Add a fetch callback to allow front-end download support

This allows a frontend to define its own download algorithm so that the
libfetch dependency can be omitted without using an external process.
The callback will be used when if it is defined, otherwise the old
behavior applies.

Signed-off-by: Sebastian Nowicki <sebnow@gmail.com>
[Dan: minor cleanups]
Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 7 insertions, 97 deletions

diff --git a/lib/libalpm/dload.c b/lib/libalpm/dload.c
index c8296f52..6b163ce6 100644
--- a/lib/libalpm/dload.c
+++ b/lib/libalpm/dload.c
@@ -263,111 +263,21 @@ cleanup:
 }
 #endif
 
-static int download_external(const char *url, const char *localpath,
-		time_t mtimeold, time_t *mtimenew) {
-	int ret = 0;
-	int retval;
-	int usepart = 0;
-	char *ptr1, *ptr2;
-	char origCmd[PATH_MAX];
-	char parsedCmd[PATH_MAX] = "";
-	char cwd[PATH_MAX];
-	char *destfile, *tempfile, *filename;
-
-	if(!handle->xfercommand) {
-		RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
-	}
-
-	filename = get_filename(url);
-	if(!filename) {
-		RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
-	}
-	destfile = get_destfile(localpath, filename);
-	tempfile = get_tempfile(localpath, filename);
-
-	/* replace all occurrences of %o with fn.part */
-	strncpy(origCmd, handle->xfercommand, sizeof(origCmd));
-	ptr1 = origCmd;
-	while((ptr2 = strstr(ptr1, "%o"))) {
-		usepart = 1;
-		ptr2[0] = '\0';
-		strcat(parsedCmd, ptr1);
-		strcat(parsedCmd, tempfile);
-		ptr1 = ptr2 + 2;
-	}
-	strcat(parsedCmd, ptr1);
-	/* replace all occurrences of %u with the download URL */
-	strncpy(origCmd, parsedCmd, sizeof(origCmd));
-	parsedCmd[0] = '\0';
-	ptr1 = origCmd;
-	while((ptr2 = strstr(ptr1, "%u"))) {
-		ptr2[0] = '\0';
-		strcat(parsedCmd, ptr1);
-		strcat(parsedCmd, url);
-		ptr1 = ptr2 + 2;
-	}
-	strcat(parsedCmd, ptr1);
-	/* cwd to the download directory */
-	getcwd(cwd, PATH_MAX);
-	if(chdir(localpath)) {
-		_alpm_log(PM_LOG_WARNING, _("could not chdir to %s\n"), localpath);
-		pm_errno = PM_ERR_EXTERNAL_DOWNLOAD;
-		ret = -1;
-		goto cleanup;
-	}
-	/* execute the parsed command via /bin/sh -c */
-	_alpm_log(PM_LOG_DEBUG, "running command: %s\n", parsedCmd);
-	retval = system(parsedCmd);
-
-	if(retval == -1) {
-		_alpm_log(PM_LOG_WARNING, _("running XferCommand: fork failed!\n"));
-		pm_errno = PM_ERR_EXTERNAL_DOWNLOAD;
-		ret = -1;
-	} else if(retval != 0) {
-		/* download failed */
-		_alpm_log(PM_LOG_DEBUG, "XferCommand command returned non-zero status "
-				"code (%d)\n", retval);
-		ret = -1;
-	} else {
-		/* download was successful */
-		if(usepart) {
-			rename(tempfile, destfile);
-		}
-		ret = 0;
-	}
-
-cleanup:
-	chdir(cwd);
-	if(ret == -1) {
-		/* hack to let an user the time to cancel a download */
-		sleep(2);
-	}
-	FREE(destfile);
-	FREE(tempfile);
-
-	return(ret);
-}
-
 static int download(const char *url, const char *localpath,
 		time_t mtimeold, time_t *mtimenew) {
-	int ret;
-
-	/* We have a few things to take into account here.
-	 * 1. If we have both internal/external available, choose based on
-	 * whether xfercommand is populated.
-	 * 2. If we only have external available, we should first check
-	 * if a command was provided before we drop into download_external.
-	 */
-	if(handle->xfercommand == NULL) {
+	if(handle->fetchcb == NULL) {
 #if defined(INTERNAL_DOWNLOAD)
-		ret = download_internal(url, localpath, mtimeold, mtimenew);
+		return(download_internal(url, localpath, mtimeold, mtimenew));
 #else
 		RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
 #endif
 	} else {
-		ret = download_external(url, localpath, mtimeold, mtimenew);
+		int ret = handle->fetchcb(url, localpath, mtimeold, mtimenew);
+		if(ret == -1) {
+			RET_ERR(PM_ERR_EXTERNAL_DOWNLOAD, -1);
+		}
+		return(ret);
 	}
-	return(ret);
 }
 
 /*