chore: sync workspace changes

api/app/services/stomp_protocol.py

@@ -0,0 +1,136 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+SUPPORTED_STOMP_VERSIONS = ("1.2", "1.1", "1.0")
+STOMP_SUBPROTOCOLS = ("v12.stomp", "v11.stomp", "v10.stomp")
+TOPIC_DESTINATION_PREFIX = "/topic/"
+
+
+@dataclass(frozen=True)
+class StompFrame:
+    command: str
+    headers: dict[str, str]
+    body: str = ""
+
+
+def select_stomp_version(accept_version_header: str | None) -> str | None:
+    if not accept_version_header:
+        return "1.0"
+    requested = {version.strip() for version in accept_version_header.split(",") if version.strip()}
+    for version in SUPPORTED_STOMP_VERSIONS:
+        if version in requested:
+            return version
+    return None
+
+
+def topic_to_destination(topic: str) -> str:
+    return f"{TOPIC_DESTINATION_PREFIX}{topic}"
+
+
+def destination_to_topic(destination: str) -> str | None:
+    if destination.startswith(TOPIC_DESTINATION_PREFIX):
+        topic = destination[len(TOPIC_DESTINATION_PREFIX):].strip()
+        return topic if topic else None
+    return None
+
+
+def build_stomp_frame(command: str, *, headers: dict[str, str] | None = None, body: str = "") -> str:
+    lines = [command]
+    for key, value in (headers or {}).items():
+        lines.append(f"{_escape_header(key)}:{_escape_header(value)}")
+    lines.append("")
+    return "\n".join(lines) + body + "\x00"
+
+
+def parse_stomp_frames(payload: str) -> list[StompFrame]:
+    frames: list[StompFrame] = []
+    cursor = 0
+    data = payload.replace("\r\n", "\n")
+
+    while cursor < len(data):
+        while cursor < len(data) and data[cursor] == "\n":
+            cursor += 1
+        if cursor >= len(data):
+            break
+
+        terminator = data.find("\x00", cursor)
+        if terminator < 0:
+            raise ValueError("frame_terminator_missing")
+
+        raw_frame = data[cursor:terminator]
+        cursor = terminator + 1
+        if not raw_frame:
+            continue
+
+        frames.append(_parse_single_frame(raw_frame))
+
+    return frames
+
+
+def _parse_single_frame(raw_frame: str) -> StompFrame:
+    header_blob, has_body, body = raw_frame.partition("\n\n")
+    header_lines = [line.rstrip("\r") for line in header_blob.split("\n")]
+    if not header_lines:
+        raise ValueError("missing_command")
+
+    command = header_lines[0].strip().upper()
+    if not command:
+        raise ValueError("missing_command")
+
+    headers: dict[str, str] = {}
+    for line in header_lines[1:]:
+        if not line:
+            continue
+        if ":" not in line:
+            raise ValueError("malformed_header")
+        key, value = line.split(":", 1)
+        headers[_unescape_header(key)] = _unescape_header(value)
+
+    if not has_body:
+        body = ""
+    if "content-length" in headers:
+        try:
+            size = int(headers["content-length"])
+        except ValueError as exc:
+            raise ValueError("invalid_content_length") from exc
+        if size < 0:
+            raise ValueError("invalid_content_length")
+        body = body[:size]
+
+    return StompFrame(command=command, headers=headers, body=body)
+
+
+def _escape_header(value: str) -> str:
+    return (
+        value.replace("\\", "\\\\")
+        .replace("\r", "\\r")
+        .replace("\n", "\\n")
+        .replace(":", "\\c")
+    )
+
+
+def _unescape_header(value: str) -> str:
+    result = ""
+    cursor = 0
+    while cursor < len(value):
+        char = value[cursor]
+        if char != "\\":
+            result += char
+            cursor += 1
+            continue
+        cursor += 1
+        if cursor >= len(value):
+            result += "\\"
+            break
+        escaped = value[cursor]
+        cursor += 1
+        if escaped == "r":
+            result += "\r"
+        elif escaped == "n":
+            result += "\n"
+        elif escaped == "c":
+            result += ":"
+        else:
+            result += escaped
+    return result