commit f7d18618e20b440b0efaccb6f4a5786842700f9c Author: Damian Johnson atagar@torproject.org Date: Sun Jan 29 17:35:28 2012 -0800

Removing CALL_MOCKING from the system module

While writing the unit and integ tests I realized that the tests could be greatly simplified by adding an override function called 'CALL_MOCKING' that would let the tests modify the call function's behavior.

This was a mistake. Production code should be designed to make testing easy because this leads to better production code, but adding hacks that are only useful for testing is bad. Now that we have a nice mocking module the CALL_MOCKING hack is no longer necessary so removing it. --- stem/util/system.py | 61 +++++++++++--------------------------------------- 1 files changed, 14 insertions(+), 47 deletions(-)

diff --git a/stem/util/system.py b/stem/util/system.py index f58f698..1a85dc8 100644 --- a/stem/util/system.py +++ b/stem/util/system.py @@ -23,16 +23,6 @@ import subprocess import stem.util.proc import stem.util.log as log

-# Functor for mocking the call function, which should either return a string -# (or None) to emulate responses, or a boolean to indicate if we should filter -# the call. Also, when set... -# - we don't check that commands exist before calling them -# - the use of proc functions is disabled -# -# This is intended for testing purposes only. - -CALL_MOCKING = None - # Mapping of commands to if they're available or not. This isn't always # reliable, failing for some special commands. For these the cache is # prepopulated to skip lookups. @@ -121,7 +111,7 @@ def is_running(command): # -o ucomm= - Shows just the ucomm attribute ("name to be used for # accounting")

- if CALL_MOCKING or is_available("ps"): + if is_available("ps"): if is_bsd(): primary_resolver = IS_RUNNING_PS_BSD secondary_resolver = IS_RUNNING_PS_LINUX @@ -166,7 +156,7 @@ def get_pid_by_name(process_name): # 3283 # 3392

- if CALL_MOCKING or is_available("pgrep"): + if is_available("pgrep"): results = call(GET_PID_BY_NAME_PGREP % process_name)

if results and len(results) == 1: @@ -180,7 +170,7 @@ def get_pid_by_name(process_name): # atagar@morrigan:~$ pidof vim # 3392 3283

- if CALL_MOCKING or is_available("pidof"): + if is_available("pidof"): results = call(GET_PID_BY_NAME_PIDOF % process_name)

if results and len(results) == 1 and len(results[0].split()) == 1: @@ -203,8 +193,8 @@ def get_pid_by_name(process_name): # 11 ?? Ss 5:47.36 DirectoryService # 12 ?? Ss 3:01.44 notifyd

- if CALL_MOCKING or is_available("ps"): - if CALL_MOCKING or not is_bsd(): + if is_available("ps"): + if not is_bsd(): # linux variant of ps results = call(GET_PID_BY_NAME_PS_LINUX % process_name)

@@ -212,7 +202,7 @@ def get_pid_by_name(process_name): pid = results[1].strip() if pid.isdigit(): return int(pid)

- if CALL_MOCKING or is_bsd(): + if is_bsd(): # bsd variant of ps results = call(GET_PID_BY_NAME_PS_BSD)

@@ -238,7 +228,7 @@ def get_pid_by_name(process_name): # 2470 # 2561

- if CALL_MOCKING or is_available("lsof"): + if is_available("lsof"): results = call(GET_PID_BY_NAME_LSOF % process_name)

if results and len(results) == 1: @@ -286,7 +276,7 @@ def get_pid_by_port(port): # udp 0 0 0.0.0.0:5353 0.0.0.0:* - # udp6 0 0 fe80::7ae4:ff:fe2f::123 :::* -

- if CALL_MOCKING or is_available("netstat"): + if is_available("netstat"): results = call(GET_PID_BY_PORT_NETSTAT)

if results: @@ -320,7 +310,7 @@ def get_pid_by_port(port): # _tor tor 4397 15 tcp4 51.64.7.84:59374 7.42.1.102:9001 # _tor tor 4397 20 tcp4 51.64.7.84:51946 32.83.7.104:443

- if CALL_MOCKING or is_available("sockstat"): + if is_available("sockstat"): results = call(GET_PID_BY_PORT_SOCKSTAT % port)

if results: @@ -348,7 +338,7 @@ def get_pid_by_port(port): # COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME # tor 1745 atagar 6u IPv4 14229 0t0 TCP 127.0.0.1:9051 (LISTEN)

- if CALL_MOCKING or is_available("lsof"): + if is_available("lsof"): results = call(GET_PID_BY_PORT_LSOF)

if results: @@ -387,7 +377,7 @@ def get_pid_by_open_file(path): # atagar@morrigan:~$ lsof -tw /tmp/foo # 4762

- if CALL_MOCKING or is_available("lsof"): + if is_available("lsof"): results = call(GET_PID_BY_FILE_LSOF % path)

if results and len(results) == 1: @@ -409,14 +399,14 @@ def get_cwd(pid): """

# try fetching via the proc contents if it's available - if stem.util.proc.is_available() and not CALL_MOCKING: + if stem.util.proc.is_available(): try: return stem.util.proc.get_cwd(pid) except IOError: pass

# Fall back to a pwdx query. This isn't available on BSD. logging_prefix = "get_cwd(%s):" % pid

- if CALL_MOCKING or is_available("pwdx"): + if is_available("pwdx"): # pwdx results are of the form: # 3799: /home/atagar # 5839: No such process @@ -447,7 +437,7 @@ def get_cwd(pid): # p75717 # n/Users/atagar/tor/src/or

- if CALL_MOCKING or is_available("lsof"): + if is_available("lsof"): results = call(GET_CWD_LSOF % pid)

if results and len(results) == 2 and results[1].startswith("n/"): @@ -563,29 +553,6 @@ def call(command, suppress_exc = True): OSError if this fails and suppress_exc is False """

- # Most of our system functions rely on system calls through this function, so - # testing may need to mock responses to exercise our various functionality. - - if CALL_MOCKING: - mock_response = CALL_MOCKING(command) - - # Mocking either returns... - # - str/None for unit tests to emulate system calls - # - bool for integ tests to indicate if we should make this system call or - # suppress it, to selectively trigger logic - - if isinstance(mock_response, bool): - if mock_response: - pass # mocking indicates that we should go on to make the real call - else: - # call should be suppressed - if suppress_exc: return None - else: raise OSError("System call filtered by mocking") - else: - if mock_response == None and not suppress_exc: - raise OSError("Mocking provided a None response") - else: return mock_response - try: start_time = time.time() stdout, stderr = subprocess.Popen(command.split(), stdout = subprocess.PIPE, stderr = subprocess.PIPE).communicate()