Module: Amp::Repositories::BranchManager

Includes:
Amp::RevlogSupport::Node
Included in:
LocalRepository
Defined in:
lib/amp/repository/branch_manager.rb

Overview

BranchManager

Michael Scott for Amp.

More seriously, this class handles reading/writing to the branch cache and figuring out what the head revisions are for each branch and such.

Constant Summary

Constants included from Amp::RevlogSupport::Node

Amp::RevlogSupport::Node::NULL_ID, Amp::RevlogSupport::Node::NULL_REV

Instance Method Summary collapse

Methods included from Amp::RevlogSupport::Node

#short

Instance Method Details

#branch_heads ⇒ Hash

Loads the head revisions for each branch. Each branch has at least one, but possible more than one, head.

Returns:

  • (Hash) —

    a map, where the branch names are keys and the values are the heads of the branch



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# File 'lib/amp/repository/branch_manager.rb', line 33

def branch_heads
  # Gets the mapping of branch names to branch heads, but uses caching to avoid
  # doing IO and tedious computation over and over. As long as our tip doesn't
  # change, the cache will remain valid.
  
  # Check our current tip
  tip = self.changelog.tip
  # Do we have a cache, and if we do, is the saved cache == tip?
  if !@branch_cache.nil? && @branch_cache_tip == tip
    # if so, cache HIT
    return @branch_cache
  end
  
  # nope? cache miss
  # save the old tip
  oldtip = @branch_cache_tip
  # save the new tip
  @branch_cache_tip = tip
  
  # reset the branch cache
  @branch_cache = @branch_cache.nil? ? {} : @branch_cache.clear # returns same hash, but empty
  # if we didn't have an old cache, or it was invalid, read in the branches again
  if oldtip.nil? || self.changelog.node_map[oldtip].nil?
    partial, last, last_rev = read_branches!
  else
    # Otherwise, dig up the cached hash!
    last_rev = self.changelog.rev(oldtip)
    # Get the last branch cache
    partial = @u_branch_cache
  end
  # Save the branch cache (updating it if we have to)
  save_branch_cache(partial, last_rev)
  
  # Cache our saved hash
  @u_branch_cache = partial
  
  # Copy the partial into the branch_cache
  partial.each { |k, v| @branch_cache[k] = v }
  @branch_cache
end

#branch_tags ⇒ Object

Returns a dict where branch names map to the tipmost head of the branch, open heads come before closed



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# File 'lib/amp/repository/branch_manager.rb', line 76

def branch_tags
  tags = {}
  branch_heads.each do |branch_node, local_heads|
    head = nil
    local_heads.reverse_each do |h| # get the tip if its a closed
      if !(changelog.read(h)[5].include?("close"))
        head = h
        break
      end
    end
    head = local_heads.last if head.nil?
    tags[branch_node] = head # it's the tip
  end
  return tags
end

#save_branch_cache(partial, last_rev) ⇒ Object

Saves the branches with the given “partial” and the last_rev index.



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# File 'lib/amp/repository/branch_manager.rb', line 14

def save_branch_cache(partial, last_rev)
  tiprev = self.size - 1
  # If our cache is outdated, then update it and re-write it
  if last_rev != tiprev
    # search for new heads
    update_branches!(partial, last_rev+1, tiprev+1)
    # write our data out
    write_branches!(partial, self.changelog.tip, tiprev)
  end
  # return our mappings
  partial
end

#save_branches(branches, tip, tip_revision) ⇒ Object

Saves the branches, the tip-most node, and the tip-most revision to the branch cache.



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# File 'lib/amp/repository/branch_manager.rb', line 96

def save_branches(branches, tip, tip_revision)
  write_branches!(branches, tip, tip_revision)
end