ls-refs.c

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