &iStorageWriter{w, c}, err
+}
+
+func (c *iStorage) reads() uint64 {
+	return atomic.LoadUint64(&c.read)
+}
+
+func (c *iStorage) writes() uint64 {
+	return atomic.LoadUint64(&c.write)
+}
+
+// newIStorage returns the given storage wrapped by iStorage.
+func newIStorage(s storage.Storage) *iStorage {
+	return &iStorage{s, 0, 0}
+}
+
+type iStorageReader struct {
+	storage.Reader
+	c *iStorage
+}
+
+func (r *iStorageReader) Read(p []byte) (n int, err error) {
+	n, err = r.Reader.Read(p)
+	atomic.AddUint64(&r.c.read, uint64(n))
+	return n, err
+}
+
+func (r *iStorageReader) ReadAt(p []byte, off int64) (n int, err error) {
+	n, err = r.Reader.ReadAt(p, off)
+	atomic.AddUint64(&r.c.read, uint64(n))
+	return n, err
+}
+
+type iStorageWriter struct {
+	storage.Writer
+	c *iStorage
+}
+
+func (w *iStorageWriter) Write(p []byte) (n int, err error) {
+	n, err = w.Writer.Write(p)
+	atomic.AddUint64(&w.c.write, uint64(n))
+	return n, err
+}

vendor/github.com/syndtr/goleveldb/leveldb/storage/file_storage_plan9.go

@@ -8,7 +8,6 @@ package storage
 
 import (
 	"os"
-	"path/filepath"
 )
 
 type plan9FileLock struct {
@@ -48,8 +47,7 @@ func rename(oldpath, newpath string) error {
 		}
 	}
 
-	_, fname := filepath.Split(newpath)
-	return os.Rename(oldpath, fname)
+	return os.Rename(oldpath, newpath)
 }
 
 func syncDir(name string) error {

vendor/github.com/syndtr/goleveldb/leveldb/util/util.go

@@ -19,7 +19,7 @@ var (
 // Releaser is the interface that wraps the basic Release method.
 type Releaser interface {
 	// Release releases associated resources. Release should always success
-	// and can be called multipe times without causing error.
+	// and can be called multiple times without causing error.
 	Release()
 }