feat: convert file manager into a plugin

plugins/file-manager/src/backend/direct-transfer-routing.ts

@@ -0,0 +1,72 @@
+export interface DirectTransferEndpoint {
+  host: string;
+  port: number;
+  username: string;
+}
+
+export const DIRECT_TRANSFER_MIN_IMPROVEMENT = 0.2;
+export const DIRECT_TRANSFER_MIN_BYTES = 32 * 1024 * 1024;
+
+export function shouldBenchmarkDirectTransfer(totalBytes: number): boolean {
+  return totalBytes >= DIRECT_TRANSFER_MIN_BYTES;
+}
+
+export function quoteShell(value: string): string {
+  return `'${value.replace(/'/g, `'"'"'`)}'`;
+}
+
+function formatHost(host: string): string {
+  return host.includes(":") && !host.startsWith("[") ? `[${host}]` : host;
+}
+
+export function buildDirectSshCommand(
+  endpoint: DirectTransferEndpoint,
+): string {
+  const target = `${endpoint.username}@${formatHost(endpoint.host)}`;
+  return [
+    "ssh",
+    "-o BatchMode=yes",
+    "-o ConnectTimeout=5",
+    "-o StrictHostKeyChecking=yes",
+    `-p ${endpoint.port}`,
+    quoteShell(target),
+  ].join(" ");
+}
+
+export function buildDirectProbeCommand(
+  endpoint: DirectTransferEndpoint,
+): string {
+  return `${buildDirectSshCommand(endpoint)} ${quoteShell("command -v rsync >/dev/null")}`;
+}
+
+export function buildDirectRsyncCommand(
+  endpoint: DirectTransferEndpoint,
+  sourcePaths: string[],
+  destPath: string,
+  destIsDirectory: boolean,
+): string {
+  const sshTransport = buildDirectSshCommand(endpoint).replace(/ '[^']+'$/, "");
+  const targetHost = `${endpoint.username}@${formatHost(endpoint.host)}`;
+  const targetPath = destIsDirectory
+    ? `${destPath.replace(/\/+$/, "") || "/"}/`
+    : destPath;
+  const sources = sourcePaths.map(quoteShell).join(" ");
+  const target = quoteShell(`${targetHost}:${targetPath}`);
+
+  return [
+    "rsync -a --partial --append-verify --protect-args --info=progress2",
+    `-e ${quoteShell(sshTransport)}`,
+    "--",
+    sources,
+    target,
+  ].join(" ");
+}
+
+export function shouldUseDirectTransfer(
+  directMs: number,
+  relayMs: number,
+  minImprovement = DIRECT_TRANSFER_MIN_IMPROVEMENT,
+): boolean {
+  if (directMs <= 0 || relayMs <= 0) return false;
+  return directMs <= relayMs * (1 - minImprovement);
+}