src/fetch.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7
   8 #include "git2/oid.h"
   9 #include "git2/refs.h"
  10 #include "git2/revwalk.h"
  11 #include "git2/transport.h"
  12
  13 #include "common.h"
  14 #include "remote.h"
  15 #include "refspec.h"
  16 #include "pack.h"
  17 #include "fetch.h"
  18 #include "netops.h"
  19 #include "repository.h"
  20 #include "refs.h"
  21
  22 static int maybe_want(git_remote *remote, git_remote_head *head, git_odb *odb, git_refspec *tagspec)
  23 {
  24         int match = 0;
  25
  26         if (!git_reference_is_valid_name(head->name))
  27                 return 0;
  28
  29         if (remote->download_tags == GIT_REMOTE_DOWNLOAD_TAGS_ALL) {
  30                 /*
  31                  * If tagopt is --tags, then we only use the default
  32                  * tags refspec and ignore the remote's
  33                  */
  34                 if (git_refspec_src_matches(tagspec, head->name))
  35                         match = 1;
  36                 else
  37                         return 0;
  38         } else if (git_remote__matching_refspec(remote, head->name))
  39                         match = 1;
  40
  41         if (!match)
  42                 return 0;
  43
  44         /* If we have the object, mark it so we don't ask for it */
  45         if (git_odb_exists(odb, &head->oid))
  46                 head->local = 1;
  47         else
  48                 remote->need_pack = 1;
  49
  50         return git_vector_insert(&remote->refs, head);
  51 }
  52
  53 static int filter_wants(git_remote *remote)
  54 {
  55         git_remote_head **heads;
  56         git_refspec tagspec, head;
  57         int error = 0;
  58         git_odb *odb;
  59         size_t i, heads_len;
  60
  61         git_vector_clear(&remote->refs);
  62         if ((error = git_refspec__parse(&tagspec, GIT_REFSPEC_TAGS, true)) < 0)
  63                 return error;
  64
  65         /*
  66          * The fetch refspec can be NULL, and what this means is that the
  67          * user didn't specify one. This is fine, as it means that we're
  68          * not interested in any particular branch but just the remote's
  69          * HEAD, which will be stored in FETCH_HEAD after the fetch.
  70          */
  71         if (remote->active_refspecs.length == 0) {
  72                 if ((error = git_refspec__parse(&head, "HEAD", true)) < 0)
  73                         goto cleanup;
  74
  75                 error = git_refspec__dwim_one(&remote->active_refspecs, &head, &remote->refs);
  76                 git_refspec__free(&head);
  77
  78                 if (error < 0)
  79                         goto cleanup;
  80         }
  81
  82         if (git_repository_odb__weakptr(&odb, remote->repo) < 0)
  83                 goto cleanup;
  84
  85         if (git_remote_ls((const git_remote_head ***)&heads, &heads_len, remote) < 0)
  86                 goto cleanup;
  87
  88         for (i = 0; i < heads_len; i++) {
  89                 if ((error = maybe_want(remote, heads[i], odb, &tagspec)) < 0)
  90                         break;
  91         }
  92
  93 cleanup:
  94         git_refspec__free(&tagspec);
  95
  96         return error;
  97 }
  98
  99 /*
 100  * In this first version, we push all our refs in and start sending
 101  * them out. When we get an ACK we hide that commit and continue
 102  * traversing until we're done
 103  */
 104 int git_fetch_negotiate(git_remote *remote)
 105 {
 106         git_transport *t = remote->transport;
 107
 108         if (filter_wants(remote) < 0) {
 109                 giterr_set(GITERR_NET, "Failed to filter the reference list for wants");
 110                 return -1;
 111         }
 112
 113         /* Don't try to negotiate when we don't want anything */
 114         if (!remote->need_pack)
 115                 return 0;
 116
 117         /*
 118          * Now we have everything set up so we can start tell the
 119          * server what we want and what we have.
 120          */
 121         return t->negotiate_fetch(t,
 122                 remote->repo,
 123                 (const git_remote_head * const *)remote->refs.contents,
 124                 remote->refs.length);
 125 }
 126
 127 int git_fetch_download_pack(git_remote *remote)
 128 {
 129         git_transport *t = remote->transport;
 130
 131         if (!remote->need_pack)
 132                 return 0;
 133
 134         return t->download_pack(t, remote->repo, &remote->stats,
 135                         remote->callbacks.transfer_progress, remote->callbacks.payload);
 136 }