Add IsVideo to types/camtypes FileInfo

It is based on MIME type then falls back to extension.

Change-Id: I71d80ec7cdcf94f4fa7feffa8186943abe0279ce

pkg/types/camtypes/search.go

@@ -19,6 +19,7 @@ package camtypes
 import (
 	"bytes"
 	"fmt"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -111,6 +112,57 @@ func (fi *FileInfo) IsImage() bool {
 	return strings.HasPrefix(fi.MIMEType, "image/")
 }
 
+var videoExtensions = map[string]bool{
+	"3gp":  true,
+	"avi":  true,
+	"flv":  true,
+	"m1v":  true,
+	"m2v":  true,
+	"m4v":  true,
+	"mkv":  true,
+	"mov":  true,
+	"mp4":  true,
+	"mpeg": true,
+	"mpg":  true,
+	"ogv":  true,
+	"wmv":  true,
+}
+
+func (fi *FileInfo) IsVideo() bool {
+	if strings.HasPrefix(fi.MIMEType, "video/") {
+		return true
+	}
+
+	var ext string
+	if e := filepath.Ext(fi.FileName); strings.HasPrefix(e, ".") {
+		ext = e[1:]
+	} else {
+		return false
+	}
+
+	// Case-insensitive lookup.
+	// Optimistically assume a short ASCII extension and be
+	// allocation-free in that case.
+	var buf [10]byte
+	lower := buf[:0]
+	const utf8RuneSelf = 0x80 // from utf8 package, but not importing it.
+	for i := 0; i < len(ext); i++ {
+		c := ext[i]
+		if c >= utf8RuneSelf {
+			// Slow path.
+			return videoExtensions[strings.ToLower(ext)]
+		}
+		if 'A' <= c && c <= 'Z' {
+			lower = append(lower, c+('a'-'A'))
+		} else {
+			lower = append(lower, c)
+		}
+	}
+	// The conversion from []byte to string doesn't allocate in
+	// a map lookup.
+	return videoExtensions[string(lower)]
+}
+
 // ImageInfo describes an image file.
 //
 // The Width and Height are uint16s to save memory in index/corpus.go, and that's

pkg/types/camtypes/search_test.go

@@ -0,0 +1,42 @@
+/*
+Copyright 2014 The Camlistore Authors
+
+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 camtypes
+
+import "testing"
+
+var fileInfoVideoTable = []struct {
+	fi    *FileInfo
+	video bool
+}{
+	{&FileInfo{FileName: "some.mp4", MIMEType: "application/octet-stream"}, true},
+	{&FileInfo{FileName: "IMG_1231.MOV", MIMEType: "application/octet-stream"}, true},
+	{&FileInfo{FileName: "movie.mkv", MIMEType: "application/octet-stream"}, true},
+	{&FileInfo{FileName: "movie.məv", MIMEType: "application/octet-stream"}, false},
+	{&FileInfo{FileName: "tape", MIMEType: "video/webm"}, true},
+	{&FileInfo{FileName: "tape", MIMEType: "application/ogg"}, false},
+	{&FileInfo{FileName: "IMG_12312.jpg", MIMEType: "application/octet-stream"}, false},
+	{&FileInfo{FileName: "IMG_12312.jpg", MIMEType: "image/jpeg"}, false},
+}
+
+func TestIsVideo(t *testing.T) {
+	for _, example := range fileInfoVideoTable {
+		if example.fi.IsVideo() != example.video {
+			t.Errorf("IsVideo failed video=%t filename=%s mimetype=%s",
+				example.video, example.fi.FileName, example.fi.MIMEType)
+		}
+	}
+}