kernel/git - git - PowerEL Git System

Commit Graph

Author	SHA1	Message	Date
Jeff King	4981fe750b	pkt-line: share buffer/descriptor reading implementation The packet_read function reads from a descriptor. The packet_get_line function is similar, but reads from an in-memory buffer, and uses a completely separate implementation. This patch teaches the generic packet_read function to accept either source, and we can do away with packet_get_line's implementation. There are two other differences to account for between the old and new functions. The first is that we used to read into a strbuf, but now read into a fixed size buffer. The only two callers are fine with that, and in fact it simplifies their code, since they can use the same static-buffer interface as the rest of the packet_read_line callers (and we provide a similar convenience wrapper for reading from a buffer rather than a descriptor). This is technically an externally-visible behavior change in that we used to accept arbitrary sized packets up to 65532 bytes, and now cap out at LARGE_PACKET_MAX, 65520. In practice this doesn't matter, as we use it only for parsing smart-http headers (of which there is exactly one defined, and it is small and fixed-size). And any extension headers would be breaking the protocol to go over LARGE_PACKET_MAX anyway. The other difference is that packet_get_line would return on error rather than dying. However, both callers of packet_get_line are actually improved by dying. The first caller does its own error checking, but we can drop that; as a result, we'll actually get more specific reporting about protocol breakage when packet_read dies internally. The only downside is that packet_read will not print the smart-http URL that failed, but that's not a big deal; anybody not debugging can already see the remote's URL already, and anybody debugging would want to run with GIT_CURL_VERBOSE anyway to see way more information. The second caller, which is just trying to skip past any extra smart-http headers (of which there are none defined, but which we allow to keep room for future expansion), did not error check at all. As a result, it would treat an error just like a flush packet. The resulting mess would generally cause an error later in get_remote_heads, but now we get error reporting much closer to the source of the problem. Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Jeff King	74543a0423	pkt-line: provide a LARGE_PACKET_MAX static buffer Most of the callers of packet_read_line just read into a static 1000-byte buffer (callers which handle arbitrary binary data already use LARGE_PACKET_MAX). This works fine in practice, because: 1. The only variable-sized data in these lines is a ref name, and refs tend to be a lot shorter than 1000 characters. 2. When sending ref lines, git-core always limits itself to 1000 byte packets. However, the only limit given in the protocol specification in Documentation/technical/protocol-common.txt is LARGE_PACKET_MAX; the 1000 byte limit is mentioned only in pack-protocol.txt, and then only describing what we write, not as a specific limit for readers. This patch lets us bump the 1000-byte limit to LARGE_PACKET_MAX. Even though git-core will never write a packet where this makes a difference, there are two good reasons to do this: 1. Other git implementations may have followed protocol-common.txt and used a larger maximum size. We don't bump into it in practice because it would involve very long ref names. 2. We may want to increase the 1000-byte limit one day. Since packets are transferred before any capabilities, it's difficult to do this in a backwards-compatible way. But if we bump the size of buffer the readers can handle, eventually older versions of git will be obsolete enough that we can justify bumping the writers, as well. We don't have plans to do this anytime soon, but there is no reason not to start the clock ticking now. Just bumping all of the reading bufs to LARGE_PACKET_MAX would waste memory. Instead, since most readers just read into a temporary buffer anyway, let's provide a single static buffer that all callers can use. We can further wrap this detail away by having the packet_read_line wrapper just use the buffer transparently and return a pointer to the static storage. That covers most of the cases, and the remaining ones already read into their own LARGE_PACKET_MAX buffers. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Jeff King	819b929d33	pkt-line: teach packet_read_line to chomp newlines The packets sent during ref negotiation are all terminated by newline; even though the code to chomp these newlines is short, we end up doing it in a lot of places. This patch teaches packet_read_line to auto-chomp the trailing newline; this lets us get rid of a lot of inline chomping code. As a result, some call-sites which are not reading line-oriented data (e.g., when reading chunks of packfiles alongside sideband) transition away from packet_read_line to the generic packet_read interface. This patch converts all of the existing callsites. Since the function signature of packet_read_line does not change (but its behavior does), there is a possibility of new callsites being introduced in later commits, silently introducing an incompatibility. However, since a later patch in this series will change the signature, such a commit would have to be merged directly into this commit, not to the tip of the series; we can therefore ignore the issue. This is an internal cleanup and should produce no change of behavior in the normal case. However, there is one corner case to note. Callers of packet_read_line have never been able to tell the difference between a flush packet ("0000") and an empty packet ("0004"), as both cause packet_read_line to return a length of 0. Readers treat them identically, even though Documentation/technical/protocol-common.txt says we must not; it also says that implementations should not send an empty pkt-line. By stripping out the newline before the result gets to the caller, we will now treat the newline-only packet ("0005\n") the same as an empty packet, which in turn gets treated like a flush packet. In practice this doesn't matter, as neither empty nor newline-only packets are part of git's protocols (at least not for the line-oriented bits, and readers who are not expecting line-oriented packets will be calling packet_read directly, anyway). But even if we do decide to care about the distinction later, it is orthogonal to this patch. The right place to tighten would be to stop treating empty packets as flush packets, and this change does not make doing so any harder. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Jeff King	0380942902	pkt-line: provide a generic reading function with options Originally we had a single function for reading packetized data: packet_read_line. Commit `46284dd` grew a more "gentle" form, packet_read, that returns an error instead of dying upon reading a truncated input stream. However, it is not clear from the names which should be called, or what the difference is. Let's instead make packet_read be a generic public interface that can take option flags, and update the single callsite that uses it. This is less code, more clear, and paves the way for introducing more options into the generic interface later. The function signature is changed, so there should be no hidden conflicts with topics in flight. While we're at it, we'll document how error conditions are handled based on the options, and rename the confusing "return_line_fail" option to "gentle_on_eof". While we are cleaning up the names, we can drop the "return_line_fail" checks in packet_read_internal entirely. They look like this: ret = safe_read(..., return_line_fail); if (return_line_fail && ret < 0) ... The check for return_line_fail is a no-op; safe_read will only ever return an error value if return_line_fail was true in the first place. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Jeff King	cdf4fb8e33	pkt-line: drop safe_write function This is just write_or_die by another name. The one distinction is that write_or_die will treat EPIPE specially by suppressing error messages. That's fine, as we die by SIGPIPE anyway (and in the off chance that it is disabled, write_or_die will simulate it). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Jeff King	e148542870	pkt-line: move a misplaced comment The comment describing the packet writing interface was originally written above packet_write, but migrated to be above safe_write in `f3a3214`, probably because it is meant to generally describe the packet writing interface and not a single function. Let's move it into the header file, where users of the interface are more likely to see it. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	12 years ago
Heiko Voigt	46284dd152	remove the impression of unexpectedness when access is denied If a server accessed through ssh is denying access git will currently issue the message "fatal: The remote end hung up unexpectedly" as the last line. This sounds as if something really ugly just happened. Since this is a quite typical situation in which users regularly get we do not say that if it happens at the beginning when reading the remote heads. If its in the very first beginning of reading the remote heads it is very likely an authentication error or a missing repository. If it happens later during reading the remote heads we still indicate that it happened during this initial contact phase. Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	13 years ago
Stephen Boyd	1e4cd68c00	sparse: Fix errors and silence warnings * load_file() returns a void pointer but is using 0 for the return value * builtin/receive-pack.c forgot to include builtin.h * packet_trace_prefix can be marked static * ll_merge takes a pointer for its last argument, not an int * crc32 expects a pointer as the second argument but Z_NULL is defined to be 0 (see `38f4d13` sparse fix: Using plain integer as NULL pointer, 2006-11-18 for more info) Signed-off-by: Stephen Boyd <bebarino@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>	14 years ago
Jeff King	bbc30f9963	add packet tracing debug code This shows a trace of all packets coming in or out of a given program. This can help with debugging object negotiation or other protocol issues. To keep the code changes simple, we operate at the lowest level, meaning we don't necessarily understand what's in the packets. The one exception is a packet starting with "PACK", which causes us to skip that packet and turn off tracing (since the gigantic pack data will not be interesting to read, at least not in the trace format). We show both written and read packets. In the local case, this may mean you will see packets twice (written by the sender and read by the receiver). However, for cases where the other end is remote, this allows you to see the full conversation. Packet tracing can be enabled with GIT_TRACE_PACKET=<foo>, where <foo> takes the same arguments as GIT_TRACE. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>	14 years ago
Shawn O. Pearce	743c4b7b0f	pkt-line: Make packet_read_line easier to debug When there is an error parsing the 4 byte length component we now display it as part of the die message, this may hint as to what data was misunderstood by the application. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
Shawn O. Pearce	f5615d2467	pkt-line: Add strbuf based functions These routines help to work with pkt-line values inside of a strbuf, permitting simple formatting of buffered network messages. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
Thomas Rast	d824cbba02	Convert existing die(..., strerror(errno)) to die_errno() Change calls to die(..., strerror(errno)) to use the new die_errno(). In the process, also make slight style adjustments: at least state _something_ about the function that failed (instead of just printing the pathname), and put paths in single quotes. Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago
Heikki Orsila	c697ad143b	Cleanup xread() loops to use read_in_full() Signed-off-by: Heikki Orsila <heikki.orsila@iki.fi> Signed-off-by: Junio C Hamano <gitster@pobox.com>	17 years ago
Junio C Hamano	a6080a0a44	War on whitespace This uses "git-apply --whitespace=strip" to fix whitespace errors that have crept in to our source files over time. There are a few files that need to have trailing whitespaces (most notably, test vectors). The results still passes the test, and build result in Documentation/ area is unchanged. Signed-off-by: Junio C Hamano <gitster@pobox.com>	18 years ago
Johan Herland	8a912bcb25	Ensure return value from xread() is always stored into an ssize_t This patch fixes all calls to xread() where the return value is not stored into an ssize_t. The patch should not have any effect whatsoever, other than putting better/more appropriate type names on variables. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Nicolas Pitre	b3d9899324	make git a bit less cryptic on fetch errors The remote server might not want to tell why it doesn't like us for security reasons, but let's make the client report such error in a bit less confusing way. The remote failure remains a mystery, but the local message might be a bit less so. [jc: with a gentle wording updates from Andy Parkins] Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Junio C Hamano	583b7ea31b	upload-pack/fetch-pack: support side-band communication This implements a protocol extension between fetch-pack and upload-pack to allow stderr stream from upload-pack (primarily used for the progress bar display) to be passed back. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Florian Forster	1d7f171c3a	Remove all void-pointer arithmetic. ANSI C99 doesn't allow void-pointer arithmetic. This patch fixes this in various ways. Usually the strategy that required the least changes was used. Signed-off-by: Florian Forster <octo@verplant.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	1c15afb934	xread/xwrite: do not worry about EINTR at calling sites. We had errno==EINTR check after read(2)/write(2) sprinkled all over the places, always doing continue. Consolidate them into xread()/xwrite() wrapper routines. Credits for suggestion goes to HPA -- bugs are mine. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Linus Torvalds	f3a3214e83	Make send/receive-pack be closer to doing something interesting	20 years ago

21 Commits (8316d18da324f44b93faf36cddbf19411b53d101)