add package

[bytom/vapor.git] / vendor / github.com / ipfs / go-ipfs-files / webfile.go

diff --git a/vendor/github.com/ipfs/go-ipfs-files/webfile.go b/vendor/github.com/ipfs/go-ipfs-files/webfile.go
new file mode 100644 (file)
index 0000000..dbc813b
--- /dev/null
+++ b/vendor/github.com/ipfs/go-ipfs-files/webfile.go
@@ -0,0 +1,64 @@
+package files
+
+import (
+       "errors"
+       "io"
+       "net/http"
+       "net/url"
+)
+
+// WebFile is an implementation of File which reads it
+// from a Web URL (http). A GET request will be performed
+// against the source when calling Read().
+type WebFile struct {
+       body          io.ReadCloser
+       url           *url.URL
+       contentLength int64
+}
+
+// NewWebFile creates a WebFile with the given URL, which
+// will be used to perform the GET request on Read().
+func NewWebFile(url *url.URL) *WebFile {
+       return &WebFile{
+               url: url,
+       }
+}
+
+// Read reads the File from it's web location. On the first
+// call to Read, a GET request will be performed against the
+// WebFile's URL, using Go's default HTTP client. Any further
+// reads will keep reading from the HTTP Request body.
+func (wf *WebFile) Read(b []byte) (int, error) {
+       if wf.body == nil {
+               resp, err := http.Get(wf.url.String())
+               if err != nil {
+                       return 0, err
+               }
+               wf.body = resp.Body
+               wf.contentLength = resp.ContentLength
+       }
+       return wf.body.Read(b)
+}
+
+// Close closes the WebFile (or the request body).
+func (wf *WebFile) Close() error {
+       if wf.body == nil {
+               return nil
+       }
+       return wf.body.Close()
+}
+
+// TODO: implement
+func (wf *WebFile) Seek(offset int64, whence int) (int64, error) {
+       return 0, ErrNotSupported
+}
+
+func (wf *WebFile) Size() (int64, error) {
+       if wf.contentLength < 0 {
+               return -1, errors.New("Content-Length hearer was not set")
+       }
+
+       return wf.contentLength, nil
+}
+
+var _ File = &WebFile{}