Traditionally libpq has collected an entire query result before passing
it back to the application. That provides a simple and transactional API,
but it's pretty inefficient for large result sets. This patch allows the
application to process each row on-the-fly instead of accumulating the
rows into the PGresult. Error recovery becomes a bit more complex, but
often that tradeoff is well worth making.
Kyotaro Horiguchi, reviewed by Marko Kreen and Tom Lane
On balance, the need to cover this case changes my mind in favor of pushing
all error-message generation duties into the two fe-secure.c routines.
So do it that way.
In many cases, pqsecure_read/pqsecure_write set up useful error messages,
which were then overwritten with useless ones by their callers. Fix this
by defining the responsibility to set an error message to be entirely that
of the lower-level function when using SSL.
Back-patch to 8.3; the code is too different in 8.2 to be worth the
trouble.
This function is like the PQserverVersion() function except
it returns the version of libpq, making it possible for a client
program or driver to determine which version of libpq is in
use at runtime, and not just at link time.
Suggested by Harald Armin Massa and several others.
My initial impression that glibc was measuring the precision in characters
(which is what the Linux man page says it does) was incorrect. It does take
the precision to be in bytes, but it also tries to truncate the string at a
character boundary. The bottom line remains the same: it will mess up
if the string is not in the encoding it expects, so we need to avoid %.*s
anytime there's a significant risk of that. Previous code changes are still
good, but adjust the comments to reflect this knowledge. Per research by
Hernan Gonzalez.
Depending on which spec you read, field widths and precisions in %s may be
counted either in bytes or characters. Our code was assuming bytes, which
is wrong at least for glibc's implementation, and in any case libc might
have a different idea of the prevailing encoding than we do. Hence, for
portable results we must avoid using anything more complex than just "%s"
unless the string to be printed is known to be all-ASCII.
This patch fixes the cases I could find, including the psql formatting
failure reported by Hernan Gonzalez. In HEAD only, I also added comments
to some places where it appears safe to continue using "%.*s".
after each other (since we already add a newline on each, this makes them
multiline).
Previously a new error would just overwrite the old one, so for example any
error caused when trying to connect with SSL enabled would be overwritten
by the error message form the non-SSL connection when using sslmode=prefer.
Per Microsoft knowledge base article Q201213, early versions of
Windows fail when we do this. Later versions of Windows appear
to have a higher limit than 64Kb, but do still fail on large
sends, so we unconditionally limit it for all versions.
Patch from Tom Lane.
we are on a 64-bit machine (ie, size_t is wider than int) and someone passes
in a query string that approaches or exceeds INT_MAX bytes. Also, just for
paranoia's sake, guard against similar overflows in sizing the input buffer.
The backend will not in the foreseeable future be prepared to send or receive
strings exceeding 1GB, so I didn't take the more invasive step of switching
all the buffer index variables from int to size_t; though someday we might
want to do that.
I have a suspicion that this is not the only such bug in libpq, but this
fix is enough to take care of the crash reported by Francisco Reyes.
renumbering of encoding IDs done between 8.2 and 8.3 turns out to break 8.2
initdb and psql if they are run with an 8.3beta1 libpq.so. For the moment
we can rearrange the order of enum pg_enc to keep the same number for
everything except PG_JOHAB, which isn't a problem since there are no direct
references to it in the 8.2 programs anyway. (This does force initdb
unfortunately.)
Going forward, we want to fix things so that encoding IDs can be changed
without an ABI break, and this commit includes the changes needed to allow
libpq's encoding IDs to be treated as fully independent of the backend's.
The main issue is that libpq clients should not include pg_wchar.h or
otherwise assume they know the specific values of libpq's encoding IDs,
since they might encounter version skew between pg_wchar.h and the libpq.so
they are using. To fix, have libpq officially export functions needed for
encoding name<=>ID conversion and validity checking; it was doing this
anyway unofficially.
It's still the case that we can't renumber backend encoding IDs until the
next bump in libpq's major version number, since doing so will break the
8.2-era client programs. However the code is now prepared to avoid this
type of problem in future.
Note that initdb is no longer a libpq client: we just pull in the two
source files we need directly. The patch also fixes a few places that
were being sloppy about checking for an unrecognized encoding name.
o remove many WIN32_CLIENT_ONLY defines
o add WIN32_ONLY_COMPILER define
o add 3rd argument to open() for portability
o add include/port/win32_msvc directory for
system includes
Magnus Hagander
rather than "return expr;" -- the latter style is used in most of the
tree. I kept the parentheses when they were necessary or useful because
the return expression was complex.
comment line where output as too long, and update typedefs for /lib
directory. Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).
Backpatch to 8.1.X.
Windows. The test itself is bypassed in configure as discussed, and
libpq has been updated appropriately to allow it to build in thread-safe
mode.
Dave Page
patch adds missing checks to the call sites of malloc(), strdup(),
PQmakeEmptyPGresult(), pqResultAlloc(), and pqResultStrdup(), and updates
the documentation. Per original report from Volkan Yazici about
PQmakeEmptyPGresult() not checking for malloc() failure.
Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...
environment variable processing to libpq.
The patch also adds code to our client apps so we set the environment
variable directly based on our binary location, unless it is already
set. This will allow our applications to emit proper locale messages
that are generated in libpq.
