From: Adam Dorsey <adam.dor...@twosixtech.com>
Expose the limit parameter of the underlying StreamReader and StreamWriter
instances.
This is helpful for the use case of transferring files in and out of a VM
via the QEMU guest agent's guest-file-open, guest-file-read, guest-file-write,
and guest-file-close methods, as it allows pushing the buffer size up to the
guest agent's limit of 48MB per transfer.
Signed-off-by: Adam Dorsey <adam@dorseys.email>
cherry picked from commit 9ba6a698344eb3b570fa4864e906c54042824cd6
cherry picked from commit e4d0d3f835d82283ee0e48438d1b154e18303491
[Squashed in linter fixups. --js]
Signed-off-by: John Snow <js...@redhat.com>
---
python/qemu/qmp/protocol.py | 25 ++++++++++++++++---------
python/qemu/qmp/qmp_client.py | 18 ++++++++++++++----
2 files changed, 30 insertions(+), 13 deletions(-)
diff --git a/python/qemu/qmp/protocol.py b/python/qemu/qmp/protocol.py
index 958aeca08ac..3d5eb553aad 100644
--- a/python/qemu/qmp/protocol.py
+++ b/python/qemu/qmp/protocol.py
@@ -53,6 +53,9 @@
UnixAddrT = str
SocketAddrT = Union[UnixAddrT, InternetAddrT]
+# Maximum allowable size of read buffer, default
+_DEFAULT_READBUFLEN = 64 * 1024
+
class Runstate(Enum):
"""Protocol session runstate."""
@@ -202,22 +205,26 @@ class AsyncProtocol(Generic[T]):
will log to 'qemu.qmp.protocol', but each individual connection
can be given its own logger by giving it a name; messages will
then log to 'qemu.qmp.protocol.${name}'.
+ :param readbuflen:
+ The maximum read buffer length of the underlying StreamReader
+ instance.
"""
# pylint: disable=too-many-instance-attributes
#: Logger object for debugging messages from this connection.
logger = logging.getLogger(__name__)
- # Maximum allowable size of read buffer
- _limit = 64 * 1024
-
# -------------------------
# Section: Public interface
# -------------------------
- def __init__(self, name: Optional[str] = None) -> None:
+ def __init__(
+ self, name: Optional[str] = None,
+ readbuflen: int = _DEFAULT_READBUFLEN
+ ) -> None:
self._name: Optional[str]
self.name = name
+ self.readbuflen = readbuflen
# stream I/O
self._reader: Optional[StreamReader] = None
@@ -574,7 +581,7 @@ async def _do_start_server(self, address: SocketAddrT,
port=address[1],
ssl=ssl,
backlog=1,
- limit=self._limit,
+ limit=self.readbuflen,
)
else:
coro = asyncio.start_unix_server(
@@ -582,7 +589,7 @@ async def _do_start_server(self, address: SocketAddrT,
path=address,
ssl=ssl,
backlog=1,
- limit=self._limit,
+ limit=self.readbuflen,
)
# Allow runstate watchers to witness 'CONNECTING' state; some
@@ -637,7 +644,7 @@ async def _do_connect(self, address: Union[SocketAddrT,
socket.socket],
"fd=%d, family=%r, type=%r",
address.fileno(), address.family, address.type)
connect = asyncio.open_connection(
- limit=self._limit,
+ limit=self.readbuflen,
ssl=ssl,
sock=address,
)
@@ -647,14 +654,14 @@ async def _do_connect(self, address: Union[SocketAddrT,
socket.socket],
address[0],
address[1],
ssl=ssl,
- limit=self._limit,
+ limit=self.readbuflen,
)
else:
self.logger.debug("Connecting to file://%s ...", address)
connect = asyncio.open_unix_connection(
path=address,
ssl=ssl,
- limit=self._limit,
+ limit=self.readbuflen,
)
self._reader, self._writer = await connect
diff --git a/python/qemu/qmp/qmp_client.py b/python/qemu/qmp/qmp_client.py
index a87fb565ab5..d826331b6d5 100644
--- a/python/qemu/qmp/qmp_client.py
+++ b/python/qemu/qmp/qmp_client.py
@@ -170,6 +170,12 @@ class QMPClient(AsyncProtocol[Message], Events):
:param name: Optional nickname for the connection, used for logging.
+ :param readbuflen:
+ The maximum buffer length for reads and writes to and from the QMP
+ server, in bytes. Default is 10MB. If `QMPClient` is used to
+ connect to a guest agent to transfer files via ``guest-file-read``/
+ ``guest-file-write``, increasing this value may be required.
+
Basic script-style usage looks like this::
qmp = QMPClient('my_virtual_machine_name')
@@ -203,14 +209,18 @@ async def run(self, address='/tmp/qemu.socket'):
#: Logger object used for debugging messages.
logger = logging.getLogger(__name__)
- # Read buffer limit; 10MB like libvirt default
- _limit = 10 * 1024 * 1024
+ # Read buffer default limit; 10MB like libvirt default
+ _readbuflen = 10 * 1024 * 1024
# Type alias for pending execute() result items
_PendingT = Union[Message, ExecInterruptedError]
- def __init__(self, name: Optional[str] = None) -> None:
- super().__init__(name)
+ def __init__(
+ self,
+ name: Optional[str] = None,
+ readbuflen: int = _readbuflen
+ ) -> None:
+ super().__init__(name, readbuflen)
Events.__init__(self)
#: Whether or not to await a greeting after establishing a connection.
--
2.50.1
