update vendor/

vendor/github.com/cavaliercoder/grab/grab.go

@@ -0,0 +1,64 @@
+package grab
+
+import (
+	"fmt"
+	"os"
+)
+
+// Get sends a HTTP request and downloads the content of the requested URL to
+// the given destination file path. The caller is blocked until the download is
+// completed, successfully or otherwise.
+//
+// An error is returned if caused by client policy (such as CheckRedirect), or
+// if there was an HTTP protocol or IO error.
+//
+// For non-blocking calls or control over HTTP client headers, redirect policy,
+// and other settings, create a Client instead.
+func Get(dst, urlStr string) (*Response, error) {
+	req, err := NewRequest(dst, urlStr)
+	if err != nil {
+		return nil, err
+	}
+
+	resp := DefaultClient.Do(req)
+	return resp, resp.Err()
+}
+
+// GetBatch sends multiple HTTP requests and downloads the content of the
+// requested URLs to the given destination directory using the given number of
+// concurrent worker goroutines.
+//
+// The Response for each requested URL is sent through the returned Response
+// channel, as soon as a worker receives a response from the remote server. The
+// Response can then be used to track the progress of the download while it is
+// in progress.
+//
+// The returned Response channel will be closed by Grab, only once all downloads
+// have completed or failed.
+//
+// If an error occurs during any download, it will be available via call to the
+// associated Response.Err.
+//
+// For control over HTTP client headers, redirect policy, and other settings,
+// create a Client instead.
+func GetBatch(workers int, dst string, urlStrs ...string) (<-chan *Response, error) {
+	fi, err := os.Stat(dst)
+	if err != nil {
+		return nil, err
+	}
+	if !fi.IsDir() {
+		return nil, fmt.Errorf("destination is not a directory")
+	}
+
+	reqs := make([]*Request, len(urlStrs))
+	for i := 0; i < len(urlStrs); i++ {
+		req, err := NewRequest(dst, urlStrs[i])
+		if err != nil {
+			return nil, err
+		}
+		reqs[i] = req
+	}
+
+	ch := DefaultClient.DoBatch(workers, reqs...)
+	return ch, nil
+}