neocgit

a more 'modern' version of cgit
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commit d3581b58890389794de5d5222c91a0129873e95c
parent ea7210bef377be4ffb088a1a8e5a9dd354f82afb
Author: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Date:   Sat, 18 Jan 2014 21:24:58 +0100

cache: use sendfile() instead of a pair of read() + write()

sendfile() does the same job and avoids to copy the content into userland
and back. One has to define NO_SENDFILE in case the OS (kernel / libc)
does not supported. It is disabled by default on non-linux environemnts.
According to the glibc, sendfile64() was added in Linux 2.4 (so it has
been there for a while) but after browsing over the mapage of FreeBSD's I
noticed that the prototype is little different.

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>

Diffstat:
MMakefile | 1+
Mcache.c | 26+++++++++++++++++++++++++-
Mcgit.mk | 8++++++++
3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile @@ -29,6 +29,7 @@ DOC_PDF = $(patsubst %.txt,%.pdf,$(MAN_TXT)) # j, z, t. (representing long long int, char, intmax_t, size_t, ptrdiff_t). # some C compilers supported these specifiers prior to C99 as an extension. # +# Define HAVE_LINUX_SENDFILE to use sendfile() #-include config.mak diff --git a/cache.c b/cache.c @@ -13,6 +13,9 @@ * */ +#ifdef HAVE_LINUX_SENDFILE +#include <sys/sendfile.h> +#endif #include "cgit.h" #include "cache.h" #include "html.h" @@ -30,7 +33,6 @@ struct cache_slot { const char *lock_name; int match; struct stat cache_st; - struct stat lock_st; int bufsize; char buf[CACHE_BUFSIZE]; }; @@ -81,6 +83,23 @@ static int close_slot(struct cache_slot *slot) /* Print the content of the active cache slot (but skip the key). */ static int print_slot(struct cache_slot *slot) { +#ifdef HAVE_LINUX_SENDFILE + off_t start_off; + int ret; + + start_off = slot->keylen + 1; + + do { + ret = sendfile(STDOUT_FILENO, slot->cache_fd, &start_off, + slot->cache_st.st_size - start_off); + if (ret < 0) { + if (errno == EAGAIN || errno == EINTR) + continue; + return errno; + } + return 0; + } while (1); +#else ssize_t i, j; i = lseek(slot->cache_fd, slot->keylen + 1, SEEK_SET); @@ -97,6 +116,7 @@ static int print_slot(struct cache_slot *slot) return errno; else return 0; +#endif } /* Check if the slot has expired */ @@ -188,6 +208,10 @@ static int fill_slot(struct cache_slot *slot) /* Generate cache content */ slot->fn(); + /* update stat info */ + if (fstat(slot->lock_fd, &slot->cache_st)) + return errno; + /* Restore stdout */ if (dup2(tmp, STDOUT_FILENO) == -1) return errno; diff --git a/cgit.mk b/cgit.mk @@ -68,6 +68,14 @@ ifeq ($(findstring BSD,$(uname_S)),) CGIT_LIBS += -ldl endif +# glibc 2.1+ offers sendfile which the most common C library on Linux +ifeq ($(uname_S),Linux) + HAVE_LINUX_SENDFILE = YesPlease +endif + +ifdef HAVE_LINUX_SENDFILE + CGIT_CFLAGS += -DHAVE_LINUX_SENDFILE +endif CGIT_OBJ_NAMES += cgit.o CGIT_OBJ_NAMES += cache.o