[ovs-dev] python: Fix decoding error when the received data is larger than 4096.

It can only receive 4096 bytes of data each time in jsonrpc,
when there are similar and Chinese characters occupy multiple bytes,
it may receive half a character, this time the decoding will be abnormal.
We need to receive the completed character to decode.

Signed-off-by: Guoshuai Li <ligs@dtdream.com>
---
 python/ovs/jsonrpc.py | 14 +++++++++-----
 tests/ovsdb-idl.at    | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 5 deletions(-)

There was a problem with the patch's encoding. I resubmit v2.
> It can only receive 4096 bytes of data each time in jsonrpc,
> when there are similar and Chinese characters occupy multiple bytes,
> it may receive half a character, this time the decoding will be abnormal.
> We need to receive the completed character to decode.
>
> Signed-off-by: Guoshuai Li <ligs@dtdream.com>
> ---
>   python/ovs/jsonrpc.py | 14 +++++++++-----
>   tests/ovsdb-idl.at    | 34 ++++++++++++++++++++++++++++++++++
>   2 files changed, 43 insertions(+), 5 deletions(-)
>
> diff --git a/python/ovs/jsonrpc.py b/python/ovs/jsonrpc.py
> index d284190e0..a46821093 100644
> --- a/python/ovs/jsonrpc.py
> +++ b/python/ovs/jsonrpc.py
> @@ -262,17 +262,21 @@ class Connection(object):
>           if self.status:
>               return self.status, None
>   
> +        recv_buffer = bytearray()
>           while True:
>               if not self.input:
> +                recv_data = None
>                   error, data = self.stream.recv(4096)
> +                recv_buffer.extend(bytes(data))
>                   # Python 3 has separate types for strings and bytes.  We
>                   # received bytes from a socket.  We expect it to be string
>                   # data, so we convert it here as soon as possible.
>                   if data and not error:
>                       try:
> -                        data = data.decode('utf-8')
> +                        recv_data = recv_buffer.decode('utf-8')
> +                        recv_buffer = bytearray()
>                       except UnicodeError:
> -                        error = errno.EILSEQ
> +                        continue
>                   if error:
>                       if (sys.platform == "win32" and
>                               error == errno.WSAEWOULDBLOCK):
> @@ -287,12 +291,12 @@ class Connection(object):
>                                     % (self.name, os.strerror(error)))
>                           self.error(error)
>                           return self.status, None
> -                elif not data:
> +                elif not recv_data:
>                       self.error(EOF)
>                       return EOF, None
>                   else:
> -                    self.input += data
> -                    self.received_bytes += len(data)
> +                    self.input += recv_data
> +                    self.received_bytes += len(recv_data)
>               else:
>                   if self.parser is None:
>                       self.parser = ovs.json.Parser()
> diff --git a/tests/ovsdb-idl.at b/tests/ovsdb-idl.at
> index 59b2c1991..d63b7758f 100644
> --- a/tests/ovsdb-idl.at
> +++ b/tests/ovsdb-idl.at
> @@ -328,6 +328,40 @@ OVSDB_CHECK_IDL([simple idl, writing via IDL with unicode],
>   003: done
>   ]])
>   
> +# same as OVSDB_CHECK_IDL but uses the Python IDL implementation.
> +m4_define([OVSDB_CHECK_IDL_PYN_WITH_EXPOUT],
> +  [AT_SETUP([$1])
> +   AT_SKIP_IF([test $7 = no])
> +   AT_KEYWORDS([ovsdb server idl positive Python $5])
> +   AT_CHECK([ovsdb_start_idltest])
> +   m4_if([$2], [], [],
> +     [AT_CHECK([ovsdb-client transact unix:socket $2], [0], [ignore], [ignore])])
> +   AT_CHECK([$8 $srcdir/test-ovsdb.py  -t10 idl $srcdir/idltest.ovsschema unix:socket $3],
> +            [0], [stdout], [ignore])
> +   echo "$4" > expout
> +   AT_CHECK([sort stdout | uuidfilt]m4_if([$6],,, [[| $6]]),
> +            [0], [expout])
> +   OVSDB_SERVER_SHUTDOWN
> +   AT_CLEANUP])
> +
> +m4_define([OVSDB_CHECK_IDL_PY_WITH_EXPOUT],
> +   [OVSDB_CHECK_IDL_PYN_WITH_EXPOUT([$1 - Python2], [$2], [$3], [$4], [$5], [$6],
> +                                    [$HAVE_PYTHON], [$PYTHON])
> +    OVSDB_CHECK_IDL_PYN_WITH_EXPOUT([$1 - Python3], [$2], [$3], [$4], [$5], [$6],
> +                                    [$HAVE_PYTHON3], [$PYTHON3])])
> +
> +OVSDB_CHECK_IDL_PY_WITH_EXPOUT([simple idl, writing large data via IDL with unicode],
> +  [['["idltest",
> +      {"op": "insert",
> +       "table": "simple",
> +       "row": {"s": "'$(printf "测试超过四千零九十六个字节的中文字符串以使解码出现问题。%.0s" {1..50})'"}}]']],
> +  [['set 0 b 1, insert 1, set 1 s '$(printf "测试超过四千零九十六个字节的中文字符串以使解码出现问题。%.0s" {1..100})'']],
> +  [[000: i=0 r=0 b=false s=$(printf "测试超过四千零九十六个字节的中文字符串以使解码出现问题。%.0s" {1..50}) u=<0> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>
> +001: commit, status=success
> +002: i=0 r=0 b=true s=$(printf "测试超过四千零九十六个字节的中文字符串以使解码出现问题。%.0s" {1..50}) u=<0> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<1>
> +002: i=1 r=0 b=false s=$(printf "测试超过四千零九十六个字节的中文字符串以使解码出现问题。%.0s" {1..100}) u=<0> ia=[] ra=[] ba=[] sa=[] ua=[] uuid=<2>
> +003: done]])
> +
>   OVSDB_CHECK_IDL([simple idl, handling verification failure],
>     [['["idltest",
>         {"op": "insert",