sparse-checkout: create 'init' subcommand

Getting started with a sparse-checkout file can be daunting. Help
users start their sparse enlistment using 'git sparse-checkout init'.
This will set 'core.sparseCheckout=true' in their config, write
an initial set of patterns to the sparse-checkout file, and update
their working directory.

Make sure to use the `extensions.worktreeConfig` setting and write
the sparse checkout config to the worktree-specific config file.
This avoids confusing interactions with other worktrees.

The use of running another process for 'git read-tree' is sub-
optimal. This will be removed in a later change.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-sparse-checkout.txt b/Documentation/git-sparse-checkout.txt
index 87ffcbbcb0f3cd132a557fa349ddd9753f50dd10..491be1345fa04b626bb63bf649505b69fc10e2e7 100644 (file)
--- a/Documentation/git-sparse-checkout.txt
+++ b/Documentation/git-sparse-checkout.txt
@@ -30,6 +30,17 @@ COMMANDS
 'list'::
        Provide a list of the contents in the sparse-checkout file.
 
+'init'::
+       Enable the `core.sparseCheckout` setting. If the
+       sparse-checkout file does not exist, then populate it with
+       patterns that match every file in the root directory and
+       no other directories, then will remove all directories tracked
+       by Git. Add patterns to the sparse-checkout file to
+       repopulate the working directory.
++
+To avoid interfering with other worktrees, it first enables the
+`extensions.worktreeConfig` setting and makes sure to set the
+`core.sparseCheckout` setting in the worktree-specific config file.
 
 SPARSE CHECKOUT
 ---------------

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index 5717c9b2cb30c06d880de3d4e7588ee2c4f1cd82..fcf97e9df8ec0d314d84a8f1166e87f06d5d0ce2 100644 (file)
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -8,7 +8,7 @@
 #include "strbuf.h"
 
 static char const * const builtin_sparse_checkout_usage[] = {
-       N_("git sparse-checkout list"),
+       N_("git sparse-checkout (init|list)"),
        NULL
 };
 
@@ -59,6 +59,77 @@ static int sparse_checkout_list(int argc, const char **argv)
        return 0;
 }
 
+static int update_working_directory(void)
+{
+       struct argv_array argv = ARGV_ARRAY_INIT;
+       int result = 0;
+       argv_array_pushl(&argv, "read-tree", "-m", "-u", "HEAD", NULL);
+
+       if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
+               error(_("failed to update index with new sparse-checkout paths"));
+               result = 1;
+       }
+
+       argv_array_clear(&argv);
+       return result;
+}
+
+enum sparse_checkout_mode {
+       MODE_NO_PATTERNS = 0,
+       MODE_ALL_PATTERNS = 1,
+};
+
+static int set_config(enum sparse_checkout_mode mode)
+{
+       const char *config_path;
+
+       if (git_config_set_gently("extensions.worktreeConfig", "true")) {
+               error(_("failed to set extensions.worktreeConfig setting"));
+               return 1;
+       }
+
+       config_path = git_path("config.worktree");
+       git_config_set_in_file_gently(config_path,
+                                     "core.sparseCheckout",
+                                     mode ? "true" : NULL);
+
+       return 0;
+}
+
+static int sparse_checkout_init(int argc, const char **argv)
+{
+       struct pattern_list pl;
+       char *sparse_filename;
+       FILE *fp;
+       int res;
+
+       if (set_config(MODE_ALL_PATTERNS))
+               return 1;
+
+       memset(&pl, 0, sizeof(pl));
+
+       sparse_filename = get_sparse_checkout_filename();
+       res = add_patterns_from_file_to_list(sparse_filename, "", 0, &pl, NULL);
+
+       /* If we already have a sparse-checkout file, use it. */
+       if (res >= 0) {
+               free(sparse_filename);
+               goto reset_dir;
+       }
+
+       /* initial mode: all blobs at root */
+       fp = xfopen(sparse_filename, "w");
+       if (!fp)
+               die(_("failed to open '%s'"), sparse_filename);
+
+       free(sparse_filename);
+       fprintf(fp, "/*\n!/*/\n");
+       fclose(fp);
+
+reset_dir:
+       return update_working_directory();
+}
+
 int cmd_sparse_checkout(int argc, const char **argv, const char *prefix)
 {
        static struct option builtin_sparse_checkout_options[] = {
@@ -79,6 +150,8 @@ int cmd_sparse_checkout(int argc, const char **argv, const char *prefix)
        if (argc > 0) {
                if (!strcmp(argv[0], "list"))
                        return sparse_checkout_list(argc, argv);
+               if (!strcmp(argv[0], "init"))
+                       return sparse_checkout_init(argc, argv);
        }
 
        usage_with_options(builtin_sparse_checkout_usage,

diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index 9b73d449071daea7e1a4a1e2e06cbe40909383bf..21143c529c698fea641e26e9bfd4313fed278ded 100755 (executable)
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -42,4 +42,44 @@ test_expect_success 'git sparse-checkout list (populated)' '
        test_cmp expect list
 '
 
+test_expect_success 'git sparse-checkout init' '
+       git -C repo sparse-checkout init &&
+       cat >expect <<-EOF &&
+               /*
+               !/*/
+       EOF
+       test_cmp expect repo/.git/info/sparse-checkout &&
+       test_cmp_config -C repo true core.sparsecheckout &&
+       ls repo >dir  &&
+       echo a >expect &&
+       test_cmp expect dir
+'
+
+test_expect_success 'git sparse-checkout list after init' '
+       git -C repo sparse-checkout list >actual &&
+       cat >expect <<-EOF &&
+               /*
+               !/*/
+       EOF
+       test_cmp expect actual
+'
+
+test_expect_success 'init with existing sparse-checkout' '
+       echo "*folder*" >> repo/.git/info/sparse-checkout &&
+       git -C repo sparse-checkout init &&
+       cat >expect <<-EOF &&
+               /*
+               !/*/
+               *folder*
+       EOF
+       test_cmp expect repo/.git/info/sparse-checkout &&
+       ls repo >dir  &&
+       cat >expect <<-EOF &&
+               a
+               folder1
+               folder2
+       EOF
+       test_cmp expect dir
+'
+
 test_done