fetch_url: look for files in cache before downloading

We lost this logic somewhere between the libfetch and libcurl
transition, as it existed in the internal downloader, but was pulled
back only into the sync workflow. Add a helper function that will let us
check for existance in the filecache prior to calling the downloader.

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

1 files changed, 60 insertions, 32 deletions

diff --git a/lib/libalpm/dload.c b/lib/libalpm/dload.c
index 29285903..928324e8 100644
--- a/lib/libalpm/dload.c
+++ b/lib/libalpm/dload.c
@@ -562,6 +562,22 @@ int _alpm_download(struct dload_payload *payload, const char *localpath,
 	}
 }
 
+static char *filecache_find_url(alpm_handle_t *handle, const char *url)
+{
+	const char *basename = strrchr(url, '/');
+
+	if(basename == NULL) {
+		return NULL;
+	}
+
+	basename++;
+	if(basename == '\0') {
+		return NULL;
+	}
+
+	return _alpm_filecache_find(handle, basename);
+}
+
 /** Fetch a remote pkg. */
 char SYMEXPORT *alpm_fetch_pkgurl(alpm_handle_t *handle, const char *url)
 {
@@ -569,7 +585,7 @@ char SYMEXPORT *alpm_fetch_pkgurl(alpm_handle_t *handle, const char *url)
 	const char *cachedir;
 	char *final_file = NULL;
 	struct dload_payload payload;
-	int ret;
+	int ret = 0;
 
 	CHECK_HANDLE(handle, return NULL);
 	ASSERT(url, RET_ERR(handle, ALPM_ERR_WRONG_ARGS, NULL));
@@ -578,51 +594,63 @@ char SYMEXPORT *alpm_fetch_pkgurl(alpm_handle_t *handle, const char *url)
 	cachedir = _alpm_filecache_setup(handle);
 
 	memset(&payload, 0, sizeof(struct dload_payload));
-	payload.handle = handle;
-	STRDUP(payload.fileurl, url, RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
-	payload.allow_resume = 1;
-
-	/* download the file */
-	ret = _alpm_download(&payload, cachedir, &final_file);
-	_alpm_dload_payload_reset(&payload);
-	if(ret == -1) {
-		_alpm_log(handle, ALPM_LOG_WARNING, _("failed to download %s\n"), url);
-		free(final_file);
-		return NULL;
+
+	/* attempt to find the file in our pkgcache */
+	filepath = filecache_find_url(handle, url);
+	if(filepath == NULL) {
+		STRDUP(payload.fileurl, url, RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
+		payload.allow_resume = 1;
+		payload.handle = handle;
+
+		/* download the file */
+		ret = _alpm_download(&payload, cachedir, &final_file);
+		_alpm_dload_payload_reset(&payload);
+		if(ret == -1) {
+			_alpm_log(handle, ALPM_LOG_WARNING, _("failed to download %s\n"), url);
+			free(final_file);
+			return NULL;
+		}
+		_alpm_log(handle, ALPM_LOG_DEBUG, "successfully downloaded %s\n", url);
 	}
-	_alpm_log(handle, ALPM_LOG_DEBUG, "successfully downloaded %s\n", url);
 
 	/* attempt to download the signature */
 	if(ret == 0 && (handle->siglevel & ALPM_SIG_PACKAGE)) {
-		char *sig_final_file = NULL;
+		char *sig_filepath, *sig_final_file = NULL;
 		size_t len;
 
 		len = strlen(url) + 5;
 		MALLOC(payload.fileurl, len, RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
 		snprintf(payload.fileurl, len, "%s.sig", url);
-		payload.handle = handle;
-		payload.force = 1;
-		payload.errors_ok = (handle->siglevel & ALPM_SIG_PACKAGE_OPTIONAL);
-
-		/* set hard upper limit of 16KiB */
-		payload.max_size = 16 * 1024;
-
-		ret = _alpm_download(&payload, cachedir, &sig_final_file);
-		if(ret == -1 && !payload.errors_ok) {
-			_alpm_log(handle, ALPM_LOG_WARNING,
-					_("failed to download %s\n"), payload.fileurl);
-			/* Warn now, but don't return NULL. We will fail later during package
-			 * load time. */
-		} else if(ret == 0) {
-			_alpm_log(handle, ALPM_LOG_DEBUG,
-					"successfully downloaded %s\n", payload.fileurl);
+
+		sig_filepath = filecache_find_url(handle, payload.fileurl);
+		if(sig_filepath == NULL) {
+			payload.handle = handle;
+			payload.force = 1;
+			payload.errors_ok = (handle->siglevel & ALPM_SIG_PACKAGE_OPTIONAL);
+
+			/* set hard upper limit of 16KiB */
+			payload.max_size = 16 * 1024;
+
+			ret = _alpm_download(&payload, cachedir, &sig_final_file);
+			if(ret == -1 && !payload.errors_ok) {
+				_alpm_log(handle, ALPM_LOG_WARNING,
+						_("failed to download %s\n"), payload.fileurl);
+				/* Warn now, but don't return NULL. We will fail later during package
+				 * load time. */
+			} else if(ret == 0) {
+				_alpm_log(handle, ALPM_LOG_DEBUG,
+						"successfully downloaded %s\n", payload.fileurl);
+			}
+			FREE(sig_final_file);
 		}
-		FREE(sig_final_file);
+		free(sig_filepath);
 		_alpm_dload_payload_reset(&payload);
 	}
 
 	/* we should be able to find the file the second time around */
-	filepath = _alpm_filecache_find(handle, final_file);
+	if(filepath == NULL) {
+		filepath = _alpm_filecache_find(handle, final_file);
+	}
 	free(final_file);
 
 	return filepath;