go gettable for github.com/google/kati
diff --git a/depgraph.go b/depgraph.go
new file mode 100644
index 0000000..a349980
--- /dev/null
+++ b/depgraph.go
@@ -0,0 +1,115 @@
+// Copyright 2015 Google Inc. All rights reserved
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package kati
+
+import (
+	"crypto/sha1"
+	"io/ioutil"
+	"time"
+)
+
+type DepGraph struct {
+	nodes    []*DepNode
+	vars     Vars
+	readMks  []*ReadMakefile
+	exports  map[string]bool
+	isCached bool
+}
+
+func (g *DepGraph) Nodes() []*DepNode        { return g.nodes }
+func (g *DepGraph) Vars() Vars               { return g.vars }
+func (g *DepGraph) Exports() map[string]bool { return g.exports }
+func (g *DepGraph) IsCached() bool           { return g.isCached }
+
+type LoadOpt struct {
+	Targets         []string
+	CommandLineVars []string
+	EnvironmentVars []string
+	UseCache        bool
+}
+
+func Load(makefile string, opt LoadOpt) (*DepGraph, error) {
+	startTime := time.Now()
+	if makefile == "" {
+		makefile = DefaultMakefile()
+	}
+
+	if opt.UseCache {
+		g := LoadDepGraphCache(makefile, opt.Targets)
+		if g != nil {
+			return g, nil
+		}
+	}
+
+	bmk := BootstrapMakefile(opt.Targets)
+
+	content, err := ioutil.ReadFile(makefile)
+	if err != nil {
+		return nil, err
+	}
+	mk, err := ParseMakefile(content, makefile)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, stmt := range mk.stmts {
+		stmt.show()
+	}
+
+	mk.stmts = append(bmk.stmts, mk.stmts...)
+
+	vars := make(Vars)
+	err = InitVars(vars, opt.EnvironmentVars, "environment")
+	if err != nil {
+		return nil, err
+	}
+	err = InitVars(vars, opt.CommandLineVars, "command line")
+	if err != nil {
+		return nil, err
+	}
+	er, err := Eval(mk, vars, opt.UseCache)
+	if err != nil {
+		return nil, err
+	}
+	vars.Merge(er.vars)
+
+	LogStats("eval time: %q", time.Since(startTime))
+	LogStats("shell func time: %q %d", shellStats.Duration(), shellStats.Count())
+
+	startTime = time.Now()
+	db := NewDepBuilder(er, vars)
+	LogStats("dep build prepare time: %q", time.Since(startTime))
+
+	startTime = time.Now()
+	nodes, err := db.Eval(opt.Targets)
+	if err != nil {
+		return nil, err
+	}
+	LogStats("dep build time: %q", time.Since(startTime))
+	var readMks []*ReadMakefile
+	// Always put the root Makefile as the first element.
+	readMks = append(readMks, &ReadMakefile{
+		Filename: makefile,
+		Hash:     sha1.Sum(content),
+		State:    FileExists,
+	})
+	readMks = append(readMks, er.readMks...)
+	return &DepGraph{
+		nodes:   nodes,
+		vars:    vars,
+		readMks: readMks,
+		exports: er.exports,
+	}, nil
+}