Allow UseDelta option to specify a delta ratio

Rework the frontend and backend to allow passing a ratio value in for
UseDelta rather than having a hardcoded #define-d 0.7 value always used.
This is useful for those with fast connections, who would likely benefit
from tuning this ratio to lower values; it is also useful for general
testing purposes.

The libalpm API changes for this, but we do support the old config file
format with a no-value 'UseDelta' option; in this case we simply use the
old default of 0.7.

We clamp the ratio values to a sane range between 0.0 and 2.0, allowing
ratios above 1.0 for testing purposes.

Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index 49a3f42d..6967b49b 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -318,13 +318,13 @@ static int compute_download_size(alpm_pkg_t *newpkg)
 
 		/* tell the caller that we have a partial */
 		ret = 1;
-	} else if(handle->usedelta) {
+	} else if(handle->deltaratio > 0.0) {
 		off_t dltsize;
 
 		dltsize = _alpm_shortest_delta_path(handle, newpkg->deltas,
 				newpkg->filename, &newpkg->delta_path);
 
-		if(newpkg->delta_path && (dltsize < newpkg->size * MAX_DELTA_RATIO)) {
+		if(newpkg->delta_path && (dltsize < newpkg->size * handle->deltaratio)) {
 			_alpm_log(handle, ALPM_LOG_DEBUG, "using delta size\n");
 			size = dltsize;
 		} else {