[PATCH v2 3/6] git-compat-util: make MAX_IO_SIZE define globally available
- From
Jeff King <peff@peff.net>
- Date
- Aug 17, 2022, 06:06 UTC
- Message-ID
- <YvyFggmzXAGf3jlL@coredump.intra.peff.net>
- In-Reply-To
- <YvyE1RDFVAg4uQo1@coredump.intra.peff.net>
We define MAX_IO_SIZE within wrapper.c, but it's useful for any code that wants to do a raw write() for whatever reason (say, because they want different EAGAIN handling). Let's make it available everywhere.
The alternative would be adding xwrite_foo() variants to give callers more options. But there's really no reason MAX_IO_SIZE needs to be abstracted away, so this give callers the most flexibility.
Signed-off-by: Jeff King <peff@peff.net> --- I did actually write xwrite_nonblock() at first, and I could be persuaded to go in that direction if we prefer. But given that using it sanely requires the caller to have a poll() loop, I feel like pipe_command() is already the right level of abstraction.
git-compat-util.h | 22 ++++++++++++++++++++++ wrapper.c | 22 ---------------------- 2 files changed, 22 insertions(+), 22 deletions(-)
diff --git a/git-compat-util.h b/git-compat-util.h index 36a25ae252..6aee4d92e7 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -998,6 +998,28 @@ static inline unsigned long cast_size_t_to_ulong(size_t a) return (unsigned long)a; } +/* + * Limit size of IO chunks, because huge chunks only cause pain. OS X + * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in + * the absence of bugs, large chunks can result in bad latencies when + * you decide to kill the process. + * + * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX + * that is smaller than that, clip it to SSIZE_MAX, as a call to + * read(2) or write(2) larger than that is allowed to fail. As the last + * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value" + * to override this, if the definition of SSIZE_MAX given by the platform + * is broken. + */ +#ifndef MAX_IO_SIZE +# define MAX_IO_SIZE_DEFAULT (8*1024*1024) +# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT) +# define MAX_IO_SIZE SSIZE_MAX +# else +# define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT +# endif +#endif + #ifdef HAVE_ALLOCA_H # include <alloca.h> # define xalloca(size) (alloca(size)) diff --git a/wrapper.c b/wrapper.c index cfe79bd081..299d6489a6 100644 --- a/wrapper.c +++ b/wrapper.c @@ -161,28 +161,6 @@ void xsetenv(const char *name, const char *value, int overwrite) die_errno(_("could not setenv '%s'"), name ? name : "(null)"); } -/* - * Limit size of IO chunks, because huge chunks only cause pain. OS X - * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in - * the absence of bugs, large chunks can result in bad latencies when - * you decide to kill the process. - * - * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX - * that is smaller than that, clip it to SSIZE_MAX, as a call to - * read(2) or write(2) larger than that is allowed to fail. As the last - * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value" - * to override this, if the definition of SSIZE_MAX given by the platform - * is broken. - */ -#ifndef MAX_IO_SIZE -# define MAX_IO_SIZE_DEFAULT (8*1024*1024) -# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT) -# define MAX_IO_SIZE SSIZE_MAX -# else -# define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT -# endif -#endif - /** * xopen() is the same as open(), but it die()s if the open() fails. */
-- 2.37.2.881.gb57357660c