refactor: move Snowflake class

README.md

@@ -24,7 +24,7 @@ snowflake4cj = { git = "https://github.com/gtn1024/snowflake4cj.git", tag = "v1.
 ## 使用 / Usage
 
 ```cj
-import snowflake4cj.snowflake.Snowflake
+import snowflake4cj.Snowflake
 
 main(): Int64 {
     let snowflake = Snowflake(0, 0)

src/snowflake.cj

@@ -1 +1,75 @@
 package snowflake4cj
+
+import std.time.{DateTime}
+import std.sync.{ReentrantMutex}
+
+public open class Snowflake {
+    internal let twepoch: Int64 = 1725148800000
+    internal let workerIdBits: Int64 = 5
+    internal let datacenterIdBits: Int64 = 5
+    internal let maxWorkerId: Int64 = -1 ^ (-1 << workerIdBits)
+    internal let maxDatacenterId: Int64 = -1 ^ (-1 << datacenterIdBits)
+    internal let sequenceBits: Int64 = 12
+    internal let workerIdShift: Int64 = sequenceBits
+    internal let datacenterIdShift: Int64 = sequenceBits + workerIdBits
+    internal let timestampLeftShift: Int64 = sequenceBits + workerIdBits + datacenterIdBits
+    internal let sequenceMask: Int64 = -1 ^ (-1 << sequenceBits)
+
+    internal let workerId: Int64
+    internal let datacenterId: Int64
+    internal var sequence: Int64 = 0
+    internal var lastTimestamp: Int64 = -1
+
+    public init(workerId: Int64, datacenterId: Int64) {
+        if (workerId > maxWorkerId || workerId < 0) {
+            throw IllegalArgumentException("workerId can't be greater than ${maxWorkerId} or less than 0")
+        }
+
+        if (datacenterId > maxDatacenterId || datacenterId < 0) {
+            throw IllegalArgumentException("datacenterId can't be greater than ${maxWorkerId} or less than 0")
+        }
+
+        this.workerId = workerId
+        this.datacenterId = datacenterId
+    }
+
+    let mtx = ReentrantMutex()
+
+    public func nextId() {
+        synchronized (mtx) {
+            var timestamp = timeGen()
+
+            if (timestamp < lastTimestamp) {
+                throw IllegalStateException("Clock moved backwards. Refusing to generate id for ${lastTimestamp - timestamp} milliseconds")
+            }
+
+            if (lastTimestamp == timestamp) {
+                sequence = (sequence + 1) & sequenceMask
+
+                if (sequence == 0) {
+                    timestamp = tilNextMillis(lastTimestamp)
+                }
+            } else {
+                sequence = 0
+            }
+
+            lastTimestamp = timestamp
+
+            ((timestamp - twepoch) << timestampLeftShift) | (datacenterId << datacenterIdShift) | (workerId << workerIdShift) | sequence
+        }
+    }
+
+    internal func tilNextMillis(lastTimestamp: Int64) {
+        var timestamp = timeGen()
+
+        while (timestamp <= lastTimestamp) {
+            timestamp = timeGen()
+        }
+
+        timestamp
+    }
+
+    internal func timeGen() {
+        DateTime.nowUTC().toUnixTimeStamp().toMilliseconds()
+    }
+}

src/snowflake/snowflake_test.cj → src/snowflake_test.cj

@@ -1,4 +1,4 @@
-package snowflake4cj.snowflake
+package snowflake4cj
 
 import std.unittest.*
 import std.unittest.testmacro.*