1 files changed, 55 insertions, 10 deletions
diff --git a/eth/downloader/queue.go b/eth/downloader/queue.go
index a21a44706..1b63a5ffb 100644
--- a/eth/downloader/queue.go
+++ b/eth/downloader/queue.go
@@ -1,6 +1,7 @@
 package downloader
 
 import (
+	"fmt"
 	"math"
 	"sync"
 	"time"
@@ -18,7 +19,9 @@ type queue struct {
 
 	mu       sync.Mutex
 	fetching map[string]*chunk
-	blocks   []*types.Block
+
+	blockOffset int
+	blocks      []*types.Block
 }
 
 func newqueue() *queue {
@@ -34,6 +37,10 @@ func (c *queue) reset() {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
+	c.resetNoTS()
+}
+func (c *queue) resetNoTS() {
+	c.blockOffset = 0
 	c.hashPool.Clear()
 	c.fetchPool.Clear()
 	c.blockHashes.Clear()
@@ -41,6 +48,10 @@ func (c *queue) reset() {
 	c.fetching = make(map[string]*chunk)
 }
 
+func (c *queue) size() int {
+	return c.hashPool.Size() + c.blockHashes.Size() + c.fetchPool.Size()
+}
+
 // reserve a `max` set of hashes for `p` peer.
 func (c *queue) get(p *peer, max int) *chunk {
 	c.mu.Lock()
@@ -89,22 +100,27 @@ func (c *queue) get(p *peer, max int) *chunk {
 }
 
 func (c *queue) has(hash common.Hash) bool {
-	return c.hashPool.Has(hash) || c.fetchPool.Has(hash)
+	return c.hashPool.Has(hash) || c.fetchPool.Has(hash) || c.blockHashes.Has(hash)
 }
 
-func (c *queue) addBlock(id string, block *types.Block) {
+func (c *queue) getBlock(hash common.Hash) *types.Block {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	// when adding a block make sure it doesn't already exist
-	if !c.blockHashes.Has(block.Hash()) {
-		c.hashPool.Remove(block.Hash())
-		c.blocks = append(c.blocks, block)
+	if !c.blockHashes.Has(hash) {
+		return nil
+	}
+
+	for _, block := range c.blocks {
+		if block.Hash() == hash {
+			return block
+		}
 	}
+	return nil
 }
 
 // deliver delivers a chunk to the queue that was requested of the peer
-func (c *queue) deliver(id string, blocks []*types.Block) {
+func (c *queue) deliver(id string, blocks []*types.Block) (err error) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
@@ -119,16 +135,45 @@ func (c *queue) deliver(id string, blocks []*types.Block) {
 			chunk.peer.ignored.Merge(chunk.hashes)
 		}
 
+		// Add the blocks
+		for i, block := range blocks {
+			// See (1) for future limitation
+			n := int(block.NumberU64()) - c.blockOffset
+			if n > len(c.blocks) || n < 0 {
+				// set the error and set the blocks which could be processed
+				// abort the rest of the blocks (FIXME this could be improved)
+				err = fmt.Errorf("received block which overflow (N=%v O=%v)", block.Number(), c.blockOffset)
+				blocks = blocks[:i]
+				break
+			}
+			c.blocks[n] = block
+		}
 		// seperate the blocks and the hashes
 		blockHashes := chunk.fetchedHashes(blocks)
 		// merge block hashes
 		c.blockHashes.Merge(blockHashes)
-		// Add the blocks
-		c.blocks = append(c.blocks, blocks...)
 		// Add back whatever couldn't be delivered
 		c.hashPool.Merge(chunk.hashes)
+		// Remove the hashes from the fetch pool
 		c.fetchPool.Separate(chunk.hashes)
 	}
+
+	return
+}
+
+func (c *queue) alloc(offset, size int) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.blockOffset < offset {
+		c.blockOffset = offset
+	}
+
+	// (1) XXX at some point we could limit allocation to memory and use the disk
+	// to store future blocks.
+	if len(c.blocks) < size {
+		c.blocks = append(c.blocks, make([]*types.Block, size)...)
+	}
 }
 
 // puts puts sets of hashes on to the queue for fetching