77 lines
1.6 KiB
Go
77 lines
1.6 KiB
Go
package snapshotter
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import (
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"bytes"
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"encoding/binary"
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"encoding/json"
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"errors"
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"fmt"
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"io"
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"github.com/influxdata/influxdb/services/meta"
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"github.com/influxdata/influxdb/tcp"
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)
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// Client provides an API for the snapshotter service.
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type Client struct {
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host string
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}
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// NewClient returns a new *Client.
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func NewClient(host string) *Client {
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return &Client{host: host}
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}
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// MetastoreBackup returns a snapshot of the meta store.
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func (c *Client) MetastoreBackup() (*meta.Data, error) {
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req := &Request{
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Type: RequestMetastoreBackup,
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}
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b, err := c.doRequest(req)
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if err != nil {
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return nil, err
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}
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// Check the magic.
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magic := binary.BigEndian.Uint64(b[:8])
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if magic != BackupMagicHeader {
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return nil, errors.New("invalid metadata received")
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}
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i := 8
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// Size of the meta store bytes.
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length := int(binary.BigEndian.Uint64(b[i : i+8]))
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i += 8
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metaBytes := b[i : i+length]
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// Unpack meta data.
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var data meta.Data
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if err := data.UnmarshalBinary(metaBytes); err != nil {
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return nil, fmt.Errorf("unmarshal: %s", err)
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}
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return &data, nil
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}
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// doRequest sends a request to the snapshotter service and returns the result.
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func (c *Client) doRequest(req *Request) ([]byte, error) {
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// Connect to snapshotter service.
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conn, err := tcp.Dial("tcp", c.host, MuxHeader)
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if err != nil {
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return nil, err
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}
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defer conn.Close()
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// Write the request
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if err := json.NewEncoder(conn).Encode(req); err != nil {
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return nil, fmt.Errorf("encode snapshot request: %s", err)
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}
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// Read snapshot from the connection
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var buf bytes.Buffer
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_, err = io.Copy(&buf, conn)
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return buf.Bytes(), err
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}
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