"""Retain bounded compiled attention executables across global JAX cache clears."""
from collections import OrderedDict
import jax

class PersistentCompiled:
    def __init__(self,function,max_executables=2):
        self.function=jax.jit(function);self.executables=OrderedDict();self.max_executables=max_executables;self.compilations=0
    def __call__(self,*args):
        leaves,tree=jax.tree_util.tree_flatten(args)
        signatures=[]
        for value in leaves:
            abstract=jax.core.get_aval(value)
            signatures.append((abstract.shape,str(abstract.dtype),bool(abstract.weak_type)))
        key=(tree,tuple(signatures))
        if key not in self.executables:
            self.executables[key]=self.function.lower(*args).compile();self.compilations+=1
            while len(self.executables)>self.max_executables:self.executables.popitem(last=False)
        self.executables.move_to_end(key)
        return self.executables[key](*args)