package git
import (
"io"
"gopkg.in/src-d/go-git.v4/plumbing"
)
// RevListObjects applies a complementary set. It gets all the hashes from all
// the reachable objects from the given commits. Ignore param are object hashes
// that we want to ignore on the result. It is a list because is
// easier to interact with other porcelain elements, but internally it is
// converted to a map. All that objects must be accessible from the Repository.
func RevListObjects(
r *Repository,
commits []*Commit,
ignore []plumbing.Hash) ([]plumbing.Hash, error) {
seen := hashListToSet(ignore)
result := make(map[plumbing.Hash]bool)
for _, c := range commits {
err := reachableObjects(r, c, seen, func(h plumbing.Hash) error {
if !seen[h] {
result[h] = true
seen[h] = true
}
return nil
})
if err != nil {
return nil, err
}
}
return hashSetToList(result), nil
}
// reachableObjects returns, using the callback function, all the reachable
// objects from the specified commit. To avoid to iterate over seen commits,
// if a commit hash is into the 'seen' set, we will not iterate all his trees
// and blobs objects.
func reachableObjects(
r *Repository,
commit *Commit,
seen map[plumbing.Hash]bool,
cb func(h plumbing.Hash) error) error {
return iterateCommits(commit, func(commit *Commit) error {
if seen[commit.Hash] {
return nil
}
if err := cb(commit.Hash); err != nil {
return err
}
return iterateCommitTrees(r, commit, func(h plumbing.Hash) error {
return cb(h)
})
})
}
// iterateCommits iterate all reachable commits from the given one
func iterateCommits(commit *Commit, cb func(c *Commit) error) error {
if err := cb(commit); err != nil {
return err
}
return WalkCommitHistory(commit, func(c *Commit) error {
return cb(c)
})
}
// iterateCommitTrees iterate all reachable trees from the given commit
func iterateCommitTrees(
repository *Repository,
commit *Commit,
cb func(h plumbing.Hash) error) error {
tree, err := commit.Tree()
if err != nil {
return err
}
if err := cb(tree.Hash); err != nil {
return err
}
treeWalker := NewTreeWalker(repository, tree, true)
for {
_, e, err := treeWalker.Next()
if err == io.EOF {
break
}
if err != nil {
return err
}
if err := cb(e.Hash); err != nil {
return err
}
}
return nil
}
func hashSetToList(hashes map[plumbing.Hash]bool) []plumbing.Hash {
var result []plumbing.Hash
for key := range hashes {
result = append(result, key)
}
return result
}
func hashListToSet(hashes []plumbing.Hash) map[plumbing.Hash]bool {
result := make(map[plumbing.Hash]bool)
for _, h := range hashes {
result[h] = true
}
return result
}
