/*
* libgit2 "checkout" example - shows how to perform checkouts
*
* Written by the libgit2 contributors
*
* To the extent possible under law, the author(s) have dedicated all copyright
* and related and neighboring rights to this software to the public domain
* worldwide. This software is distributed without any warranty.
*
* You should have received a copy of the CC0 Public Domain Dedication along
* with this software. If not, see
* <http://creativecommons.org/publicdomain/zero/1.0/>.
*/
#include "common.h"
/* Define the printf format specifier to use for size_t output */
#if defined(_MSC_VER) || defined(__MINGW32__)
# define PRIuZ "Iu"
# define PRIxZ "Ix"
# define PRIdZ "Id"
#else
# define PRIuZ "zu"
# define PRIxZ "zx"
# define PRIdZ "zd"
#endif
/**
* The following example demonstrates how to do checkouts with libgit2.
*
* Recognized options are :
* --force: force the checkout to happen.
* --[no-]progress: show checkout progress, on by default.
* --perf: show performance data.
*/
typedef struct {
int force : 1;
int progress : 1;
int perf : 1;
} checkout_options;
static void print_usage(void)
{
fprintf(stderr, "usage: checkout [options] <branch>\n"
"Options are :\n"
" --git-dir: use the following git repository.\n"
" --force: force the checkout.\n"
" --[no-]progress: show checkout progress.\n"
" --perf: show performance data.\n");
exit(1);
}
static void parse_options(const char **repo_path, checkout_options *opts, struct args_info *args)
{
if (args->argc <= 1)
print_usage();
memset(opts, 0, sizeof(*opts));
/* Default values */
opts->progress = 1;
for (args->pos = 1; args->pos < args->argc; ++args->pos) {
const char *curr = args->argv[args->pos];
int bool_arg;
if (match_arg_separator(args)) {
break;
} else if (!strcmp(curr, "--force")) {
opts->force = 1;
} else if (match_bool_arg(&bool_arg, args, "--progress")) {
opts->progress = bool_arg;
} else if (match_bool_arg(&bool_arg, args, "--perf")) {
opts->perf = bool_arg;
} else if (match_str_arg(repo_path, args, "--git-dir")) {
continue;
} else {
break;
}
}
}
/**
* This function is called to report progression, ie. it's called once with
* a NULL path and the number of total steps, then for each subsequent path,
* the current completed_step value.
*/
static void print_checkout_progress(const char *path, size_t completed_steps, size_t total_steps, void *payload)
{
(void)payload;
if (path == NULL) {
printf("checkout started: %" PRIuZ " steps\n", total_steps);
} else {
printf("checkout: %s %" PRIuZ "/%" PRIuZ "\n", path, completed_steps, total_steps);
}
}
/**
* This function is called when the checkout completes, and is used to report the
* number of syscalls performed.
*/
static void print_perf_data(const git_checkout_perfdata *perfdata, void *payload)
{
(void)payload;
printf("perf: stat: %" PRIuZ " mkdir: %" PRIuZ " chmod: %" PRIuZ "\n",
perfdata->stat_calls, perfdata->mkdir_calls, perfdata->chmod_calls);
}
/**
* This is the main "checkout <branch>" function, responsible for performing
* a branch-based checkout.
*/
static int perform_checkout_ref(git_repository *repo, git_annotated_commit *target, const char *target_ref, checkout_options *opts)
{
git_checkout_options checkout_opts = GIT_CHECKOUT_OPTIONS_INIT;
git_reference *ref = NULL, *branch = NULL;
git_commit *target_commit = NULL;
int err;
/** Setup our checkout options from the parsed options */
checkout_opts.checkout_strategy = GIT_CHECKOUT_SAFE;
if (opts->force)
checkout_opts.checkout_strategy = GIT_CHECKOUT_FORCE;
if (opts->progress)
checkout_opts.progress_cb = print_checkout_progress;
if (opts->perf)
checkout_opts.perfdata_cb = print_perf_data;
/** Grab the commit we're interested to move to */
err = git_commit_lookup(&target_commit, repo, git_annotated_commit_id(target));
if (err != 0) {
fprintf(stderr, "failed to lookup commit: %s\n", git_error_last()->message);
goto cleanup;
}
/**
* Perform the checkout so the workdir corresponds to what target_commit
* contains.
*
* Note that it's okay to pass a git_commit here, because it will be
* peeled to a tree.
*/
err = git_checkout_tree(repo, (const git_object *)target_commit, &checkout_opts);
if (err != 0) {
fprintf(stderr, "failed to checkout tree: %s\n", git_error_last()->message);
goto cleanup;
}
/**
* Now that the checkout has completed, we have to update HEAD.
*
* Depending on the "origin" of target (ie. it's an OID or a branch name),
* we might need to detach HEAD.
*/
if (git_annotated_commit_ref(target)) {
const char *target_head;
if ((err = git_reference_lookup(&ref, repo, git_annotated_commit_ref(target))) < 0)
goto error;
if (git_reference_is_remote(ref)) {
if ((err = git_branch_create_from_annotated(&branch, repo, target_ref, target, 0)) < 0)
goto error;
target_head = git_reference_name(branch);
} else {
target_head = git_annotated_commit_ref(target);
}
err = git_repository_set_head(repo, target_head);
} else {
err = git_repository_set_head_detached_from_annotated(repo, target);
}
error:
if (err != 0) {
fprintf(stderr, "failed to update HEAD reference: %s\n", git_error_last()->message);
goto cleanup;
}
cleanup:
git_commit_free(target_commit);
git_reference_free(branch);
git_reference_free(ref);
return err;
}
/**
* This corresponds to `git switch --guess`: if a given ref does
* not exist, git will by default try to guess the reference by
* seeing whether any remote has a branch called <ref>. If there
* is a single remote only that has it, then it is assumed to be
* the desired reference and a local branch is created for it.
*
* The following is a simplified implementation. It will not try
* to check whether the ref is unique across all remotes.
*/
static int guess_refish(git_annotated_commit **out, git_repository *repo, const char *ref)
{
git_strarray remotes = { NULL, 0 };
git_reference *remote_ref = NULL;
int error;
size_t i;
if ((error = git_remote_list(&remotes, repo)) < 0)
goto out;
for (i = 0; i < remotes.count; i++) {
char *refname = NULL;
size_t reflen;
reflen = snprintf(refname, 0, "refs/remotes/%s/%s", remotes.strings[i], ref);
if ((refname = malloc(reflen + 1)) == NULL) {
error = -1;
goto next;
}
snprintf(refname, reflen + 1, "refs/remotes/%s/%s", remotes.strings[i], ref);
if ((error = git_reference_lookup(&remote_ref, repo, refname)) < 0)
goto next;
break;
next:
free(refname);
if (error < 0 && error != GIT_ENOTFOUND)
break;
}
if (!remote_ref) {
error = GIT_ENOTFOUND;
goto out;
}
if ((error = git_annotated_commit_from_ref(out, repo, remote_ref)) < 0)
goto out;
out:
git_reference_free(remote_ref);
git_strarray_dispose(&remotes);
return error;
}
/** That example's entry point */
int lg2_checkout(git_repository *repo, int argc, char **argv)
{
struct args_info args = ARGS_INFO_INIT;
checkout_options opts;
git_repository_state_t state;
git_annotated_commit *checkout_target = NULL;
int err = 0;
const char *path = ".";
/** Parse our command line options */
parse_options(&path, &opts, &args);
/** Make sure we're not about to checkout while something else is going on */
state = git_repository_state(repo);
if (state != GIT_REPOSITORY_STATE_NONE) {
fprintf(stderr, "repository is in unexpected state %d\n", state);
goto cleanup;
}
if (match_arg_separator(&args)) {
/**
* Try to checkout the given path
*/
fprintf(stderr, "unhandled path-based checkout\n");
err = 1;
goto cleanup;
} else {
/**
* Try to resolve a "refish" argument to a target libgit2 can use
*/
if ((err = resolve_refish(&checkout_target, repo, args.argv[args.pos])) < 0 &&
(err = guess_refish(&checkout_target, repo, args.argv[args.pos])) < 0) {
fprintf(stderr, "failed to resolve %s: %s\n", args.argv[args.pos], git_error_last()->message);
goto cleanup;
}
err = perform_checkout_ref(repo, checkout_target, args.argv[args.pos], &opts);
}
cleanup:
git_annotated_commit_free(checkout_target);
return err;
}
