// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package ethdb
import (
"strconv"
"strings"
"sync"
"time"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/metrics"
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/errors"
"github.com/syndtr/goleveldb/leveldb/filter"
"github.com/syndtr/goleveldb/leveldb/iterator"
"github.com/syndtr/goleveldb/leveldb/opt"
gometrics "github.com/rcrowley/go-metrics"
)
var OpenFileLimit = 64
type LDBDatabase struct {
fn string // filename for reporting
db *leveldb.DB // LevelDB instance
getTimer gometrics.Timer // Timer for measuring the database get request counts and latencies
putTimer gometrics.Timer // Timer for measuring the database put request counts and latencies
delTimer gometrics.Timer // Timer for measuring the database delete request counts and latencies
missMeter gometrics.Meter // Meter for measuring the missed database get requests
readMeter gometrics.Meter // Meter for measuring the database get request data usage
writeMeter gometrics.Meter // Meter for measuring the database put request data usage
compTimeMeter gometrics.Meter // Meter for measuring the total time spent in database compaction
compReadMeter gometrics.Meter // Meter for measuring the data read during compaction
compWriteMeter gometrics.Meter // Meter for measuring the data written during compaction
quitLock sync.Mutex // Mutex protecting the quit channel access
quitChan chan chan error // Quit channel to stop the metrics collection before closing the database
log log.Logger // Contextual logger tracking the database path
}
// NewLDBDatabase returns a LevelDB wrapped object.
func NewLDBDatabase(file string, cache int, handles int) (*LDBDatabase, error) {
logger := log.New("database", file)
// Ensure we have some minimal caching and file guarantees
if cache < 16 {
cache = 16
}
if handles < 16 {
handles = 16
}
logger.Info("Allocated cache and file handles", "cache", cache, "handles", handles)
// Open the db and recover any potential corruptions
db, err := leveldb.OpenFile(file, &opt.Options{
OpenFilesCacheCapacity: handles,
BlockCacheCapacity: cache / 2 * opt.MiB,
WriteBuffer: cache / 4 * opt.MiB, // Two of these are used internally
Filter: filter.NewBloomFilter(10),
})
if _, corrupted := err.(*errors.ErrCorrupted); corrupted {
db, err = leveldb.RecoverFile(file, nil)
}
// (Re)check for errors and abort if opening of the db failed
if err != nil {
return nil, err
}
return &LDBDatabase{
fn: file,
db: db,
log: logger,
}, nil
}
// Path returns the path to the database directory.
func (db *LDBDatabase) Path() string {
return db.fn
}
// Put puts the given key / value to the queue
func (db *LDBDatabase) Put(key []byte, value []byte) error {
// Measure the database put latency, if requested
if db.putTimer != nil {
defer db.putTimer.UpdateSince(time.Now())
}
// Generate the data to write to disk, update the meter and write
//value = rle.Compress(value)
if db.writeMeter != nil {
db.writeMeter.Mark(int64(len(value)))
}
return db.db.Put(key, value, nil)
}
func (db *LDBDatabase) Has(key []byte) (bool, error) {
return db.db.Has(key, nil)
}
// Get returns the given key if it's present.
func (db *LDBDatabase) Get(key []byte) ([]byte, error) {
// Measure the database get latency, if requested
if db.getTimer != nil {
defer db.getTimer.UpdateSince(time.Now())
}
// Retrieve the key and increment the miss counter if not found
dat, err := db.db.Get(key, nil)
if err != nil {
if db.missMeter != nil {
db.missMeter.Mark(1)
}
return nil, err
}
// Otherwise update the actually retrieved amount of data
if db.readMeter != nil {
db.readMeter.Mark(int64(len(dat)))
}
return dat, nil
//return rle.Decompress(dat)
}
// Delete deletes the key from the queue and database
func (db *LDBDatabase) Delete(key []byte) error {
// Measure the database delete latency, if requested
if db.delTimer != nil {
defer db.delTimer.UpdateSince(time.Now())
}
// Execute the actual operation
return db.db.Delete(key, nil)
}
func (db *LDBDatabase) NewIterator() iterator.Iterator {
return db.db.NewIterator(nil, nil)
}
func (db *LDBDatabase) Close() {
// Stop the metrics collection to avoid internal database races
db.quitLock.Lock()
defer db.quitLock.Unlock()
if db.quitChan != nil {
errc := make(chan error)
db.quitChan <- errc
if err := <-errc; err != nil {
db.log.Error("Metrics collection failed", "err", err)
}
}
err := db.db.Close()
if err == nil {
db.log.Info("Database closed")
} else {
db.log.Error("Failed to close database", "err", err)
}
}
func (db *LDBDatabase) LDB() *leveldb.DB {
return db.db
}
// Meter configures the database metrics collectors and
func (db *LDBDatabase) Meter(prefix string) {
// Short circuit metering if the metrics system is disabled
if !metrics.Enabled {
return
}
// Initialize all the metrics collector at the requested prefix
db.getTimer = metrics.NewTimer(prefix + "user/gets")
db.putTimer = metrics.NewTimer(prefix + "user/puts")
db.delTimer = metrics.NewTimer(prefix + "user/dels")
db.missMeter = metrics.NewMeter(prefix + "user/misses")
db.readMeter = metrics.NewMeter(prefix + "user/reads")
db.writeMeter = metrics.NewMeter(prefix + "user/writes")
db.compTimeMeter = metrics.NewMeter(prefix + "compact/time")
db.compReadMeter = metrics.NewMeter(prefix + "compact/input")
db.compWriteMeter = metrics.NewMeter(prefix + "compact/output")
// Create a quit channel for the periodic collector and run it
db.quitLock.Lock()
db.quitChan = make(chan chan error)
db.quitLock.Unlock()
go db.meter(3 * time.Second)
}
// meter periodically retrieves internal leveldb counters and reports them to
// the metrics subsystem.
//
// This is how a stats table look like (currently):
// Compactions
// Level | Tables | Size(MB) | Time(sec) | Read(MB) | Write(MB)
// -------+------------+---------------+---------------+---------------+---------------
// 0 | 0 | 0.00000 | 1.27969 | 0.00000 | 12.31098
// 1 | 85 | 109.27913 | 28.09293 | 213.92493 | 214.26294
// 2 | 523 | 1000.37159 | 7.26059 | 66.86342 | 66.77884
// 3 | 570 | 1113.18458 | 0.00000 | 0.00000 | 0.00000
func (db *LDBDatabase) meter(refresh time.Duration) {
// Create the counters to store current and previous values
counters := make([][]float64, 2)
for i := 0; i < 2; i++ {
counters[i] = make([]float64, 3)
}
// Iterate ad infinitum and collect the stats
for i := 1; ; i++ {
// Retrieve the database stats
stats, err := db.db.GetProperty("leveldb.stats")
if err != nil {
db.log.Error("Failed to read database stats", "err", err)
return
}
// Find the compaction table, skip the header
lines := strings.Split(stats, "\n")
for len(lines) > 0 && strings.TrimSpace(lines[0]) != "Compactions" {
lines = lines[1:]
}
if len(lines) <= 3 {
db.log.Error("Compaction table not found")
return
}
lines = lines[3:]
// Iterate over all the table rows, and accumulate the entries
for j := 0; j < len(counters[i%2]); j++ {
counters[i%2][j] = 0
}
for _, line := range lines {
parts := strings.Split(line, "|")
if len(parts) != 6 {
break
}
for idx, counter := range parts[3:] {
value, err := strconv.ParseFloat(strings.TrimSpace(counter), 64)
if err != nil {
db.log.Error("Compaction entry parsing failed", "err", err)
return
}
counters[i%2][idx] += value
}
}
// Update all the requested meters
if db.compTimeMeter != nil {
db.compTimeMeter.Mark(int64((counters[i%2][0] - counters[(i-1)%2][0]) * 1000 * 1000 * 1000))
}
if db.compReadMeter != nil {
db.compReadMeter.Mark(int64((counters[i%2][1] - counters[(i-1)%2][1]) * 1024 * 1024))
}
if db.compWriteMeter != nil {
db.compWriteMeter.Mark(int64((counters[i%2][2] - counters[(i-1)%2][2]) * 1024 * 1024))
}
// Sleep a bit, then repeat the stats collection
select {
case errc := <-db.quitChan:
// Quit requesting, stop hammering the database
errc <- nil
return
case <-time.After(refresh):
// Timeout, gather a new set of stats
}
}
}
func (db *LDBDatabase) NewBatch() Batch {
return &ldbBatch{db: db.db, b: new(leveldb.Batch)}
}
type ldbBatch struct {
db *leveldb.DB
b *leveldb.Batch
size int
}
func (b *ldbBatch) Put(key, value []byte) error {
b.b.Put(key, value)
b.size += len(value)
return nil
}
func (b *ldbBatch) Write() error {
return b.db.Write(b.b, nil)
}
func (b *ldbBatch) ValueSize() int {
return b.size
}
type table struct {
db Database
prefix string
}
// NewTable returns a Database object that prefixes all keys with a given
// string.
func NewTable(db Database, prefix string) Database {
return &table{
db: db,
prefix: prefix,
}
}
func (dt *table) Put(key []byte, value []byte) error {
return dt.db.Put(append([]byte(dt.prefix), key...), value)
}
func (dt *table) Has(key []byte) (bool, error) {
return dt.db.Has(append([]byte(dt.prefix), key...))
}
func (dt *table) Get(key []byte) ([]byte, error) {
return dt.db.Get(append([]byte(dt.prefix), key...))
}
func (dt *table) Delete(key []byte) error {
return dt.db.Delete(append([]byte(dt.prefix), key...))
}
func (dt *table) Close() {
// Do nothing; don't close the underlying DB.
}
type tableBatch struct {
batch Batch
prefix string
}
// NewTableBatch returns a Batch object which prefixes all keys with a given string.
func NewTableBatch(db Database, prefix string) Batch {
return &tableBatch{db.NewBatch(), prefix}
}
func (dt *table) NewBatch() Batch {
return &tableBatch{dt.db.NewBatch(), dt.prefix}
}
func (tb *tableBatch) Put(key, value []byte) error {
return tb.batch.Put(append([]byte(tb.prefix), key...), value)
}
func (tb *tableBatch) Write() error {
return tb.batch.Write()
}
func (tb *tableBatch) ValueSize() int {
return tb.batch.ValueSize()
}
