git ssb

1
const {wasm2json, json2wasm} = require('wasm-json-toolkit')
2
const Message = require('./message.js')
3
const wasmMetering = require('wasm-metering')
4
const customTypes = require('./customTypes.js')
5
const typeCheckWrapper = require('./typeCheckWrapper.js')
6
const ReferanceMap = require('reference-map')
7
const leb128 = require('leb128')
8
9
const nativeTypes = new Set(['i32', 'i64', 'f32', 'f64'])
10
const LANGUAGE_TYPES = {
11
  'actor': 0x0,
12
  'buf': 0x1,
13
  'elem': 0x2,
14
  'i32': 0x7f,
15
  'i64': 0x7e,
16
  'f32': 0x7d,
17
  'f64': 0x7c,
18
  'anyFunc': 0x70,
19
  'func': 0x60,
20
  'block_type': 0x40,
21
22
  0x0: 'actor',
23
  0x1: 'buf',
24
  0x7f: 'i32',
25
  0x7e: 'i64',
26
  0x7d: 'f32',
27
  0x7c: 'f64',
28
  0x70: 'anyFunc',
29
  0x60: 'func',
30
  0x40: 'block_type'
31
}
32
33
class ElementBuffer {
34
  constructor (size) {
35
    this._array = new Array(size)
36
  }
37
38
  serialize () {
39
    const serialized = this._array.map(ref => ref.serailize())
40
    return Buffer.concat(Buffer.from([LANGUAGE_TYPES['elem']]), leb128.encode(serialized.length), serialized)
41
  }
42
43
  static deserialize (serialized) {}
44
}
45
46
class DataBuffer {
47
  constructor (memory, offset, length) {
48
    this._data = new Uint8Array(this.instance.exports.memory.buffer, offset, length)
49
  }
50
  serialize () {
51
    return Buffer.concat(Buffer.from([LANGUAGE_TYPES['elem']]), leb128.encode(this._data.length), this._data)
52
  }
53
  static deserialize (serialized) {}
54
}
55
56
class LinkRef {
57
  serialize () {
58
    return Buffer.concat(Buffer.from([LANGUAGE_TYPES['link'], this]))
59
  }
60
  static deserialize (serialized) {}
61
}
62
63
class FunctionRef {
64
  static get type () {
65
    return 'funcRef'
66
  }
67
68
  constructor (name, json, id) {
69
    this.name = name
70
    this.destId = id
71
    this.args = []
72
    const typeIndex = json.typeMap[name]
73
    const type = json.type[typeIndex]
74
    const wrapper = typeCheckWrapper(type)
75
    const wasm = json2wasm(wrapper)
76
    this.mod = WebAssembly.Module(wasm)
77
    const self = this
78
    const instance = WebAssembly.Instance(this.mod, {
79
      'env': {
80
        'checkTypes': function () {
81
          const args = [...arguments]
82
          const checkedArgs = []
83
          while (args.length) {
84
            const type = LANGUAGE_TYPES[args.shift()]
85
            let arg = args.shift()
86
            if (!nativeTypes.has(type)) {
87
              arg = self._container.refs.get(arg, type)
88
            }
89
            checkedArgs.push(arg)
90
          }
91
          const message = new Message({
92
            funcRef: self,
93
            funcArguments: checkedArgs
94
          })
95
          self._container.actor.send(message)
96
        }
97
      }
98
    })
99
    this.wrapper = instance
100
  }
101
  set container (container) {
102
    this._container = container
103
  }
104
}
105
106
module.exports = class WasmContainer {
107
  constructor (actor) {
108
    this.actor = actor
109
    this.refs = new ReferanceMap()
110
  }
111
112
  static async onCreation (wasm, id, cachedb) {
113
    WebAssembly.validate(wasm)
114
    let moduleJSON = wasm2json(wasm)
115
    const json = mergeTypeSections(moduleJSON)
116
    moduleJSON = wasmMetering.meterJSON(moduleJSON, {
117
      meterType: 'i32'
118
    })
119
    wasm = json2wasm(moduleJSON)
120
    await Promise.all([
121
      new Promise((resolve, reject) => {
122
        cachedb.put(id.toString() + 'meta', JSON.stringify(json), resolve)
123
      }),
124
      new Promise((resolve, reject) => {
125
        cachedb.put(id.toString() + 'code', wasm.toString('hex'), resolve)
126
      })
127
    ])
128
    const refs = {}
129
    Object.keys(json.typeMap).forEach(key => {
130
      refs[key] = new FunctionRef(key, json, id)
131
    })
132
    return refs
133
  }
134
135
  sendMessage () {
136
    console.log('send')
137
  }
138
139
  getInterface (funcRef) {
140
    const self = this
141
    return {
142
      func: {
143
        externalize: () => {},
144
        internalize: (ref, index) => {
145
          const funcRef = self.refs.get(ref, 'funcRef')
146
          funcRef.container = self
147
          this.instance.exports.table.set(index, funcRef.wrapper.exports.check)
148
        },
149
        catch: (ref, catchRef) => {
150
          const {funcRef} = self.refs.get(ref, FunctionRef)
151
          const {funcRef: catchFunc} = self.refs.get(ref, FunctionRef)
152
          funcRef.catch = catchFunc
153
        },
154
        getGasAmount: (funcRef) => {},
155
        setGasAmount: (funcRef) => {}
156
      },
157
      link: {
158
        wrap: (ref) => {
159
          const obj = this.refs.get(ref)
160
          const link = new LinkRef(obj.serialize())
161
          return this.refs.add(link, 'link')
162
        },
163
        unwrap: async (ref, cb) => {
164
          const obj = this.refs.get(ref, 'link')
165
          const promise = this.actor.tree.dataStore.get(obj)
166
          await this._opsQueue.push(promise)
167
          // todo
168
        }
169
      },
170
      module: {
171
        new: code => {},
172
        exports: (mod, name) => {},
173
        self: () => {
174
          return this.refs.add(this.json)
175
        }
176
      },
177
      memory: {
178
        externalize: (index, length) => {
179
          const buf = this.getMemory(index, length)
180
          return this.refs.add(buf, 'buf')
181
        },
182
        internalize: (dataRef, writeOffset, readOffset, length) => {
183
          let buf = this.refs.get(dataRef, 'buf')
184
          buf = buf.subarray(readOffset, length)
185
          const mem = this.getMemory(writeOffset, buf.length)
186
          mem.set(buf)
187
        }
188
      },
189
      table: {
190
        externalize: (index, length) => {
191
          const mem = this.getMemory(index, length * 4)
192
          const objects = []
193
          while (length--) {
194
            const ref = mem[index + length]
195
            if (this.refs.has(ref)) {
196
              objects.push(ref)
197
            } else {
198
              throw new Error('invalid ref')
199
            }
200
          }
201
          const eleBuf = new ElementBuffer(objects)
202
          return this.refs.add(eleBuf, 'ele')
203
        },
204
        internalize: (dataRef, writeOffset, readOffset, length) => {
205
          let buf = this.refs.get(dataRef, 'ele')
206
          buf = buf.subarray(readOffset, length)
207
          const mem = this.getMemory(writeOffset, buf.length)
208
          mem.set(buf)
209
        }
210
      },
211
      metering: {
212
        usegas: (amount) => {
213
          funcRef.gas -= amount
214
          if (funcRef.gas < 0) {
215
            throw new Error('out of gas! :(')
216
          }
217
        }
218
      }
219
    }
220
  }
221
222
  async onMessage (message) {
223
    const funcRef = message.funcRef
224
    const intef = this.getInterface(funcRef)
225
    this.instance = WebAssembly.Instance(this.mod, intef)
226
    if (this.instance.exports.table) {
227
      this._orginalTable = this.instance.exports.table
228
    }
229
    const args = message.funcArguments.map(arg => {
230
      if (typeof arg === 'number') {
231
        return arg
232
      } else {
233
        return this.refs.add(arg, arg.constructor.type)
234
      }
235
    })
236
    this.instance.exports[funcRef.name](...args)
237
    await this.onDone()
238
    this.refs.clear()
239
  }
240
241
  /**
242
   * returns a promise that resolves when the wasm instance is done running
243
   * @returns {Promise}
244
   */
245
  async onDone () {
246
    let prevOps
247
    while (prevOps !== this._opsQueue) {
248
      prevOps = this._opsQueue
249
      await prevOps
250
    }
251
  }
252
253
  /**
254
   * Pushed an async operation to the a promise queue that
255
   * @returns {Promise} the returned promise resolves in the order the intail
256
   * operation was pushed to the queue
257
   */
258
  pushOpsQueue (promise) {
259
    this._opsQueue = Promise.all([this._opsQueue, promise])
260
    return this._opsQueue
261
  }
262
263
  getFuncRef (name, send) {
264
    const funcRef = new FunctionRef(this.json, name, send)
265
    return funcRef
266
  }
267
268
  async onStartup () {
269
    let [json, wasm] = await Promise.all([
270
      new Promise((resolve, reject) => {
271
        this.actor.cachedb.get(this.actor.id.toString() + 'meta', (err, json) => {
272
          if (err) {
273
            reject(err)
274
          } else {
275
            resolve(json)
276
          }
277
        })
278
      }),
279
      new Promise((resolve, reject) => {
280
        this.actor.cachedb.get(this.actor.id.toString() + 'code', (err, wasm) => {
281
          if (err) {
282
            reject(err)
283
          } else {
284
            resolve(wasm)
285
          }
286
        })
287
      })
288
    ])
289
    wasm = Buffer.from(wasm, 'hex')
290
    json = JSON.parse(json)
291
    this.mod = WebAssembly.Module(wasm)
292
    this.json = json
293
  }
294
295
  getMemory (offset, length) {
296
    return new DataBuffer(this.instance.exports.memory.buffer, offset, length)
297
  }
298
299
  static get typeId () {
300
    return 9
301
  }
302
}
303
304
function mergeTypeSections (json) {
305
  const typeInfo = {
306
    typeMap: [],
307
    type: []
308
  }
309
  let typeSection = {
310
    'entries': []
311
  }
312
  let importSection = {
313
    'entries': []
314
  }
315
  let functionSection = {
316
    'entries': []
317
  }
318
  let exportSection = {
319
    'entries': []
320
  }
321
  json.forEach(section => {
322
    switch (section.name) {
323
      case 'type':
324
        typeSection = section
325
        break
326
      case 'export':
327
        exportSection = section
328
        break
329
      case 'import':
330
        importSection = section
331
        break
332
      case 'function':
333
        functionSection = section
334
        break
335
      case 'custom':
336
        switch (section.sectionName) {
337
          case 'type':
338
            typeInfo.type = customTypes.decodeType(section.payload)
339
            break
340
          case 'typeMap':
341
            typeInfo.typeMap = customTypes.decodeTypeMap(section.payload)
342
            break
343
        }
344
        break
345
    }
346
  })
347
348
  const foundTypes = new Map()
349
  const mappedFuncs = new Map()
350
  const newTypeMap = {}
351
  typeInfo.typeMap.forEach(map => mappedFuncs.set(map.func, map.type))
352
  for (let exprt of exportSection.entries) {
353
    if (exprt.kind === 'function') {
354
      if (!mappedFuncs.has(exprt.index)) {
355
        const typeIndex = functionSection.entries[exprt.index - importSection.entries.length]
356
        if (!foundTypes.has(typeIndex)) {
357
          const customIndex = typeInfo.type.push(typeSection.entries[typeIndex]) - 1
358
          foundTypes.set(typeIndex, customIndex)
359
        }
360
        const customIndex = foundTypes.get(typeIndex)
361
        newTypeMap[exprt.field_str] = customIndex
362
      } else {
363
        newTypeMap[exprt.field_str] = mappedFuncs.get(exprt.index)
364
      }
365
    }
366
  }
367
368
  typeInfo.typeMap = newTypeMap
369
  return typeInfo
370
}
371