git-bug/cache/repo_cache_bug.go
2020-11-17 08:09:52 -05:00

520 lines
11 KiB
Go

package cache
import (
"bytes"
"encoding/gob"
"errors"
"fmt"
"os"
"path"
"sort"
"strings"
"time"
"github.com/MichaelMure/git-bug/bug"
"github.com/MichaelMure/git-bug/entity"
"github.com/MichaelMure/git-bug/query"
"github.com/MichaelMure/git-bug/repository"
"github.com/blevesearch/bleve"
)
const (
bugCacheFile = "bug-cache"
searchCacheDir = "search-cache"
)
var errBugNotInCache = errors.New("bug missing from cache")
func bugCacheFilePath(repo repository.Repo) string {
return path.Join(repo.GetPath(), "git-bug", bugCacheFile)
}
func searchCacheDirPath(repo repository.Repo) string {
return path.Join(repo.GetPath(), "git-bug", searchCacheDir)
}
// bugUpdated is a callback to trigger when the excerpt of a bug changed,
// that is each time a bug is updated
func (c *RepoCache) bugUpdated(id entity.Id) error {
c.muBug.Lock()
b, ok := c.bugs[id]
if !ok {
c.muBug.Unlock()
// if the bug is not loaded at this point, it means it was loaded before
// but got evicted. Which means we potentially have multiple copies in
// memory and thus concurrent write.
// Failing immediately here is the simple and safe solution to avoid
// complicated data loss.
return errBugNotInCache
}
c.loadedBugs.Get(id)
c.bugExcerpts[id] = NewBugExcerpt(b.bug, b.Snapshot())
c.muBug.Unlock()
if err := c.addBugToSearchIndex(b.Snapshot()); err != nil {
return err
}
// we only need to write the bug cache
return c.writeBugCache()
}
// load will try to read from the disk the bug cache file
func (c *RepoCache) loadBugCache() error {
c.muBug.Lock()
defer c.muBug.Unlock()
f, err := os.Open(bugCacheFilePath(c.repo))
if err != nil {
return err
}
decoder := gob.NewDecoder(f)
aux := struct {
Version uint
Excerpts map[entity.Id]*BugExcerpt
}{}
err = decoder.Decode(&aux)
if err != nil {
return err
}
if aux.Version != formatVersion {
return fmt.Errorf("unknown cache format version %v", aux.Version)
}
c.bugExcerpts = aux.Excerpts
blevePath := searchCacheDirPath(c.repo)
searchCache, err := bleve.Open(blevePath)
if err != nil {
return fmt.Errorf("Unable to open search cache. Error: %v", err)
}
c.searchCache = searchCache
count, err := c.searchCache.DocCount()
if err != nil {
return err
}
if count != uint64(len(c.bugExcerpts)) {
return fmt.Errorf("count mismatch between bleve and bug excerpts")
}
return nil
}
func (c *RepoCache) createBleveIndex() error {
blevePath := searchCacheDirPath(c.repo)
_ = os.RemoveAll(blevePath)
mapping := bleve.NewIndexMapping()
mapping.DefaultAnalyzer = "en"
dir := searchCacheDirPath(c.repo)
bleveIndex, err := bleve.New(dir, mapping)
if err != nil {
return err
}
c.searchCache = bleveIndex
return nil
}
// write will serialize on disk the bug cache file
func (c *RepoCache) writeBugCache() error {
c.muBug.RLock()
defer c.muBug.RUnlock()
var data bytes.Buffer
aux := struct {
Version uint
Excerpts map[entity.Id]*BugExcerpt
}{
Version: formatVersion,
Excerpts: c.bugExcerpts,
}
encoder := gob.NewEncoder(&data)
err := encoder.Encode(aux)
if err != nil {
return err
}
f, err := os.Create(bugCacheFilePath(c.repo))
if err != nil {
return err
}
_, err = f.Write(data.Bytes())
if err != nil {
return err
}
return f.Close()
}
// ResolveBugExcerpt retrieve a BugExcerpt matching the exact given id
func (c *RepoCache) ResolveBugExcerpt(id entity.Id) (*BugExcerpt, error) {
c.muBug.RLock()
defer c.muBug.RUnlock()
excerpt, ok := c.bugExcerpts[id]
if !ok {
return nil, bug.ErrBugNotExist
}
return excerpt, nil
}
// ResolveBug retrieve a bug matching the exact given id
func (c *RepoCache) ResolveBug(id entity.Id) (*BugCache, error) {
c.muBug.RLock()
cached, ok := c.bugs[id]
if ok {
c.loadedBugs.Get(id)
c.muBug.RUnlock()
return cached, nil
}
c.muBug.RUnlock()
b, err := bug.ReadLocalWithResolver(c.repo, newIdentityCacheResolver(c), id)
if err != nil {
return nil, err
}
cached = NewBugCache(c, b)
c.muBug.Lock()
c.bugs[id] = cached
c.loadedBugs.Add(id)
c.muBug.Unlock()
c.evictIfNeeded()
return cached, nil
}
// evictIfNeeded will evict a bug from the cache if needed
// it also removes references of the bug from the bugs
func (c *RepoCache) evictIfNeeded() {
c.muBug.Lock()
defer c.muBug.Unlock()
if c.loadedBugs.Len() <= c.maxLoadedBugs {
return
}
for _, id := range c.loadedBugs.GetOldestToNewest() {
b := c.bugs[id]
if b.NeedCommit() {
continue
}
b.mu.Lock()
c.loadedBugs.Remove(id)
delete(c.bugs, id)
if c.loadedBugs.Len() <= c.maxLoadedBugs {
return
}
}
}
// ResolveBugExcerptPrefix retrieve a BugExcerpt matching an id prefix. It fails if multiple
// bugs match.
func (c *RepoCache) ResolveBugExcerptPrefix(prefix string) (*BugExcerpt, error) {
return c.ResolveBugExcerptMatcher(func(excerpt *BugExcerpt) bool {
return excerpt.Id.HasPrefix(prefix)
})
}
// ResolveBugPrefix retrieve a bug matching an id prefix. It fails if multiple
// bugs match.
func (c *RepoCache) ResolveBugPrefix(prefix string) (*BugCache, error) {
return c.ResolveBugMatcher(func(excerpt *BugExcerpt) bool {
return excerpt.Id.HasPrefix(prefix)
})
}
// ResolveBugCreateMetadata retrieve a bug that has the exact given metadata on
// its Create operation, that is, the first operation. It fails if multiple bugs
// match.
func (c *RepoCache) ResolveBugCreateMetadata(key string, value string) (*BugCache, error) {
return c.ResolveBugMatcher(func(excerpt *BugExcerpt) bool {
return excerpt.CreateMetadata[key] == value
})
}
func (c *RepoCache) ResolveBugExcerptMatcher(f func(*BugExcerpt) bool) (*BugExcerpt, error) {
id, err := c.resolveBugMatcher(f)
if err != nil {
return nil, err
}
return c.ResolveBugExcerpt(id)
}
func (c *RepoCache) ResolveBugMatcher(f func(*BugExcerpt) bool) (*BugCache, error) {
id, err := c.resolveBugMatcher(f)
if err != nil {
return nil, err
}
return c.ResolveBug(id)
}
func (c *RepoCache) resolveBugMatcher(f func(*BugExcerpt) bool) (entity.Id, error) {
c.muBug.RLock()
defer c.muBug.RUnlock()
// preallocate but empty
matching := make([]entity.Id, 0, 5)
for _, excerpt := range c.bugExcerpts {
if f(excerpt) {
matching = append(matching, excerpt.Id)
}
}
if len(matching) > 1 {
return entity.UnsetId, bug.NewErrMultipleMatchBug(matching)
}
if len(matching) == 0 {
return entity.UnsetId, bug.ErrBugNotExist
}
return matching[0], nil
}
// QueryBugs return the id of all Bug matching the given Query
func (c *RepoCache) QueryBugs(q *query.Query) []entity.Id {
c.muBug.RLock()
defer c.muBug.RUnlock()
if q == nil {
return c.AllBugsIds()
}
matcher := compileMatcher(q.Filters)
var filtered []*BugExcerpt
var foundBySearch map[entity.Id]*BugExcerpt
if q.Search != nil {
foundBySearch = map[entity.Id]*BugExcerpt{}
terms := make([]string, len(q.Search))
copy(terms, q.Search)
for i, search := range q.Search {
if strings.Contains(search, " ") {
terms[i] = fmt.Sprintf("\"%s\"", search)
}
}
bleveQuery := bleve.NewQueryStringQuery(strings.Join(terms, " "))
bleveSearch := bleve.NewSearchRequest(bleveQuery)
searchResults, err := c.searchCache.Search(bleveSearch)
if err != nil {
panic("bleve search failed")
}
for _, hit := range searchResults.Hits {
foundBySearch[entity.Id(hit.ID)] = c.bugExcerpts[entity.Id(hit.ID)]
}
} else {
foundBySearch = c.bugExcerpts
}
for _, excerpt := range foundBySearch {
if matcher.Match(excerpt, c) {
filtered = append(filtered, excerpt)
}
}
var sorter sort.Interface
switch q.OrderBy {
case query.OrderById:
sorter = BugsById(filtered)
case query.OrderByCreation:
sorter = BugsByCreationTime(filtered)
case query.OrderByEdit:
sorter = BugsByEditTime(filtered)
default:
panic("missing sort type")
}
switch q.OrderDirection {
case query.OrderAscending:
// Nothing to do
case query.OrderDescending:
sorter = sort.Reverse(sorter)
default:
panic("missing sort direction")
}
sort.Sort(sorter)
result := make([]entity.Id, len(filtered))
for i, val := range filtered {
result[i] = val.Id
}
return result
}
// AllBugsIds return all known bug ids
func (c *RepoCache) AllBugsIds() []entity.Id {
c.muBug.RLock()
defer c.muBug.RUnlock()
result := make([]entity.Id, len(c.bugExcerpts))
i := 0
for _, excerpt := range c.bugExcerpts {
result[i] = excerpt.Id
i++
}
return result
}
// ValidLabels list valid labels
//
// Note: in the future, a proper label policy could be implemented where valid
// labels are defined in a configuration file. Until that, the default behavior
// is to return the list of labels already used.
func (c *RepoCache) ValidLabels() []bug.Label {
c.muBug.RLock()
defer c.muBug.RUnlock()
set := map[bug.Label]interface{}{}
for _, excerpt := range c.bugExcerpts {
for _, l := range excerpt.Labels {
set[l] = nil
}
}
result := make([]bug.Label, len(set))
i := 0
for l := range set {
result[i] = l
i++
}
// Sort
sort.Slice(result, func(i, j int) bool {
return string(result[i]) < string(result[j])
})
return result
}
// NewBug create a new bug
// The new bug is written in the repository (commit)
func (c *RepoCache) NewBug(title string, message string) (*BugCache, *bug.CreateOperation, error) {
return c.NewBugWithFiles(title, message, nil)
}
// NewBugWithFiles create a new bug with attached files for the message
// The new bug is written in the repository (commit)
func (c *RepoCache) NewBugWithFiles(title string, message string, files []repository.Hash) (*BugCache, *bug.CreateOperation, error) {
author, err := c.GetUserIdentity()
if err != nil {
return nil, nil, err
}
return c.NewBugRaw(author, time.Now().Unix(), title, message, files, nil)
}
// NewBugWithFilesMeta create a new bug with attached files for the message, as
// well as metadata for the Create operation.
// The new bug is written in the repository (commit)
func (c *RepoCache) NewBugRaw(author *IdentityCache, unixTime int64, title string, message string, files []repository.Hash, metadata map[string]string) (*BugCache, *bug.CreateOperation, error) {
b, op, err := bug.CreateWithFiles(author.Identity, unixTime, title, message, files)
if err != nil {
return nil, nil, err
}
for key, value := range metadata {
op.SetMetadata(key, value)
}
err = b.Commit(c.repo)
if err != nil {
return nil, nil, err
}
c.muBug.Lock()
if _, has := c.bugs[b.Id()]; has {
c.muBug.Unlock()
return nil, nil, fmt.Errorf("bug %s already exist in the cache", b.Id())
}
cached := NewBugCache(c, b)
c.bugs[b.Id()] = cached
c.loadedBugs.Add(b.Id())
c.muBug.Unlock()
c.evictIfNeeded()
// force the write of the excerpt
err = c.bugUpdated(b.Id())
if err != nil {
return nil, nil, err
}
return cached, op, nil
}
// RemoveBug removes a bug from the cache and repo given a bug id prefix
func (c *RepoCache) RemoveBug(prefix string) error {
c.muBug.RLock()
b, err := c.ResolveBugPrefix(prefix)
if err != nil {
c.muBug.RUnlock()
return err
}
c.muBug.RUnlock()
c.muBug.Lock()
err = bug.RemoveBug(c.repo, b.Id())
delete(c.bugs, b.Id())
delete(c.bugExcerpts, b.Id())
c.loadedBugs.Remove(b.Id())
c.muBug.Unlock()
return c.writeBugCache()
}
func (c *RepoCache) addBugToSearchIndex(snap *bug.Snapshot) error {
searchableBug := struct {
Text []string
}{}
for _, comment := range snap.Comments {
searchableBug.Text = append(searchableBug.Text, comment.Message)
}
searchableBug.Text = append(searchableBug.Text, snap.Title)
err := c.searchCache.Index(snap.Id().String(), searchableBug)
if err != nil {
return err
}
return nil
}