git: add tree entries relation. (#40)

Author: smola

git/database.go

@@ -7,16 +7,18 @@ import (
 )
 
 const (
-	referencesRelationName = "references"
-	commitsRelationName    = "commits"
-	tagsRelationName       = "tags"
+	referencesRelationName  = "references"
+	commitsRelationName     = "commits"
+	tagsRelationName        = "tags"
+	treeEntriesRelationName = "tree_entries"
 )
 
 type Database struct {
 	name string
 	cr   sql.PhysicalRelation
 	tr   sql.PhysicalRelation
 	rr   sql.PhysicalRelation
+	ter  sql.PhysicalRelation
 }
 
 func NewDatabase(name string, r *git.Repository) sql.Database {
@@ -25,6 +27,7 @@ func NewDatabase(name string, r *git.Repository) sql.Database {
 		cr:   newCommitsRelation(r),
 		rr:   newReferencesRelation(r),
 		tr:   newTagsRelation(r),
+		ter:  newTreeEntriesRelation(r),
 	}
 }
 
@@ -34,8 +37,9 @@ func (d *Database) Name() string {
 
 func (d *Database) Relations() map[string]sql.PhysicalRelation {
 	return map[string]sql.PhysicalRelation{
-		commitsRelationName:    d.cr,
-		tagsRelationName:       d.tr,
-		referencesRelationName: d.rr,
+		commitsRelationName:     d.cr,
+		tagsRelationName:        d.tr,
+		referencesRelationName:  d.rr,
+		treeEntriesRelationName: d.ter,
 	}
 }

git/tree_entries.go

@@ -0,0 +1,93 @@
+package git
+
+import (
+	"strconv"
+
+	"github.com/gitql/gitql/sql"
+
+	"gopkg.in/src-d/go-git.v4"
+)
+
+type treeEntriesRelation struct {
+	r *git.Repository
+}
+
+func newTreeEntriesRelation(r *git.Repository) sql.PhysicalRelation {
+	return &treeEntriesRelation{r: r}
+}
+
+func (treeEntriesRelation) Resolved() bool {
+	return true
+}
+
+func (treeEntriesRelation) Name() string {
+	return treeEntriesRelationName
+}
+
+func (treeEntriesRelation) Schema() sql.Schema {
+	return sql.Schema{
+		sql.Field{"tree_hash", sql.String},
+		sql.Field{"entry_hash", sql.String},
+		sql.Field{"mode", sql.String},
+		sql.Field{"name", sql.String},
+	}
+}
+
+func (r *treeEntriesRelation) TransformUp(f func(sql.Node) sql.Node) sql.Node {
+	return f(r)
+}
+
+func (r *treeEntriesRelation) TransformExpressionsUp(f func(sql.Expression) sql.Expression) sql.Node {
+	return r
+}
+
+func (r treeEntriesRelation) RowIter() (sql.RowIter, error) {
+	cIter, err := r.r.Trees()
+	if err != nil {
+		return nil, err
+	}
+	iter := &treeEntryIter{i: cIter}
+	return iter, nil
+}
+
+func (treeEntriesRelation) Children() []sql.Node {
+	return []sql.Node{}
+}
+
+type treeEntryIter struct {
+	i  *git.TreeIter
+	t  *git.Tree
+	ei int
+}
+
+func (i *treeEntryIter) Next() (sql.Row, error) {
+	for {
+		if i.t == nil {
+			tree, err := i.i.Next()
+			if err != nil {
+				return nil, err
+			}
+
+			i.t = tree
+			i.ei = 0
+		}
+
+		if i.ei >= len(i.t.Entries) {
+			i.t = nil
+		}
+
+		e := i.t.Entries[i.ei]
+		i.ei++
+
+		return treeEntryToRow(i.t, e), nil
+	}
+}
+
+func treeEntryToRow(t *git.Tree, e git.TreeEntry) sql.Row {
+	return sql.NewMemoryRow(
+		t.ID().String(),
+		e.Hash.String(),
+		strconv.FormatInt(int64(e.Mode), 8),
+		e.Name,
+	)
+}

git/tree_entries_test.go

@@ -0,0 +1,43 @@
+package git
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"gopkg.in/src-d/go-git.v4"
+	"gopkg.in/src-d/go-git.v4/fixtures"
+)
+
+func TestTreeEntriesRelation(t *testing.T) {
+	assert := assert.New(t)
+
+	f := fixtures.Basic().One()
+	r, err := git.NewFilesystemRepository(f.DotGit().Base())
+	assert.Nil(err)
+
+	db := NewDatabase("foo", r)
+	assert.NotNil(db)
+
+	relations := db.Relations()
+	rel, ok := relations[treeEntriesRelationName]
+	assert.True(ok)
+	assert.NotNil(rel)
+	assert.Equal(treeEntriesRelationName, 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.Len(fields, 4)
+	assert.IsType("", fields[0])
+	assert.IsType("", fields[1])
+	assert.IsType("", fields[2])
+	assert.IsType("", fields[3])
+}