path: root/blockpool/blockpool_util_test.go

package blockpool

import (
    "fmt"
    "math/big"
    "sync"
    "testing"
    "time"

    "github.com/ethereum/go-ethereum/blockpool/test"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/errs"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/pow"
)

var (
    waitTimeout                    = 60 * time.Second
    testBlockHashesRequestInterval = 10 * time.Millisecond
    testBlocksRequestInterval      = 10 * time.Millisecond
    requestWatchInterval           = 10 * time.Millisecond
)

// test blockChain is an integer trie
type blockChain map[int][]int

// blockPoolTester provides the interface between tests and a blockPool
//
// refBlockChain is used to guide which blocks will be accepted as valid
// blockChain gives the current state of the blockchain and
// accumulates inserts so that we can check the resulting chain
type blockPoolTester struct {
    hashPool          *test.TestHashPool
    lock              sync.RWMutex
    reqlock           sync.RWMutex
    blocksRequestsMap map[int]bool
    refBlockChain     blockChain
    blockChain        blockChain
    blockPool         *BlockPool
    t                 *testing.T
    chainEvents       *event.TypeMux
    tds               map[int]int
}

func newTestBlockPool(t *testing.T) (hashPool *test.TestHashPool, blockPool *BlockPool, b *blockPoolTester) {
    hashPool = test.NewHashPool()
    b = &blockPoolTester{
        t:                 t,
        hashPool:          hashPool,
        blockChain:        make(blockChain),
        refBlockChain:     make(blockChain),
        blocksRequestsMap: make(map[int]bool),
        chainEvents:       &event.TypeMux{},
    }
    b.blockPool = New(b.hasBlock, b.insertChain, b.verifyPoW, b.chainEvents, common.Big0)
    blockPool = b.blockPool
    blockPool.Config.BlockHashesRequestInterval = testBlockHashesRequestInterval
    blockPool.Config.BlocksRequestInterval = testBlocksRequestInterval
    return
}

func (self *blockPoolTester) Errorf(format string, params ...interface{}) {
    // fmt.Printf(format+"\n", params...)
    self.t.Errorf(format, params...)
}

// blockPoolTester implements the 3 callbacks needed by the blockPool:
// hasBlock, insetChain, verifyPoW as well as provides the eventer
// to subscribe to head insertions
func (self *blockPoolTester) hasBlock(block common.Hash) (ok bool) {
    self.lock.RLock()
    defer self.lock.RUnlock()
    indexes := self.hashPool.HashesToIndexes([]common.Hash{block})
    i := indexes[0]
    _, ok = self.blockChain[i]
    // fmt.Printf("has block %v (%x...): %v\n", i, block[0:4], ok)
    return
}

// mock insertChain relies on refBlockChain to determine block validity
func (self *blockPoolTester) insertChain(blocks types.Blocks) error {
    self.lock.Lock()
    defer self.lock.Unlock()
    var parent, child int
    var children, refChildren []int
    var ok bool
    for _, block := range blocks {
        child = self.hashPool.HashesToIndexes([]common.Hash{block.Hash()})[0]
        td := child
        if self.tds != nil {
            td, ok = self.tds[child]
        }
        if !ok {
            td = child
        }
        block.Td = big.NewInt(int64(td))
        _, ok = self.blockChain[child]
        if ok {
            // fmt.Printf("block %v already in blockchain\n", child)
            continue // already in chain
        }
        parent = self.hashPool.HashesToIndexes([]common.Hash{block.ParentHeaderHash})[0]
        children, ok = self.blockChain[parent]
        if !ok {
            return fmt.Errorf("parent %v not in blockchain ", parent)
        }
        ok = false
        var found bool
        refChildren, found = self.refBlockChain[parent]
        if found {
            for _, c := range refChildren {
                if c == child {
                    ok = true
                }
            }
            if !ok {
                return fmt.Errorf("invalid block %v", child)
            }
        } else {
            ok = true
        }
        if ok {
            // accept any blocks if parent not in refBlockChain
            self.blockChain[parent] = append(children, child)
            self.blockChain[child] = nil
        }
    }
    return nil
}

// mock soft block validation always succeeds
func (self *blockPoolTester) verifyPoW(pblock pow.Block) bool {
    return true
}

// test helper that compares the resulting blockChain to the desired blockChain
func (self *blockPoolTester) checkBlockChain(blockChain map[int][]int) {
    self.lock.RLock()
    defer self.lock.RUnlock()
    // for k, v := range self.blockChain {
    //  fmt.Printf("got: %v -> %v\n", k, v)
    // }
    // for k, v := range blockChain {
    //  fmt.Printf("expected: %v -> %v\n", k, v)
    // }
    if len(blockChain) != len(self.blockChain) {
        self.Errorf("blockchain incorrect (zlength differ)")
    }
    for k, v := range blockChain {
        vv, ok := self.blockChain[k]
        if !ok || !test.ArrayEq(v, vv) {
            self.Errorf("blockchain incorrect on %v -> %v (!= %v)", k, vv, v)
        }
    }
}

// peerTester provides the peer callbacks for the blockPool
// it registers actual callbacks so that the result can be compared to desired behaviour
// provides helper functions to mock the protocol calls to the blockPool
type peerTester struct {
    // containers to record request and error callbacks
    blockHashesRequests []int
    blocksRequests      [][]int
    blocksRequestsMap   map[int]bool
    peerErrors          []int

    blockPool    *BlockPool
    hashPool     *test.TestHashPool
    lock         sync.RWMutex
    bt           *blockPoolTester
    id           string
    td           int
    currentBlock int
    t            *testing.T
}

// peerTester constructor takes hashPool and blockPool from the blockPoolTester
func (self *blockPoolTester) newPeer(id string, td int, cb int) *peerTester {
    return &peerTester{
        id:                id,
        td:                td,
        currentBlock:      cb,
        hashPool:          self.hashPool,
        blockPool:         self.blockPool,
        t:                 self.t,
        bt:                self,
        blocksRequestsMap: self.blocksRequestsMap,
    }
}

func (self *peerTester) Errorf(format string, params ...interface{}) {
    // fmt.Printf(format+"\n", params...)
    self.t.Errorf(format, params...)
}

// helper to compare actual and expected block requests
func (self *peerTester) checkBlocksRequests(blocksRequests ...[]int) {
    if len(blocksRequests) > len(self.blocksRequests) {
        self.Errorf("blocks requests incorrect (length differ)\ngot %v\nexpected %v", self.blocksRequests, blocksRequests)
    } else {
        for i, rr := range blocksRequests {
            r := self.blocksRequests[i]
            if !test.ArrayEq(r, rr) {
                self.Errorf("blocks requests incorrect\ngot %v\nexpected %v", self.blocksRequests, blocksRequests)
            }
        }
    }
}

// helper to compare actual and expected block hash requests
func (self *peerTester) checkBlockHashesRequests(blocksHashesRequests ...int) {
    rr := blocksHashesRequests
    self.lock.RLock()
    r := self.blockHashesRequests
    self.lock.RUnlock()
    if len(r) != len(rr) {
        self.Errorf("block hashes requests incorrect (length differ)\ngot %v\nexpected %v", r, rr)
    } else {
        if !test.ArrayEq(r, rr) {
            self.Errorf("block hashes requests incorrect\ngot %v\nexpected %v", r, rr)
        }
    }
}

// waiter function used by peer.serveBlocks
// blocking until requests appear
// this mocks proper wire protocol behaviour
// since block requests are sent to any random peers
// block request map is shared between peers
// times out after waitTimeout
func (self *peerTester) waitBlocksRequests(blocksRequest ...int) {
    timeout := time.After(waitTimeout)
    rr := blocksRequest
    for {
        self.lock.RLock()
        r := self.blocksRequestsMap
        // fmt.Printf("[%s] blocks request check %v (%v)\n", self.id, rr, r)
        i := 0
        for i = 0; i < len(rr); i++ {
            _, ok := r[rr[i]]
            if !ok {
                break
            }
        }
        self.lock.RUnlock()

        if i == len(rr) {
            return
        }
        time.Sleep(requestWatchInterval)
        select {
        case <-timeout:
        default:
        }
    }
}

// waiter function used by peer.serveBlockHashes
// blocking until requests appear
// this mocks proper wire protocol behaviour
// times out after a period
func (self *peerTester) waitBlockHashesRequests(blocksHashesRequest int) {
    timeout := time.After(waitTimeout)
    rr := blocksHashesRequest
    for i := 0; ; {
        self.lock.RLock()
        r := self.blockHashesRequests
        self.lock.RUnlock()
        // fmt.Printf("[%s] block hash request check %v (%v)\n", self.id, rr, r)
        for ; i < len(r); i++ {
            if rr == r[i] {
                return
            }
        }
        time.Sleep(requestWatchInterval)
        select {
        case <-timeout:
        default:
        }
    }
}

// mocks a simple blockchain 0 (genesis) ... n (head)
func (self *blockPoolTester) initRefBlockChain(n int) {
    for i := 0; i < n; i++ {
        self.refBlockChain[i] = []int{i + 1}
    }
}

// peerTester functions that mimic protocol calls to the blockpool
//  registers the peer with the blockPool
func (self *peerTester) AddPeer() (best bool) {
    hash := self.hashPool.IndexesToHashes([]int{self.currentBlock})[0]
    best, _ = self.blockPool.AddPeer(big.NewInt(int64(self.td)), hash, self.id, self.requestBlockHashes, self.requestBlocks, self.peerError)
    return
}

// peer sends blockhashes if and when gets a request
func (self *peerTester) serveBlockHashes(indexes ...int) {
    // fmt.Printf("ready to serve block hashes %v\n", indexes)

    self.waitBlockHashesRequests(indexes[0])
    self.sendBlockHashes(indexes...)
}

// peer sends blockhashes not waiting for request
func (self *peerTester) sendBlockHashes(indexes ...int) {
    // fmt.Printf("adding block hashes %v\n", indexes)
    hashes := self.hashPool.IndexesToHashes(indexes)
    i := 1
    next := func() (hash common.Hash, ok bool) {
        if i < len(hashes) {
            hash = hashes[i]
            ok = true
            i++
        }
        return
    }
    self.blockPool.AddBlockHashes(next, self.id)
}

// peer sends blocks if and when there is a request
// (in the shared request store, not necessarily to a specific peer)
func (self *peerTester) serveBlocks(indexes ...int) {
    // fmt.Printf("ready to serve blocks %v\n", indexes[1:])
    self.waitBlocksRequests(indexes[1:]...)
    self.sendBlocks(indexes...)
}

// peer sends blocks not waiting for request
func (self *peerTester) sendBlocks(indexes ...int) {
    // fmt.Printf("adding blocks %v \n", indexes)
    hashes := self.hashPool.IndexesToHashes(indexes)
    for i := 1; i < len(hashes); i++ {
        // fmt.Printf("adding block %v %x\n", indexes[i], hashes[i][:4])
        self.blockPool.AddBlock(&types.Block{HeaderHash: hashes[i], ParentHeaderHash: hashes[i-1]}, self.id)
    }
}

// the 3 mock peer callbacks

// records block hashes requests by the blockPool
// -1 is special: not found (a hash never seen)
func (self *peerTester) requestBlockHashes(hash common.Hash) error {
    indexes := self.hashPool.HashesToIndexes([]common.Hash{hash})
    // fmt.Printf("[%s] block hash request %v %x\n", self.id, indexes[0], hash[:4])
    self.lock.Lock()
    defer self.lock.Unlock()
    self.blockHashesRequests = append(self.blockHashesRequests, indexes[0])
    return nil
}

// records block requests by the blockPool
func (self *peerTester) requestBlocks(hashes []common.Hash) error {
    indexes := self.hashPool.HashesToIndexes(hashes)
    // fmt.Printf("blocks request %v %x...\n", indexes, hashes[0][:4])
    self.bt.reqlock.Lock()
    defer self.bt.reqlock.Unlock()
    self.blocksRequests = append(self.blocksRequests, indexes)
    for _, i := range indexes {
        self.blocksRequestsMap[i] = true
    }
    return nil
}

// records the error codes of all the peerErrors found the blockPool
func (self *peerTester) peerError(err *errs.Error) {
    self.peerErrors = append(self.peerErrors, err.Code)
    if err.Fatal() {
        self.blockPool.RemovePeer(self.id)
    }
}