git ssb

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var PullCont = require('pull-cont')
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var pull = require('pull-stream')
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module.exports = function wrap(sv, since, isReady) {
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  var waiting = []
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  var meta = {}
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  sv.since(function (upto) {
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    if(!isReady.value) return
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    while(waiting.length && waiting[0].seq <= upto)
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      waiting.shift().cb()
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  })
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  isReady(function (ready) {
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    if(!ready) return
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    var upto = sv.since.value
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    if(upto == undefined) return
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    while(waiting.length && waiting[0].seq <= upto)
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      waiting.shift().cb()
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  })
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  function ready (cb) {
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    if(isReady.value && since.value != null && since.value === sv.since.value) cb()
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    else
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      since.once(function (upto) {
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        if(isReady.value && upto === sv.since.value) cb()
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        else waiting.push({seq: upto, cb: cb})
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      })
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  }
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  var wrapper = {
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    source: function (fn, name) {
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      return function (opts) {
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        meta[name] ++
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        return pull(PullCont(function (cb) {
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          ready(function () { cb(null, fn(opts)) })
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        }), pull.through(function () { meta[name] ++ }))
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      }
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    },
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    async: function (fn, name) {
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      return function (opts, cb) {
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        meta[name] ++
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        ready(function () {
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          fn(opts, cb)
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        })
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      }
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    },
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    sync: function (fn, name) {
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      //return function (a, b) {
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        //meta[name] ++
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        return fn//(a, b)
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      //}
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    }
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  }
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  var o = {ready: ready, since: sv.since, close: sv.close, meta: meta}
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  if(!sv.methods) throw new Error('a stream view must have methods property')
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  for(var key in sv.methods) {
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    var type = sv.methods[key]
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    var fn = sv[key]
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    if(typeof fn !== 'function') throw new Error('expected function named:'+key+'of type: '+type)
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    //type must be either source, async, or sync
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    meta[key] = 0
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    o[key] = wrapper[type](fn, key)
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  }
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  o.methods = sv.methods
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  return o
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}
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