/**
* Short-Term Memory Manager
* Implements a FIFO-based temporary memory cache
*/
import { ShortTermMemoryEntry, MCPResponse } from './types.js';
export class ShortTermMemory {
private memories: ShortTermMemoryEntry[] = [];
private capacity: number;
constructor(capacity: number = 100) {
this.capacity = capacity;
}
/**
* Add a new entry to short-term memory
* Automatically evicts oldest entry if capacity is exceeded
*/
add(text: string): MCPResponse<void> {
try {
if (!text || text.trim().length === 0) {
return {
success: false,
error: 'Memory text cannot be empty',
};
}
const entry: ShortTermMemoryEntry = {
text: text.trim(),
timestamp: Date.now(),
};
this.memories.push(entry);
// FIFO eviction: remove oldest if capacity exceeded
if (this.memories.length > this.capacity) {
this.memories.shift(); // Remove first (oldest) element
}
return {
success: true,
data: undefined,
};
} catch (error) {
return {
success: false,
error: `Failed to add short-term memory: ${(error as Error).message}`,
};
}
}
/**
* Get all short-term memories (newest first)
*/
getAll(): MCPResponse<ShortTermMemoryEntry[]> {
try {
// Return reversed copy (newest first) without modifying original
return {
success: true,
data: [...this.memories].reverse(),
};
} catch (error) {
return {
success: false,
error: `Failed to retrieve short-term memories: ${(error as Error).message}`,
};
}
}
/**
* Clear all short-term memories
*/
clear(): MCPResponse<void> {
try {
this.memories = [];
return {
success: true,
data: undefined,
};
} catch (error) {
return {
success: false,
error: `Failed to clear short-term memory: ${(error as Error).message}`,
};
}
}
/**
* Get current count of memories
*/
getCount(): number {
return this.memories.length;
}
/**
* Update capacity (does not affect existing memories)
*/
setCapacity(newCapacity: number): MCPResponse<void> {
try {
if (newCapacity < 1) {
return {
success: false,
error: 'Capacity must be at least 1',
};
}
this.capacity = newCapacity;
// Trim if current size exceeds new capacity
while (this.memories.length > this.capacity) {
this.memories.shift();
}
return {
success: true,
data: undefined,
};
} catch (error) {
return {
success: false,
error: `Failed to set capacity: ${(error as Error).message}`,
};
}
}
}
