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# Copyright (c) 2009 Advanced Micro Devices, Inc.
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from m5.params import *
from m5.proxy import *

from m5.util import fatal
from m5.SimObject import SimObject
from m5.objects.Network import RubyNetwork
from m5.objects.BasicRouter import BasicRouter
from m5.objects.MessageBuffer import MessageBuffer

class SimpleNetwork(RubyNetwork):
    type = 'SimpleNetwork'
    cxx_header = "mem/ruby/network/simple/SimpleNetwork.hh"
    cxx_class = 'gem5::ruby::SimpleNetwork'

    buffer_size = Param.Int(0, "default internal buffer size for links and\
                                routers; 0 indicates infinite buffering")
    endpoint_bandwidth = Param.Int(1000, "bandwidth adjustment factor")

    physical_vnets_channels = VectorParam.Int([],
        "Set to emulate multiple channels for each vnet."
        "If not set, all vnets share the same physical channel.")

    physical_vnets_bandwidth = VectorParam.Int([],
        "Assign a different link bandwidth factor for each vnet channels."
        "Only valid when physical_vnets_channels is set. This overrides the"
        "bandwidth_factor parameter set for the  individual links.")

    def setup_buffers(self):
        # Setup internal buffers for links and routers
        for link in self.int_links:
            link.setup_buffers(self)
        for router in self.routers:
            router.setup_buffers(self)


class BaseRoutingUnit(SimObject):
    type = 'BaseRoutingUnit'
    abstract = True
    cxx_header = 'mem/ruby/network/simple/routing/BaseRoutingUnit.hh'
    cxx_class = 'gem5::ruby::BaseRoutingUnit'


class WeightBased(BaseRoutingUnit):
    type = 'WeightBased'
    cxx_header = 'mem/ruby/network/simple/routing/WeightBased.hh'
    cxx_class = 'gem5::ruby::WeightBased'

    adaptive_routing = Param.Bool(False, "enable adaptive routing")


class SwitchPortBuffer(MessageBuffer):
    """MessageBuffer type used internally by the Switch port buffers"""
    ordered = True
    allow_zero_latency = True

class Switch(BasicRouter):
    type = 'Switch'
    cxx_header = 'mem/ruby/network/simple/Switch.hh'
    cxx_class = 'gem5::ruby::Switch'

    virt_nets = Param.Int(Parent.number_of_virtual_networks,
                          "number of virtual networks")

    int_routing_latency = Param.Cycles(BasicRouter.latency,
                                    "Routing latency to internal links")
    ext_routing_latency = Param.Cycles(BasicRouter.latency,
                                    "Routing latency to external links")

    # Internal port buffers used between the PerfectSwitch and
    # Throttle objects. There is one buffer per virtual network
    # and per output port.
    # These are created by setup_buffers and the user should not
    # set these manually.
    port_buffers = VectorParam.MessageBuffer([], "Port buffers")

    routing_unit = Param.BaseRoutingUnit(
                        WeightBased(adaptive_routing = False),
                        "Routing strategy to be used")

    def setup_buffers(self, network):
        def vnet_buffer_size(vnet):
            """
            Gets the size of the message buffers associated to a vnet
            If physical_vnets_channels is set we just multiply the size of the
            buffers as SimpleNetwork does not actually creates multiple phy
            channels per vnet.
            """
            if len(network.physical_vnets_channels) == 0:
                return network.buffer_size
            else:
                return network.buffer_size * \
                       network.physical_vnets_channels[vnet]

        if len(self.port_buffers) > 0:
            fatal("User should not manually set routers' port_buffers")

        router_buffers = []
        # Add message buffers to routers at the end of each
        # unidirectional internal link
        for link in network.int_links:
            if link.dst_node == self:
                for i in range(int(network.number_of_virtual_networks)):
                    router_buffers.append(SwitchPortBuffer(
                                    buffer_size = vnet_buffer_size(i)))

        # Add message buffers to routers for each external link connection
        for link in network.ext_links:
            # Routers can only be int_nodes on ext_links
            if link.int_node == self:
                for i in range(int(network.number_of_virtual_networks)):
                    router_buffers.append(SwitchPortBuffer(
                                    buffer_size = vnet_buffer_size(i)))

        self.port_buffers = router_buffers