compat: Add simplified merge sort implementation from glibc
[gitweb.git] / builtin-fetch.c
index e65690f25cdadb7b75aad40718510b1b9bdb8800..320e235682340f07cb28b0a4de0c39b6bd9da383 100644 (file)
@@ -8,13 +8,46 @@
 #include "path-list.h"
 #include "remote.h"
 #include "transport.h"
-
-static const char fetch_usage[] = "git-fetch [-a | --append] [--upload-pack <upload-pack>] [-f | --force] [--no-tags] [-t | --tags] [-k | --keep] [-u | --update-head-ok] [--depth <depth>] [-v | --verbose] [<repository> <refspec>...]";
-
-static int append, force, tags, no_tags, update_head_ok, verbose, quiet;
-static char *default_rla = NULL;
+#include "run-command.h"
+#include "parse-options.h"
+
+static const char * const builtin_fetch_usage[] = {
+       "git-fetch [options] [<repository> <refspec>...]",
+       NULL
+};
+
+enum {
+       TAGS_UNSET = 0,
+       TAGS_DEFAULT = 1,
+       TAGS_SET = 2
+};
+
+static int append, force, keep, update_head_ok, verbose, quiet;
+static int tags = TAGS_DEFAULT;
+static const char *depth;
+static const char *upload_pack;
+static struct strbuf default_rla = STRBUF_INIT;
 static struct transport *transport;
 
+static struct option builtin_fetch_options[] = {
+       OPT__QUIET(&quiet),
+       OPT__VERBOSE(&verbose),
+       OPT_BOOLEAN('a', "append", &append,
+                   "append to .git/FETCH_HEAD instead of overwriting"),
+       OPT_STRING(0, "upload-pack", &upload_pack, "PATH",
+                  "path to upload pack on remote end"),
+       OPT_BOOLEAN('f', "force", &force,
+                   "force overwrite of local branch"),
+       OPT_SET_INT('t', "tags", &tags,
+                   "fetch all tags and associated objects", TAGS_SET),
+       OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
+       OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
+                   "allow updating of HEAD ref"),
+       OPT_STRING(0, "depth", &depth, "DEPTH",
+                  "deepen history of shallow clone"),
+       OPT_END()
+};
+
 static void unlock_pack(void)
 {
        if (transport)
@@ -29,7 +62,7 @@ static void unlock_pack_on_signal(int signo)
 }
 
 static void add_merge_config(struct ref **head,
-                          struct ref *remote_refs,
+                          const struct ref *remote_refs,
                           struct branch *branch,
                           struct ref ***tail)
 {
@@ -77,9 +110,9 @@ static struct ref *get_ref_map(struct transport *transport,
        struct ref *ref_map = NULL;
        struct ref **tail = &ref_map;
 
-       struct ref *remote_refs = transport_get_remote_refs(transport);
+       const struct ref *remote_refs = transport_get_remote_refs(transport);
 
-       if (ref_count || tags) {
+       if (ref_count || tags == TAGS_SET) {
                for (i = 0; i < ref_count; i++) {
                        get_fetch_map(remote_refs, &refs[i], &tail, 0);
                        if (refs[i].dst && refs[i].dst[0])
@@ -88,7 +121,7 @@ static struct ref *get_ref_map(struct transport *transport,
                /* Merge everything on the command line, but not --tags */
                for (rm = ref_map; rm; rm = rm->next)
                        rm->merge = 1;
-               if (tags) {
+               if (tags == TAGS_SET) {
                        struct refspec refspec;
                        refspec.src = "refs/tags/";
                        refspec.dst = "refs/tags/";
@@ -140,7 +173,7 @@ static int s_update_ref(const char *action,
        static struct ref_lock *lock;
 
        if (!rla)
-               rla = default_rla;
+               rla = default_rla.buf;
        snprintf(msg, sizeof(msg), "%s: %s", rla, action);
        lock = lock_any_ref_for_update(ref->name,
                                       check_old ? ref->old_sha1 : NULL, 0);
@@ -253,7 +286,7 @@ static int update_local_ref(struct ref *ref,
        }
 }
 
-static void store_updated_refs(const char *url, struct ref *ref_map)
+static int store_updated_refs(const char *url, struct ref *ref_map)
 {
        FILE *fp;
        struct commit *commit;
@@ -261,8 +294,11 @@ static void store_updated_refs(const char *url, struct ref *ref_map)
        char note[1024];
        const char *what, *kind;
        struct ref *rm;
+       char *filename = git_path("FETCH_HEAD");
 
-       fp = fopen(git_path("FETCH_HEAD"), "a");
+       fp = fopen(filename, "a");
+       if (!fp)
+               return error("cannot open %s: %s\n", filename, strerror(errno));
        for (rm = ref_map; rm; rm = rm->next) {
                struct ref *ref = NULL;
 
@@ -333,13 +369,77 @@ static void store_updated_refs(const char *url, struct ref *ref_map)
                }
        }
        fclose(fp);
+       return 0;
+}
+
+/*
+ * We would want to bypass the object transfer altogether if
+ * everything we are going to fetch already exists and connected
+ * locally.
+ *
+ * The refs we are going to fetch are in to_fetch (nr_heads in
+ * total).  If running
+ *
+ *  $ git-rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
+ *
+ * does not error out, that means everything reachable from the
+ * refs we are going to fetch exists and is connected to some of
+ * our existing refs.
+ */
+static int quickfetch(struct ref *ref_map)
+{
+       struct child_process revlist;
+       struct ref *ref;
+       char **argv;
+       int i, err;
+
+       /*
+        * If we are deepening a shallow clone we already have these
+        * objects reachable.  Running rev-list here will return with
+        * a good (0) exit status and we'll bypass the fetch that we
+        * really need to perform.  Claiming failure now will ensure
+        * we perform the network exchange to deepen our history.
+        */
+       if (depth)
+               return -1;
+
+       for (i = 0, ref = ref_map; ref; ref = ref->next)
+               i++;
+       if (!i)
+               return 0;
+
+       argv = xmalloc(sizeof(*argv) * (i + 6));
+       i = 0;
+       argv[i++] = xstrdup("rev-list");
+       argv[i++] = xstrdup("--quiet");
+       argv[i++] = xstrdup("--objects");
+       for (ref = ref_map; ref; ref = ref->next)
+               argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
+       argv[i++] = xstrdup("--not");
+       argv[i++] = xstrdup("--all");
+       argv[i++] = NULL;
+
+       memset(&revlist, 0, sizeof(revlist));
+       revlist.argv = (const char**)argv;
+       revlist.git_cmd = 1;
+       revlist.no_stdin = 1;
+       revlist.no_stdout = 1;
+       revlist.no_stderr = 1;
+       err = run_command(&revlist);
+
+       for (i = 0; argv[i]; i++)
+               free(argv[i]);
+       free(argv);
+       return err;
 }
 
 static int fetch_refs(struct transport *transport, struct ref *ref_map)
 {
-       int ret = transport_fetch_refs(transport, ref_map);
+       int ret = quickfetch(ref_map);
+       if (ret)
+               ret = transport_fetch_refs(transport, ref_map);
        if (!ret)
-               store_updated_refs(transport->url, ref_map);
+               ret |= store_updated_refs(transport->url, ref_map);
        transport_unlock_pack(transport);
        return ret;
 }
@@ -359,12 +459,12 @@ static struct ref *find_non_local_tags(struct transport *transport,
        struct path_list new_refs = { NULL, 0, 0, 1 };
        char *ref_name;
        int ref_name_len;
-       unsigned char *ref_sha1;
-       struct ref *tag_ref;
+       const unsigned char *ref_sha1;
+       const struct ref *tag_ref;
        struct ref *rm = NULL;
        struct ref *ref_map = NULL;
        struct ref **tail = &ref_map;
-       struct ref *ref;
+       const struct ref *ref;
 
        for_each_ref(add_existing, &existing_refs);
        for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
@@ -389,7 +489,7 @@ static struct ref *find_non_local_tags(struct transport *transport,
 
                if (!path_list_has_path(&existing_refs, ref_name) &&
                    !path_list_has_path(&new_refs, ref_name) &&
-                   lookup_object(ref->old_sha1)) {
+                   has_sha1_file(ref->old_sha1)) {
                        path_list_insert(ref_name, &new_refs);
 
                        rm = alloc_ref(strlen(ref_name) + 1);
@@ -413,17 +513,22 @@ static int do_fetch(struct transport *transport,
        struct ref *ref_map, *fetch_map;
        struct ref *rm;
        int autotags = (transport->remote->fetch_tags == 1);
-       if (transport->remote->fetch_tags == 2 && !no_tags)
-               tags = 1;
+       if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
+               tags = TAGS_SET;
        if (transport->remote->fetch_tags == -1)
-               no_tags = 1;
+               tags = TAGS_UNSET;
 
        if (!transport->get_refs_list || !transport->fetch)
                die("Don't know how to fetch from %s", transport->url);
 
        /* if not appending, truncate FETCH_HEAD */
-       if (!append)
-               fclose(fopen(git_path("FETCH_HEAD"), "w"));
+       if (!append) {
+               char *filename = git_path("FETCH_HEAD");
+               FILE *fp = fopen(filename, "w");
+               if (!fp)
+                       return error("cannot open %s: %s\n", filename, strerror(errno));
+               fclose(fp);
+       }
 
        ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
 
@@ -441,7 +546,7 @@ static int do_fetch(struct transport *transport,
 
        /* if neither --no-tags nor --tags was specified, do automated tag
         * following ... */
-       if (!(tags || no_tags) && autotags) {
+       if (tags == TAGS_DEFAULT && autotags) {
                ref_map = find_non_local_tags(transport, fetch_map);
                if (ref_map) {
                        transport_set_option(transport, TRANS_OPT_DEPTH, "0");
@@ -469,91 +574,22 @@ static void set_option(const char *name, const char *value)
 int cmd_fetch(int argc, const char **argv, const char *prefix)
 {
        struct remote *remote;
-       int i, j, rla_offset;
+       int i;
        static const char **refs = NULL;
        int ref_nr = 0;
-       int cmd_len = 0;
-       const char *depth = NULL, *upload_pack = NULL;
-       int keep = 0;
-
-       for (i = 1; i < argc; i++) {
-               const char *arg = argv[i];
-               cmd_len += strlen(arg);
-
-               if (arg[0] != '-')
-                       break;
-               if (!strcmp(arg, "--append") || !strcmp(arg, "-a")) {
-                       append = 1;
-                       continue;
-               }
-               if (!prefixcmp(arg, "--upload-pack=")) {
-                       upload_pack = arg + 14;
-                       continue;
-               }
-               if (!strcmp(arg, "--upload-pack")) {
-                       i++;
-                       if (i == argc)
-                               usage(fetch_usage);
-                       upload_pack = argv[i];
-                       continue;
-               }
-               if (!strcmp(arg, "--force") || !strcmp(arg, "-f")) {
-                       force = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--no-tags")) {
-                       no_tags = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--tags") || !strcmp(arg, "-t")) {
-                       tags = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--keep") || !strcmp(arg, "-k")) {
-                       keep = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--update-head-ok") || !strcmp(arg, "-u")) {
-                       update_head_ok = 1;
-                       continue;
-               }
-               if (!prefixcmp(arg, "--depth=")) {
-                       depth = arg + 8;
-                       continue;
-               }
-               if (!strcmp(arg, "--depth")) {
-                       i++;
-                       if (i == argc)
-                               usage(fetch_usage);
-                       depth = argv[i];
-                       continue;
-               }
-               if (!strcmp(arg, "--quiet") || !strcmp(arg, "-q")) {
-                       quiet = 1;
-                       continue;
-               }
-               if (!strcmp(arg, "--verbose") || !strcmp(arg, "-v")) {
-                       verbose++;
-                       continue;
-               }
-               usage(fetch_usage);
-       }
 
-       for (j = i; j < argc; j++)
-               cmd_len += strlen(argv[j]);
+       /* Record the command line for the reflog */
+       strbuf_addstr(&default_rla, "fetch");
+       for (i = 1; i < argc; i++)
+               strbuf_addf(&default_rla, " %s", argv[i]);
 
-       default_rla = xmalloc(cmd_len + 5 + argc + 1);
-       sprintf(default_rla, "fetch");
-       rla_offset = strlen(default_rla);
-       for (j = 1; j < argc; j++) {
-               sprintf(default_rla + rla_offset, " %s", argv[j]);
-               rla_offset += strlen(argv[j]) + 1;
-       }
+       argc = parse_options(argc, argv,
+                            builtin_fetch_options, builtin_fetch_usage, 0);
 
-       if (i == argc)
+       if (argc == 0)
                remote = remote_get(NULL);
        else
-               remote = remote_get(argv[i++]);
+               remote = remote_get(argv[0]);
 
        transport = transport_get(remote, remote->url[0]);
        if (verbose >= 2)
@@ -570,10 +606,10 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
        if (!transport->url)
                die("Where do you want to fetch from today?");
 
-       if (i < argc) {
+       if (argc > 1) {
                int j = 0;
-               refs = xcalloc(argc - i + 1, sizeof(const char *));
-               while (i < argc) {
+               refs = xcalloc(argc + 1, sizeof(const char *));
+               for (i = 1; i < argc; i++) {
                        if (!strcmp(argv[i], "tag")) {
                                char *ref;
                                i++;
@@ -585,7 +621,6 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
                                refs[j++] = ref;
                        } else
                                refs[j++] = argv[i];
-                       i++;
                }
                refs[j] = NULL;
                ref_nr = j;