ls-refs.c

   1 #include "git-compat-util.h"
   2 #include "environment.h"
   3 #include "gettext.h"
   4 #include "hash.h"
   5 #include "hex.h"
   6 #include "repository.h"
   7 #include "refs.h"
   8 #include "strvec.h"
   9 #include "ls-refs.h"
  10 #include "pkt-line.h"
  11 #include "config.h"
  12 #include "string-list.h"
  13
  14 static enum {
  15         UNBORN_IGNORE = 0,
  16         UNBORN_ALLOW,
  17         UNBORN_ADVERTISE /* implies ALLOW */
  18 } unborn_config(struct repository *r)
  19 {
  20         const char *str = NULL;
  21
  22         if (repo_config_get_string_tmp(r, "lsrefs.unborn", &str)) {
  23                 /*
  24                  * If there is no such config, advertise and allow it by
  25                  * default.
  26                  */
  27                 return UNBORN_ADVERTISE;
  28         } else {
  29                 if (!strcmp(str, "advertise")) {
  30                         return UNBORN_ADVERTISE;
  31                 } else if (!strcmp(str, "allow")) {
  32                         return UNBORN_ALLOW;
  33                 } else if (!strcmp(str, "ignore")) {
  34                         return UNBORN_IGNORE;
  35                 } else {
  36                         die(_("invalid value for '%s': '%s'"),
  37                             "lsrefs.unborn", str);
  38                 }
  39         }
  40 }
  41
  42 /*
  43  * If we see this many or more "ref-prefix" lines from the client, we consider
  44  * it "too many" and will avoid using the prefix feature entirely.
  45  */
  46 #define TOO_MANY_PREFIXES 65536
  47
  48 /*
  49  * Check if one of the prefixes is a prefix of the ref.
  50  * If no prefixes were provided, all refs match.
  51  */
  52 static int ref_match(const struct strvec *prefixes, const char *refname)
  53 {
  54         int i;
  55
  56         if (!prefixes->nr)
  57                 return 1; /* no restriction */
  58
  59         for (i = 0; i < prefixes->nr; i++) {
  60                 const char *prefix = prefixes->v[i];
  61
  62                 if (starts_with(refname, prefix))
  63                         return 1;
  64         }
  65
  66         return 0;
  67 }
  68
  69 struct ls_refs_data {
  70         unsigned peel;
  71         unsigned symrefs;
  72         struct strvec prefixes;
  73         struct strbuf buf;
  74         struct strvec hidden_refs;
  75         unsigned unborn : 1;
  76 };
  77
  78 static int send_ref(const char *refname, const struct object_id *oid,
  79                     int flag, void *cb_data)
  80 {
  81         struct ls_refs_data *data = cb_data;
  82         const char *refname_nons = strip_namespace(refname);
  83
  84         strbuf_reset(&data->buf);
  85
  86         if (ref_is_hidden(refname_nons, refname, &data->hidden_refs))
  87                 return 0;
  88
  89         if (!ref_match(&data->prefixes, refname_nons))
  90                 return 0;
  91
  92         if (oid)
  93                 strbuf_addf(&data->buf, "%s %s", oid_to_hex(oid), refname_nons);
  94         else
  95                 strbuf_addf(&data->buf, "unborn %s", refname_nons);
  96         if (data->symrefs && flag & REF_ISSYMREF) {
  97                 struct object_id unused;
  98                 const char *symref_target = refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
  99                                                                     refname,
 100                                                                     0,
 101                                                                     &unused,
 102                                                                     &flag);
 103
 104                 if (!symref_target)
 105                         die("'%s' is a symref but it is not?", refname);
 106
 107                 strbuf_addf(&data->buf, " symref-target:%s",
 108                             strip_namespace(symref_target));
 109         }
 110
 111         if (data->peel && oid) {
 112                 struct object_id peeled;
 113                 if (!peel_iterated_oid(oid, &peeled))
 114                         strbuf_addf(&data->buf, " peeled:%s", oid_to_hex(&peeled));
 115         }
 116
 117         strbuf_addch(&data->buf, '\n');
 118         packet_fwrite(stdout, data->buf.buf, data->buf.len);
 119
 120         return 0;
 121 }
 122
 123 static void send_possibly_unborn_head(struct ls_refs_data *data)
 124 {
 125         struct strbuf namespaced = STRBUF_INIT;
 126         struct object_id oid;
 127         int flag;
 128         int oid_is_null;
 129
 130         strbuf_addf(&namespaced, "%sHEAD", get_git_namespace());
 131         if (!refs_resolve_ref_unsafe(get_main_ref_store(the_repository), namespaced.buf, 0, &oid, &flag))
 132                 return; /* bad ref */
 133         oid_is_null = is_null_oid(&oid);
 134         if (!oid_is_null ||
 135             (data->unborn && data->symrefs && (flag & REF_ISSYMREF)))
 136                 send_ref(namespaced.buf, oid_is_null ? NULL : &oid, flag, data);
 137         strbuf_release(&namespaced);
 138 }
 139
 140 static int ls_refs_config(const char *var, const char *value,
 141                           const struct config_context *ctx UNUSED,
 142                           void *cb_data)
 143 {
 144         struct ls_refs_data *data = cb_data;
 145         /*
 146          * We only serve fetches over v2 for now, so respect only "uploadpack"
 147          * config. This may need to eventually be expanded to "receive", but we
 148          * don't yet know how that information will be passed to ls-refs.
 149          */
 150         return parse_hide_refs_config(var, value, "uploadpack", &data->hidden_refs);
 151 }
 152
 153 int ls_refs(struct repository *r, struct packet_reader *request)
 154 {
 155         struct ls_refs_data data;
 156
 157         memset(&data, 0, sizeof(data));
 158         strvec_init(&data.prefixes);
 159         strbuf_init(&data.buf, 0);
 160         strvec_init(&data.hidden_refs);
 161
 162         git_config(ls_refs_config, &data);
 163
 164         while (packet_reader_read(request) == PACKET_READ_NORMAL) {
 165                 const char *arg = request->line;
 166                 const char *out;
 167
 168                 if (!strcmp("peel", arg))
 169                         data.peel = 1;
 170                 else if (!strcmp("symrefs", arg))
 171                         data.symrefs = 1;
 172                 else if (skip_prefix(arg, "ref-prefix ", &out)) {
 173                         if (data.prefixes.nr < TOO_MANY_PREFIXES)
 174                                 strvec_push(&data.prefixes, out);
 175                 }
 176                 else if (!strcmp("unborn", arg))
 177                         data.unborn = !!unborn_config(r);
 178                 else
 179                         die(_("unexpected line: '%s'"), arg);
 180         }
 181
 182         if (request->status != PACKET_READ_FLUSH)
 183                 die(_("expected flush after ls-refs arguments"));
 184
 185         /*
 186          * If we saw too many prefixes, we must avoid using them at all; as
 187          * soon as we have any prefix, they are meant to form a comprehensive
 188          * list.
 189          */
 190         if (data.prefixes.nr >= TOO_MANY_PREFIXES)
 191                 strvec_clear(&data.prefixes);
 192
 193         send_possibly_unborn_head(&data);
 194         if (!data.prefixes.nr)
 195                 strvec_push(&data.prefixes, "");
 196         refs_for_each_fullref_in_prefixes(get_main_ref_store(r),
 197                                           get_git_namespace(), data.prefixes.v,
 198                                           hidden_refs_to_excludes(&data.hidden_refs),
 199                                           send_ref, &data);
 200         packet_fflush(stdout);
 201         strvec_clear(&data.prefixes);
 202         strbuf_release(&data.buf);
 203         strvec_clear(&data.hidden_refs);
 204         return 0;
 205 }
 206
 207 int ls_refs_advertise(struct repository *r, struct strbuf *value)
 208 {
 209         if (value && unborn_config(r) == UNBORN_ADVERTISE)
 210                 strbuf_addstr(value, "unborn");
 211
 212         return 1;
 213 }