90 lines
1.9 KiB
Go
90 lines
1.9 KiB
Go
package files
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import (
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"errors"
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"fmt"
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"io"
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"net/http"
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"net/url"
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"os"
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)
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// WebFile is an implementation of File which reads it
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// from a Web URL (http). A GET request will be performed
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// against the source when calling Read().
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type WebFile struct {
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body io.ReadCloser
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url *url.URL
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contentLength int64
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}
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// NewWebFile creates a WebFile with the given URL, which
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// will be used to perform the GET request on Read().
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func NewWebFile(url *url.URL) *WebFile {
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return &WebFile{
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url: url,
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}
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}
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func (wf *WebFile) start() error {
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if wf.body == nil {
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s := wf.url.String()
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resp, err := http.Get(s)
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if err != nil {
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return err
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}
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if resp.StatusCode < 200 || resp.StatusCode > 299 {
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return fmt.Errorf("got non-2XX status code %d: %s", resp.StatusCode, s)
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}
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wf.body = resp.Body
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wf.contentLength = resp.ContentLength
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}
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return nil
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}
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// Read reads the File from it's web location. On the first
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// call to Read, a GET request will be performed against the
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// WebFile's URL, using Go's default HTTP client. Any further
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// reads will keep reading from the HTTP Request body.
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func (wf *WebFile) Read(b []byte) (int, error) {
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if err := wf.start(); err != nil {
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return 0, err
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}
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return wf.body.Read(b)
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}
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// Close closes the WebFile (or the request body).
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func (wf *WebFile) Close() error {
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if wf.body == nil {
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return nil
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}
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return wf.body.Close()
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}
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// TODO: implement
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func (wf *WebFile) Seek(offset int64, whence int) (int64, error) {
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return 0, ErrNotSupported
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}
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func (wf *WebFile) Size() (int64, error) {
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if err := wf.start(); err != nil {
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return 0, err
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}
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if wf.contentLength < 0 {
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return -1, errors.New("Content-Length hearer was not set")
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}
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return wf.contentLength, nil
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}
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func (wf *WebFile) AbsPath() string {
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return wf.url.String()
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}
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func (wf *WebFile) Stat() os.FileInfo {
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return nil
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}
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var _ File = &WebFile{}
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var _ FileInfo = &WebFile{}
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