Golang meta.GetItemsPtr函数代码示例

// List implements storage.Interface.List.
func (s *store) List(ctx context.Context, key, resourceVersion string, pred storage.SelectionPredicate, listObj runtime.Object) error {
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	key = keyWithPrefix(s.pathPrefix, key)
	// We need to make sure the key ended with "/" so that we only get children "directories".
	// e.g. if we have key "/a", "/a/b", "/ab", getting keys with prefix "/a" will return all three,
	// while with prefix "/a/" will return only "/a/b" which is the correct answer.
	if !strings.HasSuffix(key, "/") {
		key += "/"
	}
	getResp, err := s.client.KV.Get(ctx, key, clientv3.WithPrefix())
	if err != nil {
		return err
	}

	elems := make([]*elemForDecode, len(getResp.Kvs))
	for i, kv := range getResp.Kvs {
		elems[i] = &elemForDecode{
			data: kv.Value,
			rev:  uint64(kv.ModRevision),
		}
	}
	if err := decodeList(elems, storage.SimpleFilter(pred), listPtr, s.codec, s.versioner); err != nil {
		return err
	}
	// update version with cluster level revision
	return s.versioner.UpdateList(listObj, uint64(getResp.Header.Revision))
}

// Implements storage.Interface.
func (h *etcdHelper) List(ctx context.Context, key string, resourceVersion string, filter storage.FilterFunc, listObj runtime.Object) error {
	if ctx == nil {
		glog.Errorf("Context is nil")
	}
	trace := util.NewTrace("List " + getTypeName(listObj))
	defer trace.LogIfLong(time.Second)
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	key = h.prefixEtcdKey(key)
	startTime := time.Now()
	trace.Step("About to list etcd node")
	nodes, index, err := h.listEtcdNode(ctx, key)
	metrics.RecordEtcdRequestLatency("list", getTypeName(listPtr), startTime)
	trace.Step("Etcd node listed")
	if err != nil {
		return err
	}
	if err := h.decodeNodeList(nodes, filter, listPtr); err != nil {
		return err
	}
	trace.Step("Node list decoded")
	if err := h.versioner.UpdateList(listObj, index); err != nil {
		return err
	}
	return nil
}

// Implements storage.Interface.
func (c *Cacher) List(ctx context.Context, key string, resourceVersion string, pred SelectionPredicate, listObj runtime.Object) error {
	if resourceVersion == "" {
		// If resourceVersion is not specified, serve it from underlying
		// storage (for backward compatibility).
		return c.storage.List(ctx, key, resourceVersion, pred, listObj)
	}

	// If resourceVersion is specified, serve it from cache.
	// It's guaranteed that the returned value is at least that
	// fresh as the given resourceVersion.
	listRV, err := ParseListResourceVersion(resourceVersion)
	if err != nil {
		return err
	}

	trace := util.NewTrace(fmt.Sprintf("cacher %v: List", c.objectType.String()))
	defer trace.LogIfLong(500 * time.Millisecond)

	c.ready.wait()
	trace.Step("Ready")

	// List elements with at least 'listRV' from cache.
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	listVal, err := conversion.EnforcePtr(listPtr)
	if err != nil || listVal.Kind() != reflect.Slice {
		return fmt.Errorf("need a pointer to slice, got %v", listVal.Kind())
	}
	filter := filterFunction(key, pred)

	objs, readResourceVersion, err := c.watchCache.WaitUntilFreshAndList(listRV, trace)
	if err != nil {
		return fmt.Errorf("failed to wait for fresh list: %v", err)
	}
	trace.Step(fmt.Sprintf("Listed %d items from cache", len(objs)))
	if len(objs) > listVal.Cap() && pred.Label.Empty() && pred.Field.Empty() {
		// Resize the slice appropriately, since we already know that none
		// of the elements will be filtered out.
		listVal.Set(reflect.MakeSlice(reflect.SliceOf(c.objectType.Elem()), 0, len(objs)))
		trace.Step("Resized result")
	}
	for _, obj := range objs {
		elem, ok := obj.(*storeElement)
		if !ok {
			return fmt.Errorf("non *storeElement returned from storage: %v", obj)
		}
		if filter(elem.Key, elem.Object) {
			listVal.Set(reflect.Append(listVal, reflect.ValueOf(elem.Object).Elem()))
		}
	}
	trace.Step(fmt.Sprintf("Filtered %d items", listVal.Len()))
	if c.versioner != nil {
		if err := c.versioner.UpdateList(listObj, readResourceVersion); err != nil {
			return err
		}
	}
	return nil
}

// Implements storage.Interface.
func (c *Cacher) List(ctx context.Context, key string, resourceVersion string, filter FilterFunc, listObj runtime.Object) error {
	if resourceVersion == "" {
		// If resourceVersion is not specified, serve it from underlying
		// storage (for backward compatibility).
		return c.storage.List(ctx, key, resourceVersion, filter, listObj)
	}

	// If resourceVersion is specified, serve it from cache.
	// It's guaranteed that the returned value is at least that
	// fresh as the given resourceVersion.

	listRV, err := ParseListResourceVersion(resourceVersion)
	if err != nil {
		return err
	}

	// To avoid situation when List is processed before the underlying
	// watchCache is propagated for the first time, we acquire and immediately
	// release the 'usable' lock.
	// We don't need to hold it all the time, because watchCache is thread-safe
	// and it would complicate already very difficult locking pattern.
	c.usable.RLock()
	c.usable.RUnlock()

	// List elements from cache, with at least 'listRV'.
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	listVal, err := conversion.EnforcePtr(listPtr)
	if err != nil || listVal.Kind() != reflect.Slice {
		return fmt.Errorf("need a pointer to slice, got %v", listVal.Kind())
	}
	filterFunc := filterFunction(key, c.keyFunc, filter)

	objs, readResourceVersion, err := c.watchCache.WaitUntilFreshAndList(listRV)
	if err != nil {
		return fmt.Errorf("failed to wait for fresh list: %v", err)
	}
	for _, obj := range objs {
		object, ok := obj.(runtime.Object)
		if !ok {
			return fmt.Errorf("non runtime.Object returned from storage: %v", obj)
		}
		if filterFunc(object) {
			listVal.Set(reflect.Append(listVal, reflect.ValueOf(object).Elem()))
		}
	}
	if c.versioner != nil {
		if err := c.versioner.UpdateList(listObj, readResourceVersion); err != nil {
			return err
		}
	}
	return nil
}

// Implements storage.Interface.
func (c *Cacher) GetToList(ctx context.Context, key string, resourceVersion string, pred SelectionPredicate, listObj runtime.Object) error {
	if resourceVersion == "" {
		// If resourceVersion is not specified, serve it from underlying
		// storage (for backward compatibility).
		return c.storage.GetToList(ctx, key, resourceVersion, pred, listObj)
	}

	// If resourceVersion is specified, serve it from cache.
	// It's guaranteed that the returned value is at least that
	// fresh as the given resourceVersion.
	listRV, err := ParseListResourceVersion(resourceVersion)
	if err != nil {
		return err
	}

	trace := util.NewTrace(fmt.Sprintf("cacher %v: List", c.objectType.String()))
	defer trace.LogIfLong(500 * time.Millisecond)

	c.ready.wait()
	trace.Step("Ready")

	// List elements with at least 'listRV' from cache.
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	listVal, err := conversion.EnforcePtr(listPtr)
	if err != nil || listVal.Kind() != reflect.Slice {
		return fmt.Errorf("need a pointer to slice, got %v", listVal.Kind())
	}
	filter := filterFunction(key, pred)

	obj, exists, readResourceVersion, err := c.watchCache.WaitUntilFreshAndGet(listRV, key, trace)
	if err != nil {
		return fmt.Errorf("failed to wait for fresh get: %v", err)
	}
	trace.Step("Got from cache")

	if exists {
		elem, ok := obj.(*storeElement)
		if !ok {
			return fmt.Errorf("non *storeElement returned from storage: %v", obj)
		}
		if filter(elem.Key, elem.Object) {
			listVal.Set(reflect.Append(listVal, reflect.ValueOf(elem.Object).Elem()))
		}
	}
	if c.versioner != nil {
		if err := c.versioner.UpdateList(listObj, readResourceVersion); err != nil {
			return err
		}
	}
	return nil
}

// Implements storage.Interface.
func (c *Cacher) List(ctx context.Context, key string, resourceVersion string, filter Filter, listObj runtime.Object) error {
	if resourceVersion == "" {
		// If resourceVersion is not specified, serve it from underlying
		// storage (for backward compatibility).
		return c.storage.List(ctx, key, resourceVersion, filter, listObj)
	}

	// If resourceVersion is specified, serve it from cache.
	// It's guaranteed that the returned value is at least that
	// fresh as the given resourceVersion.

	listRV, err := ParseListResourceVersion(resourceVersion)
	if err != nil {
		return err
	}

	c.ready.wait()

	// List elements from cache, with at least 'listRV'.
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	listVal, err := conversion.EnforcePtr(listPtr)
	if err != nil || listVal.Kind() != reflect.Slice {
		return fmt.Errorf("need a pointer to slice, got %v", listVal.Kind())
	}
	filterFunc := filterFunction(key, c.keyFunc, filter)

	objs, readResourceVersion, err := c.watchCache.WaitUntilFreshAndList(listRV)
	if err != nil {
		return fmt.Errorf("failed to wait for fresh list: %v", err)
	}
	for _, obj := range objs {
		object, ok := obj.(runtime.Object)
		if !ok {
			return fmt.Errorf("non runtime.Object returned from storage: %v", obj)
		}
		if filterFunc.Filter(object) {
			listVal.Set(reflect.Append(listVal, reflect.ValueOf(object).Elem()))
		}
	}
	if c.versioner != nil {
		if err := c.versioner.UpdateList(listObj, readResourceVersion); err != nil {
			return err
		}
	}
	return nil
}

// Implements storage.Interface.
func (h *etcdHelper) GetToList(ctx context.Context, key string, filter storage.FilterFunc, listObj runtime.Object) error {
	if ctx == nil {
		glog.Errorf("Context is nil")
	}
	trace := util.NewTrace("GetToList " + getTypeName(listObj))
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	key = h.prefixEtcdKey(key)
	startTime := time.Now()
	trace.Step("About to read etcd node")

	opts := &etcd.GetOptions{
		Quorum: h.quorum,
	}
	response, err := h.client.Get(ctx, key, opts)

	metrics.RecordEtcdRequestLatency("get", getTypeName(listPtr), startTime)
	trace.Step("Etcd node read")
	if err != nil {
		if etcdutil.IsEtcdNotFound(err) {
			return nil
		}
		return err
	}

	nodes := make([]*etcd.Node, 0)
	nodes = append(nodes, response.Node)

	if err := h.decodeNodeList(nodes, filter, listPtr); err != nil {
		return err
	}
	trace.Step("Object decoded")
	if h.versioner != nil {
		if err := h.versioner.UpdateList(listObj, response.Index); err != nil {
			return err
		}
	}
	return nil
}

// Implements storage.Interface.
func (c *Cacher) List(ctx context.Context, key string, resourceVersion uint64, filter FilterFunc, listObj runtime.Object) error {
	if !c.ListFromCache {
		return c.storage.List(ctx, key, resourceVersion, filter, listObj)
	}

	// To avoid situation when List is proceesed before the underlying
	// watchCache is propagated for the first time, we acquire and immediately
	// release the 'usable' lock.
	// We don't need to hold it all the time, because watchCache is thread-safe
	// and it would complicate already very difficult locking pattern.
	c.usable.RLock()
	c.usable.RUnlock()

	// List elements from cache, with at least 'resourceVersion'.
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	listVal, err := conversion.EnforcePtr(listPtr)
	if err != nil || listVal.Kind() != reflect.Slice {
		return fmt.Errorf("need a pointer to slice, got %v", listVal.Kind())
	}
	filterFunc := filterFunction(key, c.keyFunc, filter)

	objs, resourceVersion := c.watchCache.WaitUntilFreshAndList(resourceVersion)
	for _, obj := range objs {
		object, ok := obj.(runtime.Object)
		if !ok {
			return fmt.Errorf("non runtime.Object returned from storage: %v", obj)
		}
		if filterFunc(object) {
			listVal.Set(reflect.Append(listVal, reflect.ValueOf(object).Elem()))
		}
	}
	if c.versioner != nil {
		if err := c.versioner.UpdateList(listObj, resourceVersion); err != nil {
			return err
		}
	}
	return nil
}

// GetToList implements storage.Interface.GetToList.
func (s *store) GetToList(ctx context.Context, key string, resourceVersion string, pred storage.SelectionPredicate, listObj runtime.Object) error {
	listPtr, err := meta.GetItemsPtr(listObj)
	if err != nil {
		return err
	}
	key = keyWithPrefix(s.pathPrefix, key)

	getResp, err := s.client.KV.Get(ctx, key, s.getOps...)
	if err != nil {
		return err
	}
	if len(getResp.Kvs) == 0 {
		return nil
	}
	elems := []*elemForDecode{{
		data: getResp.Kvs[0].Value,
		rev:  uint64(getResp.Kvs[0].ModRevision),
	}}
	if err := decodeList(elems, storage.SimpleFilter(pred), listPtr, s.codec, s.versioner); err != nil {
		return err
	}
	// update version with cluster level revision
	return s.versioner.UpdateList(listObj, uint64(getResp.Header.Revision))
}