git: Add blob table (#42)

Author: ajnavarro

Diff for: git/blobs.go

@@ -0,0 +1,71 @@
+package git
+
+import (
+	"github.com/gitql/gitql/sql"
+
+	"gopkg.in/src-d/go-git.v4"
+)
+
+type blobsRelation struct {
+	r *git.Repository
+}
+
+func newBlobsRelation(r *git.Repository) sql.PhysicalRelation {
+	return &blobsRelation{r: r}
+}
+
+func (blobsRelation) Resolved() bool {
+	return true
+}
+
+func (blobsRelation) Name() string {
+	return blobsRelationName
+}
+
+func (blobsRelation) Schema() sql.Schema {
+	return sql.Schema{
+		sql.Field{"hash", sql.String},
+		sql.Field{"size", sql.BigInteger},
+	}
+}
+
+func (r *blobsRelation) TransformUp(f func(sql.Node) sql.Node) sql.Node {
+	return f(r)
+}
+
+func (r *blobsRelation) TransformExpressionsUp(f func(sql.Expression) sql.Expression) sql.Node {
+	return r
+}
+
+func (r blobsRelation) RowIter() (sql.RowIter, error) {
+	bIter, err := r.r.Blobs()
+	if err != nil {
+		return nil, err
+	}
+	iter := &blobIter{i: bIter}
+	return iter, nil
+}
+
+func (blobsRelation) Children() []sql.Node {
+	return []sql.Node{}
+}
+
+type blobIter struct {
+	i *git.BlobIter
+}
+
+func (i *blobIter) Next() (sql.Row, error) {
+	blob, err := i.i.Next()
+	if err != nil {
+		return nil, err
+	}
+
+	return blobToRow(blob), nil
+}
+
+func blobToRow(c *git.Blob) sql.Row {
+	return sql.NewMemoryRow(
+		c.Hash.String(),
+		c.Size,
+	)
+}

Diff for: git/blobs_test.go

@@ -0,0 +1,40 @@
+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 TestBlobsRelation(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[blobsRelationName]
+	assert.True(ok)
+	assert.NotNil(rel)
+	assert.Equal(blobsRelationName, 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(int64(0), fields[1])
+}

Diff for: git/database.go

@@ -10,6 +10,7 @@ const (
 	referencesRelationName  = "references"
 	commitsRelationName     = "commits"
 	tagsRelationName        = "tags"
+	blobsRelationName       = "blobs"
 	treeEntriesRelationName = "tree_entries"
 )
 
@@ -19,6 +20,7 @@ type Database struct {
 	tr   sql.PhysicalRelation
 	rr   sql.PhysicalRelation
 	ter  sql.PhysicalRelation
+	br   sql.PhysicalRelation
 }
 
 func NewDatabase(name string, r *git.Repository) sql.Database {
@@ -27,6 +29,7 @@ func NewDatabase(name string, r *git.Repository) sql.Database {
 		cr:   newCommitsRelation(r),
 		rr:   newReferencesRelation(r),
 		tr:   newTagsRelation(r),
+		br:   newBlobsRelation(r),
 		ter:  newTreeEntriesRelation(r),
 	}
 }
@@ -40,6 +43,7 @@ func (d *Database) Relations() map[string]sql.PhysicalRelation {
 		commitsRelationName:     d.cr,
 		tagsRelationName:        d.tr,
 		referencesRelationName:  d.rr,
+		blobsRelationName:       d.br,
 		treeEntriesRelationName: d.ter,
 	}
 }