Merge branch 'ds/bundle-uri-more' into jch

The "bundle URI" topic.

* ds/bundle-uri-more:
  fetch: add 'refs/bundle/' to log.excludeDecoration
  bundle-uri: add support for http(s):// and file://
  fetch: add --bundle-uri option
  bundle-uri: create basic file-copy logic
  remote-curl: add 'get' capability
  docs: document bundle URI standard

Author: gitster

Documentation/fetch-options.txt

@@ -317,3 +317,9 @@ endif::git-pull[]
 -6::
 --ipv6::
 	Use IPv6 addresses only, ignoring IPv4 addresses.
+
+--bundle-uri=<uri>::
+	Instead of fetching from a remote, fetch a bundle from the given
+	`<uri>` and unbundle the data into the local repository. The refs
+	in the bundle will be stored under the hidden `refs/bundle/*`
+	namespace.

Documentation/git-fetch.txt

@@ -13,6 +13,7 @@ SYNOPSIS
 'git fetch' [<options>] <group>
 'git fetch' --multiple [<options>] [(<repository> | <group>)...]
 'git fetch' --all [<options>]
+'git fetch' --bundle-uri=<uri> [<options>]
 
 
 DESCRIPTION

Documentation/gitremote-helpers.txt

@@ -168,6 +168,9 @@ Supported commands: 'list', 'import'.
 	Can guarantee that when a clone is requested, the received
 	pack is self contained and is connected.
 
+'get'::
+	Can use the 'get' command to download a file from a given URI.
+
 If a helper advertises 'connect', Git will use it if possible and
 fall back to another capability if the helper requests so when
 connecting (see the 'connect' command under COMMANDS).
@@ -418,6 +421,12 @@ Supported if the helper has the "connect" capability.
 +
 Supported if the helper has the "stateless-connect" capability.
 
+'get' <uri> <path>::
+	Downloads the file from the given `<uri>` to the given `<path>`. If
+	`<path>.temp` exists, then Git assumes that the `.temp` file is a
+	partial download from a previous attempt and will resume the
+	download from that position.
+
 If a fatal error occurs, the program writes the error message to
 stderr and exits. The caller should expect that a suitable error
 message has been printed if the child closes the connection without

Documentation/technical/bundle-uri.txt

@@ -899,6 +899,7 @@ LIB_OBJS += blob.o
 LIB_OBJS += bloom.o
 LIB_OBJS += branch.o
 LIB_OBJS += bulk-checkin.o
+LIB_OBJS += bundle-uri.o
 LIB_OBJS += bundle.o
 LIB_OBJS += cache-tree.o
 LIB_OBJS += cbtree.o

Makefile

@@ -29,6 +29,7 @@
 #include "commit-graph.h"
 #include "shallow.h"
 #include "worktree.h"
+#include "bundle-uri.h"
 
 #define FORCED_UPDATES_DELAY_WARNING_IN_MS (10 * 1000)
 
@@ -37,6 +38,7 @@ static const char * const builtin_fetch_usage[] = {
 	N_("git fetch [<options>] <group>"),
 	N_("git fetch --multiple [<options>] [(<repository> | <group>)...]"),
 	N_("git fetch --all [<options>]"),
+	N_("git fetch --bundle-uri=<uri> [<options>]"),
 	NULL
 };
 
@@ -86,6 +88,7 @@ static struct string_list negotiation_tip = STRING_LIST_INIT_NODUP;
 static int fetch_write_commit_graph = -1;
 static int stdin_refspecs = 0;
 static int negotiate_only;
+static const char *bundle_uri;
 
 static int git_fetch_config(const char *k, const char *v, void *cb)
 {
@@ -224,6 +227,8 @@ static struct option builtin_fetch_options[] = {
 		 N_("write the commit-graph after fetching")),
 	OPT_BOOL(0, "stdin", &stdin_refspecs,
 		 N_("accept refspecs from stdin")),
+	OPT_STRING(0, "bundle-uri", &bundle_uri, N_("uri"),
+		   N_("download bundle data from the given URI instead of from a remote")),
 	OPT_END()
 };
 
@@ -2176,6 +2181,11 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
 	if (dry_run)
 		write_fetch_head = 0;
 
+	if (bundle_uri) {
+		result = fetch_bundle_uri(the_repository, bundle_uri);
+		goto cleanup;
+	}
+
 	if (all) {
 		if (argc == 1)
 			die(_("fetch --all does not take a repository argument"));

builtin/fetch.c

@@ -0,0 +1,166 @@
+#include "cache.h"
+#include "bundle-uri.h"
+#include "bundle.h"
+#include "config.h"
+#include "object-store.h"
+#include "refs.h"
+#include "run-command.h"
+
+static void find_temp_filename(struct strbuf *name)
+{
+	int fd;
+	/*
+	 * Find a temporray filename that is available. This is briefly
+	 * racy, but unlikely to collide.
+	 */
+	fd = odb_mkstemp(name, "bundles/tmp_uri_XXXXXX");
+	if (fd < 0)
+		die(_("failed to create temporary file"));
+	close(fd);
+	unlink(name->buf);
+}
+
+static int download_https_uri_to_file(const char *uri, const char *file)
+{
+	int result = 0;
+	struct child_process cp = CHILD_PROCESS_INIT;
+	FILE *child_in = NULL, *child_out = NULL;
+	struct strbuf line = STRBUF_INIT;
+	int found_get = 0;
+
+	strvec_pushl(&cp.args, "git-remote-https", "origin", uri, NULL);
+	cp.in = -1;
+	cp.out = -1;
+
+	if (start_command(&cp))
+		return 1;
+
+	child_in = fdopen(cp.in, "w");
+	if (!child_in) {
+		result = 1;
+		goto cleanup;
+	}
+
+	child_out = fdopen(cp.out, "r");
+	if (!child_out) {
+		result = 1;
+		goto cleanup;
+	}
+
+	fprintf(child_in, "capabilities\n");
+	fflush(child_in);
+
+	while (!strbuf_getline(&line, child_out)) {
+		if (!line.len)
+			break;
+		if (!strcmp(line.buf, "get"))
+			found_get = 1;
+	}
+	strbuf_release(&line);
+
+	if (!found_get) {
+		result = error(_("insufficient capabilities"));
+		goto cleanup;
+	}
+
+	fprintf(child_in, "get %s %s\n\n", uri, file);
+
+cleanup:
+	if (child_in)
+		fclose(child_in);
+	if (finish_command(&cp))
+		return 1;
+	if (child_out)
+		fclose(child_out);
+	return result;
+}
+
+static int copy_uri_to_file(const char *uri, const char *file)
+{
+	const char *out;
+	if (skip_prefix(uri, "https:", &out) ||
+	    skip_prefix(uri, "http:", &out))
+		return download_https_uri_to_file(uri, file);
+
+	if (!skip_prefix(uri, "file://", &out))
+		out = uri;
+
+	/* Copy as a file */
+	return !!copy_file(file, out, 0);
+}
+
+static int unbundle_from_file(struct repository *r, const char *file)
+{
+	int result = 0;
+	int bundle_fd;
+	struct bundle_header header = BUNDLE_HEADER_INIT;
+	struct strvec extra_index_pack_args = STRVEC_INIT;
+	struct string_list_item *refname;
+	struct strbuf bundle_ref = STRBUF_INIT;
+	size_t bundle_prefix_len;
+
+	if ((bundle_fd = read_bundle_header(file, &header)) < 0)
+		return 1;
+
+	result = unbundle(r, &header, bundle_fd, &extra_index_pack_args);
+
+	/*
+	 * Convert all refs/heads/ from the bundle into refs/bundles/
+	 * in the local repository.
+	 */
+	strbuf_addstr(&bundle_ref, "refs/bundles/");
+	bundle_prefix_len = bundle_ref.len;
+
+	for_each_string_list_item(refname, &header.references) {
+		struct object_id *oid = refname->util;
+		struct object_id old_oid;
+		const char *branch_name;
+		int has_old;
+
+		if (!skip_prefix(refname->string, "refs/heads/", &branch_name))
+			continue;
+
+		strbuf_setlen(&bundle_ref, bundle_prefix_len);
+		strbuf_addstr(&bundle_ref, branch_name);
+
+		has_old = !read_ref(bundle_ref.buf, &old_oid);
+		update_ref("fetched bundle", bundle_ref.buf, oid,
+			   has_old ? &old_oid : NULL,
+			   REF_SKIP_OID_VERIFICATION,
+			   UPDATE_REFS_MSG_ON_ERR);
+	}
+
+	bundle_header_release(&header);
+	return result;
+}
+
+int fetch_bundle_uri(struct repository *r, const char *uri)
+{
+	int result = 0;
+	struct strbuf filename = STRBUF_INIT;
+
+	find_temp_filename(&filename);
+	if ((result = copy_uri_to_file(uri, filename.buf))) {
+		error(_("failed to download bundle from URI '%s'"), uri);
+		goto cleanup;
+	}
+
+	if ((result = !is_bundle(filename.buf, 0))) {
+		error(_("file at URI '%s' is not a bundle"), uri);
+		goto cleanup;
+	}
+
+	if ((result = unbundle_from_file(r, filename.buf)))
+		goto cleanup;
+
+	git_config_set_multivar_gently("log.excludedecoration",
+					"refs/bundle/",
+					"refs/bundle/",
+					CONFIG_FLAGS_FIXED_VALUE |
+					CONFIG_FLAGS_MULTI_REPLACE);
+
+cleanup:
+	unlink(filename.buf);
+	strbuf_release(&filename);
+	return result;
+}

bundle-uri.c

@@ -0,0 +1,14 @@
+#ifndef BUNDLE_URI_H
+#define BUNDLE_URI_H
+
+struct repository;
+
+/**
+ * Fetch data from the given 'uri' and unbundle the bundle data found
+ * based on that information.
+ *
+ * Returns non-zero if no bundle information is found at the given 'uri'.
+ */
+int fetch_bundle_uri(struct repository *r, const char *uri);
+
+#endif

bundle-uri.h

@@ -1276,6 +1276,34 @@ static void parse_fetch(struct strbuf *buf)
 	strbuf_reset(buf);
 }
 
+static void parse_get(struct strbuf *buf)
+{
+	struct http_get_options opts = { 0 };
+	struct strbuf url = STRBUF_INIT;
+	struct strbuf path = STRBUF_INIT;
+	const char *p, *space;
+
+	if (!skip_prefix(buf->buf, "get ", &p))
+		die(_("http transport does not support %s"), buf->buf);
+
+	space = strchr(p, ' ');
+
+	if (!space)
+		die(_("protocol error: expected '<url> <path>', missing space"));
+
+	strbuf_add(&url, p, space - p);
+	strbuf_addstr(&path, space + 1);
+
+	if (http_get_file(url.buf, path.buf, &opts))
+		die(_("failed to download file at URL '%s'"), url.buf);
+
+	strbuf_release(&url);
+	strbuf_release(&path);
+	printf("\n");
+	fflush(stdout);
+	strbuf_reset(buf);
+}
+
 static int push_dav(int nr_spec, const char **specs)
 {
 	struct child_process child = CHILD_PROCESS_INIT;
@@ -1549,9 +1577,14 @@ int cmd_main(int argc, const char **argv)
 				printf("unsupported\n");
 			fflush(stdout);
 
+		} else if (skip_prefix(buf.buf, "get ", &arg)) {
+			parse_get(&buf);
+			fflush(stdout);
+
 		} else if (!strcmp(buf.buf, "capabilities")) {
 			printf("stateless-connect\n");
 			printf("fetch\n");
+			printf("get\n");
 			printf("option\n");
 			printf("push\n");
 			printf("check-connectivity\n");

remote-curl.c

@@ -0,0 +1,37 @@
+#!/bin/sh
+
+test_description='test downloading a file by URL'
+
+. ./test-lib.sh
+
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'get by URL: 404' '
+	url="$HTTPD_URL/none.txt" &&
+	cat >input <<-EOF &&
+	capabilities
+	get $url file1
+	EOF
+
+	test_must_fail git remote-http $url $url <input 2>err &&
+	test_path_is_missing file1 &&
+	grep "failed to download file at URL" err &&
+	rm file1.temp
+'
+
+test_expect_success 'get by URL: 200' '
+	echo data >"$HTTPD_DOCUMENT_ROOT_PATH/exists.txt" &&
+
+	url="$HTTPD_URL/exists.txt" &&
+	cat >input <<-EOF &&
+	capabilities
+	get $url file2
+
+	EOF
+
+	GIT_TRACE2_PERF=1 git remote-http $url $url <input &&
+	test_cmp "$HTTPD_DOCUMENT_ROOT_PATH/exists.txt" file2
+'
+
+test_done