Mercurial > templog
diff server/utils.py @ 22:885532437100
A bit of work on the server python
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sat, 26 May 2012 10:17:27 +0800 |
parents | |
children | b5925cb4f264 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/server/utils.py Sat May 26 10:17:27 2012 +0800 @@ -0,0 +1,75 @@ +import os +import sys +import ctypes +import time +import select + +DEFAULT_TRIES = 3 + +__all__ = ('monotonic_time', 'retry') + +clock_gettime = None +no_clock_gettime = False +def monotonic_time(): + global clock_gettime + global no_clock_gettime + if no_clock_gettime: + return time.time() + + class timespec(ctypes.Structure): + _fields_ = [ + ('tv_sec', ctypes.c_long), + ('tv_nsec', ctypes.c_long) + ] + if not clock_gettime: + try: + librt = ctypes.CDLL('librt.so.0', use_errno=True) + clock_gettime = librt.clock_gettime + clock_gettime.argtypes = [ctypes.c_int, ctypes.POINTER(timespec)] + except: + print>>sys.stderr, "No clock_gettime(), using fake fallback." + no_clock_gettime = True + return time.time() + + t = timespec() + CLOCK_MONOTONIC = 1 # see <linux/time.h> + + if clock_gettime(CLOCK_MONOTONIC, ctypes.pointer(t)) != 0: + errno_ = ctypes.get_errno() + raise OSError(errno_, os.strerror(errno_)) + return t.tv_sec + t.tv_nsec * 1e-9 + +# decorator, tries a number of times, returns None on failure, sleeps between +# Must be used as "@retry()" if arguments are defaulted +def retry(retries=DEFAULT_TRIES, try_time = 1): + def inner(func): + print "inner" + def new_f(*args, **kwargs): + print "newf" + for i in range(retries): + print "retry %d" % i + d = func(*args, **kwargs) + if d: + return d + time.sleep(try_time) + new_f.func_name = func.func_name + return new_f + return inner + +def readline(sock): + timeout = READLINE_SELECT_TIMEOUT + buf = '' + while true: + (rlist, wlist, xlist) = select.select([sock], [], [], timeout) + if sock not in rlist: + # hit timeout + return None + + c = sock.recv(1) + if c == '\r': + continue + + buf.append(c) + if c == '\n': + return buf +