// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Code generated by protoc-gen-go_gapic. DO NOT EDIT.

package compute

import (
	"bytes"
	"context"
	"fmt"
	"io/ioutil"
	"math"
	"net/http"
	"net/url"
	"sort"

	gax "github.com/googleapis/gax-go/v2"
	"google.golang.org/api/googleapi"
	"google.golang.org/api/iterator"
	"google.golang.org/api/option"
	"google.golang.org/api/option/internaloption"
	httptransport "google.golang.org/api/transport/http"
	computepb "google.golang.org/genproto/googleapis/cloud/compute/v1"
	"google.golang.org/grpc"
	"google.golang.org/grpc/metadata"
	"google.golang.org/protobuf/encoding/protojson"
	"google.golang.org/protobuf/proto"
)

var newRegionCommitmentsClientHook clientHook

// RegionCommitmentsCallOptions contains the retry settings for each method of RegionCommitmentsClient.
type RegionCommitmentsCallOptions struct {
	AggregatedList []gax.CallOption
	Get            []gax.CallOption
	Insert         []gax.CallOption
	List           []gax.CallOption
	Update         []gax.CallOption
}

// internalRegionCommitmentsClient is an interface that defines the methods availaible from Google Compute Engine API.
type internalRegionCommitmentsClient interface {
	Close() error
	setGoogleClientInfo(...string)
	Connection() *grpc.ClientConn
	AggregatedList(context.Context, *computepb.AggregatedListRegionCommitmentsRequest, ...gax.CallOption) *CommitmentsScopedListPairIterator
	Get(context.Context, *computepb.GetRegionCommitmentRequest, ...gax.CallOption) (*computepb.Commitment, error)
	Insert(context.Context, *computepb.InsertRegionCommitmentRequest, ...gax.CallOption) (*Operation, error)
	List(context.Context, *computepb.ListRegionCommitmentsRequest, ...gax.CallOption) *CommitmentIterator
	Update(context.Context, *computepb.UpdateRegionCommitmentRequest, ...gax.CallOption) (*Operation, error)
}

// RegionCommitmentsClient is a client for interacting with Google Compute Engine API.
// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
//
// The RegionCommitments API.
type RegionCommitmentsClient struct {
	// The internal transport-dependent client.
	internalClient internalRegionCommitmentsClient

	// The call options for this service.
	CallOptions *RegionCommitmentsCallOptions
}

// Wrapper methods routed to the internal client.

// Close closes the connection to the API service. The user should invoke this when
// the client is no longer required.
func (c *RegionCommitmentsClient) Close() error {
	return c.internalClient.Close()
}

// setGoogleClientInfo sets the name and version of the application in
// the `x-goog-api-client` header passed on each request. Intended for
// use by Google-written clients.
func (c *RegionCommitmentsClient) setGoogleClientInfo(keyval ...string) {
	c.internalClient.setGoogleClientInfo(keyval...)
}

// Connection returns a connection to the API service.
//
// Deprecated.
func (c *RegionCommitmentsClient) Connection() *grpc.ClientConn {
	return c.internalClient.Connection()
}

// AggregatedList retrieves an aggregated list of commitments by region.
func (c *RegionCommitmentsClient) AggregatedList(ctx context.Context, req *computepb.AggregatedListRegionCommitmentsRequest, opts ...gax.CallOption) *CommitmentsScopedListPairIterator {
	return c.internalClient.AggregatedList(ctx, req, opts...)
}

// Get returns the specified commitment resource. Gets a list of available commitments by making a list() request.
func (c *RegionCommitmentsClient) Get(ctx context.Context, req *computepb.GetRegionCommitmentRequest, opts ...gax.CallOption) (*computepb.Commitment, error) {
	return c.internalClient.Get(ctx, req, opts...)
}

// Insert creates a commitment in the specified project using the data included in the request.
func (c *RegionCommitmentsClient) Insert(ctx context.Context, req *computepb.InsertRegionCommitmentRequest, opts ...gax.CallOption) (*Operation, error) {
	return c.internalClient.Insert(ctx, req, opts...)
}

// List retrieves a list of commitments contained within the specified region.
func (c *RegionCommitmentsClient) List(ctx context.Context, req *computepb.ListRegionCommitmentsRequest, opts ...gax.CallOption) *CommitmentIterator {
	return c.internalClient.List(ctx, req, opts...)
}

// Update updates the specified commitment with the data included in the request. Update is performed only on selected fields included as part of update-mask. Only the following fields can be modified: auto_renew.
func (c *RegionCommitmentsClient) Update(ctx context.Context, req *computepb.UpdateRegionCommitmentRequest, opts ...gax.CallOption) (*Operation, error) {
	return c.internalClient.Update(ctx, req, opts...)
}

// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
type regionCommitmentsRESTClient struct {
	// The http endpoint to connect to.
	endpoint string

	// The http client.
	httpClient *http.Client

	// operationClient is used to call the operation-specific management service.
	operationClient *RegionOperationsClient

	// The x-goog-* metadata to be sent with each request.
	xGoogMetadata metadata.MD
}

// NewRegionCommitmentsRESTClient creates a new region commitments rest client.
//
// The RegionCommitments API.
func NewRegionCommitmentsRESTClient(ctx context.Context, opts ...option.ClientOption) (*RegionCommitmentsClient, error) {
	clientOpts := append(defaultRegionCommitmentsRESTClientOptions(), opts...)
	httpClient, endpoint, err := httptransport.NewClient(ctx, clientOpts...)
	if err != nil {
		return nil, err
	}

	c := &regionCommitmentsRESTClient{
		endpoint:   endpoint,
		httpClient: httpClient,
	}
	c.setGoogleClientInfo()

	o := []option.ClientOption{
		option.WithHTTPClient(httpClient),
		option.WithEndpoint(endpoint),
	}
	opC, err := NewRegionOperationsRESTClient(ctx, o...)
	if err != nil {
		return nil, err
	}
	c.operationClient = opC

	return &RegionCommitmentsClient{internalClient: c, CallOptions: &RegionCommitmentsCallOptions{}}, nil
}

func defaultRegionCommitmentsRESTClientOptions() []option.ClientOption {
	return []option.ClientOption{
		internaloption.WithDefaultEndpoint("https://compute.googleapis.com"),
		internaloption.WithDefaultMTLSEndpoint("https://compute.mtls.googleapis.com"),
		internaloption.WithDefaultAudience("https://compute.googleapis.com/"),
		internaloption.WithDefaultScopes(DefaultAuthScopes()...),
	}
}

// setGoogleClientInfo sets the name and version of the application in
// the `x-goog-api-client` header passed on each request. Intended for
// use by Google-written clients.
func (c *regionCommitmentsRESTClient) setGoogleClientInfo(keyval ...string) {
	kv := append([]string{"gl-go", versionGo()}, keyval...)
	kv = append(kv, "gapic", getVersionClient(), "gax", gax.Version, "rest", "UNKNOWN")
	c.xGoogMetadata = metadata.Pairs("x-goog-api-client", gax.XGoogHeader(kv...))
}

// Close closes the connection to the API service. The user should invoke this when
// the client is no longer required.
func (c *regionCommitmentsRESTClient) Close() error {
	// Replace httpClient with nil to force cleanup.
	c.httpClient = nil
	if err := c.operationClient.Close(); err != nil {
		return err
	}
	return nil
}

// Connection returns a connection to the API service.
//
// Deprecated.
func (c *regionCommitmentsRESTClient) Connection() *grpc.ClientConn {
	return nil
}

// AggregatedList retrieves an aggregated list of commitments by region.
func (c *regionCommitmentsRESTClient) AggregatedList(ctx context.Context, req *computepb.AggregatedListRegionCommitmentsRequest, opts ...gax.CallOption) *CommitmentsScopedListPairIterator {
	it := &CommitmentsScopedListPairIterator{}
	req = proto.Clone(req).(*computepb.AggregatedListRegionCommitmentsRequest)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	it.InternalFetch = func(pageSize int, pageToken string) ([]CommitmentsScopedListPair, string, error) {
		resp := &computepb.CommitmentAggregatedList{}
		if pageToken != "" {
			req.PageToken = proto.String(pageToken)
		}
		if pageSize > math.MaxInt32 {
			req.MaxResults = proto.Uint32(math.MaxInt32)
		} else if pageSize != 0 {
			req.MaxResults = proto.Uint32(uint32(pageSize))
		}
		baseUrl, _ := url.Parse(c.endpoint)
		baseUrl.Path += fmt.Sprintf("/compute/v1/projects/%v/aggregated/commitments", req.GetProject())

		params := url.Values{}
		if req != nil && req.Filter != nil {
			params.Add("filter", fmt.Sprintf("%v", req.GetFilter()))
		}
		if req != nil && req.IncludeAllScopes != nil {
			params.Add("includeAllScopes", fmt.Sprintf("%v", req.GetIncludeAllScopes()))
		}
		if req != nil && req.MaxResults != nil {
			params.Add("maxResults", fmt.Sprintf("%v", req.GetMaxResults()))
		}
		if req != nil && req.OrderBy != nil {
			params.Add("orderBy", fmt.Sprintf("%v", req.GetOrderBy()))
		}
		if req != nil && req.PageToken != nil {
			params.Add("pageToken", fmt.Sprintf("%v", req.GetPageToken()))
		}
		if req != nil && req.ReturnPartialSuccess != nil {
			params.Add("returnPartialSuccess", fmt.Sprintf("%v", req.GetReturnPartialSuccess()))
		}

		baseUrl.RawQuery = params.Encode()

		// Build HTTP headers from client and context metadata.
		headers := buildHeaders(ctx, c.xGoogMetadata, metadata.Pairs("Content-Type", "application/json"))
		e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
			httpReq, err := http.NewRequest("GET", baseUrl.String(), nil)
			if err != nil {
				return err
			}
			httpReq.Header = headers

			httpRsp, err := c.httpClient.Do(httpReq)
			if err != nil {
				return err
			}
			defer httpRsp.Body.Close()

			if err = googleapi.CheckResponse(httpRsp); err != nil {
				return err
			}

			buf, err := ioutil.ReadAll(httpRsp.Body)
			if err != nil {
				return err
			}

			if err := unm.Unmarshal(buf, resp); err != nil {
				return maybeUnknownEnum(err)
			}

			return nil
		}, opts...)
		if e != nil {
			return nil, "", e
		}
		it.Response = resp

		elems := make([]CommitmentsScopedListPair, 0, len(resp.GetItems()))
		for k, v := range resp.GetItems() {
			elems = append(elems, CommitmentsScopedListPair{k, v})
		}
		sort.Slice(elems, func(i, j int) bool { return elems[i].Key < elems[j].Key })

		return elems, resp.GetNextPageToken(), nil
	}

	fetch := func(pageSize int, pageToken string) (string, error) {
		items, nextPageToken, err := it.InternalFetch(pageSize, pageToken)
		if err != nil {
			return "", err
		}
		it.items = append(it.items, items...)
		return nextPageToken, nil
	}

	it.pageInfo, it.nextFunc = iterator.NewPageInfo(fetch, it.bufLen, it.takeBuf)
	it.pageInfo.MaxSize = int(req.GetMaxResults())
	it.pageInfo.Token = req.GetPageToken()

	return it
}

// Get returns the specified commitment resource. Gets a list of available commitments by making a list() request.
func (c *regionCommitmentsRESTClient) Get(ctx context.Context, req *computepb.GetRegionCommitmentRequest, opts ...gax.CallOption) (*computepb.Commitment, error) {
	baseUrl, _ := url.Parse(c.endpoint)
	baseUrl.Path += fmt.Sprintf("/compute/v1/projects/%v/regions/%v/commitments/%v", req.GetProject(), req.GetRegion(), req.GetCommitment())

	// Build HTTP headers from client and context metadata.
	headers := buildHeaders(ctx, c.xGoogMetadata, metadata.Pairs("Content-Type", "application/json"))
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &computepb.Commitment{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		httpReq, err := http.NewRequest("GET", baseUrl.String(), nil)
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		httpRsp, err := c.httpClient.Do(httpReq)
		if err != nil {
			return err
		}
		defer httpRsp.Body.Close()

		if err = googleapi.CheckResponse(httpRsp); err != nil {
			return err
		}

		buf, err := ioutil.ReadAll(httpRsp.Body)
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return maybeUnknownEnum(err)
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	return resp, nil
}

// Insert creates a commitment in the specified project using the data included in the request.
func (c *regionCommitmentsRESTClient) Insert(ctx context.Context, req *computepb.InsertRegionCommitmentRequest, opts ...gax.CallOption) (*Operation, error) {
	m := protojson.MarshalOptions{AllowPartial: true}
	body := req.GetCommitmentResource()
	jsonReq, err := m.Marshal(body)
	if err != nil {
		return nil, err
	}

	baseUrl, _ := url.Parse(c.endpoint)
	baseUrl.Path += fmt.Sprintf("/compute/v1/projects/%v/regions/%v/commitments", req.GetProject(), req.GetRegion())

	params := url.Values{}
	if req != nil && req.RequestId != nil {
		params.Add("requestId", fmt.Sprintf("%v", req.GetRequestId()))
	}

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	headers := buildHeaders(ctx, c.xGoogMetadata, metadata.Pairs("Content-Type", "application/json"))
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &computepb.Operation{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		httpReq, err := http.NewRequest("POST", baseUrl.String(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		httpRsp, err := c.httpClient.Do(httpReq)
		if err != nil {
			return err
		}
		defer httpRsp.Body.Close()

		if err = googleapi.CheckResponse(httpRsp); err != nil {
			return err
		}

		buf, err := ioutil.ReadAll(httpRsp.Body)
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return maybeUnknownEnum(err)
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	op := &Operation{
		&regionOperationsHandle{
			c:       c.operationClient,
			proto:   resp,
			project: req.GetProject(),
			region:  req.GetRegion(),
		},
	}
	return op, nil
}

// List retrieves a list of commitments contained within the specified region.
func (c *regionCommitmentsRESTClient) List(ctx context.Context, req *computepb.ListRegionCommitmentsRequest, opts ...gax.CallOption) *CommitmentIterator {
	it := &CommitmentIterator{}
	req = proto.Clone(req).(*computepb.ListRegionCommitmentsRequest)
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	it.InternalFetch = func(pageSize int, pageToken string) ([]*computepb.Commitment, string, error) {
		resp := &computepb.CommitmentList{}
		if pageToken != "" {
			req.PageToken = proto.String(pageToken)
		}
		if pageSize > math.MaxInt32 {
			req.MaxResults = proto.Uint32(math.MaxInt32)
		} else if pageSize != 0 {
			req.MaxResults = proto.Uint32(uint32(pageSize))
		}
		baseUrl, _ := url.Parse(c.endpoint)
		baseUrl.Path += fmt.Sprintf("/compute/v1/projects/%v/regions/%v/commitments", req.GetProject(), req.GetRegion())

		params := url.Values{}
		if req != nil && req.Filter != nil {
			params.Add("filter", fmt.Sprintf("%v", req.GetFilter()))
		}
		if req != nil && req.MaxResults != nil {
			params.Add("maxResults", fmt.Sprintf("%v", req.GetMaxResults()))
		}
		if req != nil && req.OrderBy != nil {
			params.Add("orderBy", fmt.Sprintf("%v", req.GetOrderBy()))
		}
		if req != nil && req.PageToken != nil {
			params.Add("pageToken", fmt.Sprintf("%v", req.GetPageToken()))
		}
		if req != nil && req.ReturnPartialSuccess != nil {
			params.Add("returnPartialSuccess", fmt.Sprintf("%v", req.GetReturnPartialSuccess()))
		}

		baseUrl.RawQuery = params.Encode()

		// Build HTTP headers from client and context metadata.
		headers := buildHeaders(ctx, c.xGoogMetadata, metadata.Pairs("Content-Type", "application/json"))
		e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
			httpReq, err := http.NewRequest("GET", baseUrl.String(), nil)
			if err != nil {
				return err
			}
			httpReq.Header = headers

			httpRsp, err := c.httpClient.Do(httpReq)
			if err != nil {
				return err
			}
			defer httpRsp.Body.Close()

			if err = googleapi.CheckResponse(httpRsp); err != nil {
				return err
			}

			buf, err := ioutil.ReadAll(httpRsp.Body)
			if err != nil {
				return err
			}

			if err := unm.Unmarshal(buf, resp); err != nil {
				return maybeUnknownEnum(err)
			}

			return nil
		}, opts...)
		if e != nil {
			return nil, "", e
		}
		it.Response = resp
		return resp.GetItems(), resp.GetNextPageToken(), nil
	}

	fetch := func(pageSize int, pageToken string) (string, error) {
		items, nextPageToken, err := it.InternalFetch(pageSize, pageToken)
		if err != nil {
			return "", err
		}
		it.items = append(it.items, items...)
		return nextPageToken, nil
	}

	it.pageInfo, it.nextFunc = iterator.NewPageInfo(fetch, it.bufLen, it.takeBuf)
	it.pageInfo.MaxSize = int(req.GetMaxResults())
	it.pageInfo.Token = req.GetPageToken()

	return it
}

// Update updates the specified commitment with the data included in the request. Update is performed only on selected fields included as part of update-mask. Only the following fields can be modified: auto_renew.
func (c *regionCommitmentsRESTClient) Update(ctx context.Context, req *computepb.UpdateRegionCommitmentRequest, opts ...gax.CallOption) (*Operation, error) {
	m := protojson.MarshalOptions{AllowPartial: true}
	body := req.GetCommitmentResource()
	jsonReq, err := m.Marshal(body)
	if err != nil {
		return nil, err
	}

	baseUrl, _ := url.Parse(c.endpoint)
	baseUrl.Path += fmt.Sprintf("/compute/v1/projects/%v/regions/%v/commitments/%v", req.GetProject(), req.GetRegion(), req.GetCommitment())

	params := url.Values{}
	if req != nil && req.Paths != nil {
		params.Add("paths", fmt.Sprintf("%v", req.GetPaths()))
	}
	if req != nil && req.RequestId != nil {
		params.Add("requestId", fmt.Sprintf("%v", req.GetRequestId()))
	}
	if req != nil && req.UpdateMask != nil {
		params.Add("updateMask", fmt.Sprintf("%v", req.GetUpdateMask()))
	}

	baseUrl.RawQuery = params.Encode()

	// Build HTTP headers from client and context metadata.
	headers := buildHeaders(ctx, c.xGoogMetadata, metadata.Pairs("Content-Type", "application/json"))
	unm := protojson.UnmarshalOptions{AllowPartial: true, DiscardUnknown: true}
	resp := &computepb.Operation{}
	e := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
		httpReq, err := http.NewRequest("PATCH", baseUrl.String(), bytes.NewReader(jsonReq))
		if err != nil {
			return err
		}
		httpReq = httpReq.WithContext(ctx)
		httpReq.Header = headers

		httpRsp, err := c.httpClient.Do(httpReq)
		if err != nil {
			return err
		}
		defer httpRsp.Body.Close()

		if err = googleapi.CheckResponse(httpRsp); err != nil {
			return err
		}

		buf, err := ioutil.ReadAll(httpRsp.Body)
		if err != nil {
			return err
		}

		if err := unm.Unmarshal(buf, resp); err != nil {
			return maybeUnknownEnum(err)
		}

		return nil
	}, opts...)
	if e != nil {
		return nil, e
	}
	op := &Operation{
		&regionOperationsHandle{
			c:       c.operationClient,
			proto:   resp,
			project: req.GetProject(),
			region:  req.GetRegion(),
		},
	}
	return op, nil
}

// CommitmentIterator manages a stream of *computepb.Commitment.
type CommitmentIterator struct {
	items    []*computepb.Commitment
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*computepb.Commitment, nextPageToken string, err error)
}

// PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
func (it *CommitmentIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *CommitmentIterator) Next() (*computepb.Commitment, error) {
	var item *computepb.Commitment
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *CommitmentIterator) bufLen() int {
	return len(it.items)
}

func (it *CommitmentIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}

// CommitmentsScopedListPair is a holder type for string/*computepb.CommitmentsScopedList map entries
type CommitmentsScopedListPair struct {
	Key   string
	Value *computepb.CommitmentsScopedList
}

// CommitmentsScopedListPairIterator manages a stream of CommitmentsScopedListPair.
type CommitmentsScopedListPairIterator struct {
	items    []CommitmentsScopedListPair
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// Response is the raw response for the current page.
	// It must be cast to the RPC response type.
	// Calling Next() or InternalFetch() updates this value.
	Response interface{}

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []CommitmentsScopedListPair, nextPageToken string, err error)
}

// PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
func (it *CommitmentsScopedListPairIterator) PageInfo() *iterator.PageInfo {
	return it.pageInfo
}

// Next returns the next result. Its second return value is iterator.Done if there are no more
// results. Once Next returns Done, all subsequent calls will return Done.
func (it *CommitmentsScopedListPairIterator) Next() (CommitmentsScopedListPair, error) {
	var item CommitmentsScopedListPair
	if err := it.nextFunc(); err != nil {
		return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
}

func (it *CommitmentsScopedListPairIterator) bufLen() int {
	return len(it.items)
}

func (it *CommitmentsScopedListPairIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
}