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yixia pushed a commit to branch feature/saga
in repository https://gitbox.apache.org/repos/asf/incubator-seata-go.git
The following commit(s) were added to refs/heads/feature/saga by this push:
new d1fad744 feature saga ：support generate id by Snowflake (#670)
d1fad744 is described below
commit d1fad744aa7b6acc01efcc87a0a1315bec72a18d
Author: FanOne <[email protected]>
AuthorDate: Sat Mar 16 17:46:49 2024 +0800
feature saga ：support generate id by Snowflake (#670)
---
.../engine/process_ctrl_statemachine_engine.go | 3 +-
pkg/saga/statemachine/engine/sequence/snowflake.go | 116 +++++++++++++++++++++
.../statemachine/engine/sequence/snowflake_test.go | 28 +++++
3 files changed, 146 insertions(+), 1 deletion(-)
diff --git a/pkg/saga/statemachine/engine/process_ctrl_statemachine_engine.go
b/pkg/saga/statemachine/engine/process_ctrl_statemachine_engine.go
index afec63cb..aae9fe89 100644
--- a/pkg/saga/statemachine/engine/process_ctrl_statemachine_engine.go
+++ b/pkg/saga/statemachine/engine/process_ctrl_statemachine_engine.go
@@ -2,12 +2,13 @@ package engine
import (
"context"
+ "time"
+
"github.com/pkg/errors"
"github.com/seata/seata-go/pkg/saga/statemachine/constant"
"github.com/seata/seata-go/pkg/saga/statemachine/engine/events"
"github.com/seata/seata-go/pkg/saga/statemachine/engine/process_ctrl"
"github.com/seata/seata-go/pkg/saga/statemachine/statelang"
- "time"
)
type ProcessCtrlStateMachineEngine struct {
diff --git a/pkg/saga/statemachine/engine/sequence/snowflake.go
b/pkg/saga/statemachine/engine/sequence/snowflake.go
new file mode 100644
index 00000000..f5622b06
--- /dev/null
+++ b/pkg/saga/statemachine/engine/sequence/snowflake.go
@@ -0,0 +1,116 @@
+package sequence
+
+import (
+ "fmt"
+ "sync"
+ "time"
+
+ "github.com/seata/seata-go/pkg/util/log"
+)
+
+// SnowflakeSeqGenerator snowflake gen ids
+// ref: https://en.wikipedia.org/wiki/Snowflake_ID
+
+var (
+ // set the beginning time
+ epoch = time.Date(2024, time.January, 01, 00, 00, 00, 00,
time.UTC).UnixMilli()
+)
+
+const (
+ // timestamp occupancy bits
+ timestampBits = 41
+ // dataCenterId occupancy bits
+ dataCenterIdBits = 5
+ // workerId occupancy bits
+ workerIdBits = 5
+ // sequence occupancy bits
+ seqBits = 12
+
+ // timestamp max value, just like 2^41-1 = 2199023255551
+ timestampMaxValue = -1 ^ (-1 << timestampBits)
+ // dataCenterId max value, just like 2^5-1 = 31
+ dataCenterIdMaxValue = -1 ^ (-1 << dataCenterIdBits)
+ // workId max value, just like 2^5-1 = 31
+ workerIdMaxValue = -1 ^ (-1 << workerIdBits)
+ // sequence max value, just like 2^12-1 = 4095
+ seqMaxValue = -1 ^ (-1 << seqBits)
+
+ // number of workId offsets (seqBits)
+ workIdShift = 12
+ // number of dataCenterId offsets (seqBits + workerIdBits)
+ dataCenterIdShift = 17
+ // number of timestamp offsets (seqBits + workerIdBits +
dataCenterIdBits)
+ timestampShift = 22
+
+ defaultInitValue = 0
+)
+
+type SnowflakeSeqGenerator struct {
+ mu *sync.Mutex
+ timestamp int64
+ dataCenterId int64
+ workerId int64
+ sequence int64
+}
+
+// NewSnowflakeSeqGenerator initiates the snowflake generator
+func NewSnowflakeSeqGenerator(dataCenterId, workId int64) (r
*SnowflakeSeqGenerator, err error) {
+ if dataCenterId < 0 || dataCenterId > dataCenterIdMaxValue {
+ err = fmt.Errorf("dataCenterId should between 0 and %d",
dataCenterIdMaxValue-1)
+ return
+ }
+
+ if workId < 0 || workId > workerIdMaxValue {
+ err = fmt.Errorf("workId should between 0 and %d",
dataCenterIdMaxValue-1)
+ return
+ }
+
+ return &SnowflakeSeqGenerator{
+ mu: new(sync.Mutex),
+ timestamp: defaultInitValue - 1,
+ dataCenterId: dataCenterId,
+ workerId: workId,
+ sequence: defaultInitValue,
+ }, nil
+}
+
+// GenerateId timestamp + dataCenterId + workId + sequence
+func (S *SnowflakeSeqGenerator) GenerateId(entity string, ruleName string)
string {
+ S.mu.Lock()
+ defer S.mu.Unlock()
+
+ now := time.Now().UnixMilli()
+
+ if S.timestamp > now { // Clock callback
+ log.Errorf("Clock moved backwards. Refusing to generate ID,
last timestamp is %d, now is %d", S.timestamp, now)
+ return ""
+ }
+
+ if S.timestamp == now {
+ // generate multiple IDs in the same millisecond, incrementing
the sequence number to prevent conflicts
+ S.sequence = (S.sequence + 1) & seqMaxValue
+ if S.sequence == 0 {
+ // sequence overflow, waiting for next millisecond
+ for now <= S.timestamp {
+ now = time.Now().UnixMilli()
+ }
+ }
+ } else {
+ // initialized sequences are used directly at different
millisecond timestamps
+ S.sequence = defaultInitValue
+ }
+ tmp := now - epoch
+ if tmp > timestampMaxValue {
+ log.Errorf("epoch should between 0 and %d", timestampMaxValue-1)
+ return ""
+ }
+ S.timestamp = now
+
+ // combine the parts to generate the final ID and convert the 64-bit
binary to decimal digits.
+ r := (tmp)<<timestampShift |
+ (S.dataCenterId << dataCenterIdShift) |
+ (S.workerId << workIdShift) |
+ (S.sequence)
+
+ return fmt.Sprintf("%d", r)
+}
diff --git a/pkg/saga/statemachine/engine/sequence/snowflake_test.go
b/pkg/saga/statemachine/engine/sequence/snowflake_test.go
new file mode 100644
index 00000000..451f478d
--- /dev/null
+++ b/pkg/saga/statemachine/engine/sequence/snowflake_test.go
@@ -0,0 +1,28 @@
+package sequence
+
+import (
+ "strconv"
+ "testing"
+)
+
+func TestSnowflakeSeqGenerator_GenerateId(t *testing.T) {
+ var dataCenterId, workId int64 = 1, 1
+ generator, err := NewSnowflakeSeqGenerator(dataCenterId, workId)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+ var x, y string
+ for i := 0; i < 100; i++ {
+ y = generator.GenerateId("", "")
+ if x == y {
+ t.Errorf("x(%s) & y(%s) are the same", x, y)
+ }
+ x = y
+ }
+}
+
+func TestEpoch(t *testing.T) {
+ t.Log(epoch)
+ t.Log(len(strconv.FormatInt(epoch, 10)))
+}
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