wa-lang.org/wazero@v1.0.2/imports/proxywasm/internal/vmstate.go (about)

     1  // Copyright 2020-2021 Tetrate
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  // http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package internal
    16  
    17  import (
    18  	"wa-lang.org/wazero/imports/proxywasm/types"
    19  )
    20  
    21  type (
    22  	pluginContextState struct {
    23  		context       types.PluginContext
    24  		httpCallbacks map[uint32]*httpCallbackAttribute
    25  	}
    26  
    27  	httpCallbackAttribute struct {
    28  		callback        func(numHeaders, bodySize, numTrailers int)
    29  		callerContextID uint32
    30  	}
    31  )
    32  
    33  type state struct {
    34  	vmContext      types.VMContext
    35  	pluginContexts map[uint32]*pluginContextState
    36  	httpContexts   map[uint32]types.HttpContext
    37  	tcpContexts    map[uint32]types.TcpContext
    38  
    39  	contextIDToRootID map[uint32]uint32
    40  	activeContextID   uint32
    41  }
    42  
    43  var currentState = &state{
    44  	pluginContexts:    make(map[uint32]*pluginContextState),
    45  	httpContexts:      make(map[uint32]types.HttpContext),
    46  	tcpContexts:       make(map[uint32]types.TcpContext),
    47  	contextIDToRootID: make(map[uint32]uint32),
    48  }
    49  
    50  func SetVMContext(vmContext types.VMContext) {
    51  	currentState.vmContext = vmContext
    52  }
    53  
    54  func RegisterHttpCallout(calloutID uint32, callback func(numHeaders, bodySize, numTrailers int)) {
    55  	currentState.registerHttpCallOut(calloutID, callback)
    56  }
    57  
    58  func (s *state) createPluginContext(contextID uint32) {
    59  	ctx := s.vmContext.NewPluginContext(contextID)
    60  	s.pluginContexts[contextID] = &pluginContextState{
    61  		context:       ctx,
    62  		httpCallbacks: map[uint32]*httpCallbackAttribute{},
    63  	}
    64  
    65  	// NOTE: this is a temporary work around for avoiding nil pointer panic
    66  	// when users make http dispatch(es) on PluginContext.
    67  	// See https://github.com/tetratelabs/proxy-wasm-go-sdk/issues/110
    68  	// TODO: refactor
    69  	s.contextIDToRootID[contextID] = contextID
    70  }
    71  
    72  func (s *state) createTcpContext(contextID uint32, pluginContextID uint32) bool {
    73  	root, ok := s.pluginContexts[pluginContextID]
    74  	if !ok {
    75  		panic("invalid plugin context id")
    76  	}
    77  
    78  	if _, ok := s.tcpContexts[contextID]; ok {
    79  		panic("context id duplicated")
    80  	}
    81  
    82  	ctx := root.context.NewTcpContext(contextID)
    83  	if ctx == nil {
    84  		// NewTcpContext is not defined by the user
    85  		return false
    86  	}
    87  	s.contextIDToRootID[contextID] = pluginContextID
    88  	s.tcpContexts[contextID] = ctx
    89  	return true
    90  }
    91  
    92  func (s *state) createHttpContext(contextID uint32, pluginContextID uint32) bool {
    93  	root, ok := s.pluginContexts[pluginContextID]
    94  	if !ok {
    95  		panic("invalid plugin context id")
    96  	}
    97  
    98  	if _, ok := s.httpContexts[contextID]; ok {
    99  		panic("context id duplicated")
   100  	}
   101  
   102  	ctx := root.context.NewHttpContext(contextID)
   103  	if ctx == nil {
   104  		// NewHttpContext is not defined by the user
   105  		return false
   106  	}
   107  	s.contextIDToRootID[contextID] = pluginContextID
   108  	s.httpContexts[contextID] = ctx
   109  	return true
   110  }
   111  
   112  func (s *state) registerHttpCallOut(calloutID uint32, callback func(numHeaders, bodySize, numTrailers int)) {
   113  	r := s.pluginContexts[s.contextIDToRootID[s.activeContextID]]
   114  	r.httpCallbacks[calloutID] = &httpCallbackAttribute{callback: callback, callerContextID: s.activeContextID}
   115  }
   116  
   117  func (s *state) setActiveContextID(contextID uint32) {
   118  	s.activeContextID = contextID
   119  }