EVOLUTION-MANAGER

Edit File: walkers.js

var modes = require('../lib/modes.js');

module.exports = function (repo) {
  repo.logWalk = logWalk;   // (ref) => stream<commit>
  repo.treeWalk = treeWalk; // (treeHash) => stream<object>
};
module.exports.walk = walk;

function logWalk(ref, callback) {
  if (!callback) return logWalk.bind(this, ref);
  var last, seen = {};
  var repo = this;
  if (!repo.readRef) return onShallow();
  return repo.readRef("shallow", onShallow);

function onShallow(err, shallow) {
    last = shallow;
    resolveRef(repo, ref, onHash);
  }

function onHash(err, hash) {
    if (err) return callback(err);
    return repo.loadAs("commit", hash, function (err, commit) {
      if (commit === undefined) return callback(err);
      commit.hash = hash;
      seen[hash] = true;
      return callback(null, walk(commit, scan, loadKey, compare));
    });
  }

function scan(commit) {
    if (last === commit) return [];
    return commit.parents.filter(function (hash) {
      return !seen[hash];
    });
  }

function loadKey(hash, callback) {
    return repo.loadAs("commit", hash, function (err, commit) {
      if (!commit) return callback(err || new Error("Missing commit " + hash));
      commit.hash = hash;
      if (hash === last) commit.last = true;
      return callback(null, commit);
    });
  }

}

function compare(commit, other) {
  return commit.author.date < other.author.date;
}

function treeWalk(hash, callback) {
  if (!callback) return treeWalk.bind(this, hash);
  var repo = this;
  return repo.loadAs("tree", hash, onTree);

function onTree(err, body) {
    if (!body) return callback(err || new Error("Missing tree " + hash));
    var tree = {
      mode: modes.tree,
      hash: hash,
      body: body,
      path: "/"
    };
    return callback(null, walk(tree, treeScan, treeLoadKey, treeCompare));
  }

function treeLoadKey(entry, callback) {
    if (entry.mode !== modes.tree) return callback(null, entry);
    var type = modes.toType(entry.mode);
    return repo.loadAs(type, entry.hash, function (err, body) {
      if (err) return callback(err);
      entry.body = body;
      return callback(null, entry);
    });
  }

}

function treeCompare(first, second) {
  return first.path < second.path;
}

function walk(seed, scan, loadKey, compare) {
  var queue = [seed];
  var working = 0, error, cb;
  return {read: read, abort: abort};

function abort(callback) { return callback(); }

function onError(err) {
    if (cb) {
      var callback = cb; cb = null;
      return callback(err);
    }
    error = err;
  }

function onKey(key) {
    working++;
    loadKey(key, onItem);
  }

function onItem(err, item) {
    working--;
    if (err) return onError(err);
    var index = queue.length;
    while (index && compare(item, queue[index - 1])) index--;
    queue.splice(index, 0, item);
    if (!working && cb) {
      var callback = cb; cb = null;
      return read(callback);
    }
  }
}