git ssb

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const pull = require('pull-stream')
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const Next = require('pull-next')
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var ENDED = {}
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module.exports = nextStepper
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// TODO - this should be another module?
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function nextStepper (createStream, opts, range) {
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  range = range || (opts.reverse ? 'lt' : 'gt')
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  var last = null
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  var count = -1
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  return Next(function () {
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    if (last) {
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      if (count === 0) return
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      var value = opts[range] = last
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      if (value === ENDED) return
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      last = null
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    }
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    return pull(
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      createStream(clone(opts)),
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      pull.through(function (msg) {
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        count++
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        if (!msg.sync) {
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          last = msg
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        }
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      }, function (err) {
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        // retry on errors...
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        if (err) {
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          count = -1
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          return count
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        }
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        // end stream if there were no results
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        if (last == null) last = ENDED
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      })
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    )
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  })
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}
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function clone (obj) {
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  var _obj = {}
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  for (var k in obj) _obj[k] = obj[k]
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  return _obj
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}
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