thodg/libgit2/src/clone.c

• Show log

  Commit

• Hash : 25e0b157
  Author :
  Date : 2013-12-06T15:07:57
  

  Remove converting user error to GIT_EUSER This changes the behavior of callbacks so that the callback error code is not converted into GIT_EUSER and instead we propagate the return value through to the caller. Instead of using the giterr_capture and giterr_restore functions, we now rely on all functions to pass back the return value from a callback. To avoid having a return value with no error message, the user can call the public giterr_set_str or some such function to set an error message. There is a new helper 'giterr_set_callback' that functions can invoke after making a callback which ensures that some error message was set in case the callback did not set one. In places where the sign of the callback return value is meaningful (e.g. positive to skip, negative to abort), only the negative values are returned back to the caller, obviously, since the other values allow for continuing the loop. The hardest parts of this were in the checkout code where positive return values were overloaded as meaningful values for checkout. I fixed this by adding an output parameter to many of the internal checkout functions and removing the overload. This added some code, but it is probably a better implementation. There is some funkiness in the network code where user provided callbacks could be returning a positive or a negative value and we want to rely on that to cancel the loop. There are still a couple places where an user error might get turned into GIT_EUSER there, I think, though none exercised by the tests.

Download

• src/clone.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include <assert.h>
  
  #include "git2/clone.h"
  #include "git2/remote.h"
  #include "git2/revparse.h"
  #include "git2/branch.h"
  #include "git2/config.h"
  #include "git2/checkout.h"
  #include "git2/commit.h"
  #include "git2/tree.h"
  
  #include "common.h"
  #include "remote.h"
  #include "fileops.h"
  #include "refs.h"
  #include "path.h"
  #include "repository.h"
  
  static int create_branch(
  	git_reference **branch,
  	git_repository *repo,
  	const git_oid *target,
  	const char *name)
  {
  	git_commit *head_obj = NULL;
  	git_reference *branch_ref = NULL;
  	int error;
  
  	/* Find the target commit */
  	if ((error = git_commit_lookup(&head_obj, repo, target)) < 0)
  		return error;
  
  	/* Create the new branch */
  	error = git_branch_create(&branch_ref, repo, name, head_obj, 0);
  
  	git_commit_free(head_obj);
  
  	if (!error)
  		*branch = branch_ref;
  	else
  		git_reference_free(branch_ref);
  
  	return error;
  }
  
  static int setup_tracking_config(
  	git_repository *repo,
  	const char *branch_name,
  	const char *remote_name,
  	const char *merge_target)
  {
  	git_config *cfg;
  	git_buf remote_key = GIT_BUF_INIT, merge_key = GIT_BUF_INIT;
  	int error = -1;
  
  	if (git_repository_config__weakptr(&cfg, repo) < 0)
  		return -1;
  
  	if (git_buf_printf(&remote_key, "branch.%s.remote", branch_name) < 0)
  		goto cleanup;
  
  	if (git_buf_printf(&merge_key, "branch.%s.merge", branch_name) < 0)
  		goto cleanup;
  
  	if (git_config_set_string(cfg, git_buf_cstr(&remote_key), remote_name) < 0)
  		goto cleanup;
  
  	if (git_config_set_string(cfg, git_buf_cstr(&merge_key), merge_target) < 0)
  		goto cleanup;
  
  	error = 0;
  
  cleanup:
  	git_buf_free(&remote_key);
  	git_buf_free(&merge_key);
  	return error;
  }
  
  static int create_tracking_branch(
  	git_reference **branch,
  	git_repository *repo,
  	const git_oid *target,
  	const char *branch_name)
  {
  	int error;
  
  	if ((error = create_branch(branch, repo, target, branch_name)) < 0)
  		return error;
  
  	return setup_tracking_config(
  		repo,
  		branch_name,
  		GIT_REMOTE_ORIGIN,
  		git_reference_name(*branch));
  }
  
  struct head_info {
  	git_repository *repo;
  	git_oid remote_head_oid;
  	git_buf branchname;
  	const git_refspec *refspec;
  	bool found;
  };
  
  static int reference_matches_remote_head(
  	const char *reference_name,
  	void *payload)
  {
  	struct head_info *head_info = (struct head_info *)payload;
  	git_oid oid;
  	int error;
  
  	/* TODO: Should we guard against references
  	 * which name doesn't start with refs/heads/ ?
  	 */
  
  	error = git_reference_name_to_id(&oid, head_info->repo, reference_name);
  	if (error == GIT_ENOTFOUND) {
  		/* If the reference doesn't exists, it obviously cannot match the
  		 * expected oid. */
  		giterr_clear();
  		return 0;
  	}
  
  	if (!error && !git_oid__cmp(&head_info->remote_head_oid, &oid)) {
  		/* Determine the local reference name from the remote tracking one */
  		error = git_refspec_transform_l(
  			&head_info->branchname, head_info->refspec, reference_name);
  
  		if (!error &&
  			git_buf_len(&head_info->branchname) > 0 &&
  			!(error = git_buf_sets(
  				&head_info->branchname,
  				git_buf_cstr(&head_info->branchname) +
  				strlen(GIT_REFS_HEADS_DIR))))
  		{
  			head_info->found = true;
  			error = GIT_ITEROVER;
  		}
  	}
  
  	return error;
  }
  
  static int update_head_to_new_branch(
  	git_repository *repo,
  	const git_oid *target,
  	const char *name)
  {
  	git_reference *tracking_branch = NULL;
  	int error = create_tracking_branch(&tracking_branch, repo, target, name);
  
  	if (!error)
  		error = git_repository_set_head(
  			repo, git_reference_name(tracking_branch));
  
  	git_reference_free(tracking_branch);
  
  	return error;
  }
  
  static int update_head_to_remote(git_repository *repo, git_remote *remote)
  {
  	int error = 0;
  	size_t refs_len;
  	git_refspec dummy_spec;
  	const git_remote_head *remote_head, **refs;
  	struct head_info head_info;
  	git_buf remote_master_name = GIT_BUF_INIT;
  
  	if ((error = git_remote_ls(&refs, &refs_len, remote)) < 0)
  		return error;
  
  	/* Did we just clone an empty repository? */
  	if (refs_len == 0)
  		return setup_tracking_config(
  			repo, "master", GIT_REMOTE_ORIGIN, GIT_REFS_HEADS_MASTER_FILE);
  
  	/* Get the remote's HEAD. This is always the first ref in the list. */
  	remote_head = refs[0];
  	assert(remote_head);
  
  	memset(&head_info, 0, sizeof(head_info));
  	git_oid_cpy(&head_info.remote_head_oid, &remote_head->oid);
  	head_info.repo = repo;
  	head_info.refspec =
  		git_remote__matching_refspec(remote, GIT_REFS_HEADS_MASTER_FILE);
  
  	if (head_info.refspec == NULL) {
  		memset(&dummy_spec, 0, sizeof(git_refspec));
  		head_info.refspec = &dummy_spec;
  	}
  
  	/* Determine the remote tracking reference name from the local master */
  	if ((error = git_refspec_transform_r(
  		&remote_master_name,
  		head_info.refspec,
  		GIT_REFS_HEADS_MASTER_FILE)) < 0)
  		return error;
  
  	/* Check to see if the remote HEAD points to the remote master */
  	error = reference_matches_remote_head(
  		git_buf_cstr(&remote_master_name), &head_info);
  	if (error < 0 && error != GIT_ITEROVER)
  		goto cleanup;
  
  	if (head_info.found) {
  		error = update_head_to_new_branch(
  			repo,
  			&head_info.remote_head_oid,
  			git_buf_cstr(&head_info.branchname));
  		goto cleanup;
  	}
  
  	/* Not master. Check all the other refs. */
  	error = git_reference_foreach_name(
  		repo, reference_matches_remote_head, &head_info);
  	if (error < 0 && error != GIT_ITEROVER)
  		goto cleanup;
  
  	if (head_info.found) {
  		error = update_head_to_new_branch(
  			repo,
  			&head_info.remote_head_oid,
  			git_buf_cstr(&head_info.branchname));
  	} else {
  		error = git_repository_set_head_detached(
  			repo, &head_info.remote_head_oid);
  	}
  
  cleanup:
  	git_buf_free(&remote_master_name);
  	git_buf_free(&head_info.branchname);
  	return error;
  }
  
  static int update_head_to_branch(
  		git_repository *repo,
  		const char *remote_name,
  		const char *branch)
  {
  	int retcode;
  	git_buf remote_branch_name = GIT_BUF_INIT;
  	git_reference* remote_ref = NULL;
  
  	assert(remote_name && branch);
  
  	if ((retcode = git_buf_printf(&remote_branch_name, GIT_REFS_REMOTES_DIR "%s/%s",
  		remote_name, branch)) < 0 )
  		goto cleanup;
  
  	if ((retcode = git_reference_lookup(&remote_ref, repo, git_buf_cstr(&remote_branch_name))) < 0)
  		goto cleanup;
  
  	retcode = update_head_to_new_branch(repo, git_reference_target(remote_ref), branch);
  
  cleanup:
  	git_reference_free(remote_ref);
  	git_buf_free(&remote_branch_name);
  	return retcode;
  }
  
  /*
   * submodules?
   */
  
  static int create_and_configure_origin(
  		git_remote **out,
  		git_repository *repo,
  		const char *url,
  		const git_clone_options *options)
  {
  	int error;
  	git_remote *origin = NULL;
  	const char *name;
  
  	name = options->remote_name ? options->remote_name : "origin";
  	if ((error = git_remote_create(&origin, repo, name, url)) < 0)
  		goto on_error;
  
  	if (options->ignore_cert_errors)
  		git_remote_check_cert(origin, 0);
  
  	if ((error = git_remote_set_callbacks(origin, &options->remote_callbacks)) < 0)
  		goto on_error;
  
  	if ((error = git_remote_save(origin)) < 0)
  		goto on_error;
  
  	*out = origin;
  	return 0;
  
  on_error:
  	git_remote_free(origin);
  	return error;
  }
  
  static bool should_checkout(
  	git_repository *repo,
  	bool is_bare,
  	const git_checkout_opts *opts)
  {
  	if (is_bare)
  		return false;
  
  	if (!opts)
  		return false;
  
  	if (opts->checkout_strategy == GIT_CHECKOUT_NONE)
  		return false;
  
  	return !git_repository_head_unborn(repo);
  }
  
  int git_clone_into(git_repository *repo, git_remote *remote, const git_checkout_opts *co_opts, const char *branch)
  {
  	int error = 0, old_fetchhead;
  	git_strarray refspecs;
  
  	assert(repo && remote);
  
  	if (!git_repository_is_empty(repo)) {
  		giterr_set(GITERR_INVALID, "the repository is not empty");
  		return -1;
  	}
  
  
  	if ((error = git_remote_get_fetch_refspecs(&refspecs, remote)) < 0)
  		return error;
  
  	if ((error = git_remote_add_fetch(remote, "refs/tags/*:refs/tags/*")) < 0)
  		return error;
  
  	old_fetchhead = git_remote_update_fetchhead(remote);
  	git_remote_set_update_fetchhead(remote, 0);
  
  	if ((error = git_remote_fetch(remote)) != 0)
  		goto cleanup;
  
  	if (branch)
  		error = update_head_to_branch(repo, git_remote_name(remote), branch);
  	/* Point HEAD to the same ref as the remote's head */
  	else
  		error = update_head_to_remote(repo, remote);
  
  	if (!error && should_checkout(repo, git_repository_is_bare(repo), co_opts))
  		error = git_checkout_head(repo, co_opts);
  
  cleanup:
  	git_remote_set_update_fetchhead(remote, old_fetchhead);
  
  	/* Go back to the original refspecs */
  	{
  		int error_alt = git_remote_set_fetch_refspecs(remote, &refspecs);
  		if (!error)
  			error = error_alt;
  	}
  
  	git_strarray_free(&refspecs);
  
  	return error;
  }
  
  int git_clone(
  	git_repository **out,
  	const char *url,
  	const char *local_path,
  	const git_clone_options *_options)
  {
  	int error = 0;
  	git_repository *repo = NULL;
  	git_remote *origin;
  	git_clone_options options = GIT_CLONE_OPTIONS_INIT;
  	uint32_t rmdir_flags = GIT_RMDIR_REMOVE_FILES;
  
  	assert(out && url && local_path);
  
  	if (_options)
  		memcpy(&options, _options, sizeof(git_clone_options));
  
  	GITERR_CHECK_VERSION(&options, GIT_CLONE_OPTIONS_VERSION, "git_clone_options");
  
  	/* Only clone to a new directory or an empty directory */
  	if (git_path_exists(local_path) && !git_path_is_empty_dir(local_path)) {
  		giterr_set(GITERR_INVALID,
  			"'%s' exists and is not an empty directory", local_path);
  		return GIT_EEXISTS;
  	}
  
  	/* Only remove the root directory on failure if we create it */
  	if (git_path_exists(local_path))
  		rmdir_flags |= GIT_RMDIR_SKIP_ROOT;
  
  	if ((error = git_repository_init(&repo, local_path, options.bare)) < 0)
  		return error;
  
  	if (!(error = create_and_configure_origin(&origin, repo, url, &options))) {
  		error = git_clone_into(
  			repo, origin, &options.checkout_opts, options.checkout_branch);
  
  		git_remote_free(origin);
  	}
  
  	if (error < 0) {
  		git_repository_free(repo);
  		repo = NULL;
  		(void)git_futils_rmdir_r(local_path, NULL, rmdir_flags);
  	}
  
  	*out = repo;
  	return error;
  }
  

Download