lbcd/sqlite3/sqlitedbcache.go
2013-05-29 10:09:26 -05:00

261 lines
6.3 KiB
Go

// Copyright (c) 2013 Conformal Systems LLC.
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package sqlite3
import (
"bytes"
"container/list"
"github.com/conformal/btcdb"
"github.com/conformal/btcutil"
"github.com/conformal/btcwire"
"sync"
)
type txCache struct {
maxcount int
fifo list.List
// NOTE: the key is specifically ShaHash, not *ShaHash
txMap map[btcwire.ShaHash]*txCacheObj
cacheLock sync.RWMutex
}
type txCacheObj struct {
next *txCacheObj
sha btcwire.ShaHash
blksha btcwire.ShaHash
pver uint32
tx *btcwire.MsgTx
txbuf []byte
}
type blockCache struct {
maxcount int
fifo list.List
blockMap map[btcwire.ShaHash]*blockCacheObj
cacheLock sync.RWMutex
}
type blockCacheObj struct {
next *blockCacheObj
sha btcwire.ShaHash
blk *btcutil.Block
}
// FetchBlockBySha - return a btcutil Block, object may be a cached.
func (db *SqliteDb) FetchBlockBySha(sha *btcwire.ShaHash) (blk *btcutil.Block, err error) {
blkcache, ok := db.fetchBlockCache(sha)
if ok {
return blkcache.blk, nil
}
buf, pver, height, err := db.fetchSha(*sha)
if err != nil {
return
}
blk, err = btcutil.NewBlockFromBytes(buf, pver)
if err != nil {
return
}
blk.SetHeight(height)
db.insertBlockCache(sha, blk)
return
}
// fetchBlockCache check if a block is in the block cache, if so return it.
func (db *SqliteDb) fetchBlockCache(sha *btcwire.ShaHash) (*blockCacheObj, bool) {
db.blockCache.cacheLock.RLock()
defer db.blockCache.cacheLock.RUnlock()
blkobj, ok := db.blockCache.blockMap[*sha]
if !ok { // could this just return the map deref?
return nil, false
}
return blkobj, true
}
// insertBlockCache insert the given sha/block into the cache map.
// If the block cache is determined to be full, it will release
// an old entry in FIFO order.
func (db *SqliteDb) insertBlockCache(sha *btcwire.ShaHash, blk *btcutil.Block) {
bc := &db.blockCache
bc.cacheLock.Lock()
defer bc.cacheLock.Unlock()
blkObj := blockCacheObj{sha: *sha, blk: blk}
bc.fifo.PushBack(&blkObj)
if bc.fifo.Len() > bc.maxcount {
listobj := bc.fifo.Front()
bc.fifo.Remove(listobj)
tailObj, ok := listobj.Value.(*blockCacheObj)
if ok {
delete(bc.blockMap, tailObj.sha)
} else {
panic("invalid type pushed on blockCache list")
}
}
bc.blockMap[blkObj.sha] = &blkObj
}
type TxListReply struct {
Sha *btcwire.ShaHash
Tx *btcwire.MsgTx
Err error
}
// FetchTxByShaList given a array of ShaHash, look up the transactions
// and return them in a TxListReply array.
func (db *SqliteDb) FetchTxByShaList(txShaList []*btcwire.ShaHash) []*btcdb.TxListReply {
var replies []*btcdb.TxListReply
for _, txsha := range txShaList {
tx, _, _, err := db.FetchTxBySha(txsha)
txlre := btcdb.TxListReply{Sha: txsha, Tx: tx, Err: err}
replies = append(replies, &txlre)
}
return replies
}
// FetchTxAllBySha returns several pieces of data regarding the given sha.
func (db *SqliteDb) FetchTxAllBySha(txsha *btcwire.ShaHash) (rtx *btcwire.MsgTx, rtxbuf []byte, rpver uint32, rblksha *btcwire.ShaHash, err error) {
// Check Tx cache
if txc, ok := db.fetchTxCache(txsha); ok {
return txc.tx, txc.txbuf, txc.pver, &txc.blksha, nil
}
// If not cached load it
bidx, toff, tlen, err := db.FetchLocationBySha(txsha)
if err != nil {
log.Warnf("unable to find location of origin tx %v", txsha)
return
}
blksha, err := db.FetchBlockShaByIdx(bidx)
if err != nil {
log.Warnf("block idx lookup %v to %v", bidx, err)
return
}
log.Tracef("transaction %v is at block %v %v tx %v",
txsha, blksha, bidx, toff)
blk, err := db.FetchBlockBySha(blksha)
if err != nil {
log.Warnf("unable to fetch block %v %v ",
bidx, &blksha)
return
}
blkbuf, pver, err := blk.Bytes()
if err != nil {
log.Warnf("unable to decode block %v %v", bidx, &blksha)
return
}
txbuf := make([]byte, tlen)
copy(txbuf[:], blkbuf[toff:toff+tlen])
rbuf := bytes.NewBuffer(txbuf)
var tx btcwire.MsgTx
err = tx.BtcDecode(rbuf, pver)
if err != nil {
log.Warnf("unable to decode tx block %v %v txoff %v txlen %v",
bidx, &blksha, toff, tlen)
return
}
// Shove data into TxCache
// XXX -
var txc txCacheObj
txc.sha = *txsha
txc.tx = &tx
txc.txbuf = txbuf
txc.pver = pver
txc.blksha = *blksha
db.insertTxCache(&txc)
return &tx, txbuf, pver, blksha, nil
}
// FetchTxBySha returns some data for the given Tx Sha.
func (db *SqliteDb) FetchTxBySha(txsha *btcwire.ShaHash) (rtx *btcwire.MsgTx, rpver uint32, blksha *btcwire.ShaHash, err error) {
rtx, _, rpver, blksha, err = db.FetchTxAllBySha(txsha)
return
}
// FetchTxBufBySha return the bytestream data and associated protocol version.
// for the given Tx Sha
func (db *SqliteDb) FetchTxBufBySha(txsha *btcwire.ShaHash) (txbuf []byte, rpver uint32, err error) {
_, txbuf, rpver, _, err = db.FetchTxAllBySha(txsha)
return
}
// fetchTxCache look up the given transaction in the Tx cache.
func (db *SqliteDb) fetchTxCache(sha *btcwire.ShaHash) (*txCacheObj, bool) {
tc := &db.txCache
tc.cacheLock.RLock()
defer tc.cacheLock.RUnlock()
txObj, ok := tc.txMap[*sha]
if !ok { // could this just return the map deref?
return nil, false
}
return txObj, true
}
// insertTxCache, insert the given txobj into the cache.
// if the tx cache is determined to be full, it will release
// an old entry in FIFO order.
func (db *SqliteDb) insertTxCache(txObj *txCacheObj) {
tc := &db.txCache
tc.cacheLock.Lock()
defer tc.cacheLock.Unlock()
tc.fifo.PushBack(txObj)
if tc.fifo.Len() >= tc.maxcount {
listobj := tc.fifo.Front()
tc.fifo.Remove(listobj)
tailObj, ok := listobj.Value.(*txCacheObj)
if ok {
delete(tc.txMap, tailObj.sha)
} else {
panic("invalid type pushed on tx list")
}
}
tc.txMap[txObj.sha] = txObj
}
// InvalidateTxCache clear/release all cached transactions.
func (db *SqliteDb) InvalidateTxCache() {
tc := &db.txCache
tc.cacheLock.Lock()
defer tc.cacheLock.Unlock()
tc.txMap = map[btcwire.ShaHash]*txCacheObj{}
tc.fifo = list.List{}
}
// InvalidateTxCache clear/release all cached blocks.
func (db *SqliteDb) InvalidateBlockCache() {
bc := &db.blockCache
bc.cacheLock.Lock()
defer bc.cacheLock.Unlock()
bc.blockMap = map[btcwire.ShaHash]*blockCacheObj{}
bc.fifo = list.List{}
}
// InvalidateCache clear/release all cached blocks and transactions.
func (db *SqliteDb) InvalidateCache() {
db.InvalidateTxCache()
db.InvalidateBlockCache()
}