[PATCH 13/14] remote-curl: resume interrupted bundle transfers

[Jeff King <peff@peff.net>]

If we have a bundle file from a previous fetch that matches
this URL, then we should resume the transfer where we left
off.

Signed-off-by: Jeff King <peff@peff.net>
---
The second half of the diff is hard to read because I re-indent a big
chunk. It's much easier to see what's going on with "diff -b".

 remote-curl.c |   64 +++++++++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/remote-curl.c b/remote-curl.c
index 6b0820e..43ad1b6 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -9,6 +9,7 @@
 #include "sideband.h"
 #include "bundle.h"
 #include "progress.h"
+#include "dir.h"
 
 static struct remote *remote;
 static const char *url; /* always ends with a trailing slash */
@@ -171,6 +172,32 @@ static int get_refs_from_url(const char *url, struct strbuf *out, int options,
 	return ret;
 }
 
+static int resume_bundle(const char *url, const char *tmpname)
+{
+	struct get_refs_cb_data data;
+	int ret;
+
+	data.fh = fopen(tmpname, "ab");
+	if (!data.fh)
+		die_errno("unable to open %s", tmpname);
+
+	data.is_bundle = 1;
+	data.total = ftell(data.fh);
+	if (options.progress) {
+		data.progress = start_progress("Resuming bundle", 0);
+		display_progress(data.progress, 0);
+		display_throughput(data.progress, data.total);
+	}
+
+	ret = http_get_callback(url, get_refs_callback, &data, data.total, 0);
+
+	if (fclose(data.fh))
+		die_errno("unable to write to %s", tmpname);
+	stop_progress(&data.progress);
+
+	return ret;
+}
+
 static const char *url_to_bundle_tmpfile(const char *url)
 {
 	struct strbuf buf = STRBUF_INIT;
@@ -210,20 +237,35 @@ static int get_refs_from_url(const char *url, struct strbuf *out, int options,
 	free_discovery(last);
 
 	filename = url_to_bundle_tmpfile(url);
+	if (file_exists(filename)) {
+		struct strbuf trimmed = STRBUF_INIT;
 
-	strbuf_addf(&buffer, "%sinfo/refs", url);
-	if (!prefixcmp(url, "http://") || !prefixcmp(url, "https://")) {
-		is_http = 1;
-		if (!strchr(url, '?'))
-			strbuf_addch(&buffer, '?');
-		else
-			strbuf_addch(&buffer, '&');
-		strbuf_addf(&buffer, "service=%s", service);
+		strbuf_addstr(&trimmed, url);
+		while (trimmed.len > 0 && trimmed.buf[trimmed.len-1] == '/')
+			strbuf_setlen(&trimmed, trimmed.len - 1);
+		refs_url = strbuf_detach(&trimmed, NULL);
+
+		http_ret = resume_bundle(refs_url, filename);
+		is_bundle = 1;
 	}
-	refs_url = strbuf_detach(&buffer, NULL);
+	else
+		http_ret = HTTP_MISSING_TARGET;
+
+	if (http_ret != HTTP_OK && http_ret != HTTP_NOAUTH) {
+		strbuf_addf(&buffer, "%sinfo/refs", url);
+		if (!prefixcmp(url, "http://") || !prefixcmp(url, "https://")) {
+			is_http = 1;
+			if (!strchr(url, '?'))
+				strbuf_addch(&buffer, '?');
+			else
+				strbuf_addch(&buffer, '&');
+			strbuf_addf(&buffer, "service=%s", service);
+		}
+		refs_url = strbuf_detach(&buffer, NULL);
 
-	http_ret = get_refs_from_url(refs_url, &buffer, HTTP_NO_CACHE,
-				     filename, &is_bundle);
+		http_ret = get_refs_from_url(refs_url, &buffer, HTTP_NO_CACHE,
+					     filename, &is_bundle);
+	}
 
 	/* try again with "plain" url (no ? or & appended) */
 	if (http_ret != HTTP_OK && http_ret != HTTP_NOAUTH) {
-- 
1.7.7.2.7.g9f96f