Golang Chunk.IsEmpty方法代码示例

// SomeChunksP invokes callbacks on every unique chunk reachable from |r| in top-down order. Callbacks are invoked only once for each chunk regardless of how many times the chunk appears.
//
// |stopCb| is invoked for the types.Ref of every chunk. It can return true to stop SomeChunksP from descending any further.
// |chunkCb| is optional, invoked with the chunks.Chunk referenced by |stopCb| if it didn't return true.
func SomeChunksP(r types.Ref, bs types.BatchStore, stopCb SomeChunksStopCallback, chunkCb SomeChunksChunkCallback, concurrency int) {
	rq := newRefQueue()
	wg := sync.WaitGroup{}
	mu := sync.Mutex{}
	visitedRefs := map[hash.Hash]bool{}

	walkChunk := func(r types.Ref) {
		defer wg.Done()

		tr := r.TargetHash()

		mu.Lock()
		visited := visitedRefs[tr]
		visitedRefs[tr] = true
		mu.Unlock()

		if visited || stopCb(r) {
			return
		}

		// Try to avoid the cost of reading |c|. It's only necessary if the caller wants to know about every chunk, or if we need to descend below |c| (ref height > 1).
		var c chunks.Chunk

		if chunkCb != nil || r.Height() > 1 {
			c = bs.Get(tr)
			d.Chk.False(c.IsEmpty())

			if chunkCb != nil {
				chunkCb(r, c)
			}
		}

		if r.Height() == 1 {
			return
		}

		v := types.DecodeValue(c, nil)
		for _, r1 := range v.Chunks() {
			wg.Add(1)
			rq.tail() <- r1
		}
	}

	iter := func() {
		for r := range rq.head() {
			walkChunk(r)
		}
	}

	for i := 0; i < concurrency; i++ {
		go iter()
	}

	wg.Add(1)
	rq.tail() <- r
	wg.Wait()
	rq.close()
}

// DecodeValue decodes a value from a chunk source. It is an error to provide an empty chunk.
func DecodeValue(c chunks.Chunk, vr ValueReader) Value {
	d.Chk.False(c.IsEmpty())
	v := DecodeFromBytes(c.Data(), vr, staticTypeCache)
	if cacher, ok := v.(hashCacher); ok {
		assignHash(cacher, c.Hash())
	}

	return v
}

// DecodeValue decodes a value from a chunk source. It is an error to provide an empty chunk.
func DecodeValue(c chunks.Chunk, vr ValueReader) Value {
	d.Chk.False(c.IsEmpty())
	data := c.Data()
	dec := newValueDecoder(&binaryNomsReader{data, 0}, vr)
	v := dec.readValue()

	if cacher, ok := v.(hashCacher); ok {
		assignHash(cacher, c.Hash())
	}

	return v
}