git-push-clone

1 files changed, 148 insertions, 0 deletions

diff --git a/dot/local/bin/git-push-clone b/dot/local/bin/git-push-clone
new file mode 100755
index 0000000..06d045e
--- /dev/null
+++ b/dot/local/bin/git-push-clone
@@ -0,0 +1,148 @@
+#!/bin/sh
+set -e
+
+usage()
+{
+    cat <<EOF
+Usage:
+    $0 [git-push options] <destination> [refspec]
+EOF
+}
+
+die() { printf "Error: %s\n" "$*" >&2; exit 1; }
+
+loudly() { (set -x; "$@"); }
+
+quietly() { "$@" >/dev/null 2>&1; }
+
+bad_usage()
+{
+    usage >&2
+    exit 1
+}
+
+check_existence()
+{
+    (set +e;
+     quietly rsync "$rsync_dest"
+     case $? in
+         23) return 0;;
+         0) die "Destination already exists: '$rsync_dest'";;
+         *) die "rsync returned $? when checking for destination existence.";;
+     esac) || [ "$NO_ACT" ] || exit
+}
+
+git_init_push_checkout()
+{
+    TEMP_DIR=$(mktemp -d)
+    trap 'rm -rf "$TEMP_DIR"' EXIT
+    git init --bare "$TEMP_DIR"/.git
+    loudly git push "$TEMP_DIR" "$@"
+
+    if [ "$CHECKOUT_BRANCH" -a ! "$BARE" ]; then
+        (cd "$TEMP_DIR";
+        git config --unset core.bare
+        git checkout "$CHECKOUT_BRANCH")
+    fi
+}
+
+go()
+{
+    check_existence
+    git_init_push_checkout "$@"
+}
+
+# What we want to do is push a branch, and then checkout the branch we just
+# pushed. Determining the branch to checkout requires parsing the branch out of
+# the git push args in $@
+
+check_source_ref()
+{
+    local src="$1"
+    git rev-parse --verify --quiet "$src^{commit}" >/dev/null
+}
+
+pop=$(cat <<'EOF'
+i=$#;
+while [ $i -gt 0 ]; do
+    lastarg=$1;
+    shift;
+    i=$((i - 1))
+    if [ $i -eq 0 ]; then
+        break;
+    else
+        set -- "$@" "$lastarg";
+    fi
+done
+EOF
+)
+
+parse_target()
+{
+    case "$1" in
+        ssh://*) rsync_dest=${1#ssh://} ;;
+        *:*) rsync_dest=$1 ;;
+        *) die "Unrecognized git URL: '$1'" ;;
+    esac
+    target=$1
+
+    case "$target" in
+        *[^/].git) BARE=y ;;
+        *) BARE= ;;
+    esac
+}
+
+parse_refspec()
+{
+    local refspec="$1"
+    case "$refspec" in
+        *:*:*) die "expected <local-ref>:<remote-ref> but got too many colons" ;;
+        ?*:?*)
+            check_source_ref "${1%:*}" || die "invalid source ref: $src"
+            CHECKOUT_BRANCH=${1#*:}
+            ;;
+        *) if check_source_ref "$1"; then CHECKOUT_BRANCH=$1; fi;;
+    esac
+}
+
+current_branch() { git status -bs|sed -ne 's/^## //p'; }
+
+REFSPEC_UNNEEDED=
+option_count=0
+for arg in "$@"; do
+    case "$arg" in
+        -h|--help|--usage) usage; exit;;
+        --all|--mirror|--tags) REFSPEC_UNNEEDED=y;;
+        --) option_count=$((option_count+1)); break;;
+        -*) ;;
+        *) break;;
+    esac
+    option_count=$((option_count+1))
+done
+arg_count=$(($# - option_count))
+
+case $arg_count in
+    1)
+        eval "$pop"
+        parse_target "$lastarg"
+        b=$(current_branch)
+        parse_refspec "$b:$b"
+        if ! [ "$REFSPEC_UNNEEDED" ]; then
+            set -- "$@" "$b"
+        fi
+        ;;
+    2)
+        eval "$pop"
+        refspec=$lastarg
+        parse_refspec "$refspec"
+        eval "$pop"
+        parse_target "$lastarg"
+        set -- "$@" "$refspec"
+       ;;
+    *) bad_usage;;
+esac
+
+go "$@"
+
+loudly rsync ${NO_ACT:+-n} -zrlp --info=stats1 "$TEMP_DIR"/"${BARE:+.git/}" "$rsync_dest"/
+