Class: Braid::Mirror

Inherits:
Object
  • Object
show all
Includes:
Operations::VersionControl
Defined in:
lib/braid/mirror.rb

Defined Under Namespace

Classes: NoTagAndBranch, PathRequired, UnknownType

Constant Summary collapse

ATTRIBUTES =

Since Braid 1.1.0, the attributes are written to .braids.json in this canonical order. For now, the order is chosen to match what Braid 1.0.22 produced for newly added mirrors.

%w(url branch path tag revision)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Operations::VersionControl

#git, #git_cache

Constructor Details

#initialize(path, attributes = {}, breaking_change_cb = DUMMY_BREAKING_CHANGE_CB) ⇒ Mirror

Returns a new instance of Mirror.



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# File 'lib/braid/mirror.rb', line 28

def initialize(path, attributes = {}, breaking_change_cb = DUMMY_BREAKING_CHANGE_CB)
  @path       = path.sub(/\/$/, '')
  @attributes = attributes.dup

  # Not that it's terribly important to check for such an old feature.  This
  # is mainly to demonstrate the RemoveMirrorDueToBreakingChange mechanism
  # in case we want to use it for something else in the future.
  if !@attributes['type'].nil? && @attributes['type'] != 'git'
    breaking_change_cb.call <<-DESC
- Mirror '#{path}' is of a Subversion repository, which is no
  longer supported.  The mirror will be removed from your configuration, leaving
  the data in the tree.
DESC
    raise Config::RemoveMirrorDueToBreakingChange
  end
  @attributes.delete('type')

  # Migrate revision locks from Braid < 1.0.18.  We no longer store the
  # original branch or tag (the user has to specify it again when
  # unlocking); we simply represent a locked revision by the absence of a
  # branch or tag.
  if @attributes['lock']
    @attributes.delete('lock')
    @attributes['branch'] = nil
    @attributes['tag'] = nil
  end

  # Removal of support for full-history mirrors from Braid < 1.0.17 is a
  # breaking change for users who wanted to use the imported history in some
  # way.
  if !@attributes['squashed'].nil? && @attributes['squashed'] != true
    breaking_change_cb.call <<-DESC
- Mirror '#{path}' is full-history, which is no longer supported.
  It will be changed to squashed.  Upstream history already imported will remain
  in your project's history and will have no effect on Braid.
DESC
  end
  @attributes.delete('squashed')
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args) ⇒ Object (private) 



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# File 'lib/braid/mirror.rb', line 229

def method_missing(name, *args)
  if ATTRIBUTES.find { |attribute| name.to_s =~ /^(#{attribute})(=)?$/ }
    if $2
      attributes[$1] = args[0]
    else
      attributes[$1]
    end
  else
    raise NameError, "unknown attribute `#{name}'"
  end
end

Instance Attribute Details

#attributes ⇒ Object (readonly)

Returns the value of attribute attributes.



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# File 'lib/braid/mirror.rb', line 26

def attributes
  @attributes
end

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/braid/mirror.rb', line 26

def path
  @path
end

Class Method Details

.new_from_options(url, options = {}) ⇒ Object

Raises:



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# File 'lib/braid/mirror.rb', line 68

def self.new_from_options(url, options = {})
  url    = url.sub(/\/$/, '')

  raise NoTagAndBranch if options['tag'] && options['branch']

  tag = options['tag']
  branch = options['branch'] || (tag.nil? ? 'master' : nil)

  path = (options['path'] || extract_path_from_url(url, options['remote_path'])).sub(/\/$/, '')
  raise PathRequired unless path

  remote_path = options['remote_path']

  attributes = {'url' => url, 'branch' => branch, 'path' => remote_path, 'tag' => tag}
  self.new(path, attributes)
end

Instance Method Details

#==(comparison) ⇒ Object 



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# File 'lib/braid/mirror.rb', line 85

def ==(comparison)
  path == comparison.path && attributes == comparison.attributes
end

#base_revision ⇒ Object 



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# File 'lib/braid/mirror.rb', line 188

def base_revision
  if revision
    git.rev_parse(revision)
  else
    inferred_revision
  end
end

#cached? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/braid/mirror.rb', line 184

def cached?
  git.remote_url(remote) == cached_url
end

#cached_url ⇒ Object 



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# File 'lib/braid/mirror.rb', line 214

def cached_url
  git_cache.path(url)
end

#diff ⇒ Object

Precondition: the remote for this mirror is set up.



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# File 'lib/braid/mirror.rb', line 159

def diff
  fetch_base_revision_if_missing
  git.diff(diff_args)
end

#diff_args(user_args = []) ⇒ Object

Return the arguments that should be passed to “git diff” to diff this mirror (including uncommitted changes by default), incorporating the given user-specified arguments. Having the caller run “git diff” is convenient for now but violates encapsulation a little; we may have to reorganize the code in order to add features.



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# File 'lib/braid/mirror.rb', line 109

def diff_args(user_args = [])
  upstream_item = upstream_item_for_revision(base_revision)

  # We do not need to spend the time to copy the content outside the
  # mirror from HEAD because --relative will exclude it anyway.  Rename
  # detection seems to apply only to the files included in the diff, so we
  # shouldn't have another bug like
  # https://github.com/cristibalan/braid/issues/41.
  base_tree = git.make_tree_with_item(nil, path, upstream_item)

  # Note: --relative does a naive prefix comparison.  If we set (for
  # example) `--relative=a/b`, that will match an unrelated file or
  # directory name `a/bb`.  If the mirror is a directory, we can avoid this
  # by adding a trailing slash to the prefix.
  #
  # If the mirror is a file, the only way we can avoid matching a path like
  # `a/bb` is to pass a path argument to limit the diff.  This means if the
  # user passes additional path arguments, we won't get the behavior we
  # expect, which is the intersection of the user-specified paths with the
  # mirror.  However, it's probably unreasonable for a user to pass path
  # arguments when diffing a single-file mirror, so we ignore the issue.
  #
  # Note: This code doesn't handle various cases in which a directory at the
  # root of a mirror turns into a file or vice versa.  If that happens,
  # hopefully the user takes corrective action manually.
  if upstream_item.is_a?(git.BlobWithMode)
    # For a single-file mirror, we use the upstream basename for the
    # upstream side of the diff and the downstream basename for the
    # downstream side, like what `git diff` does when given two blobs as
    # arguments.  Use --relative to strip away the entire downstream path
    # before we add the basenames.
    return [
      '--relative=' + path,
      '--src-prefix=a/' + File.basename(remote_path),
      '--dst-prefix=b/' + File.basename(path),
      base_tree,
      # user_args may contain options, which must come before paths.
      *user_args,
      path
    ]
  else
    return [
      '--relative=' + path + '/',
      base_tree,
      *user_args
    ]
  end
end

#fetch ⇒ Object 



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# File 'lib/braid/mirror.rb', line 179

def fetch
  git_cache.fetch(url) if cached?
  git.fetch(remote)
end

#fetch_base_revision_if_missing ⇒ Object

Re-fetching the remote after deleting and re-adding it may be slow even if all objects are still present in the repository (github.com/cristibalan/braid/issues/71). Mitigate this for ‘braid diff` and other commands that need the diff by skipping the fetch if the base revision is already present in the repository.



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# File 'lib/braid/mirror.rb', line 169

def fetch_base_revision_if_missing
  begin
    # Without ^{commit}, this will happily pass back an object hash even if
    # the object isn't present.  See the git-rev-parse(1) man page.
    git.rev_parse(base_revision + '^{commit}')
  rescue Operations::UnknownRevision
    fetch
  end
end

#local_ref ⇒ Object 



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# File 'lib/braid/mirror.rb', line 196

def local_ref
  return "#{self.remote}/#{self.branch}" unless self.branch.nil?
  return "tags/#{self.tag}" unless self.tag.nil?
  self.revision
end

#locked? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/braid/mirror.rb', line 89

def locked?
  branch.nil? && tag.nil?
end

#merged?(commit) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/braid/mirror.rb', line 93

def merged?(commit)
  # tip from spearce in #git:
  # `test z$(git merge-base A B) = z$(git rev-parse --verify A)`
  commit = git.rev_parse(commit)
  !!base_revision && git.merge_base(commit, base_revision) == commit
end

#remote ⇒ Object 



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# File 'lib/braid/mirror.rb', line 218

def remote
  "#{branch || tag || 'revision'}/braid/#{path}".gsub(/\/\./, '/_')
end

#remote_path ⇒ Object 



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# File 'lib/braid/mirror.rb', line 206

def remote_path
  self.attributes['path']
end

#remote_path=(remote_path) ⇒ Object 



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# File 'lib/braid/mirror.rb', line 210

def remote_path=(remote_path)
  self.attributes['path'] = remote_path
end

#remote_ref ⇒ Object 



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# File 'lib/braid/mirror.rb', line 202

def remote_ref
  self.branch.nil? ? "+refs/tags/#{self.tag}" : "+refs/heads/#{self.branch}"
end

#upstream_item_for_revision(revision) ⇒ Object 



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# File 'lib/braid/mirror.rb', line 100

def upstream_item_for_revision(revision)
  git.get_tree_item(revision, self.remote_path)
end