cache: lock the repo with a pid file; automatic cleaning

1 files changed, 144 insertions, 0 deletions

diff --git a/cache/repo_cache.go b/cache/repo_cache.go
new file mode 100644
index 00000000..e58165d2
--- /dev/null
+++ b/cache/repo_cache.go
@@ -0,0 +1,144 @@
+package cache
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/MichaelMure/git-bug/bug"
+	"github.com/MichaelMure/git-bug/bug/operations"
+	"github.com/MichaelMure/git-bug/repository"
+	"github.com/MichaelMure/git-bug/util"
+)
+
+type RepoCacher interface {
+	Repository() repository.Repo
+	ResolveBug(id string) (BugCacher, error)
+	ResolveBugPrefix(prefix string) (BugCacher, error)
+	AllBugIds() ([]string, error)
+	ClearAllBugs()
+
+	// Mutations
+	NewBug(title string, message string) (BugCacher, error)
+	NewBugWithFiles(title string, message string, files []util.Hash) (BugCacher, error)
+	Fetch(remote string) (string, error)
+	MergeAll(remote string) <-chan bug.MergeResult
+	Pull(remote string, out io.Writer) error
+	Push(remote string) (string, error)
+}
+
+type RepoCache struct {
+	repo repository.Repo
+	bugs map[string]BugCacher
+}
+
+func NewRepoCache(r repository.Repo) RepoCacher {
+	return &RepoCache{
+		repo: r,
+		bugs: make(map[string]BugCacher),
+	}
+}
+
+func (c *RepoCache) Repository() repository.Repo {
+	return c.repo
+}
+
+func (c *RepoCache) ResolveBug(id string) (BugCacher, error) {
+	cached, ok := c.bugs[id]
+	if ok {
+		return cached, nil
+	}
+
+	b, err := bug.ReadLocalBug(c.repo, id)
+	if err != nil {
+		return nil, err
+	}
+
+	cached = NewBugCache(c.repo, b)
+	c.bugs[id] = cached
+
+	return cached, nil
+}
+
+func (c *RepoCache) ResolveBugPrefix(prefix string) (BugCacher, error) {
+	// preallocate but empty
+	matching := make([]string, 0, 5)
+
+	for id := range c.bugs {
+		if strings.HasPrefix(id, prefix) {
+			matching = append(matching, id)
+		}
+	}
+
+	// TODO: should check matching bug in the repo as well
+
+	if len(matching) > 1 {
+		return nil, fmt.Errorf("Multiple matching bug found:\n%s", strings.Join(matching, "\n"))
+	}
+
+	if len(matching) == 1 {
+		b := c.bugs[matching[0]]
+		return b, nil
+	}
+
+	b, err := bug.FindLocalBug(c.repo, prefix)
+
+	if err != nil {
+		return nil, err
+	}
+
+	cached := NewBugCache(c.repo, b)
+	c.bugs[b.Id()] = cached
+
+	return cached, nil
+}
+
+func (c *RepoCache) AllBugIds() ([]string, error) {
+	return bug.ListLocalIds(c.repo)
+}
+
+func (c *RepoCache) ClearAllBugs() {
+	c.bugs = make(map[string]BugCacher)
+}
+
+func (c *RepoCache) NewBug(title string, message string) (BugCacher, error) {
+	return c.NewBugWithFiles(title, message, nil)
+}
+
+func (c *RepoCache) NewBugWithFiles(title string, message string, files []util.Hash) (BugCacher, error) {
+	author, err := bug.GetUser(c.repo)
+	if err != nil {
+		return nil, err
+	}
+
+	b, err := operations.CreateWithFiles(author, title, message, files)
+	if err != nil {
+		return nil, err
+	}
+
+	err = b.Commit(c.repo)
+	if err != nil {
+		return nil, err
+	}
+
+	cached := NewBugCache(c.repo, b)
+	c.bugs[b.Id()] = cached
+
+	return cached, nil
+}
+
+func (c *RepoCache) Fetch(remote string) (string, error) {
+	return bug.Fetch(c.repo, remote)
+}
+
+func (c *RepoCache) MergeAll(remote string) <-chan bug.MergeResult {
+	return bug.MergeAll(c.repo, remote)
+}
+
+func (c *RepoCache) Pull(remote string, out io.Writer) error {
+	return bug.Pull(c.repo, out, remote)
+}
+
+func (c *RepoCache) Push(remote string) (string, error) {
+	return bug.Push(c.repo, remote)
+}