def bisect(a, too_high):
"""Return the first index i in a such that too_high(a[i]) is true; or
len(a) if too_high(x) is true for all elements x in a.
The usual use for this function is deciding where to insert element;
e.g. my_list.insert(bisect(my_list, lambda elem,x=x: x < elem), x)
Requires: a is monotonic non-decreasing in the truth of too_high;
i.e. exists[pos] ((all[j in [0, pos)] not too_high(a[j]))
and all[j in [pos, len(a))] too_high(a[j])).
Put another way:
all[(i,j) s.t. i <= j] too_high(a[i]) implies too_high(a[j]).
Note that this more or less requires that neither a nor too_high change
during execution (say due to writes from another thread).
Ensures: The return value equals pos above. I.e.:
(all[j in [0, ret)] not too_high(a[j]))
and (all[j in [ret, len(a))] too_high(a[j])).
"""
check.check_has_type(a, types.ListType)
check.check_is_callable(too_high)
lo = 0
hi = len(a)
while lo < hi:
mid = (lo+hi) >> 1
if too_high(a[mid]):
hi = mid
else:
lo = mid+1
check.check_assertion((0 <= lo) and (lo <= len(a)))
## Check sortedness:
#for elem in a[:lo]:
# if too_high(elem):
# check.show_bug('utility.bisect: unsorted input list (or bug in bisect code)')
#for elem in a[lo:]:
# if not too_high(elem):
# check.show_bug('utility.bisect: unsorted input list (or bug in bisect code)')
return lo
def schedule_mainthread(t_plus, func, *parameters):
""" Schedule an action:
after t_plus milliseconds, func will be called in the main thread with
the parameters given.
If func returns true, it will be called again after another t_plus
milliseconds"""
check.check_has_type(t_plus, types.FloatType)
check.check_is_callable(func)
daemon_action_lock.acquire()
try:
new_time = time.time() + t_plus/1000.0
action_item = (new_time,
func,
parameters,
t_plus)
pos = bisect(daemon_action_list,
lambda elem, new_time=new_time: new_time < elem[0])
daemon_action_list.insert(pos, action_item)
finally:
daemon_action_lock.release()
