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Revision f3badaed5106a16499d0fae31a382f9047b272d7 authored by Jeff King on 11 February 2016, 22:26:18 UTC, committed by Junio C Hamano on 16 March 2016, 17:41:03 UTC 
list-objects: convert name_path to a strbuf
 
The "struct name_path" data is examined in only two places:
we generate it in process_tree(), and we convert it to a
single string in path_name(). Everyone else just passes it
through to those functions.

We can further note that process_tree() already keeps a
single strbuf with the leading tree path, for use with
tree_entry_interesting().

Instead of building a separate name_path linked list, let's
just use the one we already build in "base". This reduces
the amount of code (especially tricky code in path_name()
which did not check for integer overflows caused by deep
or large pathnames).

It is also more efficient in some instances.  Any time we
were using tree_entry_interesting, we were building up the
strbuf anyway, so this is an immediate and obvious win
there. In cases where we were not, we trade off storing
"pathname/" in a strbuf on the heap for each level of the
path, instead of two pointers and an int on the stack (with
one pointer into the tree object). On a 64-bit system, the
latter is 20 bytes; so if path components are less than that
on average, this has lower peak memory usage.  In practice
it probably doesn't matter either way; we are already
holding in memory all of the tree objects leading up to each
pathname, and for normal-depth pathnames, we are only
talking about hundreds of bytes.

This patch leaves "struct name_path" as a thin wrapper
around the strbuf, to avoid disrupting callbacks. We should
fix them, but leaving it out makes this diff easier to view.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 8eee9f9
Raw File
archive.c 
/*
 * Copyright (c) 2006 Franck Bui-Huu
 * Copyright (c) 2006 Rene Scharfe
 */
#include "cache.h"
#include "builtin.h"
#include "archive.h"
#include "transport.h"
#include "parse-options.h"
#include "pkt-line.h"
#include "sideband.h"

static void create_output_file(const char *output_file)
{
	int output_fd = open(output_file, O_CREAT | O_WRONLY | O_TRUNC, 0666);
	if (output_fd < 0)
		die_errno(_("could not create archive file '%s'"), output_file);
	if (output_fd != 1) {
		if (dup2(output_fd, 1) < 0)
			die_errno(_("could not redirect output"));
		else
			close(output_fd);
	}
}

static int run_remote_archiver(int argc, const char **argv,
			       const char *remote, const char *exec,
			       const char *name_hint)
{
	char *buf;
	int fd[2], i, rv;
	struct transport *transport;
	struct remote *_remote;

	_remote = remote_get(remote);
	if (!_remote->url[0])
		die(_("git archive: Remote with no URL"));
	transport = transport_get(_remote, _remote->url[0]);
	transport_connect(transport, "git-upload-archive", exec, fd);

	/*
	 * Inject a fake --format field at the beginning of the
	 * arguments, with the format inferred from our output
	 * filename. This way explicit --format options can override
	 * it.
	 */
	if (name_hint) {
		const char *format = archive_format_from_filename(name_hint);
		if (format)
			packet_write(fd[1], "argument --format=%s\n", format);
	}
	for (i = 1; i < argc; i++)
		packet_write(fd[1], "argument %s\n", argv[i]);
	packet_flush(fd[1]);

	buf = packet_read_line(fd[0], NULL);
	if (!buf)
		die(_("git archive: expected ACK/NAK, got EOF"));
	if (strcmp(buf, "ACK")) {
		if (starts_with(buf, "NACK "))
			die(_("git archive: NACK %s"), buf + 5);
		if (starts_with(buf, "ERR "))
			die(_("remote error: %s"), buf + 4);
		die(_("git archive: protocol error"));
	}

	if (packet_read_line(fd[0], NULL))
		die(_("git archive: expected a flush"));

	/* Now, start reading from fd[0] and spit it out to stdout */
	rv = recv_sideband("archive", fd[0], 1);
	rv |= transport_disconnect(transport);

	return !!rv;
}

#define PARSE_OPT_KEEP_ALL ( PARSE_OPT_KEEP_DASHDASH | 	\
			     PARSE_OPT_KEEP_ARGV0 | 	\
			     PARSE_OPT_KEEP_UNKNOWN |	\
			     PARSE_OPT_NO_INTERNAL_HELP	)

int cmd_archive(int argc, const char **argv, const char *prefix)
{
	const char *exec = "git-upload-archive";
	const char *output = NULL;
	const char *remote = NULL;
	struct option local_opts[] = {
		OPT_STRING('o', "output", &output, N_("file"),
			N_("write the archive to this file")),
		OPT_STRING(0, "remote", &remote, N_("repo"),
			N_("retrieve the archive from remote repository <repo>")),
		OPT_STRING(0, "exec", &exec, N_("command"),
			N_("path to the remote git-upload-archive command")),
		OPT_END()
	};

	argc = parse_options(argc, argv, prefix, local_opts, NULL,
			     PARSE_OPT_KEEP_ALL);

	if (output)
		create_output_file(output);

	if (remote)
		return run_remote_archiver(argc, argv, remote, exec, output);

	setvbuf(stderr, NULL, _IOLBF, BUFSIZ);

	return write_archive(argc, argv, prefix, 1, output, 0);
}
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