Re: [PATCH 6/6] odb/transaction: add transaction interface to write packfiles

>  static int unpack_with_sideband(struct odb_transaction *transaction,
>  				const char *shallow_file,
>  				struct strbuf *err_msg)
>  {
> -	struct unpack_opts opts = {
> +	struct odb_transaction_write_pack_opts opts = {
>  		.fsck_objects = (receive_fsck_objects >= 0
>  				 ? receive_fsck_objects
>  				 : transfer_fsck_objects >= 0
> @@ -2462,7 +2326,7 @@ static int unpack_with_sideband(struct odb_transaction *transaction,
>  	int ret;
>  
>  	if (!use_sideband)
> -		return unpack(transaction, 0, err_msg, &opts);
> +		return odb_transaction_write_pack(transaction, 0, err_msg, &opts);
>  
>  	use_keepalive = KEEPALIVE_AFTER_NUL;
>  	memset(&muxer, 0, sizeof(muxer));
> @@ -2472,7 +2336,7 @@ static int unpack_with_sideband(struct odb_transaction *transaction,
>  		return 0;
>  
>  	opts.err_fd = muxer.in;
> -	ret = unpack(transaction, 0, err_msg, &opts);
> +	ret = odb_transaction_write_pack(transaction, 0, err_msg, &opts);
>  
>  	finish_async(&muxer);
>  	return ret;

> diff --git a/object-file.c b/object-file.c
> index 30b4717d3e..ec3b9a185e 100644
> --- a/object-file.c
> +++ b/object-file.c
> @@ -1292,6 +1297,148 @@ static int odb_transaction_files_commit(struct odb_transaction *base)

> +static int odb_transaction_files_write_pack(struct odb_transaction *base,
> +					    int pack_fd, struct strbuf *err_msg,
> +					    const struct odb_transaction_write_pack_opts *opts)
> +{
> +	struct odb_transaction_files *transaction =
> +		container_of(base, struct odb_transaction_files, base);
> +	struct repository *repo = base->source->odb->repo;
> +	struct child_process child = CHILD_PROCESS_INIT;
> +	struct pack_header hdr;
> +	const char *hdr_err;
> +	int err_fd = opts->err_fd;
> +	int status;
> +
> +	hdr_err = parse_pack_header(&hdr, pack_fd);
> +	if (hdr_err) {
> +		if (err_fd > 0)
> +			close(err_fd);
> +		strbuf_addstr(err_msg, hdr_err);
> +		return -1;
> +	}
> +
> +	if (opts->shallow_file) {
> +		strvec_push(&child.args, "--shallow-file");
> +		strvec_push(&child.args, opts->shallow_file);
> +	}
> +
> +	odb_transaction_env(base, &child.env);
> +
> +	if (ntohl(hdr.hdr_entries) < (unsigned int)opts->unpack_limit) {
> +		strvec_push(&child.args, "unpack-objects");
> +		push_header_arg(&child.args, &hdr);
> +		if (opts->quiet)
> +			strvec_push(&child.args, "-q");
> +		if (opts->fsck_objects)
> +			strvec_pushf(&child.args, "--strict%s",
> +				     opts->fsck_msg_types);
> +		if (opts->max_input_size)
> +			strvec_pushf(&child.args, "--max-input-size=%"PRIuMAX,
> +				     (uintmax_t)opts->max_input_size);
> +		child.no_stdout = 1;
> +		child.in = pack_fd;
> +		child.err = err_fd;
> +		child.git_cmd = 1;
> +		status = run_command(&child);
> +		if (status) {
> +			strbuf_addstr(err_msg, "unpack-objects abnormal exit");
> +			return -1;
> +		}
> +	} else {
> +		char hostname[HOST_NAME_MAX + 1];
> +		char *lockfile;
> +
> +		strvec_pushl(&child.args, "index-pack", "--stdin", NULL);
> +		push_header_arg(&child.args, &hdr);
> +
> +		if (xgethostname(hostname, sizeof(hostname)))
> +			xsnprintf(hostname, sizeof(hostname), "localhost");
> +		strvec_pushf(&child.args,
> +			     "--keep=receive-pack %"PRIuMAX" on %s",
> +			     (uintmax_t)getpid(),
> +			     hostname);
> +
> +		if (!opts->quiet && err_fd)
> +			strvec_push(&child.args, "--show-resolving-progress");
> +		if (err_fd)
> +			strvec_push(&child.args, "--report-end-of-input");
> +		if (opts->fsck_objects)
> +			strvec_pushf(&child.args, "--strict%s",
> +				     opts->fsck_msg_types);
> +		if (!opts->reject_thin)
> +			strvec_push(&child.args, "--fix-thin");
> +		if (opts->max_input_size)
> +			strvec_pushf(&child.args, "--max-input-size=%"PRIuMAX,
> +				     (uintmax_t)opts->max_input_size);
> +		child.out = -1;
> +		child.in = pack_fd;
> +		child.err = err_fd;
> +		child.git_cmd = 1;
> +		status = start_command(&child);
> +		if (status) {
> +			strbuf_addstr(err_msg, "index-pack fork failed");
> +			return -1;
> +		}
> +
> +		lockfile = index_pack_lockfile(repo, child.out, NULL);
> +		if (lockfile) {
> +			ALLOC_GROW(transaction->pack_lockfiles,
> +				   transaction->pack_lockfiles_nr + 1,
> +				   transaction->pack_lockfiles_alloc);
> +			transaction->pack_lockfiles[transaction->pack_lockfiles_nr++] =
> +				register_tempfile(lockfile);
> +			free(lockfile);
> +		}
> +		close(child.out);

> +		status = finish_command(&child);
> +		if (status) {
> +			strbuf_addstr(err_msg, "index-pack abnormal exit");
> +			return -1;
> +		}
> +		odb_reprepare(repo->objects);

> diff --git a/odb/transaction.h b/odb/transaction.h
> index ec0b27c449..491026e815 100644
> --- a/odb/transaction.h
> +++ b/odb/transaction.h
> @@ -4,6 +4,51 @@
>  #include "gettext.h"
>  #include "odb.h"
>  
> +/*
> + * Options controlling how odb_transaction_write_pack() ingests a packfile.
> + */
> +struct odb_transaction_write_pack_opts {
> +	/*
> +	 * Optional fsck severity configuration to apply when incoming objects
> +	 * are verified.
> +	 */
> +	const char *fsck_msg_types;
> +	/*
> +	 * Path to an alternative shallow file describing the shallow boundaries
> +	 * to honor while ingesting the pack.
> +	 */
> +	const char *shallow_file;
> +	/*
> +	 * The max size in bytes of the incoming packfile allowed. No limit is
> +	 * enforced when set to 0.
> +	 */
> +	off_t max_input_size;
> +	/*
> +	 * Whether the validity of incoming objects should be verified.
> +	 */
> +	int fsck_objects;
> +	/*
> +	 * The threshold for the number of incoming objects required to store
> +	 * the objects in a packfile. This option may not be relevant to
> +	 * backends that do not store obejcts in loose/packed formats and can be
> +	 * ignored.
> +	 */
> +	int unpack_limit;

> +	/*
> +	 * Whether to reject an incoming packfile if it is "thin".
> +	 */
> +	int reject_thin;
> +	/*
> +	 * Optional file descriptor for reporting progress and errors. Set to 0
> +	 * for none.
> +	 */
> +	int err_fd;
> +	/*
> +	 * Suppresses progress reporting.
> +	 */
> +	int quiet;
> +};