| // Copyright 2015 Google Inc. All Rights Reserved. |
| // |
| // 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 |
| // |
| // http://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. |
| |
| package bigquery |
| |
| import ( |
| "golang.org/x/net/context" |
| "google.golang.org/api/iterator" |
| ) |
| |
| // Dataset is a reference to a BigQuery dataset. |
| type Dataset struct { |
| projectID string |
| id string |
| service service |
| } |
| |
| // Create creates a dataset in the BigQuery service. An error will be returned |
| // if the dataset already exists. |
| func (d *Dataset) Create(ctx context.Context) error { |
| return d.service.insertDataset(ctx, d.id, d.projectID) |
| } |
| |
| // Table creates a handle to a BigQuery table in the dataset. |
| // To determine if a table exists, call Table.Metadata. |
| // If the table does not already exist, use Table.Create to create it. |
| func (d *Dataset) Table(tableID string) *Table { |
| return &Table{ProjectID: d.projectID, DatasetID: d.id, TableID: tableID, service: d.service} |
| } |
| |
| // Tables returns an iterator over the tables in the Dataset. |
| func (d *Dataset) Tables(ctx context.Context) *TableIterator { |
| it := &TableIterator{ |
| ctx: ctx, |
| dataset: d, |
| } |
| it.pageInfo, it.nextFunc = iterator.NewPageInfo( |
| it.fetch, |
| func() int { return len(it.tables) }, |
| func() interface{} { b := it.tables; it.tables = nil; return b }) |
| return it |
| } |
| |
| // A TableIterator is an iterator over Tables. |
| type TableIterator struct { |
| ctx context.Context |
| dataset *Dataset |
| tables []*Table |
| pageInfo *iterator.PageInfo |
| nextFunc func() error |
| } |
| |
| // Next returns the next result. Its second return value is Done if there are |
| // no more results. Once Next returns Done, all subsequent calls will return |
| // Done. |
| func (it *TableIterator) Next() (*Table, error) { |
| if err := it.nextFunc(); err != nil { |
| return nil, err |
| } |
| t := it.tables[0] |
| it.tables = it.tables[1:] |
| return t, nil |
| } |
| |
| // PageInfo supports pagination. See the google.golang.org/api/iterator package for details. |
| func (it *TableIterator) PageInfo() *iterator.PageInfo { return it.pageInfo } |
| |
| func (it *TableIterator) fetch(pageSize int, pageToken string) (string, error) { |
| tables, tok, err := it.dataset.service.listTables(it.ctx, it.dataset.projectID, it.dataset.id, pageSize, pageToken) |
| if err != nil { |
| return "", err |
| } |
| it.tables = append(it.tables, tables...) |
| return tok, nil |
| } |
| |
| // Datasets returns an iterator over the datasets in the Client's project. |
| func (c *Client) Datasets(ctx context.Context) *DatasetIterator { |
| return c.DatasetsInProject(ctx, c.projectID) |
| } |
| |
| // DatasetsInProject returns an iterator over the datasets in the provided project. |
| func (c *Client) DatasetsInProject(ctx context.Context, projectID string) *DatasetIterator { |
| it := &DatasetIterator{ |
| ctx: ctx, |
| service: c.service, |
| projectID: projectID, |
| } |
| it.pageInfo, it.nextFunc = iterator.NewPageInfo( |
| it.fetch, |
| func() int { return len(it.items) }, |
| func() interface{} { b := it.items; it.items = nil; return b }) |
| return it |
| } |
| |
| // DatasetIterator iterates over the datasets in a project. |
| type DatasetIterator struct { |
| // ListHidden causes hidden datasets to be listed when set to true. |
| ListHidden bool |
| |
| // Filter restricts the datasets returned by label. The filter syntax is described in |
| // https://cloud.google.com/bigquery/docs/labeling-datasets#filtering_datasets_using_labels |
| Filter string |
| |
| ctx context.Context |
| projectID string |
| service service |
| pageInfo *iterator.PageInfo |
| nextFunc func() error |
| items []*Dataset |
| } |
| |
| // PageInfo supports pagination. See the google.golang.org/api/iterator package for details. |
| func (it *DatasetIterator) PageInfo() *iterator.PageInfo { return it.pageInfo } |
| |
| func (it *DatasetIterator) Next() (*Dataset, error) { |
| if err := it.nextFunc(); err != nil { |
| return nil, err |
| } |
| item := it.items[0] |
| it.items = it.items[1:] |
| return item, nil |
| } |
| |
| func (it *DatasetIterator) fetch(pageSize int, pageToken string) (string, error) { |
| datasets, nextPageToken, err := it.service.listDatasets(it.ctx, it.projectID, |
| pageSize, pageToken, it.ListHidden, it.Filter) |
| if err != nil { |
| return "", err |
| } |
| it.items = append(it.items, datasets...) |
| return nextPageToken, nil |
| } |