Merge pull request #453 from asciinema/feature/fifo-reopen

Improved handling of named pipes (FIFO)

asciinema/asciicast/raw.py

@@ -1,40 +1,36 @@
-from os import path, stat
-from typing import IO, Any, Optional
+import os
+from os import path
+from typing import Any, Callable, Optional
+
+from ..file_writer import file_writer
 
 
-class writer:
+class writer(file_writer):
     def __init__(
         self,
         path_: str,
         metadata: Any = None,
         append: bool = False,
         buffering: int = 0,
+        on_error: Optional[Callable[[str], None]] = None,
     ) -> None:
+        super().__init__(path_, on_error)
+
         if (
-            append and path.exists(path_) and stat(path_).st_size == 0
+            append and path.exists(path_) and os.stat(path_).st_size == 0
         ):  # true for pipes
             append = False
 
-        self.path = path_
         self.buffering = buffering
         self.mode: str = "ab" if append else "wb"
-        self.file: Optional[IO[Any]] = None
         self.metadata = metadata
 
-    def __enter__(self) -> Any:
-        self.file = open(self.path, mode=self.mode, buffering=self.buffering)
-        return self
-
-    def __exit__(
-        self, exc_type: str, exc_value: str, exc_traceback: str
-    ) -> None:
-        assert self.file is not None
-        self.file.close()
-
     def write_stdout(self, _ts: float, data: Any) -> None:
-        assert self.file is not None
-        self.file.write(data)
+        self._write(data)
 
     # pylint: disable=no-self-use
     def write_stdin(self, ts: float, data: Any) -> None:
         pass
+
+    def _open_file(self) -> None:
+        self.file = open(self.path, mode=self.mode, buffering=self.buffering)

asciinema/asciicast/v2.py

@@ -1,9 +1,19 @@
 import codecs
 import json
 from codecs import StreamReader
-from io import IOBase
 from json.decoder import JSONDecodeError
-from typing import IO, Any, Dict, Generator, List, Optional, TextIO, Union
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    Generator,
+    List,
+    Optional,
+    TextIO,
+    Union,
+)
+
+from ..file_writer import file_writer
 
 
 class LoadError(Exception):
@@ -86,21 +96,22 @@ def build_header(
     return header
 
 
-class writer:
+class writer(file_writer):
     def __init__(  # pylint: disable=too-many-arguments
         self,
-        path: str,
+        path_: str,
         metadata: Any = None,
         append: bool = False,
         buffering: int = 1,
         width: Optional[int] = None,
         height: Optional[int] = None,
+        on_error: Optional[Callable[[str], None]] = None,
     ) -> None:
-        self.path = path
+        super().__init__(path_, on_error)
+
         self.buffering = buffering
         self.stdin_decoder = codecs.getincrementaldecoder("UTF-8")("replace")
         self.stdout_decoder = codecs.getincrementaldecoder("UTF-8")("replace")
-        self.file: Optional[IO[Any]] = None
 
         if append:
             self.mode = "a"
@@ -110,24 +121,13 @@ class writer:
             self.header = build_header(width, height, metadata or {})
 
     def __enter__(self) -> Any:
-        self.file = open(
-            self.path,
-            mode=self.mode,
-            buffering=self.buffering,
-            encoding="utf-8",
-        )
+        self._open_file()
 
         if self.header:
             self.__write_line(self.header)
 
         return self
 
-    def __exit__(
-        self, exc_type: str, exc_value: str, exc_traceback: str
-    ) -> None:
-        assert isinstance(self.file, IOBase)
-        self.file.close()
-
     def write_stdout(self, ts: float, data: Union[str, bytes]) -> None:
         if isinstance(data, str):
             data = data.encode(encoding="utf-8", errors="strict")
@@ -140,6 +140,14 @@ class writer:
         data = self.stdin_decoder.decode(data)
         self.__write_event(ts, "i", data)
 
+    def _open_file(self) -> None:
+        self.file = open(
+            self.path,
+            mode=self.mode,
+            buffering=self.buffering,
+            encoding="utf-8",
+        )
+
     def __write_event(self, ts: float, etype: str, data: str) -> None:
         self.__write_line([round(ts, 6), etype, data])
 
@@ -147,5 +155,5 @@ class writer:
         line = json.dumps(
             obj, ensure_ascii=False, indent=None, separators=(", ", ": ")
         )
-        assert isinstance(self.file, IOBase)
-        self.file.write(f"{line}\n")
+
+        self._write(f"{line}\n")

asciinema/async_worker.py

@@ -31,6 +31,11 @@ class async_worker:
         assert isinstance(self.process, Process)
         self.process.join()
 
+        if self.process.exitcode != 0:
+            raise RuntimeError(
+                f"worker process exited with code {self.process.exitcode}"
+            )
+
     def enqueue(self, payload: Any) -> None:
         self.queue.put(payload)
 

asciinema/file_writer.py

@@ -0,0 +1,43 @@
+import os
+import stat
+from typing import IO, Any, Callable, Optional
+
+
+class file_writer:
+    def __init__(
+        self,
+        path: str,
+        on_error: Optional[Callable[[str], None]] = None,
+    ) -> None:
+        self.path = path
+        self.file: Optional[IO[Any]] = None
+        self.on_error = on_error
+
+    def __enter__(self) -> Any:
+        self._open_file()
+        return self
+
+    def __exit__(
+        self, exc_type: str, exc_value: str, exc_traceback: str
+    ) -> None:
+        assert self.file is not None
+        self.file.close()
+
+    def _open_file(self) -> None:
+        raise NotImplementedError
+
+    def _write(self, data: Any) -> None:
+        try:
+            self.file.write(data)  # type: ignore
+        except BrokenPipeError as e:
+            if stat.S_ISFIFO(os.stat(self.path).st_mode):
+                if self.on_error:
+                    self.on_error("Broken pipe, reopening...")
+                    self._open_file()
+                    self.on_error("Output pipe reopened successfully")
+                else:
+                    self._open_file()
+
+                self.file.write(data)  # type: ignore
+            else:
+                raise e

asciinema/recorder.py

@@ -64,8 +64,14 @@ def record(  # pylint: disable=too-many-arguments,too-many-locals
     if append and os.stat(path_).st_size > 0:
         time_offset = v2.get_duration(path_)
 
-    with async_writer(writer, path_, full_metadata, append) as _writer:
     with async_notifier(notifier) as _notifier:
+        with async_writer(
+            writer,
+            path_,
+            full_metadata,
+            append,
+            _notifier.queue,
+        ) as _writer:
             record_(
                 ["sh", "-c", command],
                 _writer,
@@ -79,13 +85,19 @@ def record(  # pylint: disable=too-many-arguments,too-many-locals
 
 class async_writer(async_worker):
     def __init__(
-        self, writer: Type[w2], path_: str, metadata: Any, append: bool = False
+        self,
+        writer: Type[w2],
+        path_: str,
+        metadata: Any,
+        append: bool = False,
+        notifier_q: Any = None,
     ) -> None:
         async_worker.__init__(self)
         self.writer = writer
         self.path = path_
         self.metadata = metadata
         self.append = append
+        self.notifier_q = notifier_q
 
     def write_stdin(self, ts: float, data: Any) -> None:
         self.enqueue([ts, "i", data])
@@ -95,7 +107,10 @@ class async_writer(async_worker):
 
     def run(self) -> None:
         with self.writer(
-            self.path, metadata=self.metadata, append=self.append
+            self.path,
+            metadata=self.metadata,
+            append=self.append,
+            on_error=self.__on_error,
         ) as w:
             event: Tuple[float, str, Any]
             for event in iter(self.queue.get, None):
@@ -107,6 +122,10 @@ class async_writer(async_worker):
                 elif etype == "i":
                     w.write_stdin(ts, data)
 
+    def __on_error(self, reason: str) -> None:
+        if self.notifier_q:
+            self.notifier_q.put(reason)
+
 
 class async_notifier(async_worker):
     def __init__(self, notifier: Any) -> None: