[Init] Initial commit - NetMesh terminal manager

components/terminal/runtime/terminalPerCharacterInput.ts

@@ -0,0 +1,45 @@
+/**
+ * Strict bastion prompts (e.g. QAX/奇安信) treat one SSH channel write as a
+ * single keystroke and silently drop every multi-character chunk (#3077). IME
+ * commits and short raw pastes therefore have to leave the renderer as
+ * per-character writes, which is what typing produces and what Xshell does.
+ */
+
+/** Raw pastes longer than this keep the single-write behavior. */
+export const MAX_RAW_PASTE_PER_CHARACTER_LENGTH = 32;
+
+const ESC = "\x1b";
+
+/** True while the payload only carries plain text and no escape sequence. */
+export const isPlainTerminalInputText = (data: string): boolean => !data.includes(ESC);
+
+/** One chunk per Unicode code point so surrogate pairs stay intact. */
+export const splitTextIntoCodePointWrites = (data: string): string[] => Array.from(data);
+
+/** IME commits: any plain text with more than one character splits per glyph. */
+export const shouldSplitImeTextInputForWire = (text: string): boolean =>
+  Array.from(text).length > 1 && isPlainTerminalInputText(text);
+
+/**
+ * Raw (non-bracketed) paste: short plain text goes out as keystrokes, longer
+ * pastes keep the single write so bulk pastes do not degrade.
+ */
+export const shouldSplitRawPasteInputForWire = (data: string): boolean => {
+  if (data.length <= 1 || !isPlainTerminalInputText(data)) return false;
+  let codePoints = 0;
+  for (let index = 0; index < data.length; ) {
+    index += (data.codePointAt(index) ?? 0) > 0xffff ? 2 : 1;
+    codePoints += 1;
+    if (codePoints > MAX_RAW_PASTE_PER_CHARACTER_LENGTH) return false;
+  }
+  return true;
+};
+
+/** Chunks to write for one input payload; escape sequences are never split. */
+export const getTextInputWireChunks = (
+  data: string,
+  perCharacterWrites: boolean,
+): string[] =>
+  perCharacterWrites && isPlainTerminalInputText(data)
+    ? splitTextIntoCodePointWrites(data)
+    : [data];