Added some more skeleton around strategies.
This commit is contained in:
Michael Whittaker
parent
56992f1c8d
commit
efbeb8dc44
1 changed files with 94 additions and 19 deletions
|
|
@ -1,5 +1,8 @@
|
|||
from typing import Iterator, Generic, List, Optional, Set, TypeVar
|
||||
from typing import (Dict, Iterator, Generic, List, Optional, Set, Tuple,
|
||||
TypeVar, Union)
|
||||
import itertools
|
||||
import numpy as np
|
||||
import pulp
|
||||
|
||||
|
||||
T = TypeVar('T')
|
||||
|
|
@ -139,15 +142,53 @@ def _or(lhs: Expr[T], rhs: Expr[T]) -> 'Or[T]':
|
|||
return Or([lhs, rhs])
|
||||
|
||||
|
||||
def choose(k: int, es: List[Expr[T]]) -> Choose[T]:
|
||||
def choose(k: int, es: List[Expr[T]]) -> Expr[T]:
|
||||
if k == 1:
|
||||
return Or(es)
|
||||
elif k == len(es):
|
||||
return And(es)
|
||||
else:
|
||||
return Choose(k, es)
|
||||
|
||||
|
||||
def majority(es: List[Expr[T]]) -> Choose[T]:
|
||||
return Choose(len(es) // 2 + 1, es)
|
||||
def majority(es: List[Expr[T]]) -> Expr[T]:
|
||||
return choose(len(es) // 2 + 1, es)
|
||||
|
||||
|
||||
class QuorumSystem:
|
||||
Distribution = Union[int, float, Dict[float, float], List[Tuple[float, float]]]
|
||||
|
||||
|
||||
def _canonicalize_distribution(d: Distribution) -> Dict[float, float]:
|
||||
if isinstance(d, int):
|
||||
if d < 0 or d > 1:
|
||||
raise ValueError('distribution must be in the range [0, 1]')
|
||||
return {float(d): 1.}
|
||||
elif isinstance(d, float):
|
||||
if d < 0 or d > 1:
|
||||
raise ValueError('distribution must be in the range [0, 1]')
|
||||
return {d: 1.}
|
||||
elif isinstance(d, dict):
|
||||
if len(d) == 0:
|
||||
raise ValueError('distribution cannot empty')
|
||||
|
||||
if any(weight < 0 for weight in d.values()):
|
||||
raise ValueError('distribution cannot have negative weights')
|
||||
|
||||
total_weight = sum(d.values())
|
||||
if total_weight == 0:
|
||||
raise ValueError('distribution cannot have zero weight')
|
||||
|
||||
return {float(f): weight / total_weight
|
||||
for (f, weight) in d.items()
|
||||
if weight > 0}
|
||||
elif isinstance(d, list):
|
||||
return _canonicalize_distribution({f: weight for (f, weight) in d})
|
||||
else:
|
||||
raise ValueError('distribution must be an int, a float, a Dict[float, '
|
||||
'float] or a List[Tuple[float, float]]')
|
||||
|
||||
|
||||
class QuorumSystem(Generic[T]):
|
||||
def __init__(self, reads: Optional[Expr[T]] = None,
|
||||
writes: Optional[Expr[T]] = None) -> None:
|
||||
if reads is not None and writes is not None:
|
||||
|
|
@ -170,17 +211,55 @@ class QuorumSystem:
|
|||
def __repr__(self) -> str:
|
||||
return f'QuorumSystem(reads={self.reads}, writes={self.writes})'
|
||||
|
||||
def strategy(self, read_fraction: Distribution) -> 'Strategy[T]':
|
||||
# TODO(mwhittaker): Implement.
|
||||
reads = list(self.read_quorums())
|
||||
writes = list(self.write_quorums())
|
||||
return ExplicitStrategy(reads, [1 / len(reads)] * len(reads),
|
||||
writes, [1 / len(writes)] * len(writes))
|
||||
|
||||
def is_read_quorum(self, xs: Set[T]) -> bool:
|
||||
return self.reads.is_quorum(xs)
|
||||
|
||||
def read_quorums(self) -> Iterator[Set[T]]:
|
||||
return self.reads.quorums()
|
||||
|
||||
def write_quorums(self) -> Iterator[Set[T]]:
|
||||
return self.writes.quorums()
|
||||
|
||||
def is_read_quorum(self, xs: Set[T]) -> bool:
|
||||
return self.reads.is_quorum(xs)
|
||||
|
||||
def is_write_quorum(self, xs: Set[T]) -> bool:
|
||||
return self.writes.is_quorum(xs)
|
||||
class Strategy(Generic[T]):
|
||||
def load(self, read_fraction: Distribution) -> int:
|
||||
raise NotImplementedError
|
||||
|
||||
def get_read_quorum(self) -> Set[T]:
|
||||
raise NotImplementedError
|
||||
|
||||
def get_write_quorum(self) -> Set[T]:
|
||||
raise NotImplementedError
|
||||
|
||||
|
||||
class ExplicitStrategy(Strategy[T]):
|
||||
def __init__(self,
|
||||
reads: List[Set[T]],
|
||||
read_weights: List[float],
|
||||
writes: List[Set[T]],
|
||||
write_weights: List[float]) -> None:
|
||||
self.reads = reads
|
||||
self.read_weights = read_weights
|
||||
self.writes = writes
|
||||
self.write_weights = write_weights
|
||||
|
||||
# TODO(mwhittaker): Implement __str__ and __repr__.
|
||||
|
||||
def load(self, read_fraction: Distribution) -> int:
|
||||
raise NotImplementedError
|
||||
|
||||
def get_read_quorum(self) -> Set[T]:
|
||||
return np.random.choice(self.reads, p=self.read_weights)
|
||||
|
||||
def get_write_quorum(self) -> Set[T]:
|
||||
return np.random.choice(self.writes, p=self.write_weights)
|
||||
|
||||
|
||||
a = Node('a')
|
||||
|
|
@ -188,18 +267,14 @@ b = Node('b')
|
|||
c = Node('c')
|
||||
d = Node('d')
|
||||
e = Node('e')
|
||||
f = Node('g')
|
||||
f = Node('f')
|
||||
g = Node('g')
|
||||
h = Node('h')
|
||||
i = Node('i')
|
||||
|
||||
disjunction = a + b + c
|
||||
conjunction = disjunction * disjunction * disjunction
|
||||
print(conjunction)
|
||||
print(conjunction.dual())
|
||||
print(conjunction.dual().dual())
|
||||
print(QuorumSystem(reads=conjunction))
|
||||
|
||||
grid = QuorumSystem(reads=a*b*c + d*e*f + g*h*i)
|
||||
sigma = grid.strategy(0.1)
|
||||
for _ in range(10):
|
||||
print(sigma.get_write_quorum())
|
||||
|
||||
# - num_quorums
|
||||
# - has dups?
|
||||
|
|
|
|||
Loading…
Reference in a new issue