forgejo-federation/modules/git/commit_info_gogit.go
zeripath a2cfcdb91a
Slightly simplify LastCommitCache (#20444)
The LastCommitCache code is a little complex and there is unnecessary
duplication between the gogit and nogogit variants.

This PR adds the LastCommitCache as a field to the git.Repository and
pre-creates it in the ReferencesGit helpers etc. There has been some
simplification and unification of the variant code.

Signed-off-by: Andrew Thornton <art27@cantab.net>
2022-07-25 16:39:42 +01:00

305 lines
8.4 KiB
Go

// Copyright 2017 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
//go:build gogit
package git
import (
"context"
"path"
"github.com/emirpasic/gods/trees/binaryheap"
"github.com/go-git/go-git/v5/plumbing"
"github.com/go-git/go-git/v5/plumbing/object"
cgobject "github.com/go-git/go-git/v5/plumbing/object/commitgraph"
)
// GetCommitsInfo gets information of all commits that are corresponding to these entries
func (tes Entries) GetCommitsInfo(ctx context.Context, commit *Commit, treePath string) ([]CommitInfo, *Commit, error) {
entryPaths := make([]string, len(tes)+1)
// Get the commit for the treePath itself
entryPaths[0] = ""
for i, entry := range tes {
entryPaths[i+1] = entry.Name()
}
commitNodeIndex, commitGraphFile := commit.repo.CommitNodeIndex()
if commitGraphFile != nil {
defer commitGraphFile.Close()
}
c, err := commitNodeIndex.Get(commit.ID)
if err != nil {
return nil, nil, err
}
var revs map[string]*Commit
if commit.repo.LastCommitCache != nil {
var unHitPaths []string
revs, unHitPaths, err = getLastCommitForPathsByCache(commit.ID.String(), treePath, entryPaths, commit.repo.LastCommitCache)
if err != nil {
return nil, nil, err
}
if len(unHitPaths) > 0 {
revs2, err := GetLastCommitForPaths(ctx, commit.repo.LastCommitCache, c, treePath, unHitPaths)
if err != nil {
return nil, nil, err
}
for k, v := range revs2 {
revs[k] = v
}
}
} else {
revs, err = GetLastCommitForPaths(ctx, nil, c, treePath, entryPaths)
}
if err != nil {
return nil, nil, err
}
commit.repo.gogitStorage.Close()
commitsInfo := make([]CommitInfo, len(tes))
for i, entry := range tes {
commitsInfo[i] = CommitInfo{
Entry: entry,
}
// Check if we have found a commit for this entry in time
if entryCommit, ok := revs[entry.Name()]; ok {
commitsInfo[i].Commit = entryCommit
}
// If the entry if a submodule add a submodule file for this
if entry.IsSubModule() {
subModuleURL := ""
var fullPath string
if len(treePath) > 0 {
fullPath = treePath + "/" + entry.Name()
} else {
fullPath = entry.Name()
}
if subModule, err := commit.GetSubModule(fullPath); err != nil {
return nil, nil, err
} else if subModule != nil {
subModuleURL = subModule.URL
}
subModuleFile := NewSubModuleFile(commitsInfo[i].Commit, subModuleURL, entry.ID.String())
commitsInfo[i].SubModuleFile = subModuleFile
}
}
// Retrieve the commit for the treePath itself (see above). We basically
// get it for free during the tree traversal and it's used for listing
// pages to display information about newest commit for a given path.
var treeCommit *Commit
var ok bool
if treePath == "" {
treeCommit = commit
} else if treeCommit, ok = revs[""]; ok {
treeCommit.repo = commit.repo
}
return commitsInfo, treeCommit, nil
}
type commitAndPaths struct {
commit cgobject.CommitNode
// Paths that are still on the branch represented by commit
paths []string
// Set of hashes for the paths
hashes map[string]plumbing.Hash
}
func getCommitTree(c cgobject.CommitNode, treePath string) (*object.Tree, error) {
tree, err := c.Tree()
if err != nil {
return nil, err
}
// Optimize deep traversals by focusing only on the specific tree
if treePath != "" {
tree, err = tree.Tree(treePath)
if err != nil {
return nil, err
}
}
return tree, nil
}
func getFileHashes(c cgobject.CommitNode, treePath string, paths []string) (map[string]plumbing.Hash, error) {
tree, err := getCommitTree(c, treePath)
if err == object.ErrDirectoryNotFound {
// The whole tree didn't exist, so return empty map
return make(map[string]plumbing.Hash), nil
}
if err != nil {
return nil, err
}
hashes := make(map[string]plumbing.Hash)
for _, path := range paths {
if path != "" {
entry, err := tree.FindEntry(path)
if err == nil {
hashes[path] = entry.Hash
}
} else {
hashes[path] = tree.Hash
}
}
return hashes, nil
}
func getLastCommitForPathsByCache(commitID, treePath string, paths []string, cache *LastCommitCache) (map[string]*Commit, []string, error) {
var unHitEntryPaths []string
results := make(map[string]*Commit)
for _, p := range paths {
lastCommit, err := cache.Get(commitID, path.Join(treePath, p))
if err != nil {
return nil, nil, err
}
if lastCommit != nil {
results[p] = lastCommit
continue
}
unHitEntryPaths = append(unHitEntryPaths, p)
}
return results, unHitEntryPaths, nil
}
// GetLastCommitForPaths returns last commit information
func GetLastCommitForPaths(ctx context.Context, cache *LastCommitCache, c cgobject.CommitNode, treePath string, paths []string) (map[string]*Commit, error) {
refSha := c.ID().String()
// We do a tree traversal with nodes sorted by commit time
heap := binaryheap.NewWith(func(a, b interface{}) int {
if a.(*commitAndPaths).commit.CommitTime().Before(b.(*commitAndPaths).commit.CommitTime()) {
return 1
}
return -1
})
resultNodes := make(map[string]cgobject.CommitNode)
initialHashes, err := getFileHashes(c, treePath, paths)
if err != nil {
return nil, err
}
// Start search from the root commit and with full set of paths
heap.Push(&commitAndPaths{c, paths, initialHashes})
heaploop:
for {
select {
case <-ctx.Done():
if ctx.Err() == context.DeadlineExceeded {
break heaploop
}
return nil, ctx.Err()
default:
}
cIn, ok := heap.Pop()
if !ok {
break
}
current := cIn.(*commitAndPaths)
// Load the parent commits for the one we are currently examining
numParents := current.commit.NumParents()
var parents []cgobject.CommitNode
for i := 0; i < numParents; i++ {
parent, err := current.commit.ParentNode(i)
if err != nil {
break
}
parents = append(parents, parent)
}
// Examine the current commit and set of interesting paths
pathUnchanged := make([]bool, len(current.paths))
parentHashes := make([]map[string]plumbing.Hash, len(parents))
for j, parent := range parents {
parentHashes[j], err = getFileHashes(parent, treePath, current.paths)
if err != nil {
break
}
for i, path := range current.paths {
if parentHashes[j][path] == current.hashes[path] {
pathUnchanged[i] = true
}
}
}
var remainingPaths []string
for i, pth := range current.paths {
// The results could already contain some newer change for the same path,
// so don't override that and bail out on the file early.
if resultNodes[pth] == nil {
if pathUnchanged[i] {
// The path existed with the same hash in at least one parent so it could
// not have been changed in this commit directly.
remainingPaths = append(remainingPaths, pth)
} else {
// There are few possible cases how can we get here:
// - The path didn't exist in any parent, so it must have been created by
// this commit.
// - The path did exist in the parent commit, but the hash of the file has
// changed.
// - We are looking at a merge commit and the hash of the file doesn't
// match any of the hashes being merged. This is more common for directories,
// but it can also happen if a file is changed through conflict resolution.
resultNodes[pth] = current.commit
if err := cache.Put(refSha, path.Join(treePath, pth), current.commit.ID().String()); err != nil {
return nil, err
}
}
}
}
if len(remainingPaths) > 0 {
// Add the parent nodes along with remaining paths to the heap for further
// processing.
for j, parent := range parents {
// Combine remainingPath with paths available on the parent branch
// and make union of them
remainingPathsForParent := make([]string, 0, len(remainingPaths))
newRemainingPaths := make([]string, 0, len(remainingPaths))
for _, path := range remainingPaths {
if parentHashes[j][path] == current.hashes[path] {
remainingPathsForParent = append(remainingPathsForParent, path)
} else {
newRemainingPaths = append(newRemainingPaths, path)
}
}
if remainingPathsForParent != nil {
heap.Push(&commitAndPaths{parent, remainingPathsForParent, parentHashes[j]})
}
if len(newRemainingPaths) == 0 {
break
} else {
remainingPaths = newRemainingPaths
}
}
}
}
// Post-processing
result := make(map[string]*Commit)
for path, commitNode := range resultNodes {
commit, err := commitNode.Commit()
if err != nil {
return nil, err
}
result[path] = convertCommit(commit)
}
return result, nil
}