second commit

env/lib/python3.11/site-packages/websockets/streams.py

@@ -0,0 +1,151 @@
+from __future__ import annotations
+
+from collections.abc import Generator
+
+
+class StreamReader:
+    """
+    Generator-based stream reader.
+
+    This class doesn't support concurrent calls to :meth:`read_line`,
+    :meth:`read_exact`, or :meth:`read_to_eof`. Make sure calls are
+    serialized.
+
+    """
+
+    def __init__(self) -> None:
+        self.buffer = bytearray()
+        self.eof = False
+
+    def read_line(self, m: int) -> Generator[None, None, bytes]:
+        """
+        Read a LF-terminated line from the stream.
+
+        This is a generator-based coroutine.
+
+        The return value includes the LF character.
+
+        Args:
+            m: Maximum number bytes to read; this is a security limit.
+
+        Raises:
+            EOFError: If the stream ends without a LF.
+            RuntimeError: If the stream ends in more than ``m`` bytes.
+
+        """
+        n = 0  # number of bytes to read
+        p = 0  # number of bytes without a newline
+        while True:
+            n = self.buffer.find(b"\n", p) + 1
+            if n > 0:
+                break
+            p = len(self.buffer)
+            if p > m:
+                raise RuntimeError(f"read {p} bytes, expected no more than {m} bytes")
+            if self.eof:
+                raise EOFError(f"stream ends after {p} bytes, before end of line")
+            yield
+        if n > m:
+            raise RuntimeError(f"read {n} bytes, expected no more than {m} bytes")
+        r = self.buffer[:n]
+        del self.buffer[:n]
+        return r
+
+    def read_exact(self, n: int) -> Generator[None, None, bytes]:
+        """
+        Read a given number of bytes from the stream.
+
+        This is a generator-based coroutine.
+
+        Args:
+            n: How many bytes to read.
+
+        Raises:
+            EOFError: If the stream ends in less than ``n`` bytes.
+
+        """
+        assert n >= 0
+        while len(self.buffer) < n:
+            if self.eof:
+                p = len(self.buffer)
+                raise EOFError(f"stream ends after {p} bytes, expected {n} bytes")
+            yield
+        r = self.buffer[:n]
+        del self.buffer[:n]
+        return r
+
+    def read_to_eof(self, m: int) -> Generator[None, None, bytes]:
+        """
+        Read all bytes from the stream.
+
+        This is a generator-based coroutine.
+
+        Args:
+            m: Maximum number bytes to read; this is a security limit.
+
+        Raises:
+            RuntimeError: If the stream ends in more than ``m`` bytes.
+
+        """
+        while not self.eof:
+            p = len(self.buffer)
+            if p > m:
+                raise RuntimeError(f"read {p} bytes, expected no more than {m} bytes")
+            yield
+        r = self.buffer[:]
+        del self.buffer[:]
+        return r
+
+    def at_eof(self) -> Generator[None, None, bool]:
+        """
+        Tell whether the stream has ended and all data was read.
+
+        This is a generator-based coroutine.
+
+        """
+        while True:
+            if self.buffer:
+                return False
+            if self.eof:
+                return True
+            # When all data was read but the stream hasn't ended, we can't
+            # tell if until either feed_data() or feed_eof() is called.
+            yield
+
+    def feed_data(self, data: bytes) -> None:
+        """
+        Write data to the stream.
+
+        :meth:`feed_data` cannot be called after :meth:`feed_eof`.
+
+        Args:
+            data: Data to write.
+
+        Raises:
+            EOFError: If the stream has ended.
+
+        """
+        if self.eof:
+            raise EOFError("stream ended")
+        self.buffer += data
+
+    def feed_eof(self) -> None:
+        """
+        End the stream.
+
+        :meth:`feed_eof` cannot be called more than once.
+
+        Raises:
+            EOFError: If the stream has ended.
+
+        """
+        if self.eof:
+            raise EOFError("stream ended")
+        self.eof = True
+
+    def discard(self) -> None:
+        """
+        Discard all buffered data, but don't end the stream.
+
+        """
+        del self.buffer[:]