/**
* Schema Cache
* In-memory cache for dataset schemas to reduce API calls
* Requirements: 2.4
*/
/**
* Column information from a dataset schema
*/
export interface ColumnInfo {
name: string; // Human-readable name
fieldName: string; // API field name for SoQL
dataType: string; // Data type (text, number, calendar_date, etc.)
}
/**
* Schema result containing dataset metadata and columns
*/
export interface SchemaResult {
columns: ColumnInfo[];
datasetName: string;
rowCount: number;
}
/**
* Internal cache entry with timestamp for TTL expiration
*/
interface CacheEntry {
schema: SchemaResult;
timestamp: number;
}
/**
* In-memory cache for dataset schemas with TTL support
*/
export class SchemaCache {
private cache: Map<string, CacheEntry>;
private ttlMs: number;
/**
* Create a new SchemaCache
* @param ttlMs Time-to-live in milliseconds (default: 5 minutes)
*/
constructor(ttlMs: number = 5 * 60 * 1000) {
this.cache = new Map();
this.ttlMs = ttlMs;
}
/**
* Get a schema from the cache if it exists and hasn't expired
* @param datasetId The 4x4 dataset ID
* @returns The cached schema or null if not found/expired
*/
get(datasetId: string): SchemaResult | null {
const entry = this.cache.get(datasetId);
if (!entry) {
return null;
}
// Check if entry has expired
if (Date.now() - entry.timestamp > this.ttlMs) {
this.cache.delete(datasetId);
return null;
}
return entry.schema;
}
/**
* Store a schema in the cache
* @param datasetId The 4x4 dataset ID
* @param schema The schema to cache
*/
set(datasetId: string, schema: SchemaResult): void {
this.cache.set(datasetId, {
schema,
timestamp: Date.now()
});
}
/**
* Check if a non-expired schema exists in the cache
* @param datasetId The 4x4 dataset ID
* @returns true if a valid cached entry exists
*/
has(datasetId: string): boolean {
return this.get(datasetId) !== null;
}
/**
* Clear all entries from the cache
*/
clear(): void {
this.cache.clear();
}
}
