Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

replication: Support GTID tag in PreviousGTIDsEvent #952

Open
wants to merge 7 commits into
base: master
Choose a base branch
from
Open
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
67 changes: 63 additions & 4 deletions replication/event.go
Original file line number Diff line number Diff line change
Expand Up @@ -229,15 +229,69 @@ type PreviousGTIDsEvent struct {
GTIDSets string
}

type GtidFormat int

const (
GtidFormatClassic = iota
GtidFormatTagged
)

// Decode the number of sids (source identifiers) and if it is using
// tagged GTIDs or classic (non-tagged) GTIDs.
//
// Note that each gtid tag increases the sidno here, so a single UUID
// might turn up multiple times if there are multipl tags.
//
// see also:
// decode_nsids_format in mysql/mysql-server
// https://github.com/mysql/mysql-server/blob/61a3a1d8ef15512396b4c2af46e922a19bf2b174/sql/rpl_gtid_set.cc#L1363-L1378
func decodeSid(data []byte) (format GtidFormat, sidnr uint64) {
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

can you put the referenced MySQL source code or document in comment, so other reviewers can double check the implementation?

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

done

gtidinfo := make([]byte, 8)
copy(gtidinfo, data[:8])

if gtidinfo[7] == 1 {
format = GtidFormatTagged
}

if format == GtidFormatTagged {
sid_mask := []byte{0, 255, 255, 255, 255, 255, 255, 0}

// Apply the mask
for i, _ := range gtidinfo[:8] {
gtidinfo[i] &= sid_mask[i]
}
gtidinfo = append(gtidinfo, 0)

// sidnr
sidnr = binary.LittleEndian.Uint64(gtidinfo[1:])
return
}
sidnr = binary.LittleEndian.Uint64(gtidinfo)
return
}

func (e *PreviousGTIDsEvent) Decode(data []byte) error {
pos := 0
uuidCount := binary.LittleEndian.Uint16(data[pos : pos+8])

format, uuidCount := decodeSid(data)
pos += 8

previousGTIDSets := make([]string, uuidCount)
for i := range previousGTIDSets {
currentSetnr := 0
for range previousGTIDSets {
uuid := e.decodeUuid(data[pos : pos+16])
pos += 16
isTag := false
var tag string
if format == GtidFormatTagged {
tagLength := int(data[pos]) / 2
pos += 1
if tagLength > 0 { // 0 == no tag, >0 == tag
isTag = true
tag = string(data[pos : pos+tagLength])
pos += tagLength
}
}
sliceCount := binary.LittleEndian.Uint16(data[pos : pos+8])
pos += 8
intervals := make([]string, sliceCount)
Expand All @@ -254,9 +308,14 @@ func (e *PreviousGTIDsEvent) Decode(data []byte) error {
}
intervals[i] = interval
}
previousGTIDSets[i] = fmt.Sprintf("%s:%s", uuid, strings.Join(intervals, ":"))
if isTag {
previousGTIDSets[currentSetnr-1] += fmt.Sprintf(":%s:%s", tag, strings.Join(intervals, ":"))
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Because string is immutable, string += will create a new string object each time. If there are too many tags the performance will drop. Maybe store every "tag+intervals" and join them once at all

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, I think we should try to do that.

} else {
previousGTIDSets[currentSetnr] = fmt.Sprintf("%s:%s", uuid, strings.Join(intervals, ":"))
currentSetnr += 1
}
}
e.GTIDSets = strings.Join(previousGTIDSets, ",")
e.GTIDSets = strings.Join(previousGTIDSets[:currentSetnr], ",")
return nil
}

Expand Down
50 changes: 50 additions & 0 deletions replication/event_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -140,3 +140,53 @@ func TestIntVarEvent(t *testing.T) {
require.Equal(t, INSERT_ID, ev.Type)
require.Equal(t, uint64(23), ev.Value)
}

func TestDecodeSid(t *testing.T) {
testcases := []struct {
input []byte
gtidFormat GtidFormat
uuidCount uint64
}{
{[]byte{1, 2, 0, 0, 0, 0, 0, 1}, GtidFormatTagged, 2},
{[]byte{1, 1, 0, 0, 0, 0, 0, 1}, GtidFormatTagged, 1},
{[]byte{1, 0, 0, 0, 0, 0, 0, 1}, GtidFormatTagged, 0},
{[]byte{1, 0, 0, 0, 0, 0, 0, 0}, GtidFormatClassic, 1},
}

for _, tc := range testcases {
format, uuidCount := decodeSid(tc.input)
assert.Equal(t, tc.gtidFormat, format)
assert.Equal(t, tc.uuidCount, uuidCount)
}
}

func TestPreviousGTIDEvent(t *testing.T) {
testcases := []struct {
input []byte
GTIDSets string
}{
{
[]byte{0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1},
"",
},
{
[]byte{0x1, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
"896e7882-18fe-11ef-ab88-22222d34d411:1-3",
},
{
[]byte{0x1, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x5, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0x8, 0x61, 0x61, 0x61, 0x61, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
"896e7882-18fe-11ef-ab88-22222d34d411:1-4:aaaa:1",
},
{
[]byte{0x1, 0x7, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x5, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0x8, 0x61, 0x61, 0x61, 0x61, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0x6, 0x61, 0x62, 0x63, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0xa, 0x62, 0x62, 0x62, 0x62, 0x62, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0xc, 0x62, 0x62, 0x62, 0x62, 0x62, 0x62, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x11, 0x2, 0x78, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x89, 0x6e, 0x78, 0x82, 0x18, 0xfe, 0x11, 0xef, 0xab, 0x88, 0x22, 0x22, 0x2d, 0x34, 0xd4, 0x12, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x3, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},
"896e7882-18fe-11ef-ab88-22222d34d411:1-4:aaaa:1:abc:1-3:bbbbb:1:bbbbbb:1:x:1,896e7882-18fe-11ef-ab88-22222d34d412:1-2",
},
}

for _, tc := range testcases {
e := PreviousGTIDsEvent{}
err := e.Decode(tc.input)
require.NoError(t, err)
require.Equal(t, tc.GTIDSets, e.GTIDSets)
}
}
Loading