From mboxrd@z Thu Jan 1 00:00:00 1970 From: cgit at ml.breakpoint.cc (cgit at ml.breakpoint.cc) Date: Thu, 21 Jun 2012 09:09:47 +0200 Subject: [PATCH 2/3] cache: use sendfile() instead of a pair of read() + write() In-Reply-To: <1340262588-24202-1-git-send-email-cgit@ml.breakpoint.cc> References: <1340262588-24202-1-git-send-email-cgit@ml.breakpoint.cc> Message-ID: <1340262588-24202-2-git-send-email-cgit@ml.breakpoint.cc> From: Sebastian Andrzej Siewior 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 --- Makefile | 10 ++++++++++ cache.c | 26 +++++++++++++++++++++++++- 2 files changed, 35 insertions(+), 1 deletions(-) diff --git a/Makefile b/Makefile index eac24ad..5cc84f4 100644 --- a/Makefile +++ b/Makefile @@ -33,6 +33,9 @@ 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 NO_SENDFILE to avoid using the sendfile() offered by libc. Use this +# if your OS does not provide support for sendfile() +# #-include config.mak @@ -49,6 +52,10 @@ ifeq ($(uname_O),Cygwin) NEEDS_LIBICONV = YesPlease endif +ifneq ($(uname_S),Linux) + NO_SENDFILE = YesPlease +endif + # # Let the user override the above settings. # @@ -157,6 +164,9 @@ ifdef NO_OPENSSL else EXTLIBS += -lcrypto endif +ifdef NO_SENDFILE + CFLAGS += -DNO_SENDFILE +endif cgit: $(OBJECTS) libgit $(QUIET_CC)$(CC) $(CFLAGS) $(LDFLAGS) -o cgit $(OBJECTS) $(EXTLIBS) diff --git a/cache.c b/cache.c index d7a8d5a..19bbc11 100644 --- a/cache.c +++ b/cache.c @@ -13,6 +13,9 @@ * */ +#ifndef NO_SENDFILE +#include +#endif #include "cgit.h" #include "cache.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 +83,7 @@ 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 NO_SENDFILE ssize_t i, j; i = lseek(slot->cache_fd, slot->keylen + 1, SEEK_SET); @@ -97,6 +100,23 @@ static int print_slot(struct cache_slot *slot) return errno; else return 0; +#else + 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); +#endif } /* Check if the slot has expired */ @@ -188,6 +208,10 @@ static int fill_slot(struct cache_slot *slot) /* Generate cache content */ slot->fn(slot->cbdata); + /* update stat info */ + if (fstat(slot->lock_fd, &slot->cache_st)) + return errno; + /* Restore stdout */ if (dup2(tmp, STDOUT_FILENO) == -1) return errno; -- 1.7.2.5