git ssb

1
var pull = require('pull-stream')
2
var cat = require('pull-cat')
3
var cache = require('pull-cache')
4
var buffered = require('pull-buffered')
5
var pack = require('./lib/pack')
6
var pktLine = require('./lib/pkt-line')
7
var indexPack = require('./lib/index-pack')
8
var util = require('./lib/util')
9
var multicb = require('multicb')
10
var ProgressBar = require('progress')
11
12
function handleOption(options, name, value) {
13
  switch (name) {
14
    case 'verbosity':
15
      options.verbosity = +value || 0
16
      return true
17
    case 'progress':
18
      options.progress = !!value && value !== 'false'
19
      return true
20
    default:
21
      console.error('unknown option', name + ': ' + value)
22
      return false
23
  }
24
}
25
26
function capabilitiesSource() {
27
  return pull.once([
28
    'option',
29
    'connect',
30
  ].join('\n') + '\n\n')
31
}
32
33
function optionSource(cmd, options) {
34
  var args = util.split2(cmd)
35
  var msg = handleOption(options, args[0], args[1])
36
  msg = (msg === true) ? 'ok'
37
      : (msg === false) ? 'unsupported'
38
      : 'error ' + msg
39
  return pull.once(msg + '\n')
40
}
41
42
// transform ref objects into lines
43
function listRefs(read) {
44
  var ended
45
  return function (abort, cb) {
46
    if (ended) return cb(ended)
47
    read(abort, function (end, ref) {
48
      ended = end
49
      if (end === true) cb(null, '\n')
50
      if (end) cb(end)
51
      else cb(null,
52
        [ref.value, ref.name].concat(ref.attrs || []).join(' ') + '\n')
53
    })
54
  }
55
}
56
57
// upload-pack: fetch to client
58
function uploadPack(read, repo, options) {
59
  /* multi_ack thin-pack side-band side-band-64k ofs-delta shallow no-progress
60
   * include-tag multi_ack_detailed
61
   * agent=git/2.7.0 */
62
  var sendRefs = receivePackHeader([
63
    'thin-pack',
64
  ], repo.refs(), repo.symrefs(), false)
65
66
  var lines = pktLine.decode(read, options)
67
  var readHave = lines.haves()
68
  var acked
69
  var commonHash
70
  var sendPack
71
  var wants = {}
72
  var shallows = {}
73
74
  // Packfile negotiation
75
  return cat([
76
    pktLine.encode(cat([
77
      sendRefs,
78
      pull.once(''),
79
      function (abort, cb) {
80
        if (abort) return
81
        if (acked) return cb(true)
82
83
        // read upload request (wants list) from client
84
        var readWant = lines.wants()
85
        readWant(null, function (end, want) {
86
          if (end === true) return cb(true) // early client disconnect
87
          else if (end) cb(end)
88
          else nextWant(null, want)
89
        })
90
        function nextWant(end, want) {
91
          if (end) return wantsDone(end === true ? null : end)
92
          if (want.type == 'want') {
93
            wants[want.hash] = true
94
          } else if (want.type == 'shallow') {
95
            shallows[want.hash] = true
96
          } else {
97
            var err = new Error("Unknown thing", want.type, want.hash)
98
            return readWant(err, function (e) { cb(e || err) })
99
          }
100
          readWant(null, nextWant)
101
        }
102
103
        function wantsDone(err) {
104
          if (err) return cb(err)
105
          // Read upload haves (haves list).
106
          // On first obj-id that we have, ACK
107
          // If we have none, NAK.
108
          // TODO: implement multi_ack_detailed
109
          readHave(null, function next(end, have) {
110
            if (end === true) {
111
              // found no common object
112
              acked = true
113
              cb(null, 'NAK')
114
            } else if (end)
115
              cb(end)
116
            else if (have.type != 'have')
117
              cb(new Error('Unknown have' + JSON.stringify(have)))
118
            else
119
              repo.hasObject(have.hash, function (err, haveIt) {
120
                if (err) return cb(err)
121
                if (!haveIt)
122
                  return readHave(null, next)
123
                commonHash = haveIt
124
                acked = true
125
                cb(null, 'ACK ' + have.hash)
126
              })
127
          })
128
        }
129
      },
130
    ])),
131
132
    function havesDone(abort, cb) {
133
      if (abort) return cb(abort)
134
      // send pack file to client
135
      if (sendPack)
136
        return sendPack(abort, cb)
137
      getObjects(repo, commonHash, wants, shallows,
138
        function (err, numObjects, readObjects) {
139
          if (err) return cb(err)
140
          var progress = progressObjects(options)
141
          progress.setNumObjects(numObjects)
142
          sendPack = pack.encode(options, numObjects,
143
            progress(readObjects))
144
          havesDone(abort, cb)
145
        }
146
      )
147
    }
148
  ])
149
}
150
151
// through stream to show a progress bar for objects being read
152
function progressObjects(options) {
153
  // Only show progress bar if it is requested and if it won't interfere with
154
  // the debug output
155
  if (!options.progress || options.verbosity > 1) {
156
    var dummyProgress = function (readObject) { return readObject }
157
    dummyProgress.setNumObjects = function () {}
158
    return dummyProgress
159
  }
160
161
  var numObjects
162
  var size = process.stderr.columns
163
  var bar = new ProgressBar(':percent :bar', {
164
    total: size,
165
    clear: true
166
  })
167
168
  var progress = function (readObject) {
169
    return function (abort, cb) {
170
      readObject(abort, function next(end, object) {
171
        if (end === true) {
172
          bar.terminate()
173
        } else if (!end) {
174
          var name = object.type + ' ' + object.length
175
          bar.tick(size / numObjects)
176
        }
177
178
        cb(end, object)
179
      })
180
    }
181
  }
182
  // TODO: put the num objects in the objects stream as a header object
183
  progress.setNumObjects = function (n) {
184
    numObjects = n
185
  }
186
  return progress
187
}
188
189
function getObjects(repo, commonHash, heads, shallows, cb) {
190
  // get objects from commonHash to each head, inclusive.
191
  // if commonHash is falsy, use root
192
  var objects = []
193
  var objectsAdded = {}
194
  var done = multicb({pluck: 1})
195
  var ended
196
197
  // walk back from heads until get to commonHash
198
  for (var hash in heads)
199
    addObject(hash, done())
200
201
  // TODO: only add new objects
202
203
  function addObject(hash, cb) {
204
    if (ended) return cb(ended)
205
    if (hash in objectsAdded || hash == commonHash) return cb()
206
    objectsAdded[hash] = true
207
    repo.getObject(hash, function (err, object) {
208
      if (err) return cb(err)
209
      if (object.type == 'blob') {
210
        objects.push(object)
211
        cb()
212
      } else {
213
        // object must be read twice, so buffer it
214
        bufferObject(object, function (err, object) {
215
          if (err) return cb(err)
216
          objects.push(object)
217
          var hashes = getObjectLinks(object)
218
          for (var sha1 in hashes)
219
            addObject(sha1, done())
220
          cb()
221
        })
222
      }
223
    })
224
  }
225
226
  done(function (err) {
227
    if (err) return cb(err)
228
    cb(null, objects.length, pull.values(objects))
229
  })
230
}
231
232
function bufferObject(object, cb) {
233
  pull(
234
    object.read,
235
    pull.collect(function (err, bufs) {
236
      if (err) return cb(err)
237
      var buf = Buffer.concat(bufs, object.length)
238
      cb(null, {
239
        type: object.type,
240
        length: object.length,
241
        data: buf,
242
        read: pull.once(buf)
243
      })
244
    })
245
  )
246
}
247
248
// get hashes of git objects linked to from other git objects
249
function getObjectLinks(object, cb) {
250
  switch (object.type) {
251
    case 'blob':
252
      return {}
253
    case 'tree':
254
      return getTreeLinks(object.data)
255
    case 'tag':
256
    case 'commit':
257
      return getCommitOrTagLinks(object.data)
258
  }
259
}
260
261
function getTreeLinks(buf) {
262
  var links = {}
263
  for (var i = 0, j; j = buf.indexOf(0, i, 'ascii') + 1; i = j + 20) {
264
    var hash = buf.slice(j, j + 20).toString('hex')
265
    if (!(hash in links))
266
      links[hash] = true
267
  }
268
  return links
269
}
270
271
function getCommitOrTagLinks(buf) {
272
  var lines = buf.toString('utf8').split('\n')
273
  var links = {}
274
  // iterate until reach blank line (indicating start of commit/tag body)
275
  for (var i = 0; lines[i]; i++) {
276
    var args = lines[i].split(' ')
277
    switch (args[0]) {
278
      case 'tree':
279
      case 'parent':
280
      case 'object':
281
        var hash = args[1]
282
        if (!(hash in links))
283
          links[hash] = true
284
    }
285
  }
286
  return links
287
}
288
289
/*
290
TODO: investigate capabilities
291
report-status delete-refs side-band-64k quiet atomic ofs-delta
292
*/
293
294
// Get a line for each ref that we have. The first line also has capabilities.
295
// Wrap with pktLine.encode.
296
function receivePackHeader(capabilities, refSource, symrefs, usePlaceholder) {
297
  var first = true
298
  var symrefed = {}
299
  var symrefsObj = {}
300
301
  return cat([
302
    function (end, cb) {
303
      if (end) cb(true)
304
      else if (!symrefs) cb(true)
305
      else pull(
306
        symrefs,
307
        pull.map(function (sym) {
308
          symrefed[sym.ref] = true
309
          symrefsObj[sym.name] = sym.ref
310
          return 'symref=' + sym.name + ':' + sym.ref
311
        }),
312
        pull.collect(function (err, symrefCaps) {
313
          if (err) return cb(err)
314
          capabilities = capabilities.concat(symrefCaps)
315
          cb(true)
316
        })
317
      )
318
    },
319
    pull(
320
      refSource,
321
      pull.map(function (ref) {
322
        // insert symrefs next to the refs that they point to
323
        var out = [ref]
324
        if (ref.name in symrefed)
325
          for (var symrefName in symrefsObj)
326
            if (symrefsObj[symrefName] === ref.name)
327
              out.push({name: symrefName, hash: ref.hash})
328
        return out
329
      }),
330
      pull.flatten(),
331
      pull.map(function (ref) {
332
        var name = ref.name
333
        var value = ref.hash
334
        if (first && usePlaceholder) {
335
          first = false
336
          /*
337
          if (end) {
338
            // use placeholder data if there are no refs
339
            value = '0000000000000000000000000000000000000000'
340
            name = 'capabilities^{}'
341
          }
342
          */
343
          name += '\0' + capabilities.join(' ')
344
        }
345
        return value + ' ' + name
346
      })
347
    )
348
  ])
349
}
350
351
// receive-pack: push from client
352
function receivePack(read, repo, options) {
353
  var sendRefs = receivePackHeader([
354
    'delete-refs',
355
  ], repo.refs(), null, true)
356
  var done = multicb({pluck: 1})
357
358
  return pktLine.encode(
359
    cat([
360
      // send our refs
361
      sendRefs,
362
      pull.once(''),
363
      function (abort, cb) {
364
        if (abort) return
365
        // receive their refs
366
        var lines = pktLine.decode(read, options)
367
        pull(
368
          lines.updates,
369
          pull.collect(function (err, updates) {
370
            if (err) return cb(err)
371
            if (updates.length === 0) return cb(true)
372
            var progress = progressObjects(options)
373
374
            if (repo.uploadPack) {
375
              var idxCb = done()
376
              var packfile = cache(lines.passthrough)
377
              indexPack(packfile(), function (err, idx) {
378
                if (err) return idxCb(err)
379
                repo.uploadPack(pull.values(updates), packfile(), idx, idxCb)
380
              })
381
            } else {
382
              repo.update(pull.values(updates), pull(
383
                lines.passthrough,
384
                pack.decode({
385
                  verbosity: options.verbosity,
386
                  onHeader: function (numObjects) {
387
                    progress.setNumObjects(numObjects)
388
                  }
389
                }, repo, done()),
390
                progress
391
              ), done())
392
            }
393
394
            done(function (err) {
395
              cb(err || true)
396
            })
397
          })
398
        )
399
      },
400
      pull.once('unpack ok')
401
    ])
402
  )
403
}
404
405
function prepend(data, read) {
406
  var done
407
  return function (end, cb) {
408
    if (done) {
409
      read(end, cb)
410
    } else {
411
      done = true
412
      cb(null, data)
413
    }
414
  }
415
}
416
417
module.exports = function (repo) {
418
  var ended
419
  var options = {
420
    verbosity: 1,
421
    progress: false
422
  }
423
424
  function handleConnect(cmd, read) {
425
    var args = util.split2(cmd)
426
    switch (args[0]) {
427
      case 'git-upload-pack':
428
        return prepend('\n', uploadPack(read, repo, options))
429
      case 'git-receive-pack':
430
        return prepend('\n', receivePack(read, repo, options))
431
      default:
432
        return pull.error(new Error('Unknown service ' + args[0]))
433
    }
434
  }
435
436
  function handleCommand(line, read) {
437
    var args = util.split2(line)
438
    switch (args[0]) {
439
      case 'capabilities':
440
        return capabilitiesSource()
441
      case 'list':
442
        return listRefs(refSource)
443
      case 'connect':
444
        return handleConnect(args[1], read)
445
      case 'option':
446
        return optionSource(args[1], options)
447
      default:
448
        return pull.error(new Error('Unknown command ' + line))
449
    }
450
  }
451
452
  return function (read) {
453
    var b = buffered()
454
    b(read)
455
    var command
456
457
    function getCommand(cb) {
458
      b.lines(null, function next(end, line) {
459
        if (ended = end)
460
          return cb(end)
461
462
        if (line == '')
463
          return b.lines(null, next)
464
465
        if (options.verbosity > 1)
466
          console.error('command:', line)
467
468
        var cmdSource = handleCommand(line, b.passthrough)
469
        cb(null, cmdSource)
470
      })
471
    }
472
473
    return function next(abort, cb) {
474
      if (ended) return cb(ended)
475
476
      if (!command) {
477
        if (abort) return
478
        getCommand(function (end, cmd) {
479
          command = cmd
480
          next(end, cb)
481
        })
482
        return
483
      }
484
485
      command(abort, function (err, data) {
486
        if (err) {
487
          command = null
488
          if (err !== true)
489
            cb(err, data)
490
          else
491
            next(abort, cb)
492
        } else {
493
          // HACK: silence error when writing to closed stream
494
          try {
495
            cb(null, data)
496
          } catch(e) {
497
            if (e.message == 'process.stdout cannot be closed.'
498
             || e.message == 'This socket is closed.')
499
              process.exit(1)
500
            throw e
501
          }
502
        }
503
      })
504
    }
505
  }
506
}
507