dex: remove gasprice package and use eth/gasprice instead

We did not change anything in eth/gasprice, don't copy it into dex.

4 files changed, 3 insertions, 192 deletions

diff --git a/dex/api_backend.go b/dex/api_backend.go
index d8d52974d..c6c1d214d 100644
--- a/dex/api_backend.go
+++ b/dex/api_backend.go
@@ -29,8 +29,8 @@ import (
 	"github.com/dexon-foundation/dexon/core/state"
 	"github.com/dexon-foundation/dexon/core/types"
 	"github.com/dexon-foundation/dexon/core/vm"
-	"github.com/dexon-foundation/dexon/dex/gasprice"
 	"github.com/dexon-foundation/dexon/eth/downloader"
+	"github.com/dexon-foundation/dexon/eth/gasprice"
 
 	"github.com/dexon-foundation/dexon/ethdb"
 	"github.com/dexon-foundation/dexon/event"
diff --git a/dex/backend.go b/dex/backend.go
index 3b727adde..d7bc4630e 100644
--- a/dex/backend.go
+++ b/dex/backend.go
@@ -34,9 +34,9 @@ import (
 	"github.com/dexon-foundation/dexon/core/bloombits"
 	"github.com/dexon-foundation/dexon/core/rawdb"
 	"github.com/dexon-foundation/dexon/core/vm"
-	"github.com/dexon-foundation/dexon/dex/gasprice"
 	"github.com/dexon-foundation/dexon/eth/downloader"
 	"github.com/dexon-foundation/dexon/eth/filters"
+	"github.com/dexon-foundation/dexon/eth/gasprice"
 	"github.com/dexon-foundation/dexon/ethdb"
 	"github.com/dexon-foundation/dexon/event"
 	"github.com/dexon-foundation/dexon/internal/ethapi"
diff --git a/dex/config.go b/dex/config.go
index e74425ea3..cd9d1b1db 100644
--- a/dex/config.go
+++ b/dex/config.go
@@ -26,8 +26,8 @@ import (
 	"time"
 
 	"github.com/dexon-foundation/dexon/core"
-	"github.com/dexon-foundation/dexon/dex/gasprice"
 	"github.com/dexon-foundation/dexon/eth/downloader"
+	"github.com/dexon-foundation/dexon/eth/gasprice"
 	"github.com/dexon-foundation/dexon/params"
 )
 
diff --git a/dex/gasprice/gasprice.go b/dex/gasprice/gasprice.go
deleted file mode 100644
index 9af33c682..000000000
--- a/dex/gasprice/gasprice.go
+++ /dev/null
@@ -1,189 +0,0 @@
-// Copyright 2015 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 gasprice
-
-import (
-	"context"
-	"math/big"
-	"sort"
-	"sync"
-
-	"github.com/dexon-foundation/dexon/common"
-	"github.com/dexon-foundation/dexon/core/types"
-	"github.com/dexon-foundation/dexon/internal/ethapi"
-	"github.com/dexon-foundation/dexon/params"
-	"github.com/dexon-foundation/dexon/rpc"
-)
-
-var maxPrice = big.NewInt(500 * params.GWei)
-
-type Config struct {
-	Blocks     int
-	Percentile int
-	Default    *big.Int `toml:",omitempty"`
-}
-
-// Oracle recommends gas prices based on the content of recent
-// blocks. Suitable for both light and full clients.
-type Oracle struct {
-	backend   ethapi.Backend
-	lastHead  common.Hash
-	lastPrice *big.Int
-	cacheLock sync.RWMutex
-	fetchLock sync.Mutex
-
-	checkBlocks, maxEmpty, maxBlocks int
-	percentile                       int
-}
-
-// NewOracle returns a new oracle.
-func NewOracle(backend ethapi.Backend, params Config) *Oracle {
-	blocks := params.Blocks
-	if blocks < 1 {
-		blocks = 1
-	}
-	percent := params.Percentile
-	if percent < 0 {
-		percent = 0
-	}
-	if percent > 100 {
-		percent = 100
-	}
-	return &Oracle{
-		backend:     backend,
-		lastPrice:   params.Default,
-		checkBlocks: blocks,
-		maxEmpty:    blocks / 2,
-		maxBlocks:   blocks * 5,
-		percentile:  percent,
-	}
-}
-
-// SuggestPrice returns the recommended gas price.
-func (gpo *Oracle) SuggestPrice(ctx context.Context) (*big.Int, error) {
-	gpo.cacheLock.RLock()
-	lastHead := gpo.lastHead
-	lastPrice := gpo.lastPrice
-	gpo.cacheLock.RUnlock()
-
-	head, _ := gpo.backend.HeaderByNumber(ctx, rpc.LatestBlockNumber)
-	headHash := head.Hash()
-	if headHash == lastHead {
-		return lastPrice, nil
-	}
-
-	gpo.fetchLock.Lock()
-	defer gpo.fetchLock.Unlock()
-
-	// try checking the cache again, maybe the last fetch fetched what we need
-	gpo.cacheLock.RLock()
-	lastHead = gpo.lastHead
-	lastPrice = gpo.lastPrice
-	gpo.cacheLock.RUnlock()
-	if headHash == lastHead {
-		return lastPrice, nil
-	}
-
-	blockNum := head.Number.Uint64()
-	ch := make(chan getBlockPricesResult, gpo.checkBlocks)
-	sent := 0
-	exp := 0
-	var blockPrices []*big.Int
-	for sent < gpo.checkBlocks && blockNum > 0 {
-		go gpo.getBlockPrices(ctx, types.MakeSigner(gpo.backend.ChainConfig(), big.NewInt(int64(blockNum))), blockNum, ch)
-		sent++
-		exp++
-		blockNum--
-	}
-	maxEmpty := gpo.maxEmpty
-	for exp > 0 {
-		res := <-ch
-		if res.err != nil {
-			return lastPrice, res.err
-		}
-		exp--
-		if res.price != nil {
-			blockPrices = append(blockPrices, res.price)
-			continue
-		}
-		if maxEmpty > 0 {
-			maxEmpty--
-			continue
-		}
-		if blockNum > 0 && sent < gpo.maxBlocks {
-			go gpo.getBlockPrices(ctx, types.MakeSigner(gpo.backend.ChainConfig(), big.NewInt(int64(blockNum))), blockNum, ch)
-			sent++
-			exp++
-			blockNum--
-		}
-	}
-	price := lastPrice
-	if len(blockPrices) > 0 {
-		sort.Sort(bigIntArray(blockPrices))
-		price = blockPrices[(len(blockPrices)-1)*gpo.percentile/100]
-	}
-	if price.Cmp(maxPrice) > 0 {
-		price = new(big.Int).Set(maxPrice)
-	}
-
-	gpo.cacheLock.Lock()
-	gpo.lastHead = headHash
-	gpo.lastPrice = price
-	gpo.cacheLock.Unlock()
-	return price, nil
-}
-
-type getBlockPricesResult struct {
-	price *big.Int
-	err   error
-}
-
-type transactionsByGasPrice []*types.Transaction
-
-func (t transactionsByGasPrice) Len() int           { return len(t) }
-func (t transactionsByGasPrice) Swap(i, j int)      { t[i], t[j] = t[j], t[i] }
-func (t transactionsByGasPrice) Less(i, j int) bool { return t[i].GasPrice().Cmp(t[j].GasPrice()) < 0 }
-
-// getBlockPrices calculates the lowest transaction gas price in a given block
-// and sends it to the result channel. If the block is empty, price is nil.
-func (gpo *Oracle) getBlockPrices(ctx context.Context, signer types.Signer, blockNum uint64, ch chan getBlockPricesResult) {
-	block, err := gpo.backend.BlockByNumber(ctx, rpc.BlockNumber(blockNum))
-	if block == nil {
-		ch <- getBlockPricesResult{nil, err}
-		return
-	}
-
-	blockTxs := block.Transactions()
-	txs := make([]*types.Transaction, len(blockTxs))
-	copy(txs, blockTxs)
-	sort.Sort(transactionsByGasPrice(txs))
-
-	for _, tx := range txs {
-		sender, err := types.Sender(signer, tx)
-		if err == nil && sender != block.Coinbase() {
-			ch <- getBlockPricesResult{tx.GasPrice(), nil}
-			return
-		}
-	}
-	ch <- getBlockPricesResult{nil, nil}
-}
-
-type bigIntArray []*big.Int
-
-func (s bigIntArray) Len() int           { return len(s) }
-func (s bigIntArray) Less(i, j int) bool { return s[i].Cmp(s[j]) < 0 }
-func (s bigIntArray) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }