Index: client/common_lib/utils.py |
diff --git a/client/common_lib/utils.py b/client/common_lib/utils.py |
index a117cec4acaad7e7a330d155af846f080ed46818..8a34ef17a02856ded4fcd3be9dd341718f8eb5d3 100644 |
--- a/client/common_lib/utils.py |
+++ b/client/common_lib/utils.py |
@@ -202,6 +202,44 @@ def open_write_close(filename, data): |
f.close() |
+def matrix_to_string(matrix, header=None): |
+ """ |
+ Return a pretty, aligned string representation of a nxm matrix. |
+ |
+ This representation can be used to print any tabular data, such as |
+ database results. It works by scanning the lengths of each element |
+ in each column, and determining the format string dynamically. |
+ |
+ @param matrix: Matrix representation (list with n rows of m elements). |
+ @param header: Optional tuple with header elements to be displayed. |
+ """ |
+ lengths = [] |
+ for row in matrix: |
+ for column in row: |
+ i = row.index(column) |
+ cl = len(column) |
+ try: |
+ ml = lengths[i] |
+ if cl > ml: |
+ lengths[i] = cl |
+ except IndexError: |
+ lengths.append(cl) |
+ |
+ lengths = tuple(lengths) |
+ format_string = "" |
+ for length in lengths: |
+ format_string += "%-" + str(length) + "s " |
+ format_string += "\n" |
+ |
+ matrix_str = "" |
+ if header: |
+ matrix_str += format_string % header |
+ for row in matrix: |
+ matrix_str += format_string % tuple(row) |
+ |
+ return matrix_str |
+ |
+ |
def read_keyval(path): |
""" |
Read a key-value pair format file into a dictionary, and return it. |
@@ -1230,3 +1268,35 @@ def args_to_dict(args): |
logging.warning("args_to_dict: argument '%s' doesn't match " |
"'%s' pattern. Ignored." % (arg, arg_re.pattern)) |
return dict |
+ |
+ |
+def get_unused_port(): |
+ """ |
+ Finds a semi-random available port. A race condition is still |
+ possible after the port number is returned, if another process |
+ happens to bind it. |
+ |
+ Returns: |
+ A port number that is unused on both TCP and UDP. |
+ """ |
+ |
+ def try_bind(port, socket_type, socket_proto): |
+ s = socket.socket(socket.AF_INET, socket_type, socket_proto) |
+ try: |
+ try: |
+ s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) |
+ s.bind(('', port)) |
+ return s.getsockname()[1] |
+ except socket.error: |
+ return None |
+ finally: |
+ s.close() |
+ |
+ # On the 2.6 kernel, calling try_bind() on UDP socket returns the |
+ # same port over and over. So always try TCP first. |
+ while True: |
+ # Ask the OS for an unused port. |
+ port = try_bind(0, socket.SOCK_STREAM, socket.IPPROTO_TCP) |
+ # Check if this port is unused on the other protocol. |
+ if port and try_bind(port, socket.SOCK_DGRAM, socket.IPPROTO_UDP): |
+ return port |