git: Add tags relation (#36)

Author: ajnavarro

git/database.go

@@ -8,17 +8,20 @@ import (
 
 const (
 	commitsRelationName = "commits"
+	tagsRelationName    = "tags"
 )
 
 type Database struct {
 	name string
 	cr   sql.PhysicalRelation
+	tr   sql.PhysicalRelation
 }
 
 func NewDatabase(name string, r *git.Repository) sql.Database {
 	return &Database{
 		name: name,
 		cr:   newCommitsRelation(r),
+		tr:   newTagsRelation(r),
 	}
 }
 
@@ -29,5 +32,6 @@ func (d *Database) Name() string {
 func (d *Database) Relations() map[string]sql.PhysicalRelation {
 	return map[string]sql.PhysicalRelation{
 		commitsRelationName: d.cr,
+		tagsRelationName:    d.tr,
 	}
 }

git/tags.go

@@ -0,0 +1,81 @@
+package git
+
+import (
+	"github.com/gitql/gitql/sql"
+
+	"gopkg.in/src-d/go-git.v4"
+)
+
+type tagsRelation struct {
+	r *git.Repository
+}
+
+func newTagsRelation(r *git.Repository) sql.PhysicalRelation {
+	return &tagsRelation{r: r}
+}
+
+func (tagsRelation) Resolved() bool {
+	return true
+}
+
+func (tagsRelation) Name() string {
+	return tagsRelationName
+}
+
+func (tagsRelation) Schema() sql.Schema {
+	return sql.Schema{
+		sql.Field{"hash", sql.String},
+		sql.Field{"name", sql.String},
+		sql.Field{"tagger_email", sql.String},
+		sql.Field{"tagger_name", sql.String},
+		sql.Field{"tagger_when", sql.Timestamp},
+		sql.Field{"message", sql.String},
+		sql.Field{"target", sql.String},
+	}
+}
+
+func (r *tagsRelation) TransformUp(f func(sql.Node) sql.Node) sql.Node {
+	return f(r)
+}
+
+func (r *tagsRelation) TransformExpressionsUp(f func(sql.Expression) sql.Expression) sql.Node {
+	return r
+}
+
+func (r tagsRelation) RowIter() (sql.RowIter, error) {
+	tIter, err := r.r.Tags()
+	if err != nil {
+		return nil, err
+	}
+	iter := &tagIter{i: tIter}
+	return iter, nil
+}
+
+func (tagsRelation) Children() []sql.Node {
+	return []sql.Node{}
+}
+
+type tagIter struct {
+	i *git.TagIter
+}
+
+func (i *tagIter) Next() (sql.Row, error) {
+	tag, err := i.i.Next()
+	if err != nil {
+		return nil, err
+	}
+
+	return tagToRow(tag), nil
+}
+
+func tagToRow(c *git.Tag) sql.Row {
+	return sql.NewMemoryRow(
+		c.Hash.String(),
+		c.Name,
+		c.Tagger.Email,
+		c.Tagger.Name,
+		c.Tagger.When,
+		c.Message,
+		c.Target.String(),
+	)
+}

git/tags_test.go

@@ -0,0 +1,47 @@
+package git
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"gopkg.in/src-d/go-git.v4"
+	"gopkg.in/src-d/go-git.v4/fixtures"
+)
+
+func TestTagsRelation(t *testing.T) {
+	assert := assert.New(t)
+
+	f := fixtures.ByTag("tags").One()
+	r, err := git.NewFilesystemRepository(f.DotGit().Base())
+	assert.Nil(err)
+
+	db := NewDatabase("foo", r)
+	assert.NotNil(db)
+
+	relations := db.Relations()
+	rel, ok := relations[tagsRelationName]
+	assert.True(ok)
+	assert.NotNil(rel)
+	assert.Equal(tagsRelationName, rel.Name())
+	assert.Equal(0, len(rel.Children()))
+
+	iter, err := rel.RowIter()
+	assert.Nil(err)
+	assert.NotNil(iter)
+
+	row, err := iter.Next()
+	assert.Nil(err)
+	assert.NotNil(row)
+
+	fields := row.Fields()
+	assert.NotNil(fields)
+
+	assert.IsType("", fields[0])
+	assert.IsType("", fields[1])
+	assert.IsType("", fields[2])
+	assert.IsType("", fields[3])
+	assert.IsType(time.Time{}, fields[4])
+	assert.IsType("", fields[5])
+	assert.IsType("", fields[6])
+}