*: support parsing BACKUP and RESTORE statements

[kennytm]

What problem does this PR solve?

Added the BACKUP, RESTORE and SHOW BACKUP/RESTORE statements to parser.

BACKUP DATABASE * TO 'local:///tmp/archive01/';
BACKUP DATABASE `a` TO 'local:///tmp/archive02/';
BACKUP TABLE `a`.`b` TO 'local:///tmp/archive03/';
RESTORE DATABASE * FROM 'local:///tmp/archive01/';
RESTORE DATABASE `a` FROM 'local:///tmp/archive02/';
RESTORE TABLE `a`.`b` FROM 'local:///tmp/archive03/';
BACKUP DATABASE * FULL TO 'local:///tmp/archive04/';
BACKUP DATABASE * INCREMENTAL UNTIL TIMESTAMP '2020-02-02 14:15:16' TO 'local:///tmp/archive05/';
BACKUP DATABASE * INCREMENTAL UNTIL TIMESTAMP_ORACLE 1234567890 TO 'local:///tmp/archive06/';

BACKUP DATABASE * TO 's3://my_bucket/path' 
    RATE_LIMIT = 100 MB/SECOND 
    SNAPSHOT = 2 HOUR AGO 
    CONCURRENCY = 32 
    S3_REGION = 'us-west-1' 
    S3_USE_ACCELERATE_ENDPOINT = 1;

SHOW BACKUP;
SHOW RESTORE;
SHOW BACKUP LIKE 'b01234';
SHOW BACKUP WHERE status <> 'running';

These are needed for integrating BR into TiDB (PR will come later).

(Note: because the new unresolved keyword S3_USE_ACCELERATE_ENDPOINT is longer than all existing tokens, forcing gofmt to replace the entire token map, I've taken advantage of this to sort the entire tokenMap)

What is changed and how it works?

↑

Check List

Tests

• Unit test

Code changes

Side effects

Related changes

• Need to update the documentation
• Need to be included in the release note

[codecov]

Codecov Report

Merging #746 into master will increase coverage by 0.21%.
The diff coverage is 81.42%.

@@            Coverage Diff             @@
##           master     #746      +/-   ##
==========================================
+ Coverage   77.82%   78.03%   +0.21%     
==========================================
  Files          40       40              
  Lines       14421    14632     +211     
==========================================
+ Hits        11223    11418     +195     
- Misses       2514     2535      +21     
+ Partials      684      679       -5

[tangenta]

LGTM

[tangenta]

How can it overflow ❔

[kennytm]

@tangenta RATE_LIMIT = 9223372036854775807 MB/SECOND... admittedly this is not a real issue 😅

[tangenta]

Should we also handle SetPwdStmt.Restore()?

[kennytm]

😱. Perhaps deal with this later (e.g. add a WriteSecureString() method). This needs to be considered together with how TiDB uses Restore().

[tiancaiamao]

LGTM
With this feature implemented, preparing some test cases can be much faster.

[IANTHEREAL]

@kennytm please resolve conflicts, it seems to be merged soon

[kennytm]

PTAL again @tangenta @tiancaiamao thanks.

[tangenta]

LGTM

[tiancaiamao]

LGTM