69 lines
1.4 KiB
Go
69 lines
1.4 KiB
Go
package images
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import (
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"bytes"
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"compress/flate"
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"encoding/base64"
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"fmt"
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"io"
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"strings"
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)
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func UIDFromPath(path string) (uid string, err error) {
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var b bytes.Buffer
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// NewWriter with NoDict (nil) creates a raw DEFLATE compressor
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zw, _ := flate.NewWriter(&b, flate.BestCompression)
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_, err = zw.Write([]byte(path))
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if err != nil {
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return
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}
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err = zw.Close() // Essential to flush the final bits
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if err != nil {
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return
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}
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return base64.RawURLEncoding.EncodeToString(b.Bytes()), nil
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}
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func URLFromPath(path string) (url string, err error) {
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uid, err := UIDFromPath(path)
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url = "/images/" + uid
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return
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}
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func PathFromUID(uid string) (string, error) {
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// 1. Decode the Base64 string back to compressed bytes
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compressedBytes, err := base64.RawURLEncoding.DecodeString(uid)
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if err != nil {
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return "", err
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}
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// 2. Create a flate reader (NoDict/nil since you used nil in the writer)
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// flate.NewReader returns an io.ReadCloser
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reader := flate.NewReader(bytes.NewReader(compressedBytes))
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defer reader.Close()
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// 3. Read the decompressed data into a buffer
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var out bytes.Buffer
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_, err = io.Copy(&out, reader)
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if err != nil {
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return "", err
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}
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return out.String(), nil
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}
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func SourceSet(src string) string {
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sb := strings.Builder{}
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for i := range 19 {
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sb.WriteString(fmt.Sprintf("%s?w=%d %dw, ", src, 100*(i+1), 100*(i+1)))
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}
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i := 20
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sb.WriteString(fmt.Sprintf("%s?w=%d %dw", src, 100*(i+1), 100*(i+1)))
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return sb.String()
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}
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