lilleman
45d2f5548e
* Regression tests for a receipt body read under a data_coding it is not written in * Read a delivery receipt's body as the octets that arrived, not by its data_coding * Assert SMPPSim's UCS2 receipt body parses like every other segment's * Record the receipt-body defect as fixed * Retain a multipart segment's octets once, not twice * Sort the new type import into its file's order
71 lines
1.7 KiB
TypeScript
71 lines
1.7 KiB
TypeScript
import type { Result } from './result.ts';
|
|
import { framingRefusal } from './pdu-refusal.ts';
|
|
|
|
/**
|
|
* Cuts a byte stream into whole PDUs.
|
|
*
|
|
* Chunks are held in a list and only joined when a complete PDU is available, so a peer dribbling
|
|
* bytes cannot make this quadratic the way concatenating the whole queue on every chunk does.
|
|
*/
|
|
export class PduFramer {
|
|
private chunks: Buffer[] = [];
|
|
private length = 0;
|
|
|
|
get buffered(): number {
|
|
return this.length;
|
|
}
|
|
|
|
push(chunk: Buffer): void {
|
|
if (chunk.length === 0) return;
|
|
|
|
this.chunks.push(chunk);
|
|
this.length += chunk.length;
|
|
}
|
|
|
|
/**
|
|
* Every complete PDU buffered so far. An error means the stream is unusable — the peer sent a
|
|
* command length that cannot be honoured — and the caller should close the connection.
|
|
*/
|
|
next(): Result<{ pdus: Buffer[] }> {
|
|
const pdus: Buffer[] = [];
|
|
|
|
while (this.length >= 16) {
|
|
const cmdLength = this.join(16).readUInt32BE(0);
|
|
const unframable = framingRefusal(cmdLength);
|
|
|
|
if (unframable) return { err: unframable };
|
|
|
|
if (this.length < cmdLength) break;
|
|
|
|
pdus.push(this.take(cmdLength));
|
|
}
|
|
|
|
return { pdus };
|
|
}
|
|
|
|
/** Makes sure the first chunk holds at least `size` octets, then returns it. */
|
|
private join(size: number): Buffer {
|
|
const first = this.chunks[0];
|
|
|
|
if (first && first.length >= size) return first;
|
|
|
|
const joined = Buffer.concat(this.chunks, this.length);
|
|
|
|
this.chunks = [joined];
|
|
|
|
return joined;
|
|
}
|
|
|
|
private take(size: number): Buffer {
|
|
const source = this.join(size);
|
|
const pdu = source.subarray(0, size);
|
|
const rest = source.subarray(size);
|
|
|
|
this.chunks[0] = rest;
|
|
if (rest.length === 0) this.chunks.shift();
|
|
this.length -= size;
|
|
|
|
return pdu;
|
|
}
|
|
}
|