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git/builtin/get-tar-commit-id.c

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Add copyright notice of Rene Scharfe to tar-tree.c
2005-05-09 23:33:02 +02:00
/*
tar-tree: Introduce write_entry() ... and use it initially to write global extended header records. Improvements compared to the old write_header(): - Uses a struct ustar_header instead of hardcoded offsets. - Takes one struct strbuf as path argument instead of a (basedir, prefix, name) tuple. - Not only writes the tar header, but also the contents of the file, if any. - Does not write directly into the ring buffer. This allows the code to be layed out more naturally, because there is no more ordering constraint. Before we had to first finish writing the extended header, now we can construct the extended and normal headers in parallel. - The typeflag parameter has been replaced by (reasonable) magic values. path == NULL indicates an extended header, additionally sha1 == NULL means it is a global extended header. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-25 23:21:03 +01:00
* Copyright (c) 2005, 2006 Rene Scharfe
Add copyright notice of Rene Scharfe to tar-tree.c
2005-05-09 23:33:02 +02:00
*/
[PATCH] create tar archives of tree on the fly This is an improved version of tar-tree, a streaming archive creator for GIT. The major added feature is blocking; all write(2) calls now have a size of 10240, just as GNU tar (and tape drives) likes them. The buffering overhead does not seem to degrade performance because most files in the repositories I tested this with are smaller than 10KB, so we need fewer system calls. File names are still restricted to 500 bytes and the archive format currently only allows for files up to 8GB. Both restrictions can be lifted if need be with more pax extended headers. The archive format used is the pax interchange format, i.e. POSIX tar format. It can be read by (and created with) GNU tar. If I read the specs correctly tar-tree should now be standards compliant (modulo bugs). Because it streams the archive (think ls-tree merged with cat-file), tar-tree doesn't need to create any temporary files. That makes it quite fast. It accepts tree IDs and commit IDs as first parameter. In the latter case tar-tree tries to get the commit date out of the committer line. Else all files in the archive are time-stamped with the current time. An optional second parameter is used as a path prefix for all files in the archive. Example: $ tar-tree a2755a80f40e5794ddc20e00f781af9d6320fafb \ linux-2.6.12-rc3 | bzip9 -9 > linux-2.6.12-rc3.tar.bz2 Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-28 21:16:43 +02:00
#include "cache.h"
Use struct commit in tar-tree It was open-coding getting the commit date from a commit. Signed-off-by: Daniel Barkalow <barkalow@iabervon> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-29 20:05:20 +01:00
#include "commit.h"
tar-tree: Introduce write_entry() ... and use it initially to write global extended header records. Improvements compared to the old write_header(): - Uses a struct ustar_header instead of hardcoded offsets. - Takes one struct strbuf as path argument instead of a (basedir, prefix, name) tuple. - Not only writes the tar header, but also the contents of the file, if any. - Does not write directly into the ring buffer. This allows the code to be layed out more naturally, because there is no more ordering constraint. Before we had to first finish writing the extended header, now we can construct the extended and normal headers in parallel. - The typeflag parameter has been replaced by (reasonable) magic values. path == NULL indicates an extended header, additionally sha1 == NULL means it is a global extended header. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-25 23:21:03 +01:00
#include "tar.h"
Builtin git-tar-tree. Signed-off-by: Peter Eriksen <s022018@student.dtu.dk> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-23 14:15:31 +02:00
#include "builtin.h"
Remove upload-tar and make git-tar-tree a thin wrapper to git-archive The command now issues a big deprecation warning message and runs git-archive command with appropriate arguments. git-tar-tree $tree_ish $base always forces $base to be the leading directory name, so the --prefix parameter passed internally to git-archive is a slash appended to it, i.e. "--prefix=$base/". Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-24 23:42:01 +02:00
#include "quote.h"
[PATCH] create tar archives of tree on the fly This is an improved version of tar-tree, a streaming archive creator for GIT. The major added feature is blocking; all write(2) calls now have a size of 10240, just as GNU tar (and tape drives) likes them. The buffering overhead does not seem to degrade performance because most files in the repositories I tested this with are smaller than 10KB, so we need fewer system calls. File names are still restricted to 500 bytes and the archive format currently only allows for files up to 8GB. Both restrictions can be lifted if need be with more pax extended headers. The archive format used is the pax interchange format, i.e. POSIX tar format. It can be read by (and created with) GNU tar. If I read the specs correctly tar-tree should now be standards compliant (modulo bugs). Because it streams the archive (think ls-tree merged with cat-file), tar-tree doesn't need to create any temporary files. That makes it quite fast. It accepts tree IDs and commit IDs as first parameter. In the latter case tar-tree tries to get the commit date out of the committer line. Else all files in the archive are time-stamped with the current time. An optional second parameter is used as a path prefix for all files in the archive. Example: $ tar-tree a2755a80f40e5794ddc20e00f781af9d6320fafb \ linux-2.6.12-rc3 | bzip9 -9 > linux-2.6.12-rc3.tar.bz2 Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-28 21:16:43 +02:00
Show usage string for 'git get-tar-commit-id -h' Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-11-09 16:04:50 +01:00
static const char builtin_get_tar_commit_id_usage[] =
usage: do not insist that standard input must come from a file The synopsys text and the usage string of subcommands that read list of things from the standard input are often shown like this: git gostak [--distim] < <list-of-doshes> This is problematic in a number of ways: * The way to use these commands is more often to feed them the output from another command, not feed them from a file. * Manual pages outside Git, commands that operate on the data read from the standard input, e.g "sort", "grep", "sed", etc., are not described with such a "< redirection-from-file" in their synopsys text. Our doing so introduces inconsistency. * We do not insist on where the output should go, by saying git gostak [--distim] < <list-of-doshes> > <output> * As it is our convention to enclose placeholders inside <braket>, the redirection operator followed by a placeholder filename becomes very hard to read, both in the documentation and in the help text. Let's clean them all up, after making sure that the documentation clearly describes the modes that take information from the standard input and what kind of things are expected on the input. [jc: stole example for fmt-merge-msg from Jonathan] Helped-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-16 20:27:42 +02:00
"git get-tar-commit-id";
Show usage string for 'git get-tar-commit-id -h' Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-11-09 16:04:50 +01:00
Built-in git-get-tar-commit-id By being an internal command git-get-commit-id can make use of struct ustar_header and other stuff and stops wasting precious disk space. Note: I recycled one of the two "tar-tree" entries instead of splitting that cleanup into a separate patch. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-10 16:13:41 +02:00
/* ustar header + extended global header content */
Remove upload-tar and make git-tar-tree a thin wrapper to git-archive The command now issues a big deprecation warning message and runs git-archive command with appropriate arguments. git-tar-tree $tree_ish $base always forces $base to be the leading directory name, so the --prefix parameter passed internally to git-archive is a slash appended to it, i.e. "--prefix=$base/". Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-09-24 23:42:01 +02:00
#define RECORDSIZE (512)
Built-in git-get-tar-commit-id By being an internal command git-get-commit-id can make use of struct ustar_header and other stuff and stops wasting precious disk space. Note: I recycled one of the two "tar-tree" entries instead of splitting that cleanup into a separate patch. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-10 16:13:41 +02:00
#define HEADERSIZE (2 * RECORDSIZE)
Call setup_git_directory() much earlier This changes the calling convention of built-in commands and passes the "prefix" (i.e. pathname of $PWD relative to the project root level) down to them. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-07-29 07:44:25 +02:00
int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
Built-in git-get-tar-commit-id By being an internal command git-get-commit-id can make use of struct ustar_header and other stuff and stops wasting precious disk space. Note: I recycled one of the two "tar-tree" entries instead of splitting that cleanup into a separate patch. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-10 16:13:41 +02:00
{
char buffer[HEADERSIZE];
struct ustar_header *header = (struct ustar_header *)buffer;
char *content = buffer + RECORDSIZE;
use skip_prefix() to avoid more magic numbers Continue where ae021d87 (use skip_prefix to avoid magic numbers) left off and use skip_prefix() in more places for determining the lengths of prefix strings to avoid using dependent constants and other indirect methods. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-04 20:54:50 +02:00
const char *comment;
Built-in git-get-tar-commit-id By being an internal command git-get-commit-id can make use of struct ustar_header and other stuff and stops wasting precious disk space. Note: I recycled one of the two "tar-tree" entries instead of splitting that cleanup into a separate patch. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-10 16:13:41 +02:00
ssize_t n;
Show usage string for 'git get-tar-commit-id -h' Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-11-09 16:04:50 +01:00
if (argc != 1)
usage(builtin_get_tar_commit_id_usage);
short i/o: fix calls to read to use xread or read_in_full We have a number of badly checked read() calls. Often we are expecting read() to read exactly the size we requested or fail, this fails to handle interrupts or short reads. Add a read_in_full() providing those semantics. Otherwise we at a minimum need to check for EINTR and EAGAIN, where this is appropriate use xread(). Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-08 16:58:08 +01:00
n = read_in_full(0, buffer, HEADERSIZE);
distinguish error versus short read from read_in_full() Many callers of read_in_full() expect to see the exact number of bytes requested, but their error handling lumps together true read errors and short reads due to unexpected EOF. We can give more specific error messages by separating these cases (showing errno when appropriate, and otherwise describing the short read). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27 08:02:11 +02:00
if (n < 0)
die_errno("git get-tar-commit-id: read error");
prefer "!=" when checking read_in_full() result Comparing the result of read_in_full() using less-than is potentially dangerous, as a negative return value may be converted to an unsigned type and be considered a success. This is discussed further in 561598cfcf (read_pack_header: handle signed/unsigned comparison in read result, 2017-09-13). Each of these instances is actually fine in practice: - in get-tar-commit-id, the HEADERSIZE macro expands to a signed integer. If it were switched to an unsigned type (e.g., a size_t), then it would be a bug. - the other two callers check for a short read only after handling a negative return separately. This is a fine practice, but we'd prefer to model "!=" as a general rule. So all of these cases can be considered cleanups and not actual bugfixes. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27 08:00:28 +02:00
if (n != HEADERSIZE)
distinguish error versus short read from read_in_full() Many callers of read_in_full() expect to see the exact number of bytes requested, but their error handling lumps together true read errors and short reads due to unexpected EOF. We can give more specific error messages by separating these cases (showing errno when appropriate, and otherwise describing the short read). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27 08:02:11 +02:00
die_errno("git get-tar-commit-id: EOF before reading tar header");
Built-in git-get-tar-commit-id By being an internal command git-get-commit-id can make use of struct ustar_header and other stuff and stops wasting precious disk space. Note: I recycled one of the two "tar-tree" entries instead of splitting that cleanup into a separate patch. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-10 16:13:41 +02:00
if (header->typeflag[0] != 'g')
return 1;
use skip_prefix() to avoid more magic numbers Continue where ae021d87 (use skip_prefix to avoid magic numbers) left off and use skip_prefix() in more places for determining the lengths of prefix strings to avoid using dependent constants and other indirect methods. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-04 20:54:50 +02:00
if (!skip_prefix(content, "52 comment=", &comment))
Built-in git-get-tar-commit-id By being an internal command git-get-commit-id can make use of struct ustar_header and other stuff and stops wasting precious disk space. Note: I recycled one of the two "tar-tree" entries instead of splitting that cleanup into a separate patch. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-10 16:13:41 +02:00
return 1;
get-tar-commit-id: check write_in_full() return against 0 We ask to write 41 bytes and make sure that the return value is at least 41. This is the same "dangerous" pattern that was fixed in the prior commit (wherein a negative return value is promoted to unsigned), though it is not dangerous here because our "41" is a constant, not an unsigned variable. But we should convert it anyway to avoid modeling a dangerous construct. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-13 19:11:28 +02:00
if (write_in_full(1, comment, 41) < 0)
Use die_errno() instead of die() when checking syscalls Lots of die() calls did not actually report the kind of error, which can leave the user confused as to the real problem. Use die_errno() where we check a system/library call that sets errno on failure, or one of the following that wrap such calls: Function Passes on error from -------- -------------------- odb_pack_keep open read_ancestry fopen read_in_full xread strbuf_read xread strbuf_read_file open or strbuf_read_file strbuf_readlink readlink write_in_full xwrite Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-27 17:58:47 +02:00
die_errno("git get-tar-commit-id: write error");
Built-in git-get-tar-commit-id By being an internal command git-get-commit-id can make use of struct ustar_header and other stuff and stops wasting precious disk space. Note: I recycled one of the two "tar-tree" entries instead of splitting that cleanup into a separate patch. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-10 16:13:41 +02:00
return 0;
}
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