builtin/config.c: rename check_blob_write() -> check_write()
[gitweb.git] / builtin / receive-pack.c
index 67ce1ef105d1494e7905e66750b14676e082e11c..85bba356fab7743506f00bb0c5ca955eb9112bd5 100644 (file)
@@ -13,6 +13,7 @@
 #include "string-list.h"
 #include "sha1-array.h"
 #include "connected.h"
+#include "argv-array.h"
 #include "version.h"
 
 static const char receive_pack_usage[] = "git receive-pack <git-dir>";
@@ -43,6 +44,8 @@ static int fix_thin = 1;
 static const char *head_name;
 static void *head_name_to_free;
 static int sent_capabilities;
+static int shallow_update;
+static const char *alt_shallow_file;
 
 static enum deny_action parse_deny_action(const char *var, const char *value)
 {
@@ -121,6 +124,11 @@ static int receive_pack_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
+       if (strcmp(var, "receive.shallowupdate") == 0) {
+               shallow_update = git_config_bool(var, value);
+               return 0;
+       }
+
        return git_default_config(var, value, cb);
 }
 
@@ -178,6 +186,8 @@ static void write_head_info(void)
        if (!sent_capabilities)
                show_ref("capabilities^{}", null_sha1);
 
+       advertise_shallow_grafts(1);
+
        /* EOF */
        packet_flush(1);
 }
@@ -187,6 +197,7 @@ struct command {
        const char *error_string;
        unsigned int skip_update:1,
                     did_not_exist:1;
+       int index;
        unsigned char old_sha1[20];
        unsigned char new_sha1[20];
        char ref_name[FLEX_ARRAY]; /* more */
@@ -418,7 +429,46 @@ static void refuse_unconfigured_deny_delete_current(void)
                rp_error("%s", refuse_unconfigured_deny_delete_current_msg[i]);
 }
 
-static const char *update(struct command *cmd)
+static int command_singleton_iterator(void *cb_data, unsigned char sha1[20]);
+static int update_shallow_ref(struct command *cmd, struct shallow_info *si)
+{
+       static struct lock_file shallow_lock;
+       struct sha1_array extra = SHA1_ARRAY_INIT;
+       const char *alt_file;
+       uint32_t mask = 1 << (cmd->index % 32);
+       int i;
+
+       trace_printf_key("GIT_TRACE_SHALLOW",
+                        "shallow: update_shallow_ref %s\n", cmd->ref_name);
+       for (i = 0; i < si->shallow->nr; i++)
+               if (si->used_shallow[i] &&
+                   (si->used_shallow[i][cmd->index / 32] & mask) &&
+                   !delayed_reachability_test(si, i))
+                       sha1_array_append(&extra, si->shallow->sha1[i]);
+
+       setup_alternate_shallow(&shallow_lock, &alt_file, &extra);
+       if (check_shallow_connected(command_singleton_iterator,
+                                   0, cmd, alt_file)) {
+               rollback_lock_file(&shallow_lock);
+               sha1_array_clear(&extra);
+               return -1;
+       }
+
+       commit_lock_file(&shallow_lock);
+
+       /*
+        * Make sure setup_alternate_shallow() for the next ref does
+        * not lose these new roots..
+        */
+       for (i = 0; i < extra.nr; i++)
+               register_shallow(extra.sha1[i]);
+
+       si->shallow_ref[cmd->index] = 0;
+       sha1_array_clear(&extra);
+       return 0;
+}
+
+static const char *update(struct command *cmd, struct shallow_info *si)
 {
        const char *name = cmd->ref_name;
        struct strbuf namespaced_name_buf = STRBUF_INIT;
@@ -428,7 +478,7 @@ static const char *update(struct command *cmd)
        struct ref_lock *lock;
 
        /* only refs/... are allowed */
-       if (prefixcmp(name, "refs/") || check_refname_format(name + 5, 0)) {
+       if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
                rp_error("refusing to create funny ref '%s' remotely", name);
                return "funny refname";
        }
@@ -459,7 +509,7 @@ static const char *update(struct command *cmd)
        }
 
        if (!is_null_sha1(old_sha1) && is_null_sha1(new_sha1)) {
-               if (deny_deletes && !prefixcmp(name, "refs/heads/")) {
+               if (deny_deletes && starts_with(name, "refs/heads/")) {
                        rp_error("denying ref deletion for %s", name);
                        return "deletion prohibited";
                }
@@ -483,7 +533,7 @@ static const char *update(struct command *cmd)
 
        if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
            !is_null_sha1(old_sha1) &&
-           !prefixcmp(name, "refs/heads/")) {
+           starts_with(name, "refs/heads/")) {
                struct object *old_object, *new_object;
                struct commit *old_commit, *new_commit;
 
@@ -526,6 +576,10 @@ static const char *update(struct command *cmd)
                return NULL; /* good */
        }
        else {
+               if (shallow_update && si->shallow_ref[cmd->index] &&
+                   update_shallow_ref(cmd, si))
+                       return "shallow error";
+
                lock = lock_any_ref_for_update(namespaced_name, old_sha1,
                                               0, NULL);
                if (!lock) {
@@ -666,12 +720,16 @@ static int command_singleton_iterator(void *cb_data, unsigned char sha1[20])
        return 0;
 }
 
-static void set_connectivity_errors(struct command *commands)
+static void set_connectivity_errors(struct command *commands,
+                                   struct shallow_info *si)
 {
        struct command *cmd;
 
        for (cmd = commands; cmd; cmd = cmd->next) {
                struct command *singleton = cmd;
+               if (shallow_update && si->shallow_ref[cmd->index])
+                       /* to be checked in update_shallow_ref() */
+                       continue;
                if (!check_everything_connected(command_singleton_iterator,
                                                0, &singleton))
                        continue;
@@ -679,18 +737,26 @@ static void set_connectivity_errors(struct command *commands)
        }
 }
 
+struct iterate_data {
+       struct command *cmds;
+       struct shallow_info *si;
+};
+
 static int iterate_receive_command_list(void *cb_data, unsigned char sha1[20])
 {
-       struct command **cmd_list = cb_data;
+       struct iterate_data *data = cb_data;
+       struct command **cmd_list = &data->cmds;
        struct command *cmd = *cmd_list;
 
-       while (cmd) {
-               if (!is_null_sha1(cmd->new_sha1)) {
+       for (; cmd; cmd = cmd->next) {
+               if (shallow_update && data->si->shallow_ref[cmd->index])
+                       /* to be checked in update_shallow_ref() */
+                       continue;
+               if (!is_null_sha1(cmd->new_sha1) && !cmd->skip_update) {
                        hashcpy(sha1, cmd->new_sha1);
                        *cmd_list = cmd->next;
                        return 0;
                }
-               cmd = cmd->next;
        }
        *cmd_list = NULL;
        return -1; /* end of list */
@@ -710,10 +776,14 @@ static void reject_updates_to_hidden(struct command *commands)
        }
 }
 
-static void execute_commands(struct command *commands, const char *unpacker_error)
+static void execute_commands(struct command *commands,
+                            const char *unpacker_error,
+                            struct shallow_info *si)
 {
+       int checked_connectivity;
        struct command *cmd;
        unsigned char sha1[20];
+       struct iterate_data data;
 
        if (unpacker_error) {
                for (cmd = commands; cmd; cmd = cmd->next)
@@ -721,10 +791,10 @@ static void execute_commands(struct command *commands, const char *unpacker_erro
                return;
        }
 
-       cmd = commands;
-       if (check_everything_connected(iterate_receive_command_list,
-                                      0, &cmd))
-               set_connectivity_errors(commands);
+       data.cmds = commands;
+       data.si = si;
+       if (check_everything_connected(iterate_receive_command_list, 0, &data))
+               set_connectivity_errors(commands, si);
 
        reject_updates_to_hidden(commands);
 
@@ -741,6 +811,7 @@ static void execute_commands(struct command *commands, const char *unpacker_erro
        free(head_name_to_free);
        head_name = head_name_to_free = resolve_refdup("HEAD", sha1, 0, NULL);
 
+       checked_connectivity = 1;
        for (cmd = commands; cmd; cmd = cmd->next) {
                if (cmd->error_string)
                        continue;
@@ -748,11 +819,26 @@ static void execute_commands(struct command *commands, const char *unpacker_erro
                if (cmd->skip_update)
                        continue;
 
-               cmd->error_string = update(cmd);
+               cmd->error_string = update(cmd, si);
+               if (shallow_update && !cmd->error_string &&
+                   si->shallow_ref[cmd->index]) {
+                       error("BUG: connectivity check has not been run on ref %s",
+                             cmd->ref_name);
+                       checked_connectivity = 0;
+               }
+       }
+
+       if (shallow_update) {
+               if (!checked_connectivity)
+                       error("BUG: run 'git fsck' for safety.\n"
+                             "If there are errors, try to remove "
+                             "the reported refs above");
+               if (alt_shallow_file && *alt_shallow_file)
+                       unlink(alt_shallow_file);
        }
 }
 
-static struct command *read_head_info(void)
+static struct command *read_head_info(struct sha1_array *shallow)
 {
        struct command *commands = NULL;
        struct command **p = &commands;
@@ -766,6 +852,14 @@ static struct command *read_head_info(void)
                line = packet_read_line(0, &len);
                if (!line)
                        break;
+
+               if (len == 48 && starts_with(line, "shallow ")) {
+                       if (get_sha1_hex(line + 8, old_sha1))
+                               die("protocol error: expected shallow sha, got '%s'", line + 8);
+                       sha1_array_append(shallow, old_sha1);
+                       continue;
+               }
+
                if (len < 83 ||
                    line[40] != ' ' ||
                    line[81] != ' ' ||
@@ -817,11 +911,14 @@ static const char *parse_pack_header(struct pack_header *hdr)
 
 static const char *pack_lockfile;
 
-static const char *unpack(int err_fd)
+static const char *unpack(int err_fd, struct shallow_info *si)
 {
        struct pack_header hdr;
+       struct argv_array av = ARGV_ARRAY_INIT;
        const char *hdr_err;
+       int status;
        char hdr_arg[38];
+       struct child_process child;
        int fsck_objects = (receive_fsck_objects >= 0
                            ? receive_fsck_objects
                            : transfer_fsck_objects >= 0
@@ -838,72 +935,63 @@ static const char *unpack(int err_fd)
                        "--pack_header=%"PRIu32",%"PRIu32,
                        ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
 
+       if (si->nr_ours || si->nr_theirs) {
+               alt_shallow_file = setup_temporary_shallow(si->shallow);
+               argv_array_pushl(&av, "--shallow-file", alt_shallow_file, NULL);
+       }
+
+       memset(&child, 0, sizeof(child));
        if (ntohl(hdr.hdr_entries) < unpack_limit) {
-               int code, i = 0;
-               struct child_process child;
-               const char *unpacker[5];
-               unpacker[i++] = "unpack-objects";
+               argv_array_pushl(&av, "unpack-objects", hdr_arg, NULL);
                if (quiet)
-                       unpacker[i++] = "-q";
+                       argv_array_push(&av, "-q");
                if (fsck_objects)
-                       unpacker[i++] = "--strict";
-               unpacker[i++] = hdr_arg;
-               unpacker[i++] = NULL;
-               memset(&child, 0, sizeof(child));
-               child.argv = unpacker;
+                       argv_array_push(&av, "--strict");
+               child.argv = av.argv;
                child.no_stdout = 1;
                child.err = err_fd;
                child.git_cmd = 1;
-               code = run_command(&child);
-               if (!code)
-                       return NULL;
-               return "unpack-objects abnormal exit";
+               status = run_command(&child);
+               if (status)
+                       return "unpack-objects abnormal exit";
        } else {
-               const char *keeper[7];
-               int s, status, i = 0;
+               int s;
                char keep_arg[256];
-               struct child_process ip;
 
                s = sprintf(keep_arg, "--keep=receive-pack %"PRIuMAX" on ", (uintmax_t) getpid());
                if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
                        strcpy(keep_arg + s, "localhost");
 
-               keeper[i++] = "index-pack";
-               keeper[i++] = "--stdin";
+               argv_array_pushl(&av, "index-pack",
+                                "--stdin", hdr_arg, keep_arg, NULL);
                if (fsck_objects)
-                       keeper[i++] = "--strict";
+                       argv_array_push(&av, "--strict");
                if (fix_thin)
-                       keeper[i++] = "--fix-thin";
-               keeper[i++] = hdr_arg;
-               keeper[i++] = keep_arg;
-               keeper[i++] = NULL;
-               memset(&ip, 0, sizeof(ip));
-               ip.argv = keeper;
-               ip.out = -1;
-               ip.err = err_fd;
-               ip.git_cmd = 1;
-               status = start_command(&ip);
-               if (status) {
+                       argv_array_push(&av, "--fix-thin");
+               child.argv = av.argv;
+               child.out = -1;
+               child.err = err_fd;
+               child.git_cmd = 1;
+               status = start_command(&child);
+               if (status)
                        return "index-pack fork failed";
-               }
-               pack_lockfile = index_pack_lockfile(ip.out);
-               close(ip.out);
-               status = finish_command(&ip);
-               if (!status) {
-                       reprepare_packed_git();
-                       return NULL;
-               }
-               return "index-pack abnormal exit";
+               pack_lockfile = index_pack_lockfile(child.out);
+               close(child.out);
+               status = finish_command(&child);
+               if (status)
+                       return "index-pack abnormal exit";
+               reprepare_packed_git();
        }
+       return NULL;
 }
 
-static const char *unpack_with_sideband(void)
+static const char *unpack_with_sideband(struct shallow_info *si)
 {
        struct async muxer;
        const char *ret;
 
        if (!use_sideband)
-               return unpack(0);
+               return unpack(0, si);
 
        memset(&muxer, 0, sizeof(muxer));
        muxer.proc = copy_to_sideband;
@@ -911,12 +999,101 @@ static const char *unpack_with_sideband(void)
        if (start_async(&muxer))
                return NULL;
 
-       ret = unpack(muxer.in);
+       ret = unpack(muxer.in, si);
 
        finish_async(&muxer);
        return ret;
 }
 
+static void prepare_shallow_update(struct command *commands,
+                                  struct shallow_info *si)
+{
+       int i, j, k, bitmap_size = (si->ref->nr + 31) / 32;
+
+       si->used_shallow = xmalloc(sizeof(*si->used_shallow) *
+                                  si->shallow->nr);
+       assign_shallow_commits_to_refs(si, si->used_shallow, NULL);
+
+       si->need_reachability_test =
+               xcalloc(si->shallow->nr, sizeof(*si->need_reachability_test));
+       si->reachable =
+               xcalloc(si->shallow->nr, sizeof(*si->reachable));
+       si->shallow_ref = xcalloc(si->ref->nr, sizeof(*si->shallow_ref));
+
+       for (i = 0; i < si->nr_ours; i++)
+               si->need_reachability_test[si->ours[i]] = 1;
+
+       for (i = 0; i < si->shallow->nr; i++) {
+               if (!si->used_shallow[i])
+                       continue;
+               for (j = 0; j < bitmap_size; j++) {
+                       if (!si->used_shallow[i][j])
+                               continue;
+                       si->need_reachability_test[i]++;
+                       for (k = 0; k < 32; k++)
+                               if (si->used_shallow[i][j] & (1 << k))
+                                       si->shallow_ref[j * 32 + k]++;
+               }
+
+               /*
+                * true for those associated with some refs and belong
+                * in "ours" list aka "step 7 not done yet"
+                */
+               si->need_reachability_test[i] =
+                       si->need_reachability_test[i] > 1;
+       }
+
+       /*
+        * keep hooks happy by forcing a temporary shallow file via
+        * env variable because we can't add --shallow-file to every
+        * command. check_everything_connected() will be done with
+        * true .git/shallow though.
+        */
+       setenv(GIT_SHALLOW_FILE_ENVIRONMENT, alt_shallow_file, 1);
+}
+
+static void update_shallow_info(struct command *commands,
+                               struct shallow_info *si,
+                               struct sha1_array *ref)
+{
+       struct command *cmd;
+       int *ref_status;
+       remove_nonexistent_theirs_shallow(si);
+       if (!si->nr_ours && !si->nr_theirs) {
+               shallow_update = 0;
+               return;
+       }
+
+       for (cmd = commands; cmd; cmd = cmd->next) {
+               if (is_null_sha1(cmd->new_sha1))
+                       continue;
+               sha1_array_append(ref, cmd->new_sha1);
+               cmd->index = ref->nr - 1;
+       }
+       si->ref = ref;
+
+       if (shallow_update) {
+               prepare_shallow_update(commands, si);
+               return;
+       }
+
+       ref_status = xmalloc(sizeof(*ref_status) * ref->nr);
+       assign_shallow_commits_to_refs(si, NULL, ref_status);
+       for (cmd = commands; cmd; cmd = cmd->next) {
+               if (is_null_sha1(cmd->new_sha1))
+                       continue;
+               if (ref_status[cmd->index]) {
+                       cmd->error_string = "shallow update not allowed";
+                       cmd->skip_update = 1;
+               }
+       }
+       if (alt_shallow_file && *alt_shallow_file) {
+               unlink(alt_shallow_file);
+               alt_shallow_file = NULL;
+       }
+       free(ref_status);
+}
+
 static void report(struct command *commands, const char *unpack_status)
 {
        struct command *cmd;
@@ -958,6 +1135,9 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
        int i;
        char *dir = NULL;
        struct command *commands;
+       struct sha1_array shallow = SHA1_ARRAY_INIT;
+       struct sha1_array ref = SHA1_ARRAY_INIT;
+       struct shallow_info si;
 
        packet_trace_identity("receive-pack");
 
@@ -998,9 +1178,6 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
        if (!enter_repo(dir, 0))
                die("'%s' does not appear to be a git repository", dir);
 
-       if (is_repository_shallow())
-               die("attempt to push into a shallow repository");
-
        git_config(receive_pack_config, NULL);
 
        if (0 <= transfer_unpack_limit)
@@ -1014,12 +1191,17 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
        if (advertise_refs)
                return 0;
 
-       if ((commands = read_head_info()) != NULL) {
+       if ((commands = read_head_info(&shallow)) != NULL) {
                const char *unpack_status = NULL;
 
-               if (!delete_only(commands))
-                       unpack_status = unpack_with_sideband();
-               execute_commands(commands, unpack_status);
+               prepare_shallow_info(&si, &shallow);
+               if (!si.nr_ours && !si.nr_theirs)
+                       shallow_update = 0;
+               if (!delete_only(commands)) {
+                       unpack_status = unpack_with_sideband(&si);
+                       update_shallow_info(commands, &si, &ref);
+               }
+               execute_commands(commands, unpack_status, &si);
                if (pack_lockfile)
                        unlink_or_warn(pack_lockfile);
                if (report_status)
@@ -1035,8 +1217,11 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix)
                }
                if (auto_update_server_info)
                        update_server_info(0);
+               clear_shallow_info(&si);
        }
        if (use_sideband)
                packet_flush(1);
+       sha1_array_clear(&shallow);
+       sha1_array_clear(&ref);
        return 0;
 }