cg-clone

   1 #!/usr/bin/env bash
   2 #
   3 # Clone a remote repository
   4 # Copyright (c) Petr Baudis, 2005
   5 #
   6 # This clones a remote GIT repository and checks it out locally.
   7 #
   8 # Takes a parameter specifying the location of the source repository and an
   9 # optional second parameter specifying the destination. If the second
  10 # parameter is omitted, the basename of the source repository is used as the
  11 # destination.
  12 #
  13 # For detailed description of the location of the source repository format
  14 # (available protocols, specifying different remote branch, etc) please see
  15 # the `cg-branch-add` documentation.
  16 #
  17 # OPTIONS
  18 # -------
  19 # -b::  Create a bare repository - do not check out working copy
  20 #       Create only the bare repository, without a working copy attached;
  21 #       this is useful e.g. for public repository mirrors. `cg-clone`
  22 #       is to `cg-init` as `cg-clone -b` is to `cg-admin-setuprepo`.
  23 #       (Still, if you are setting up a public or a central repository
  24 #       other people will push into, it might be more practical to just
  25 #       `cg-admin-setuprepo` it and then populate it with `cg-push`
  26 #       from the other side.)
  27 #
  28 # -l::  "Borrow" the object database when cloning locally
  29 #       Instead of hardlinking all the objects, set up an "alternate"
  30 #       record pointing at the source object database; this will cause
  31 #       any objects not found locally to be looked up remotely, which
  32 #       effectively eliminates the need to copy/hardlink the objects
  33 #       around. This is suitable for very fast cloning of arbitrarily
  34 #       big repositories, but your repository will become largely useless
  35 #       if the source repository disappears or gets damaged (note that
  36 #       it is generally BAD IDEA to prune the original repository if any
  37 #       repository is borrowing objects from it).  The choice is yours.
  38 #
  39 # --reference PATH:: "Borrow" the object database from a third-party source
  40 #       This does the same thing as '-l' but instead of borrowing the
  41 #       objects from the source repository, it borrows them from yet
  42 #       another local repository. E.g. if you have Linus' kernel repository
  43 #       cloned locally and now want to clone akpm's repository, you can
  44 #       do something like
  45 #
  46 #               cg-clone --reference /path/to/linus/repo git://kernel.org/akpm/repo
  47 #
  48 #       and it will download and keep only the objects that are really
  49 #       missing. Same considerations and warnings on the third-party source
  50 #       as in the case of '-l' apply. Also, you can reference only local
  51 #       repositories.
  52 #
  53 # -s::  Clone into the current directory
  54 #       Clone in the current directory instead of creating a new one.
  55 #       Specifying both -s and a destination directory makes no sense.
  56 #
  57 # NOTES
  58 # -----
  59 # If the clone has been interrupted for any reason, do not panic, calmly
  60 # cd to the destination directory and run `cg-fetch`, which will in this case
  61 # restart the initial clone. Chances are that you will not actually download
  62 # any duplicate data. (At the time of writing this, the chances aren't for
  63 # the native git protocol and ssh, but this may change in the future).
  64 #
  65 # EXAMPLE USAGE
  66 # -------------
  67 # If you want to clone the Cogito repository, you can say:
  68 #
  69 #       $ cg-clone http://www.kernel.org/pub/scm/cogito/cogito.git
  70 #
  71 # and it will be cloned to the 'cogito' subdirectory of the current directory.
  72 #
  73 # To clone the 'next' branch of the Git repository, do e.g.:
  74 #
  75 #       $ cg-clone git://git.kernel.org/pub/scm/git/git.git#next
  76
  77 # Testsuite: Checked as part of t-9105-fetch-local but tests for some features
  78 # are missing.
  79
  80 USAGE="cg-clone [-l] [-b] [-s] LOCATION [DESTDIR]"
  81 _git_repo_unneeded=1
  82
  83 . "${COGITO_LIB}"cg-Xlib || exit 1
  84
  85 same_dir=
  86 repoonly=
  87 alternate=
  88 reference=()
  89 while optparse; do
  90         if optparse -l; then
  91                 alternate=1
  92         elif optparse -b; then
  93                 repoonly=1
  94         elif optparse --reference=; then
  95                 reference[${#reference[@]}]="$OPTARG"
  96         elif optparse -s; then
  97                 same_dir=1
  98         else
  99                 optfail
 100         fi
 101 done
 102
 103 location="${ARGS[0]}"
 104
 105 [ -n "$location" ] || usage
 106 location="${location%/}"
 107
 108 destdir="${ARGS[1]}"
 109 if [ "$destdir" ]; then
 110         [ ! "$same_dir" ] || die "specifying both -s and DESTDIR makes no sense"
 111         dir="$destdir"
 112 else
 113         dir="${location%#*}"; dir="${dir%/.git}"; dir="${dir##*/}"; dir="${dir%.git}"
 114         [ "$repoonly" ] && dir="$dir.git"
 115 fi
 116
 117 if ! echo "$location" | grep -q ":" ; then
 118         location=$(echo "$location" | sed -e "s#^[^/]#$(pwd)\/&#")
 119 else
 120         [ ! "$alternate" ] || die "specifying -l for non-local clone makes no sense"
 121         location="$location"
 122 fi
 123
 124 if [ ! "$same_dir" ]; then
 125         [ -e "$dir" ] && die "$dir/ already exists"
 126         if [ "$repoonly" ]; then
 127                 cg-admin-setuprepo "$dir" || exit $?
 128         else
 129                 mkdir -p "$dir" || exit $?
 130         fi
 131         cd "$dir" || exit $?
 132 else
 133         dir=.
 134 fi
 135
 136 if [ "$repoonly" ]; then
 137         _git=.
 138         export GIT_DIR=.
 139         _git_no_wc=1
 140 fi
 141
 142
 143 cleanup ()
 144 {
 145         if [ -s "$_git/info/cg-fetch-earlydie" ] && [ ! "$same_dir" ]; then
 146                 cd ..
 147                 rm -rf "$dir"
 148         fi
 149 }
 150
 151 cleanup_trap "cleanup"
 152
 153
 154 if [ ! "$repoonly" ]; then
 155         cg-init -I || die "init failed"
 156 fi
 157 echo $$ >"$_git/info/cg-fetch-earlydie"
 158
 159 repoloc="$location"
 160 [ ! -d "$repoloc/.git/objects" ] || repoloc="$repoloc/.git"
 161 [ "$alternate" ] && echo "$repoloc/objects" >> "$_git/objects/info/alternates"
 162 for ref in "${reference[@]}"; do
 163         relpath=
 164         [ "${ref#/}" != "$ref" ] || relpath=1
 165         # Relative path; reference is relative to the object repository; we
 166         # need to add one .. for objects, another .. for .git/, another .. for
 167         # projdir unless ! same_Dir
 168
 169         if [ ! "$same_dir" ] && [ "$relpath" ]; then
 170                 # Relative path, account for project subdir
 171                 ref="../$ref"
 172         fi
 173
 174         [ -d "$ref" ] || die "referenced repository $ref not found"
 175         [ ! -d "$ref/.git/objects" ] || ref="$ref/.git"
 176         [ -d "$ref/objects" ] || die "reference $ref not a git repository"
 177         [ ! "$relpath" ] || ref="../../$ref"
 178         echo "$ref/objects" >>"$_git/objects/info/alternates"
 179 done
 180
 181 cg-branch-add origin "$location"
 182
 183 mkdir -p "$_git/info"
 184 [ "$repoonly" ] && echo $$ >"$_git/info/cg-fetch-initial-wcless"
 185 echo $$ >"$_git/info/cg-fetch-initial"
 186 cat >___ <<__EOT__
 187 This is a clone-in-progress GIT working tree containing a GIT repository
 188 in the .git subdirectory. If you see this file and noone is fetching or
 189 cloning in this repository, the clone has been interrupted; you can restart
 190 it by issuing this command (it's enough as-is):
 191
 192         cg-fetch
 193 __EOT__
 194 cg-fetch origin || { cleanup; exit 1; }
 195
 196 echo "Cloned to $dir/ (origin $location available as branch \"origin\")"