Add config option to specify amount of parallel download streams

It includes pacman.conf new 'ParallelDownloads' option that
specifies how many concurrent downloads cURL starts in parallel.

Add alpm_option_set_parallel_downloads() ALPM function that
allows to set this config option programmatically.

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

3 files changed, 25 insertions, 0 deletions

diff --git a/lib/libalpm/alpm.h b/lib/libalpm/alpm.h
index c2a069ad..5d559db1 100644
--- a/lib/libalpm/alpm.h
+++ b/lib/libalpm/alpm.h
@@ -903,6 +903,15 @@ int alpm_option_set_remote_file_siglevel(alpm_handle_t *handle, int level);
 
 int alpm_option_set_disable_dl_timeout(alpm_handle_t *handle, unsigned short disable_dl_timeout);
 
+/** Sets number of parallel streams to download database and package files.
+ * If the function is not called then the default value of '1' stream
+ * (i.e. sequential download) is used.
+ * @param handle the context handle
+ * @param num_streams number of parallel download streams
+ * @return 0 on success, -1 on error
+ */
+int alpm_option_set_parallel_downloads(alpm_handle_t *handle, unsigned int num_streams);
+
 /** @} */
 
 /** @addtogroup alpm_api_databases Database Functions
diff --git a/lib/libalpm/handle.c b/lib/libalpm/handle.c
index 6b19a703..e3b2c911 100644
--- a/lib/libalpm/handle.c
+++ b/lib/libalpm/handle.c
@@ -856,3 +856,18 @@ int SYMEXPORT alpm_option_set_disable_dl_timeout(alpm_handle_t *handle,
 #endif
 	return 0;
 }
+
+int SYMEXPORT alpm_option_set_parallel_downloads(alpm_handle_t *handle,
+		unsigned int num_streams)
+{
+	CHECK_HANDLE(handle, return -1);
+#ifdef HAVE_LIBCURL
+	if(num_streams < 1) {
+		return -1;
+	}
+	handle->parallel_downloads = num_streams;
+#else
+	(void)num_streams; /* silence unused variable warnings */
+#endif
+	return 0;
+}
diff --git a/lib/libalpm/handle.h b/lib/libalpm/handle.h
index c343f6e0..cd7104f9 100644
--- a/lib/libalpm/handle.h
+++ b/lib/libalpm/handle.h
@@ -61,6 +61,7 @@ struct __alpm_handle_t {
 	/* libcurl handle */
 	CURL *curl;             /* reusable curl_easy handle */
 	unsigned short disable_dl_timeout;
+	unsigned int parallel_downloads; /* number of download streams */
 #endif
 
 #ifdef HAVE_LIBGPGME