Stratum V2 initial commit

src/models/sv2/sv2-extranonce-manager.ts

@@ -0,0 +1,113 @@
+// ── SV2 Extranonce Manager ──────────────────────────────────────────
+// Manages extranonce prefix allocation for extended mining channels.
+// Ensures no two channels share the same prefix to prevent hash collisions.
+
+export class Sv2ExtranonceManager {
+  private nextPrefix: number;
+  private readonly workerOffset: number;
+  private readonly maxPrefix: number;
+  private allocatedPrefixes = new Map<number, number>(); // channelId → prefix
+  private usedPrefixes = new Set<number>();
+  private readonly prefixSize: number;
+  private readonly totalExtranonceSize: number;
+
+  /**
+   * @param prefixSize Bytes used for pool-assigned prefix (default 4)
+   * @param totalExtranonceSize Total extranonce bytes (default 12: 4 prefix + 8 miner-controlled).
+   *        Must match MiningJob.ts's coinbase slot size (12 bytes) — both
+   *        protocols share the same coinbase template. Bumped from the
+   *        previous 8-byte total because the Braiins Hashpower marketplace
+   *        requires extranonce2_size >= 7 (compatibility spec).
+   */
+  constructor(prefixSize = 4, totalExtranonceSize = 12) {
+    this.prefixSize = prefixSize;
+    this.totalExtranonceSize = totalExtranonceSize;
+
+    const workerId = 0;
+    const bitsPerWorker = (prefixSize - 1) * 8;
+    this.workerOffset = workerId * Math.pow(2, bitsPerWorker);
+    this.maxPrefix = Math.pow(2, bitsPerWorker) - 1; // max within this worker's slice
+    this.nextPrefix = 1;
+  }
+
+  get minerExtranonceSize(): number {
+    return this.totalExtranonceSize - this.prefixSize;
+  }
+
+  /**
+   * Allocate a unique extranonce prefix for a channel.
+   * Returns a Buffer of `prefixSize` bytes.
+   */
+  allocate(channelId: number): Buffer {
+    // Check if already allocated
+    if (this.allocatedPrefixes.has(channelId)) {
+      const existing = this.allocatedPrefixes.get(channelId)!;
+      return this.prefixToBuffer(existing);
+    }
+
+    // Find next available prefix within this worker's partition
+    let localPrefix = this.nextPrefix;
+    let attempts = 0;
+    const globalPrefix = () => this.workerOffset + localPrefix;
+
+    while (this.usedPrefixes.has(globalPrefix()) && attempts <= this.maxPrefix) {
+      localPrefix = localPrefix + 1;
+      if (localPrefix > this.maxPrefix) localPrefix = 1; // Wrap within partition, skip 0
+      attempts++;
+    }
+
+    if (this.usedPrefixes.has(globalPrefix())) {
+      throw new Error('Extranonce prefix space exhausted');
+    }
+
+    const prefix = globalPrefix();
+    this.allocatedPrefixes.set(channelId, prefix);
+    this.usedPrefixes.add(prefix);
+    this.nextPrefix = localPrefix + 1;
+    if (this.nextPrefix > this.maxPrefix) this.nextPrefix = 1;
+
+    return this.prefixToBuffer(prefix);
+  }
+
+  /**
+   * Release the prefix allocated to a channel.
+   */
+  release(channelId: number): void {
+    const prefix = this.allocatedPrefixes.get(channelId);
+    if (prefix !== undefined) {
+      this.allocatedPrefixes.delete(channelId);
+      this.usedPrefixes.delete(prefix);
+    }
+  }
+
+  /**
+   * Get the prefix for a channel, or undefined if not allocated.
+   */
+  getPrefix(channelId: number): Buffer | undefined {
+    const prefix = this.allocatedPrefixes.get(channelId);
+    if (prefix === undefined) return undefined;
+    return this.prefixToBuffer(prefix);
+  }
+
+  get allocatedCount(): number {
+    return this.allocatedPrefixes.size;
+  }
+
+  private prefixToBuffer(prefix: number): Buffer {
+    const buf = Buffer.alloc(this.prefixSize);
+    // Write as big-endian so prefix 1 = 0x00000001
+    if (this.prefixSize === 4) {
+      buf.writeUInt32BE(prefix, 0);
+    } else if (this.prefixSize === 2) {
+      buf.writeUInt16BE(prefix, 0);
+    } else {
+      // Generic: write big-endian
+      let val = prefix;
+      for (let i = this.prefixSize - 1; i >= 0; i--) {
+        buf[i] = val & 0xff;
+        val = val >>> 8;
+      }
+    }
+    return buf;
+  }
+}