git ssb

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var pull = require('pull-stream')
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var Next = require('pull-next')
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function first (list, test) {
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  for(var i in list) {
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    var value = test(list[i], i, list)
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    if(value) return value
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  }
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}
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function decorate (list, value, caller) {
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  caller = caller || function (d,e,v) { return d(e, v) }
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  return list.reduce(function (element, decorator) {
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    return caller(decorator, element, value) || element
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  }, null)
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}
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function get(obj, path) {
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  if(obj == null) return obj
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  if('string' === typeof path) return obj[path]
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  for(var i = 0; i < path.length; i++) {
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    obj = obj[path[i]]
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    if(obj == null) return
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  }
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  return obj
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}
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exports.first = first
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exports.decorate = decorate
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exports.next = function (createStream, opts, property, range) {
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  range = range || opts.reverse ? 'lt' : 'gt'
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  property = property || 'timestamp'
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  var last = null, 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] = get(last, property)
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      if(value == null) return
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      last = null
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    }
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    return pull(
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      createStream(opts),
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      pull.through(function (msg) {
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        count ++
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        if(!msg.sync) last = msg
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      }, function (err) {
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        //retry on errors...
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        if(err) return count = -1
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        //end stream if there were no results
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        if(last == null) last = {}
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      })
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    )
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  })
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}
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exports.firstPlug = function (plugs) {
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  if(!Array.isArray(plugs)) throw new Error('plugs must be an array')
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  var args = [].slice.call(arguments)
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  var plugs = args.shift()
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  return exports.first(plugs, function (fn) {
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    return fn.apply(null, args)
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  })
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}
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