contentdb replaced by new mimedb

pkg/mimedb/util/gen-db.go

@@ -0,0 +1,146 @@
+/*
+ * mimedb: Mime Database, (C) 2015 Minio, Inc.
+ *
+ * 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 mimedb is a database of file extension to mime content-type.
+// Definitions are imported from NodeJS mime-db project under MIT license.
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+	"text/template"
+)
+
+const progTempl = `// DO NOT EDIT THIS FILE. IT IS AUTO-GENERATED BY "gen-db.go". //
+/*
+ * mimedb: Mime Database, (C) 2016 Minio, Inc.
+ *
+ * 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 mimedb is a database of file extension to mime content-type.
+// Definitions are imported from NodeJS mime-db project under MIT license.
+package mimedb
+
+// Mime is a collection of mime types with extension as key and content-type as value.
+var DB = map[string]struct {
+	ContentType  string
+	Compressible bool
+}{
+{{range $extension, $entry := . }}	"{{$extension}}": {
+		ContentType:  "{{$entry.ContentType}}",
+		Compressible: {{$entry.Compressible}},
+	},
+{{end}}}
+`
+
+type mimeEntry struct {
+	ContentType  string `json:"contentType"`
+	Compressible bool   `json:"compresible"`
+}
+
+type mimeDB map[string]mimeEntry
+
+var ()
+
+//  JSON data from gobindata and parse them into extDB.
+func convertDB(jsonFile string) (mimeDB, error) {
+	// Structure of JSON data from mime-db project.
+	type dbEntry struct {
+		Source       string   `json:"source"`
+		Compressible bool     `json:"compresible"`
+		Extensions   []string `json:"extensions"`
+	}
+
+	// Access embedded "db.json" inside go-bindata.
+	jsonDB, err := ioutil.ReadFile(jsonFile)
+	if err != nil {
+		return nil, err
+	}
+
+	// Convert db.json into go's typed structure.
+	db := make(map[string]dbEntry)
+	if err := json.Unmarshal(jsonDB, &db); err != nil {
+		return nil, err
+	}
+
+	mDB := make(mimeDB)
+
+	// Generate a new database from mime-db.
+	for key, val := range db {
+		if len(val.Extensions) > 0 {
+			/* Denormalize - each extension has its own
+			unique content-type now. Looks will be fast. */
+			for _, ext := range val.Extensions {
+				/* Single extension type may map to
+				multiple content-types. In that case,
+				simply prefer the longest content-type
+				to maintain some level of
+				consistency. Only guarantee is,
+				whatever content type is assigned, it
+				is appropriate and valid type. */
+				if strings.Compare(mDB[ext].ContentType, key) < 0 {
+					mDB[ext] = mimeEntry{
+						ContentType:  key,
+						Compressible: val.Compressible,
+					}
+				}
+			}
+		}
+	}
+	return mDB, nil
+}
+
+func main() {
+	// Take input json file from command-line".
+	if len(os.Args) != 2 {
+		fmt.Print("Syntax:\n\tgen-db /path/to/db.json\n")
+		os.Exit(1)
+	}
+
+	// Load and convert db.json into new database with extension
+	// as key.
+	mDB, err := convertDB(os.Args[1])
+	if err != nil {
+		panic(err)
+	}
+
+	// Generate db embedded go program.
+	tmpl := template.New("mimedb")
+	mimeTmpl, err := tmpl.Parse(progTempl)
+	if err != nil {
+		panic(err)
+	}
+
+	err = mimeTmpl.Execute(os.Stdout, mDB)
+	if err != nil {
+		panic(err)
+	}
+}