collapse data and transform packages into proxy

proxy/data.go

@@ -0,0 +1,112 @@
+// Copyright 2013 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 data provides common shared data structures for imageproxy.
+package proxy
+
+import (
+	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Options specifies transformations that can be performed on a
+// requested image.
+type Options struct {
+	Width  float64 // requested width, in pixels
+	Height float64 // requested height, in pixels
+
+	// If true, resize the image to fit in the specified dimensions.  Image
+	// will not be cropped, and aspect ratio will be maintained.
+	Fit bool
+
+	// Rotate image the specified degrees counter-clockwise.  Valid values are 90, 180, 270.
+	Rotate int
+
+	FlipVertical   bool
+	FlipHorizontal bool
+}
+
+func (o Options) String() string {
+	return fmt.Sprintf("%vx%v", o.Width, o.Height)
+}
+
+func ParseOptions(str string) *Options {
+	o := new(Options)
+	var h, w string
+
+	parts := strings.Split(str, ",")
+
+	// parse size
+	size := strings.SplitN(parts[0], "x", 2)
+	w = size[0]
+	if len(size) > 1 {
+		h = size[1]
+	} else {
+		h = w
+	}
+
+	if w != "" {
+		o.Width, _ = strconv.ParseFloat(w, 64)
+	}
+	if h != "" {
+		o.Height, _ = strconv.ParseFloat(h, 64)
+	}
+
+	for _, part := range parts[1:] {
+		if part == "fit" {
+			o.Fit = true
+			continue
+		}
+		if part == "fv" {
+			o.FlipVertical = true
+			continue
+		}
+		if part == "fh" {
+			o.FlipHorizontal = true
+			continue
+		}
+
+		if len(part) > 2 && strings.HasPrefix(part, "r") {
+			o.Rotate, _ = strconv.Atoi(part[1:])
+			continue
+		}
+	}
+
+	return o
+}
+
+type Request struct {
+	URL     *url.URL // URL of the image to proxy
+	Options *Options // Image transformation to perform
+}
+
+// Image represents a remote image that is being proxied.  It tracks where
+// the image was originally retrieved from and how long the image can be cached.
+type Image struct {
+	// URL of original remote image.
+	URL string
+
+	// Expires is the cache expiration time for the original image, as
+	// returned by the remote server.
+	Expires time.Time
+
+	// Etag returned from server when fetching image.
+	Etag string
+
+	// Bytes contains the actual image.
+	Bytes []byte
+}