git ssb

1
var packCodec = require('js-git/lib/pack-codec')
2
var pull = require('pull-stream')
3
var cat = require('pull-cat')
4
var buffered = require('pull-buffered')
5
var pack = require('./pack')
6
7
function handleOption(options, name, value) {
8
  switch (name) {
9
    case 'verbosity':
10
      options.verbosity = +value || 0
11
      return true
12
    case 'progress':
13
      options.progress = !!value && value !== 'false'
14
      return true
15
    default:
16
      console.error('unknown option', name + ': ' + value)
17
      return false
18
  }
19
}
20
21
function capabilitiesSource() {
22
  return pull.once([
23
    'option',
24
    'connect',
25
  ].join('\n') + '\n\n')
26
}
27
28
function split2(str, delim) {
29
  var i = str.indexOf(delim || ' ')
30
  return (i === -1) ? [str, ''] : [
31
    str.substr(0, i),
32
    str.substr(i + 1)
33
  ]
34
}
35
36
function split3(str) {
37
  var args = split2(str)
38
  return [args[0]].concat(split2(args[1]))
39
}
40
41
function optionSource(cmd, options) {
42
  var args = split2(cmd)
43
  var msg = handleOption(options, args[0], args[1])
44
  msg = (msg === true) ? 'ok'
45
      : (msg === false) ? 'unsupported'
46
      : 'error ' + msg
47
  return pull.once(msg + '\n')
48
}
49
50
// transform ref objects into lines
51
function listRefs(read) {
52
  var ended
53
  return function (abort, cb) {
54
    if (ended) return cb(ended)
55
    read(abort, function (end, ref) {
56
      ended = end
57
      if (end === true) cb(null, '\n')
58
      if (end) cb(end)
59
      else cb(null,
60
        [ref.value, ref.name].concat(ref.attrs || []).join(' ') + '\n')
61
    })
62
  }
63
}
64
65
// upload-pack: fetch to client
66
function uploadPack(read, getObjects, refSource, wantSink, options) {
67
  /* multi_ack thin-pack side-band side-band-64k ofs-delta shallow no-progress
68
   * include-tag multi_ack_detailed symref=HEAD:refs/heads/master
69
   * agent=git/2.7.0 */
70
  var sendRefs = receivePackHeader([
71
  ], refSource, false)
72
73
  var lines = packLineDecode(read, options)
74
  // var havesSink = pull.drain(console.error.bind(console, 'have:'))
75
  var readHave = lines.haves()
76
  var acked
77
  var commonHash
78
  var sendPack
79
  var earlyDisconnect
80
81
  function haveObject(hash, cb) {
82
    cb(/* TODO */)
83
    // cb(true)
84
  }
85
86
  // Packfile negotiation
87
  return cat([
88
    packLineEncode(cat([
89
      sendRefs,
90
      pull.once(''),
91
      function (abort, cb) {
92
        if (abort) return
93
        if (acked) return cb(true)
94
        // read upload request (wants list) from client
95
        var readWant = lines.wants(wantsDone)
96
        readWant(null, function (end, want) {
97
          if (end === true) {
98
            // client disconnected before sending wants
99
            earlyDisconnect = true
100
            cb(true)
101
          } else if (end) {
102
            cb(end)
103
          } else {
104
            wantSink(readWant)
105
          }
106
        })
107
108
        function wantsDone(err) {
109
          // console.error('wants done', err, earlyDisconnect)
110
          if (err) return cb(err)
111
          if (earlyDisconnect) return cb(true)
112
          // Read upload haves (haves list).
113
          // On first obj-id that we have, ACK
114
          // If we have none, NAK.
115
          // TODO: implement multi_ack_detailed
116
          readHave(null, function next(end, have) {
117
            if (end === true) {
118
              // found no common object
119
              acked = true
120
              cb(null, 'NAK')
121
            } else if (end)
122
              cb(end)
123
            else if (have.type != 'have')
124
              cb(new Error('Unknown have' + JSON.stringify(have)))
125
            else
126
              console.error('got have', have),
127
              haveObject(have.hash, function (haveIt) {
128
                if (!haveIt)
129
                  return readHave(null, next)
130
                commonHash = haveIt
131
                acked = true
132
                cb(null, 'ACK ' + have.hash)
133
              })
134
          })
135
        }
136
      },
137
    ])),
138
    function havesDone(abort, cb) {
139
      // console.error("haves done", abort && typeof abort, sendPack && typeof sendPack, abort, earlyDisconnect)
140
      if (abort || earlyDisconnect) return cb(abort || true)
141
      // send pack file to client
142
      if (!sendPack)
143
        getObjects(commonHash, function (err, numObjects, readObject) {
144
          sendPack = pack.encode(numObjects, readObject)
145
          havesDone(abort, cb)
146
        })
147
      else
148
        sendPack(abort, cb)
149
    }
150
  ])
151
}
152
153
function packLineEncode(read) {
154
  var ended
155
  return function (end, cb) {
156
    if (ended) return cb(ended)
157
    read(end, function (end, data) {
158
      if (ended = end) {
159
        cb(end)
160
      } else {
161
        // console.error("data", data)
162
        if (data)
163
          data += '\n'
164
        else
165
          data = ''
166
        var len = data ? data.length + 4 : 0
167
        var hexLen = ('000' + len.toString(16)).substr(-4)
168
        var pkt = hexLen + data
169
        console.error('>', JSON.stringify(pkt))
170
        cb(end, pkt)
171
      }
172
    })
173
  }
174
}
175
176
function rev(str) {
177
  return str === '0000000000000000000000000000000000000000' ? null : str
178
}
179
180
/* pull-stream/source.js */
181
function abortCb(cb, abort, onAbort) {
182
  cb(abort)
183
  onAbort && onAbort(abort === true ? null: abort)
184
  return
185
}
186
187
function packLineDecode(read, options) {
188
  var b = buffered(read)
189
  var readPrefix = b.chunks(4)
190
  var ended
191
192
  function readPackLine(abort, cb) {
193
    if (ended) return cb(ended)
194
    readPrefix(abort, function (end, buf) {
195
      if (ended = end) return cb(end)
196
      var len = parseInt(buf, 16)
197
      if (!len)
198
        return cb(null, new Buffer(''))
199
      // TODO: figure out this -4 thing
200
      b.chunks(len - 4)(null, function (end, buf) {
201
        if (ended = end) return cb(end)
202
        cb(end, buf)
203
      })
204
    })
205
  }
206
207
  function readPackLineStr(abort, cb) {
208
    if (ended) return cb(ended)
209
    readPackLine(abort, function (end, buf) {
210
      if (ended = end) return cb(end)
211
      // trim newline
212
      var len = buf.length
213
      if (buf[len - 1] == 0xa)
214
        len--
215
      var line = buf.toString('ascii', 0, len)
216
      cb(null, line)
217
    })
218
  }
219
220
  function readUpdate(abort, cb) {
221
    readPackLine(abort, function (end, line) {
222
      if (end) return cb(end)
223
      if (options.verbosity >= 2)
224
        console.error('line', line.toString('ascii'))
225
      if (!line.length) return cb(true)
226
      var args = split3(line.toString('ascii'))
227
      var args2 = split2(args[2], '\0')
228
      var caps = args2[1]
229
      if (caps && options.verbosity >= 2)
230
        console.error('update capabilities:', caps)
231
      cb(null, {
232
        old: rev(args[0]),
233
        new: rev(args[1]),
234
        name: args2[0]
235
      })
236
    })
237
  }
238
239
  function havesWants(onEnd) {
240
    return function readWant(abort, cb) {
241
      readPackLineStr(abort, function (end, line) {
242
        if (end) return abortCb(cb, end, onEnd)
243
        if (options.verbosity >= 2)
244
          console.error('line', line)
245
        // if (!line.length) return cb(true)
246
        if (!line.length || line == 'done')
247
          return abortCb(cb, true, onEnd)
248
        var args = split3(line)
249
        var caps = args[2]
250
        if (caps && options.verbosity >= 2)
251
          console.error('want capabilities:', caps)
252
        cb(null, {
253
          type: args[0],
254
          hash: args[1],
255
        })
256
      })
257
    }
258
  }
259
260
  /*
261
  function readWant(abort, cb) {
262
    readPackLine(abort, function (end, line) {
263
      if (end) return cb(end)
264
      if (options.verbosity >= 2)
265
        console.error('line', line.toString('ascii'))
266
      if (!line.length || line == 'done') {
267
        console.error('WANTS done', line, line.length)
268
        return cb(true)
269
      }
270
      var args = split3(line.toString('ascii'))
271
      var caps = args[2]
272
      if (caps && options.verbosity >= 2)
273
        console.error('want capabilities:', caps)
274
      cb(null, {
275
        type: args[0],
276
        hash: args[1].replace(/\n$/, ''),
277
      })
278
    })
279
  }
280
  */
281
282
  b.packLines = readPackLine
283
  b.updates = readUpdate
284
  b.wants = b.haves = havesWants
285
286
  return b
287
}
288
289
// run a callback when a pipeline ends
290
// TODO: find a better way to do this
291
function onThroughEnd(onEnd) {
292
  return function (read) {
293
    return function (end, cb) {
294
      read(end, function (end, data) {
295
        cb(end, data)
296
        if (end)
297
          onEnd(end === true ? null : end)
298
      })
299
    }
300
  }
301
}
302
303
/*
304
TODO: investigate capabilities
305
report-status delete-refs side-band-64k quiet atomic ofs-delta
306
*/
307
308
// Get a line for each ref that we have. The first line also has capabilities.
309
// Wrap with packLineEncode.
310
function receivePackHeader(capabilities, refSource, usePlaceholder) {
311
  var first = true
312
  var ended
313
  return function (abort, cb) {
314
    if (ended) return cb(true)
315
    refSource(abort, function (end, ref) {
316
      ended = end
317
      var name = ref && ref.name
318
      var value = ref && ref.value
319
      if (first && usePlaceholder) {
320
        first = false
321
        if (end) {
322
          // use placeholder data if there are no refs
323
          value = '0000000000000000000000000000000000000000'
324
          name = 'capabilities^{}'
325
        }
326
        name += '\0' + capabilities.join(' ')
327
      } else if (end) {
328
        return cb(true)
329
      }
330
      cb(null, value + ' ' + name)
331
    })
332
  }
333
}
334
335
// receive-pack: push from client
336
function receivePack(read, objectSink, refSource, refSink, options) {
337
  var ended
338
  var sendRefs = receivePackHeader([
339
    'delete-refs',
340
  ], refSource, true)
341
342
  return packLineEncode(
343
    cat([
344
      // send our refs
345
      sendRefs,
346
      pull.once(''),
347
      function (abort, cb) {
348
        if (abort) return
349
        // receive their refs
350
        var lines = packLineDecode(read, options)
351
        pull(
352
          lines.updates,
353
          onThroughEnd(refsDone),
354
          refSink
355
        )
356
        function refsDone(err) {
357
          if (err) return cb(err)
358
          pull(
359
            lines.passthrough,
360
            pack.decode(cb),
361
            objectSink
362
          )
363
        }
364
      },
365
      pull.once('unpack ok')
366
    ])
367
  )
368
}
369
370
function prepend(data, read) {
371
  var done
372
  return function (end, cb) {
373
    if (done) {
374
      read(end, cb)
375
    } else {
376
      done = true
377
      cb(null, data)
378
    }
379
  }
380
}
381
382
module.exports = function (opts) {
383
  var ended
384
  var objectSink = opts.objectSink
385
  var getObjects = opts.getObjects || function (id, cb) {
386
    cb(null, 0, pull.empty())
387
  }
388
  var refSource = opts.refSource || pull.empty()
389
  var refSink = opts.refSink || pull.drain()
390
  var wantSink = opts.wantSink || pull.drain()
391
392
  var options = {
393
    verbosity: 1,
394
    progress: false
395
  }
396
397
  function handleConnect(cmd, read) {
398
    var args = split2(cmd)
399
    switch (args[0]) {
400
      case 'git-upload-pack':
401
        return prepend('\n', uploadPack(read, getObjects, refSource,
402
          wantSink, options))
403
      case 'git-receive-pack':
404
        return prepend('\n', receivePack(read, objectSink, refSource,
405
          refSink, options))
406
      default:
407
        return pull.error(new Error('Unknown service ' + args[0]))
408
    }
409
  }
410
411
  function handleCommand(line, read) {
412
    var args = split2(line)
413
    switch (args[0]) {
414
      case 'capabilities':
415
        return capabilitiesSource()
416
      case 'list':
417
        return listRefs(refSource)
418
      case 'connect':
419
        return handleConnect(args[1], read)
420
      case 'option':
421
        return optionSource(args[1], options)
422
      default:
423
        return pull.error(new Error('Unknown command ' + line))
424
    }
425
  }
426
427
  return function (read) {
428
    var b = buffered()
429
    b(read)
430
    var command
431
432
    function getCommand(cb) {
433
      b.lines(null, function next(end, line) {
434
        if (ended = end)
435
          return cb(end)
436
437
        if (line == '')
438
          return b.lines(null, next)
439
440
        if (options.verbosity > 1)
441
          console.error('command:', line)
442
443
        var cmdSource = handleCommand(line, b.passthrough)
444
        cb(null, cmdSource)
445
      })
446
    }
447
448
    return function next(abort, cb) {
449
      if (ended) return cb(ended)
450
451
      if (!command) {
452
        if (abort) return
453
        getCommand(function (end, cmd) {
454
          command = cmd
455
          next(end, cb)
456
        })
457
        return
458
      }
459
460
      command(abort, function (err, data) {
461
        if (err) {
462
          command = null
463
          if (err !== true)
464
            cb(err, data)
465
          else
466
            next(abort, cb)
467
        } else {
468
          cb(null, data)
469
        }
470
      })
471
    }
472
  }
473
}
474