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('./lib/pack')
6
var pktLine = require('./lib/pkt-line')
7
var util = require('./lib/util')
8
9
function handleOption(options, name, value) {
10
  switch (name) {
11
    case 'verbosity':
12
      options.verbosity = +value || 0
13
      return true
14
    case 'progress':
15
      options.progress = !!value && value !== 'false'
16
      return true
17
    default:
18
      console.error('unknown option', name + ': ' + value)
19
      return false
20
  }
21
}
22
23
function capabilitiesSource() {
24
  return pull.once([
25
    'option',
26
    'connect',
27
  ].join('\n') + '\n\n')
28
}
29
30
function optionSource(cmd, options) {
31
  var args = util.split2(cmd)
32
  var msg = handleOption(options, args[0], args[1])
33
  msg = (msg === true) ? 'ok'
34
      : (msg === false) ? 'unsupported'
35
      : 'error ' + msg
36
  return pull.once(msg + '\n')
37
}
38
39
// transform ref objects into lines
40
function listRefs(read) {
41
  var ended
42
  return function (abort, cb) {
43
    if (ended) return cb(ended)
44
    read(abort, function (end, ref) {
45
      ended = end
46
      if (end === true) cb(null, '\n')
47
      if (end) cb(end)
48
      else cb(null,
49
        [ref.value, ref.name].concat(ref.attrs || []).join(' ') + '\n')
50
    })
51
  }
52
}
53
54
// upload-pack: fetch to client
55
function uploadPack(read, repo, options) {
56
  // getObjects, wantSink
57
  /* multi_ack thin-pack side-band side-band-64k ofs-delta shallow no-progress
58
   * include-tag multi_ack_detailed symref=HEAD:refs/heads/master
59
   * agent=git/2.7.0 */
60
  var refSource = repo.refs.bind(repo)
61
  var sendRefs = receivePackHeader([
62
  ], refSource, false)
63
64
  var lines = pktLine.decode(read, options)
65
  var readHave = lines.haves()
66
  var acked
67
  var commonHash
68
  var sendPack
69
  var earlyDisconnect
70
71
  // Packfile negotiation
72
  return cat([
73
    pktLine.encode(cat([
74
      sendRefs,
75
      pull.once(''),
76
      function (abort, cb) {
77
        if (abort) return
78
        if (acked) return cb(true)
79
        // read upload request (wants list) from client
80
        var readWant = lines.wants(wantsDone)
81
        readWant(null, function (end, want) {
82
          if (end === true) {
83
            // client disconnected before sending wants
84
            earlyDisconnect = true
85
            cb(true)
86
          } else if (end) {
87
            cb(end)
88
          } else {
89
            wantSink(readWant)
90
          }
91
        })
92
93
        function wantsDone(err) {
94
          // console.error('wants done', err, earlyDisconnect)
95
          if (err) return cb(err)
96
          if (earlyDisconnect) return cb(true)
97
          // Read upload haves (haves list).
98
          // On first obj-id that we have, ACK
99
          // If we have none, NAK.
100
          // TODO: implement multi_ack_detailed
101
          readHave(null, function next(end, have) {
102
            if (end === true) {
103
              // found no common object
104
              acked = true
105
              cb(null, 'NAK')
106
            } else if (end)
107
              cb(end)
108
            else if (have.type != 'have')
109
              cb(new Error('Unknown have' + JSON.stringify(have)))
110
            else
111
              repo.hasObject(have.hash, function (err, haveIt) {
112
                if (err) return cb(err)
113
                if (!haveIt)
114
                  return readHave(null, next)
115
                commonHash = haveIt
116
                acked = true
117
                cb(null, 'ACK ' + have.hash)
118
              })
119
          })
120
        }
121
      },
122
    ])),
123
    function havesDone(abort, cb) {
124
      // console.error("haves done", abort && typeof abort, sendPack && typeof sendPack, abort, earlyDisconnect)
125
      if (abort || earlyDisconnect) return cb(abort || true)
126
      // send pack file to client
127
      if (!sendPack)
128
        getObjects(commonHash, function (err, numObjects, readObject) {
129
          sendPack = pack.encode(numObjects, readObject)
130
          havesDone(abort, cb)
131
        })
132
      else
133
        sendPack(abort, cb)
134
    }
135
  ])
136
}
137
138
/*
139
TODO: investigate capabilities
140
report-status delete-refs side-band-64k quiet atomic ofs-delta
141
*/
142
143
// Get a line for each ref that we have. The first line also has capabilities.
144
// Wrap with pktLine.encode.
145
function receivePackHeader(capabilities, refSource, usePlaceholder) {
146
  var first = true
147
  var ended
148
  return function (abort, cb) {
149
    if (ended) return cb(true)
150
    refSource(abort, function (end, ref) {
151
      ended = end
152
      var name = ref && ref.name
153
      var value = ref && ref.value
154
      if (first && usePlaceholder) {
155
        first = false
156
        if (end) {
157
          // use placeholder data if there are no refs
158
          value = '0000000000000000000000000000000000000000'
159
          name = 'capabilities^{}'
160
        }
161
        name += '\0' + capabilities.join(' ')
162
      } else if (end) {
163
        return cb(true)
164
      }
165
      cb(null, value + ' ' + name)
166
    })
167
  }
168
}
169
170
// receive-pack: push from client
171
function receivePack(read, repo, options) {
172
  var ended
173
  var refSource = repo.refs.bind(repo)
174
  var sendRefs = receivePackHeader([
175
    'delete-refs',
176
  ], refSource, true)
177
178
  return pktLine.encode(
179
    cat([
180
      // send our refs
181
      sendRefs,
182
      pull.once(''),
183
      function (abort, cb) {
184
        if (abort) return
185
        // receive their refs
186
        var lines = pktLine.decode(read, options)
187
        pull(
188
          lines.updates,
189
          pull.collect(function (err, updates) {
190
            if (err) return cb(err)
191
            repo.update(pull.values(updates), pull(
192
              lines.passthrough,
193
              pack.decode(onEnd)
194
            ), onEnd)
195
          })
196
        )
197
        function onEnd(err) {
198
          if (!ended)
199
            cb(ended = err)
200
        }
201
      },
202
      pull.once('unpack ok')
203
    ])
204
  )
205
}
206
207
function prepend(data, read) {
208
  var done
209
  return function (end, cb) {
210
    if (done) {
211
      read(end, cb)
212
    } else {
213
      done = true
214
      cb(null, data)
215
    }
216
  }
217
}
218
219
module.exports = function (repo) {
220
  var ended
221
  /*
222
  var getObjects = opts.getObjects || function (id, cb) {
223
    cb(null, 0, pull.empty())
224
  }
225
  */
226
227
  var options = {
228
    verbosity: 1,
229
    progress: false
230
  }
231
232
  function handleConnect(cmd, read) {
233
    var args = util.split2(cmd)
234
    switch (args[0]) {
235
      case 'git-upload-pack':
236
        return prepend('\n', uploadPack(read, repo, options))
237
      case 'git-receive-pack':
238
        return prepend('\n', receivePack(read, repo, options))
239
      default:
240
        return pull.error(new Error('Unknown service ' + args[0]))
241
    }
242
  }
243
244
  function handleCommand(line, read) {
245
    var args = util.split2(line)
246
    switch (args[0]) {
247
      case 'capabilities':
248
        return capabilitiesSource()
249
      case 'list':
250
        return listRefs(refSource)
251
      case 'connect':
252
        return handleConnect(args[1], read)
253
      case 'option':
254
        return optionSource(args[1], options)
255
      default:
256
        return pull.error(new Error('Unknown command ' + line))
257
    }
258
  }
259
260
  return function (read) {
261
    var b = buffered()
262
    b(read)
263
    var command
264
265
    function getCommand(cb) {
266
      b.lines(null, function next(end, line) {
267
        if (ended = end)
268
          return cb(end)
269
270
        if (line == '')
271
          return b.lines(null, next)
272
273
        if (options.verbosity > 1)
274
          console.error('command:', line)
275
276
        var cmdSource = handleCommand(line, b.passthrough)
277
        cb(null, cmdSource)
278
      })
279
    }
280
281
    return function next(abort, cb) {
282
      if (ended) return cb(ended)
283
284
      if (!command) {
285
        if (abort) return
286
        getCommand(function (end, cmd) {
287
          command = cmd
288
          next(end, cb)
289
        })
290
        return
291
      }
292
293
      command(abort, function (err, data) {
294
        if (err) {
295
          command = null
296
          if (err !== true)
297
            cb(err, data)
298
          else
299
            next(abort, cb)
300
        } else {
301
          cb(null, data)
302
        }
303
      })
304
    }
305
  }
306
}
307