http: use off_t to store partial file size

When we try to resume transfer of a partially-downloaded
object or pack, we fopen() the existing file for append,
then use ftell() to get the current position. We use a
"long", which can hold only 2GB on a 32-bit system, even
though packfiles may be larger than that.

Let's switch to using off_t, which should hold any file size
our system is capable of storing. We need to use ftello() to
get the off_t. This is in POSIX and hopefully available
everywhere; if not, we should be able to wrap it by falling
back to ftell(), which would presumably return "-1" on such
a large file (and we would simply skip resuming in that case).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/http.c b/http.c
index 5f368464e8f3e3980b36b4692d095dd06d89a0d6..42f29ce0aaf7aac1e81849cf733e8ea92738f5b0 100644 (file)
--- a/http.c
+++ b/http.c
@@ -1205,7 +1205,7 @@ static int http_request(const char *url,
                curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
 
                if (target == HTTP_REQUEST_FILE) {
-                       long posn = ftell(result);
+                       off_t posn = ftello(result);
                        curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
                                         fwrite);
                        if (posn > 0)
@@ -1581,7 +1581,7 @@ int finish_http_pack_request(struct http_pack_request *preq)
 struct http_pack_request *new_http_pack_request(
        struct packed_git *target, const char *base_url)
 {
-       long prev_posn = 0;
+       off_t prev_posn = 0;
        struct strbuf buf = STRBUF_INIT;
        struct http_pack_request *preq;
 
@@ -1613,7 +1613,7 @@ struct http_pack_request *new_http_pack_request(
         * If there is data present from a previous transfer attempt,
         * resume where it left off
         */
-       prev_posn = ftell(preq->packfile);
+       prev_posn = ftello(preq->packfile);
        if (prev_posn>0) {
                if (http_is_verbose)
                        fprintf(stderr,
@@ -1668,7 +1668,7 @@ struct http_object_request *new_http_object_request(const char *base_url,
        int prevlocal;
        char prev_buf[PREV_BUF_SIZE];
        ssize_t prev_read = 0;
-       long prev_posn = 0;
+       off_t prev_posn = 0;
        struct http_object_request *freq;
 
        freq = xcalloc(1, sizeof(*freq));