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nginx-sso/vendor/cloud.google.com/go/spanner/apiv1/spanner_client.go

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// Copyright 2019 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 gapic-generator. DO NOT EDIT.
package spanner
import (
"context"
"fmt"
"math"
"time"
"github.com/golang/protobuf/proto"
gax "github.com/googleapis/gax-go/v2"
"google.golang.org/api/iterator"
"google.golang.org/api/option"
"google.golang.org/api/transport"
spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/metadata"
)
// CallOptions contains the retry settings for each method of Client.
type CallOptions struct {
CreateSession []gax.CallOption
GetSession []gax.CallOption
ListSessions []gax.CallOption
DeleteSession []gax.CallOption
ExecuteSql []gax.CallOption
ExecuteStreamingSql []gax.CallOption
ExecuteBatchDml []gax.CallOption
Read []gax.CallOption
StreamingRead []gax.CallOption
BeginTransaction []gax.CallOption
Commit []gax.CallOption
Rollback []gax.CallOption
PartitionQuery []gax.CallOption
PartitionRead []gax.CallOption
}
func defaultClientOptions() []option.ClientOption {
return []option.ClientOption{
option.WithEndpoint("spanner.googleapis.com:443"),
option.WithScopes(DefaultAuthScopes()...),
}
}
func defaultCallOptions() *CallOptions {
retry := map[[2]string][]gax.CallOption{
{"default", "idempotent"}: {
gax.WithRetry(func() gax.Retryer {
return gax.OnCodes([]codes.Code{
codes.DeadlineExceeded,
codes.Unavailable,
}, gax.Backoff{
Initial: 1000 * time.Millisecond,
Max: 32000 * time.Millisecond,
Multiplier: 1.3,
})
}),
},
{"long_running", "long_running"}: {
gax.WithRetry(func() gax.Retryer {
return gax.OnCodes([]codes.Code{
codes.Unavailable,
}, gax.Backoff{
Initial: 1000 * time.Millisecond,
Max: 32000 * time.Millisecond,
Multiplier: 1.3,
})
}),
},
}
return &CallOptions{
CreateSession: retry[[2]string{"default", "idempotent"}],
GetSession: retry[[2]string{"default", "idempotent"}],
ListSessions: retry[[2]string{"default", "idempotent"}],
DeleteSession: retry[[2]string{"default", "idempotent"}],
ExecuteSql: retry[[2]string{"default", "idempotent"}],
ExecuteStreamingSql: retry[[2]string{"streaming", "non_idempotent"}],
ExecuteBatchDml: retry[[2]string{"default", "idempotent"}],
Read: retry[[2]string{"default", "idempotent"}],
StreamingRead: retry[[2]string{"streaming", "non_idempotent"}],
BeginTransaction: retry[[2]string{"default", "idempotent"}],
Commit: retry[[2]string{"long_running", "long_running"}],
Rollback: retry[[2]string{"default", "idempotent"}],
PartitionQuery: retry[[2]string{"default", "idempotent"}],
PartitionRead: retry[[2]string{"default", "idempotent"}],
}
}
// Client is a client for interacting with Cloud Spanner API.
//
// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
type Client struct {
// The connection to the service.
conn *grpc.ClientConn
// The gRPC API client.
client spannerpb.SpannerClient
// The call options for this service.
CallOptions *CallOptions
// The x-goog-* metadata to be sent with each request.
xGoogMetadata metadata.MD
}
// NewClient creates a new spanner client.
//
// Cloud Spanner API
//
// The Cloud Spanner API can be used to manage sessions and execute
// transactions on data stored in Cloud Spanner databases.
func NewClient(ctx context.Context, opts ...option.ClientOption) (*Client, error) {
conn, err := transport.DialGRPC(ctx, append(defaultClientOptions(), opts...)...)
if err != nil {
return nil, err
}
c := &Client{
conn: conn,
CallOptions: defaultCallOptions(),
client: spannerpb.NewSpannerClient(conn),
}
c.SetGoogleClientInfo()
return c, nil
}
// Connection returns the client's connection to the API service.
func (c *Client) Connection() *grpc.ClientConn {
return c.conn
}
// Close closes the connection to the API service. The user should invoke this when
// the client is no longer required.
func (c *Client) Close() error {
return c.conn.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 *Client) SetGoogleClientInfo(keyval ...string) {
kv := append([]string{"gl-go", versionGo()}, keyval...)
kv = append(kv, "gapic", versionClient, "gax", gax.Version, "grpc", grpc.Version)
c.xGoogMetadata = metadata.Pairs("x-goog-api-client", gax.XGoogHeader(kv...))
}
// CreateSession creates a new session. A session can be used to perform
// transactions that read and/or modify data in a Cloud Spanner database.
// Sessions are meant to be reused for many consecutive
// transactions.
//
// Sessions can only execute one transaction at a time. To execute
// multiple concurrent read-write/write-only transactions, create
// multiple sessions. Note that standalone reads and queries use a
// transaction internally, and count toward the one transaction
// limit.
//
// Cloud Spanner limits the number of sessions that can exist at any given
// time; thus, it is a good idea to delete idle and/or unneeded sessions.
// Aside from explicit deletes, Cloud Spanner can delete sessions for which no
// operations are sent for more than an hour. If a session is deleted,
// requests to it return NOT_FOUND.
//
// Idle sessions can be kept alive by sending a trivial SQL query
// periodically, e.g., "SELECT 1".
func (c *Client) CreateSession(ctx context.Context, req *spannerpb.CreateSessionRequest, opts ...gax.CallOption) (*spannerpb.Session, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "database", req.GetDatabase()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.CreateSession[0:len(c.CallOptions.CreateSession):len(c.CallOptions.CreateSession)], opts...)
var resp *spannerpb.Session
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.CreateSession(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// GetSession gets a session. Returns NOT_FOUND if the session does not exist.
// This is mainly useful for determining whether a session is still
// alive.
func (c *Client) GetSession(ctx context.Context, req *spannerpb.GetSessionRequest, opts ...gax.CallOption) (*spannerpb.Session, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "name", req.GetName()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.GetSession[0:len(c.CallOptions.GetSession):len(c.CallOptions.GetSession)], opts...)
var resp *spannerpb.Session
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.GetSession(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// ListSessions lists all sessions in a given database.
func (c *Client) ListSessions(ctx context.Context, req *spannerpb.ListSessionsRequest, opts ...gax.CallOption) *SessionIterator {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "database", req.GetDatabase()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.ListSessions[0:len(c.CallOptions.ListSessions):len(c.CallOptions.ListSessions)], opts...)
it := &SessionIterator{}
req = proto.Clone(req).(*spannerpb.ListSessionsRequest)
it.InternalFetch = func(pageSize int, pageToken string) ([]*spannerpb.Session, string, error) {
var resp *spannerpb.ListSessionsResponse
req.PageToken = pageToken
if pageSize > math.MaxInt32 {
req.PageSize = math.MaxInt32
} else {
req.PageSize = int32(pageSize)
}
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.ListSessions(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, "", err
}
return resp.Sessions, resp.NextPageToken, 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.PageSize)
return it
}
// DeleteSession ends a session, releasing server resources associated with it. This will
// asynchronously trigger cancellation of any operations that are running with
// this session.
func (c *Client) DeleteSession(ctx context.Context, req *spannerpb.DeleteSessionRequest, opts ...gax.CallOption) error {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "name", req.GetName()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.DeleteSession[0:len(c.CallOptions.DeleteSession):len(c.CallOptions.DeleteSession)], opts...)
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
_, err = c.client.DeleteSession(ctx, req, settings.GRPC...)
return err
}, opts...)
return err
}
// ExecuteSql executes an SQL statement, returning all results in a single reply. This
// method cannot be used to return a result set larger than 10 MiB;
// if the query yields more data than that, the query fails with
// a FAILED_PRECONDITION error.
//
// Operations inside read-write transactions might return ABORTED. If
// this occurs, the application should restart the transaction from
// the beginning. See [Transaction][google.spanner.v1.Transaction] for more
// details.
//
// Larger result sets can be fetched in streaming fashion by calling
// [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql]
// instead.
func (c *Client) ExecuteSql(ctx context.Context, req *spannerpb.ExecuteSqlRequest, opts ...gax.CallOption) (*spannerpb.ResultSet, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.ExecuteSql[0:len(c.CallOptions.ExecuteSql):len(c.CallOptions.ExecuteSql)], opts...)
var resp *spannerpb.ResultSet
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.ExecuteSql(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// ExecuteStreamingSql like [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql], except returns the
// result set as a stream. Unlike
// [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql], there is no limit on
// the size of the returned result set. However, no individual row in the
// result set can exceed 100 MiB, and no column value can exceed 10 MiB.
func (c *Client) ExecuteStreamingSql(ctx context.Context, req *spannerpb.ExecuteSqlRequest, opts ...gax.CallOption) (spannerpb.Spanner_ExecuteStreamingSqlClient, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.ExecuteStreamingSql[0:len(c.CallOptions.ExecuteStreamingSql):len(c.CallOptions.ExecuteStreamingSql)], opts...)
var resp spannerpb.Spanner_ExecuteStreamingSqlClient
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.ExecuteStreamingSql(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// ExecuteBatchDml executes a batch of SQL DML statements. This method allows many statements
// to be run with lower latency than submitting them sequentially with
// [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql].
//
// Statements are executed in order, sequentially.
// [ExecuteBatchDmlResponse][Spanner.ExecuteBatchDmlResponse] will contain a
// [ResultSet][google.spanner.v1.ResultSet] for each DML statement that has successfully executed. If a
// statement fails, its error status will be returned as part of the
// [ExecuteBatchDmlResponse][Spanner.ExecuteBatchDmlResponse]. Execution will
// stop at the first failed statement; the remaining statements will not run.
//
// ExecuteBatchDml is expected to return an OK status with a response even if
// there was an error while processing one of the DML statements. Clients must
// inspect response.status to determine if there were any errors while
// processing the request.
//
// See more details in
// [ExecuteBatchDmlRequest][Spanner.ExecuteBatchDmlRequest] and
// [ExecuteBatchDmlResponse][Spanner.ExecuteBatchDmlResponse].
func (c *Client) ExecuteBatchDml(ctx context.Context, req *spannerpb.ExecuteBatchDmlRequest, opts ...gax.CallOption) (*spannerpb.ExecuteBatchDmlResponse, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.ExecuteBatchDml[0:len(c.CallOptions.ExecuteBatchDml):len(c.CallOptions.ExecuteBatchDml)], opts...)
var resp *spannerpb.ExecuteBatchDmlResponse
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.ExecuteBatchDml(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// Read reads rows from the database using key lookups and scans, as a
// simple key/value style alternative to
// [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql]. This method cannot be
// used to return a result set larger than 10 MiB; if the read matches more
// data than that, the read fails with a FAILED_PRECONDITION
// error.
//
// Reads inside read-write transactions might return ABORTED. If
// this occurs, the application should restart the transaction from
// the beginning. See [Transaction][google.spanner.v1.Transaction] for more
// details.
//
// Larger result sets can be yielded in streaming fashion by calling
// [StreamingRead][google.spanner.v1.Spanner.StreamingRead] instead.
func (c *Client) Read(ctx context.Context, req *spannerpb.ReadRequest, opts ...gax.CallOption) (*spannerpb.ResultSet, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.Read[0:len(c.CallOptions.Read):len(c.CallOptions.Read)], opts...)
var resp *spannerpb.ResultSet
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.Read(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// StreamingRead like [Read][google.spanner.v1.Spanner.Read], except returns the result set
// as a stream. Unlike [Read][google.spanner.v1.Spanner.Read], there is no
// limit on the size of the returned result set. However, no individual row in
// the result set can exceed 100 MiB, and no column value can exceed
// 10 MiB.
func (c *Client) StreamingRead(ctx context.Context, req *spannerpb.ReadRequest, opts ...gax.CallOption) (spannerpb.Spanner_StreamingReadClient, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.StreamingRead[0:len(c.CallOptions.StreamingRead):len(c.CallOptions.StreamingRead)], opts...)
var resp spannerpb.Spanner_StreamingReadClient
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.StreamingRead(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// BeginTransaction begins a new transaction. This step can often be skipped:
// [Read][google.spanner.v1.Spanner.Read],
// [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql] and
// [Commit][google.spanner.v1.Spanner.Commit] can begin a new transaction as a
// side-effect.
func (c *Client) BeginTransaction(ctx context.Context, req *spannerpb.BeginTransactionRequest, opts ...gax.CallOption) (*spannerpb.Transaction, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.BeginTransaction[0:len(c.CallOptions.BeginTransaction):len(c.CallOptions.BeginTransaction)], opts...)
var resp *spannerpb.Transaction
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.BeginTransaction(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// Commit commits a transaction. The request includes the mutations to be
// applied to rows in the database.
//
// Commit might return an ABORTED error. This can occur at any time;
// commonly, the cause is conflicts with concurrent
// transactions. However, it can also happen for a variety of other
// reasons. If Commit returns ABORTED, the caller should re-attempt
// the transaction from the beginning, re-using the same session.
func (c *Client) Commit(ctx context.Context, req *spannerpb.CommitRequest, opts ...gax.CallOption) (*spannerpb.CommitResponse, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.Commit[0:len(c.CallOptions.Commit):len(c.CallOptions.Commit)], opts...)
var resp *spannerpb.CommitResponse
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.Commit(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// Rollback rolls back a transaction, releasing any locks it holds. It is a good
// idea to call this for any transaction that includes one or more
// [Read][google.spanner.v1.Spanner.Read] or
// [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql] requests and ultimately
// decides not to commit.
//
// Rollback returns OK if it successfully aborts the transaction, the
// transaction was already aborted, or the transaction is not
// found. Rollback never returns ABORTED.
func (c *Client) Rollback(ctx context.Context, req *spannerpb.RollbackRequest, opts ...gax.CallOption) error {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.Rollback[0:len(c.CallOptions.Rollback):len(c.CallOptions.Rollback)], opts...)
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
_, err = c.client.Rollback(ctx, req, settings.GRPC...)
return err
}, opts...)
return err
}
// PartitionQuery creates a set of partition tokens that can be used to execute a query
// operation in parallel. Each of the returned partition tokens can be used
// by [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql] to
// specify a subset of the query result to read. The same session and
// read-only transaction must be used by the PartitionQueryRequest used to
// create the partition tokens and the ExecuteSqlRequests that use the
// partition tokens.
//
// Partition tokens become invalid when the session used to create them
// is deleted, is idle for too long, begins a new transaction, or becomes too
// old. When any of these happen, it is not possible to resume the query, and
// the whole operation must be restarted from the beginning.
func (c *Client) PartitionQuery(ctx context.Context, req *spannerpb.PartitionQueryRequest, opts ...gax.CallOption) (*spannerpb.PartitionResponse, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.PartitionQuery[0:len(c.CallOptions.PartitionQuery):len(c.CallOptions.PartitionQuery)], opts...)
var resp *spannerpb.PartitionResponse
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.PartitionQuery(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// PartitionRead creates a set of partition tokens that can be used to execute a read
// operation in parallel. Each of the returned partition tokens can be used
// by [StreamingRead][google.spanner.v1.Spanner.StreamingRead] to specify a
// subset of the read result to read. The same session and read-only
// transaction must be used by the PartitionReadRequest used to create the
// partition tokens and the ReadRequests that use the partition tokens. There
// are no ordering guarantees on rows returned among the returned partition
// tokens, or even within each individual StreamingRead call issued with a
// partition_token.
//
// Partition tokens become invalid when the session used to create them
// is deleted, is idle for too long, begins a new transaction, or becomes too
// old. When any of these happen, it is not possible to resume the read, and
// the whole operation must be restarted from the beginning.
func (c *Client) PartitionRead(ctx context.Context, req *spannerpb.PartitionReadRequest, opts ...gax.CallOption) (*spannerpb.PartitionResponse, error) {
md := metadata.Pairs("x-goog-request-params", fmt.Sprintf("%s=%v", "session", req.GetSession()))
ctx = insertMetadata(ctx, c.xGoogMetadata, md)
opts = append(c.CallOptions.PartitionRead[0:len(c.CallOptions.PartitionRead):len(c.CallOptions.PartitionRead)], opts...)
var resp *spannerpb.PartitionResponse
err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
var err error
resp, err = c.client.PartitionRead(ctx, req, settings.GRPC...)
return err
}, opts...)
if err != nil {
return nil, err
}
return resp, nil
}
// SessionIterator manages a stream of *spannerpb.Session.
type SessionIterator struct {
items []*spannerpb.Session
pageInfo *iterator.PageInfo
nextFunc func() error
// 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 []*spannerpb.Session, nextPageToken string, err error)
}
// PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
func (it *SessionIterator) 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 *SessionIterator) Next() (*spannerpb.Session, error) {
var item *spannerpb.Session
if err := it.nextFunc(); err != nil {
return item, err
}
item = it.items[0]
it.items = it.items[1:]
return item, nil
}
func (it *SessionIterator) bufLen() int {
return len(it.items)
}
func (it *SessionIterator) takeBuf() interface{} {
b := it.items
it.items = nil
return b
}