lancedb/nodejs/lancedb/util.ts

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: Copyright The LanceDB Authors

export type IntoSql =
  | string
  | number
  | boolean
  | null
  | Date
  | ArrayBufferLike
  | Buffer
  | IntoSql[];

export function toSQL(value: IntoSql): string {
  if (typeof value === "string") {
    return `'${value.replace(/'/g, "''")}'`;
  } else if (typeof value === "number") {
    return value.toString();
  } else if (typeof value === "boolean") {
    return value ? "TRUE" : "FALSE";
  } else if (value === null) {
    return "NULL";
  } else if (value instanceof Date) {
    return `'${value.toISOString()}'`;
  } else if (Array.isArray(value)) {
    return `[${value.map(toSQL).join(", ")}]`;
  } else if (Buffer.isBuffer(value)) {
    return `X'${value.toString("hex")}'`;
  } else if (value instanceof ArrayBuffer) {
    return `X'${Buffer.from(value).toString("hex")}'`;
  } else {
    throw new Error(
      `Unsupported value type: ${typeof value} value: (${value})`,
    );
  }
}

export function packBits(data: Array<number>): Array<number> {
  const packed = Array(data.length >> 3).fill(0);
  for (let i = 0; i < data.length; i++) {
    const byte = i >> 3;
    const bit = i & 7;
    packed[byte] |= data[i] << bit;
  }
  return packed;
}

export class TTLCache {
  // biome-ignore lint/suspicious/noExplicitAny: <explanation>
  private readonly cache: Map<string, { value: any; expires: number }>;

  /**
   * @param ttl Time to live in milliseconds
   */
  constructor(private readonly ttl: number) {
    this.cache = new Map();
  }

  // biome-ignore lint/suspicious/noExplicitAny: <explanation>
  get(key: string): any | undefined {
    const entry = this.cache.get(key);
    if (entry === undefined) {
      return undefined;
    }

    if (entry.expires < Date.now()) {
      this.cache.delete(key);
      return undefined;
    }

    return entry.value;
  }

  // biome-ignore lint/suspicious/noExplicitAny: <explanation>
  set(key: string, value: any): void {
    this.cache.set(key, { value, expires: Date.now() + this.ttl });
  }

  delete(key: string): void {
    this.cache.delete(key);
  }
}