[Libguestfs] [PATCH 2/2] builder: support for download resume

Partially downloaded file is not deleted on exit anymore. There is a check for partially downloaded image in cache directory based on its name. When found, download_to crafts appropriate options to continue its download. --- builder/downloader.ml | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/builder/downloader.ml b/builder/downloader.ml index 8a23bdc..6e19ee4 100644 --- a/builder/downloader.ml +++ b/builder/downloader.ml @@ -65,11 +65,11 @@ let rec download ~prog t ?template ?progress_bar ?(proxy = SystemProxy) uri = * If not, download it. *) if not (Sys.file_exists filename) then - download_to ~prog t ?progress_bar ~proxy uri filename; + download_to ~prog t ?progress_bar ?continue:(Some true) ~proxy uri filename; (filename, false) -and download_to ~prog t ?(progress_bar = false) ~proxy uri filename = +and download_to ~prog t ?(progress_bar = false) ?(continue = false) ~proxy uri filename = let parseduri = try URI.parse_uri uri with Invalid_argument "URI.parse_uri" -> @@ -82,7 +82,6 @@ and download_to ~prog t ?(progress_bar = false) ~proxy uri filename = * atomically rename it to the final filename. *) let filename_new = filename ^ "." ^ string_random8 () in - unlink_on_exit filename_new; (match parseduri.URI.protocol with | "file" -> @@ -115,11 +114,20 @@ and download_to ~prog t ?(progress_bar = false) ~proxy uri filename = if bad_status_code status_code then error (f_"failed to download %s: HTTP status code %s") uri status_code; + let cmd = sprintf "ls %s.* 2>/dev/null" filename in + let lines = if continue + then external_command ~prog ?ignore_error:(Some true) cmd + else [] in + let filename_new, continue_download = match List.length lines with + | 0 -> filename_new, "" + | _ -> List.hd lines, " -C -" in + (* Now download the file. *) - let cmd = sprintf "%s%s%s -g -o %s %s" + let cmd = sprintf "%s%s%s%s -g -o %s %s" outenv t.curl (if t.verbose then "" else if progress_bar then " -#" else " -s -S") + continue_download (quote filename_new) (quote uri) in if t.verbose then printf "%s\n%!" cmd; let r = Sys.command cmd in -- 1.9.3