[Libguestfs] [PATCH 3/5] output/rhv-upload-plugin: Extract send_flush() helper

[Richard W.M. Jones]

On Sat, Dec 18, 2021 at 10:36:31PM +0200, Nir Soffer wrote:
> Extract a helper for sending flush request for single connection, and
> inline the iter_http_pool() helper into flush(), its only user.
> ---
>  output/rhv-upload-plugin.py | 54 ++++++++++++++++---------------------
>  1 file changed, 23 insertions(+), 31 deletions(-)
> 
> diff --git a/output/rhv-upload-plugin.py b/output/rhv-upload-plugin.py
> index bad0e8a3..f7e5950f 100644
> --- a/output/rhv-upload-plugin.py
> +++ b/output/rhv-upload-plugin.py
> @@ -271,36 +271,51 @@ def emulate_zero(h, count, offset, flags):
>          r = http.getresponse()
>          if r.status != 200:
>              request_failed(r,
>                             "could not write zeroes offset %d size %d" %
>                             (offset, count))
>  
>          r.read()
>  
>  
>  def flush(h, flags):
> +    # Wait until all inflight requests are completed, and send a flush
> +    # request for all imageio connections.
> +    locked = []
> +
> +    # Lock the pool by taking all connections out.
> +    while len(locked) < pool.maxsize:
> +        locked.append(pool.get())
> +
> +    try:
> +        for http in locked:
> +            send_flush(http)
> +    finally:
> +        # Unlock the pool by puting the connection back.
> +        for http in locked:
> +            pool.put(http)
> +
> +
> +def send_flush(http):
>      # Construct the JSON request for flushing.
>      buf = json.dumps({'op': "flush"}).encode()
>  
>      headers = {"Content-Type": "application/json",
>                 "Content-Length": str(len(buf))}
>  
> -    # Wait until all inflight requests are completed, and send a flush
> -    # request for all imageio connections.
> -    for http in iter_http_pool(pool):
> -        http.request("PATCH", url.path, body=buf, headers=headers)
> +    http.request("PATCH", url.path, body=buf, headers=headers)
>  
> -        r = http.getresponse()
> -        if r.status != 200:
> -            request_failed(r, "could not flush")
> +    r = http.getresponse()
> +    if r.status != 200:
> +        request_failed(r, "could not flush")
>  
> -        r.read()
> +    r.read()
>  
>  
>  # Modify http.client.HTTPConnection to work over a Unix domain socket.
>  # Derived from uhttplib written by Erik van Zijst under an MIT license.
>  # (https://pypi.org/project/uhttplib/)
>  # Ported to Python 3 by Irit Goihman.
>  class UnixHTTPConnection(HTTPConnection):
>      def __init__(self, path, timeout=socket._GLOBAL_DEFAULT_TIMEOUT):
>          self.path = path
>          HTTPConnection.__init__(self, "localhost", timeout=timeout)
> @@ -337,43 +352,20 @@ def http_context(pool):
>      Context manager yielding an imageio http connection from the pool. Blocks
>      until a connection is available.
>      """
>      http = pool.get()
>      try:
>          yield http
>      finally:
>          pool.put(http)
>  
>  
> -def iter_http_pool(pool):
> -    """
> -    Wait until all inflight requests are done, and iterate on imageio
> -    connections.
> -
> -    The pool is empty during iteration. New requests issued during iteration
> -    will block until iteration is done.
> -    """
> -    locked = []
> -
> -    # Lock the pool by taking all connections out.
> -    while len(locked) < pool.maxsize:
> -        locked.append(pool.get())
> -
> -    try:
> -        for http in locked:
> -            yield http
> -    finally:
> -        # Unlock the pool by puting the connection back.
> -        for http in locked:
> -            pool.put(http)
> -
> -
>  def close_http_pool(pool):
>      """
>      Wait until all inflight requests are done, close all connections and remove
>      them from the pool.
>  
>      No request can be served by the pool after this call.
>      """
>      nbdkit.debug("closing http pool")
>  
>      locked = []

This one looks like a neutral refactoring, so ACK

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.
http://fedoraproject.org/wiki/MinGW