not so initial commit

snowflake.ts

@@ -0,0 +1,68 @@
+export class SnowflakeGenerator {
+  private epoch: bigint;
+  private workerId: bigint;
+  private processId: bigint;
+  private sequence: bigint;
+  private lastTimestamp: bigint;
+
+  constructor(workerId: bigint = 1n, processId: bigint = 1n, epoch: bigint = 1766617200000n) {
+    // dec 1 2025 (creation of this)
+    this.epoch = epoch;
+    this.workerId = workerId;
+    this.processId = processId;
+    this.sequence = 0n;
+    this.lastTimestamp = -1n;
+  }
+
+  private getCurrentTimestamp(): bigint {
+    return BigInt(Date.now());
+  }
+
+  private waitForNextMillisecond(lastTimestamp: bigint): bigint {
+    let timestamp = this.getCurrentTimestamp();
+    while (timestamp <= lastTimestamp) {
+      timestamp = this.getCurrentTimestamp();
+    }
+    return timestamp;
+  }
+
+  public generateSnowflake(): number {
+    const timestamp = this.getCurrentTimestamp() - this.epoch;
+
+    if (timestamp === this.lastTimestamp) {
+      this.sequence += 1n;
+      if (this.sequence > 4095n) {  // max sequence value (12 bits)
+        // Wait for the next millisecond if we've reached the max sequence value
+        const newTimestamp = this.waitForNextMillisecond(this.lastTimestamp);
+        this.sequence = 0n;
+        return Number.parseInt(String(this.createSnowflake(newTimestamp)));
+      }
+    } else {
+      this.sequence = 0n;
+    }
+
+    this.lastTimestamp = timestamp;
+    return Number.parseInt(String(this.createSnowflake(timestamp)));
+  }
+
+  private createSnowflake(timestamp: bigint): bigint {
+    return (timestamp << 22n) | (BigInt(this.workerId) << 18n) | (BigInt(this.processId) << 12n) | BigInt(this.sequence);
+  }
+
+    public decodeSnowflake(id: bigint | number) {
+    const snowflake = BigInt(id);
+
+    const sequence  = snowflake & (1n << 6n) - 1n;
+    const processId = (snowflake >> 6n)  & ((1n << 6n) - 1n);
+    const workerId  = (snowflake >> 12n) & ((1n << 10n) - 1n);
+    const timestamp = (snowflake >> 22n) + this.epoch;
+
+    return {
+      timestamp,                // bigint (ms since Unix epoch)
+      date: new Date(Number(timestamp)),
+      workerId,
+      processId,
+      sequence,
+    };
+  }
+}