Use atomic updates to the fast-import mark file
[gitweb.git] / fast-import.c
index 1ae125a040e6dfcf83b2cdc4aeea8fa248d2ba22..a09221242e3866d8b5f01d21ca2e27adbb1558e4 100644 (file)
@@ -220,7 +220,8 @@ struct branch
        const char *name;
        struct tree_entry branch_tree;
        uintmax_t last_commit;
-       unsigned int pack_id;
+       unsigned active : 1;
+       unsigned pack_id : PACK_ID_BITS;
        unsigned char sha1[20];
 };
 
@@ -528,6 +529,7 @@ static struct branch *new_branch(const char *name)
        b->table_next_branch = branch_table[hc];
        b->branch_tree.versions[0].mode = S_IFDIR;
        b->branch_tree.versions[1].mode = S_IFDIR;
+       b->active = 0;
        b->pack_id = MAX_PACK_ID;
        branch_table[hc] = b;
        branch_count++;
@@ -891,7 +893,7 @@ static int store_object(
        SHA_CTX c;
        z_stream s;
 
-       hdrlen = sprintf((char*)hdr,"%s %lu", type_names[type],
+       hdrlen = sprintf((char*)hdr,"%s %lu", typename(type),
                (unsigned long)datlen) + 1;
        SHA1_Init(&c);
        SHA1_Update(&c, hdr, hdrlen);
@@ -1008,11 +1010,11 @@ static void *gfi_unpack_entry(
        struct object_entry *oe,
        unsigned long *sizep)
 {
-       static char type[20];
+       enum object_type type;
        struct packed_git *p = all_packs[oe->pack_id];
        if (p == pack_data)
                p->pack_size = pack_size + 20;
-       return unpack_entry(p, oe->offset, type, sizep);
+       return unpack_entry(p, oe->offset, &type, sizep);
 }
 
 static const char *get_mode(const char *str, uint16_t *modep)
@@ -1049,9 +1051,9 @@ static void load_tree(struct tree_entry *root)
                t->delta_depth = 0;
                buf = gfi_unpack_entry(myoe, &size);
        } else {
-               char type[20];
-               buf = read_sha1_file(sha1, type, &size);
-               if (!buf || strcmp(type, tree_type))
+               enum object_type type;
+               buf = read_sha1_file(sha1, &type, &size);
+               if (!buf || type != OBJ_TREE)
                        die("Can't load tree %s", sha1_to_hex(sha1));
        }
 
@@ -1312,7 +1314,7 @@ static int update_branch(struct branch *b)
                        return error("Branch %s is missing commits.", b->name);
                }
 
-               if (!in_merge_bases(old_cmit, new_cmit)) {
+               if (!in_merge_bases(old_cmit, &new_cmit, 1)) {
                        unlock_ref(lock);
                        warn("Not updating %s"
                                " (new tip %s does not contain %s)",
@@ -1373,16 +1375,33 @@ static void dump_marks_helper(FILE *f,
 
 static void dump_marks(void)
 {
-       if (mark_file)
-       {
-               FILE *f = fopen(mark_file, "w");
-               if (f) {
-                       dump_marks_helper(f, 0, marks);
-                       fclose(f);
-               } else
-                       failure |= error("Unable to write marks file %s: %s",
-                               mark_file, strerror(errno));
+       static struct lock_file mark_lock;
+       int mark_fd;
+       FILE *f;
+
+       if (!mark_file)
+               return;
+
+       mark_fd = hold_lock_file_for_update(&mark_lock, mark_file, 0);
+       if (mark_fd < 0) {
+               failure |= error("Unable to write marks file %s: %s",
+                       mark_file, strerror(errno));
+               return;
        }
+
+       f = fdopen(mark_fd, "w");
+       if (!f) {
+               rollback_lock_file(&mark_lock);
+               failure |= error("Unable to write marks file %s: %s",
+                       mark_file, strerror(errno));
+               return;
+       }
+
+       dump_marks_helper(f, 0, marks);
+       fclose(f);
+       if (commit_lock_file(&mark_lock))
+               failure |= error("Unable to write marks file %s: %s",
+                       mark_file, strerror(errno));
 }
 
 static void read_next_command(void)
@@ -1392,7 +1411,7 @@ static void read_next_command(void)
 
 static void cmd_mark(void)
 {
-       if (!strncmp("mark :", command_buf.buf, 6)) {
+       if (!prefixcmp(command_buf.buf, "mark :")) {
                next_mark = strtoumax(command_buf.buf + 6, NULL, 10);
                read_next_command();
        }
@@ -1405,10 +1424,10 @@ static void *cmd_data (size_t *size)
        size_t length;
        char *buffer;
 
-       if (strncmp("data ", command_buf.buf, 5))
+       if (prefixcmp(command_buf.buf, "data "))
                die("Expected 'data n' command, found: %s", command_buf.buf);
 
-       if (!strncmp("<<", command_buf.buf + 5, 2)) {
+       if (!prefixcmp(command_buf.buf + 5, "<<")) {
                char *term = xstrdup(command_buf.buf + 5 + 2);
                size_t sz = 8192, term_len = command_buf.len - 5 - 2;
                length = 0;
@@ -1547,6 +1566,7 @@ static void unload_one_branch(void)
                        e = active_branches;
                        active_branches = e->active_next_branch;
                }
+               e->active = 0;
                e->active_next_branch = NULL;
                if (e->branch_tree.tree) {
                        release_tree_content_recursive(e->branch_tree.tree);
@@ -1559,10 +1579,13 @@ static void unload_one_branch(void)
 static void load_branch(struct branch *b)
 {
        load_tree(&b->branch_tree);
-       b->active_next_branch = active_branches;
-       active_branches = b;
-       cur_active_branches++;
-       branch_load_count++;
+       if (!b->active) {
+               b->active = 1;
+               b->active_next_branch = active_branches;
+               active_branches = b;
+               cur_active_branches++;
+               branch_load_count++;
+       }
 }
 
 static void file_change_m(struct branch *b)
@@ -1573,7 +1596,6 @@ static void file_change_m(struct branch *b)
        struct object_entry *oe = oe;
        unsigned char sha1[20];
        uint16_t mode, inline_data = 0;
-       char type[20];
 
        p = get_mode(p, &mode);
        if (!p)
@@ -1595,7 +1617,7 @@ static void file_change_m(struct branch *b)
                oe = find_mark(strtoumax(p + 1, &x, 10));
                hashcpy(sha1, oe->sha1);
                p = x;
-       } else if (!strncmp("inline", p, 6)) {
+       } else if (!prefixcmp(p, "inline")) {
                inline_data = 1;
                p += 6;
        } else {
@@ -1626,13 +1648,14 @@ static void file_change_m(struct branch *b)
        } else if (oe) {
                if (oe->type != OBJ_BLOB)
                        die("Not a blob (actually a %s): %s",
-                               command_buf.buf, type_names[oe->type]);
+                               command_buf.buf, typename(oe->type));
        } else {
-               if (sha1_object_info(sha1, type, NULL))
+               enum object_type type = sha1_object_info(sha1, NULL);
+               if (type < 0)
                        die("Blob not found: %s", command_buf.buf);
-               if (strcmp(blob_type, type))
+               if (type != OBJ_BLOB)
                        die("Not a blob (actually a %s): %s",
-                               command_buf.buf, type);
+                           typename(type), command_buf.buf);
        }
 
        tree_content_set(&b->branch_tree, p, sha1, S_IFREG | mode);
@@ -1668,7 +1691,7 @@ static void cmd_from(struct branch *b)
        const char *from;
        struct branch *s;
 
-       if (strncmp("from ", command_buf.buf, 5))
+       if (prefixcmp(command_buf.buf, "from "))
                return;
 
        if (b->branch_tree.tree) {
@@ -1711,7 +1734,7 @@ static void cmd_from(struct branch *b)
                        char *buf;
 
                        buf = read_object_with_reference(b->sha1,
-                               type_names[OBJ_COMMIT], &size, b->sha1);
+                               commit_type, &size, b->sha1);
                        if (!buf || size < 46)
                                die("Not a valid commit: %s", from);
                        if (memcmp("tree ", buf, 5)
@@ -1734,7 +1757,7 @@ static struct hash_list *cmd_merge(unsigned int *count)
        struct branch *s;
 
        *count = 0;
-       while (!strncmp("merge ", command_buf.buf, 6)) {
+       while (!prefixcmp(command_buf.buf, "merge ")) {
                from = strchr(command_buf.buf, ' ') + 1;
                n = xmalloc(sizeof(*n));
                s = lookup_branch(from);
@@ -1746,7 +1769,14 @@ static struct hash_list *cmd_merge(unsigned int *count)
                        if (oe->type != OBJ_COMMIT)
                                die("Mark :%" PRIuMAX " not a commit", idnum);
                        hashcpy(n->sha1, oe->sha1);
-               } else if (get_sha1(from, n->sha1))
+               } else if (!get_sha1(from, n->sha1)) {
+                       unsigned long size;
+                       char *buf = read_object_with_reference(n->sha1,
+                               commit_type, &size, n->sha1);
+                       if (!buf || size < 46)
+                               die("Not a valid commit: %s", from);
+                       free(buf);
+               } else
                        die("Invalid ref name or SHA1 expression: %s", from);
 
                n->next = NULL;
@@ -1780,11 +1810,11 @@ static void cmd_new_commit(void)
 
        read_next_command();
        cmd_mark();
-       if (!strncmp("author ", command_buf.buf, 7)) {
+       if (!prefixcmp(command_buf.buf, "author ")) {
                author = parse_ident(command_buf.buf + 7);
                read_next_command();
        }
-       if (!strncmp("committer ", command_buf.buf, 10)) {
+       if (!prefixcmp(command_buf.buf, "committer ")) {
                committer = parse_ident(command_buf.buf + 10);
                read_next_command();
        }
@@ -1805,9 +1835,9 @@ static void cmd_new_commit(void)
        for (;;) {
                if (1 == command_buf.len)
                        break;
-               else if (!strncmp("M ", command_buf.buf, 2))
+               else if (!prefixcmp(command_buf.buf, "M "))
                        file_change_m(b);
-               else if (!strncmp("D ", command_buf.buf, 2))
+               else if (!prefixcmp(command_buf.buf, "D "))
                        file_change_d(b);
                else if (!strcmp("deleteall", command_buf.buf))
                        file_change_deleteall(b);
@@ -1877,7 +1907,7 @@ static void cmd_new_tag(void)
        read_next_command();
 
        /* from ... */
-       if (strncmp("from ", command_buf.buf, 5))
+       if (prefixcmp(command_buf.buf, "from "))
                die("Expected from command, got %s", command_buf.buf);
        from = strchr(command_buf.buf, ' ') + 1;
        s = lookup_branch(from);
@@ -1895,7 +1925,7 @@ static void cmd_new_tag(void)
                char *buf;
 
                buf = read_object_with_reference(sha1,
-                       type_names[OBJ_COMMIT], &size, sha1);
+                       commit_type, &size, sha1);
                if (!buf || size < 46)
                        die("Not a valid commit: %s", from);
                free(buf);
@@ -1904,7 +1934,7 @@ static void cmd_new_tag(void)
        read_next_command();
 
        /* tagger ... */
-       if (strncmp("tagger ", command_buf.buf, 7))
+       if (prefixcmp(command_buf.buf, "tagger "))
                die("Expected tagger command, got %s", command_buf.buf);
        tagger = parse_ident(command_buf.buf + 7);
 
@@ -1916,7 +1946,7 @@ static void cmd_new_tag(void)
        size_dbuf(&new_data, 67+strlen(t->name)+strlen(tagger)+msglen);
        sp = new_data.buffer;
        sp += sprintf(sp, "object %s\n", sha1_to_hex(sha1));
-       sp += sprintf(sp, "type %s\n", type_names[OBJ_COMMIT]);
+       sp += sprintf(sp, "type %s\n", commit_type);
        sp += sprintf(sp, "tag %s\n", t->name);
        sp += sprintf(sp, "tagger %s\n", tagger);
        *sp++ = '\n';
@@ -1975,13 +2005,19 @@ int main(int argc, const char **argv)
        int i, show_stats = 1;
 
        git_config(git_default_config);
+       alloc_objects(object_entry_alloc);
+       strbuf_init(&command_buf);
+       atom_table = xcalloc(atom_table_sz, sizeof(struct atom_str*));
+       branch_table = xcalloc(branch_table_sz, sizeof(struct branch*));
+       avail_tree_table = xcalloc(avail_tree_table_sz, sizeof(struct avail_tree_content*));
+       marks = pool_calloc(1, sizeof(struct mark_set));
 
        for (i = 1; i < argc; i++) {
                const char *a = argv[i];
 
                if (*a != '-' || !strcmp(a, "--"))
                        break;
-               else if (!strncmp(a, "--date-format=", 14)) {
+               else if (!prefixcmp(a, "--date-format=")) {
                        const char *fmt = a + 14;
                        if (!strcmp(fmt, "raw"))
                                whenspec = WHENSPEC_RAW;
@@ -1992,15 +2028,15 @@ int main(int argc, const char **argv)
                        else
                                die("unknown --date-format argument %s", fmt);
                }
-               else if (!strncmp(a, "--max-pack-size=", 16))
+               else if (!prefixcmp(a, "--max-pack-size="))
                        max_packsize = strtoumax(a + 16, NULL, 0) * 1024 * 1024;
-               else if (!strncmp(a, "--depth=", 8))
+               else if (!prefixcmp(a, "--depth="))
                        max_depth = strtoul(a + 8, NULL, 0);
-               else if (!strncmp(a, "--active-branches=", 18))
+               else if (!prefixcmp(a, "--active-branches="))
                        max_active_branches = strtoul(a + 18, NULL, 0);
-               else if (!strncmp(a, "--export-marks=", 15))
+               else if (!prefixcmp(a, "--export-marks="))
                        mark_file = a + 15;
-               else if (!strncmp(a, "--export-pack-edges=", 20)) {
+               else if (!prefixcmp(a, "--export-pack-edges=")) {
                        if (pack_edges)
                                fclose(pack_edges);
                        pack_edges = fopen(a + 20, "a");
@@ -2018,14 +2054,6 @@ int main(int argc, const char **argv)
        if (i != argc)
                usage(fast_import_usage);
 
-       alloc_objects(object_entry_alloc);
-       strbuf_init(&command_buf);
-
-       atom_table = xcalloc(atom_table_sz, sizeof(struct atom_str*));
-       branch_table = xcalloc(branch_table_sz, sizeof(struct branch*));
-       avail_tree_table = xcalloc(avail_tree_table_sz, sizeof(struct avail_tree_content*));
-       marks = pool_calloc(1, sizeof(struct mark_set));
-
        start_packfile();
        for (;;) {
                read_next_command();
@@ -2033,11 +2061,11 @@ int main(int argc, const char **argv)
                        break;
                else if (!strcmp("blob", command_buf.buf))
                        cmd_new_blob();
-               else if (!strncmp("commit ", command_buf.buf, 7))
+               else if (!prefixcmp(command_buf.buf, "commit "))
                        cmd_new_commit();
-               else if (!strncmp("tag ", command_buf.buf, 4))
+               else if (!prefixcmp(command_buf.buf, "tag "))
                        cmd_new_tag();
-               else if (!strncmp("reset ", command_buf.buf, 6))
+               else if (!prefixcmp(command_buf.buf, "reset "))
                        cmd_reset_branch();
                else if (!strcmp("checkpoint", command_buf.buf))
                        cmd_checkpoint();