From 4c139229611631a3497c224a61107b6b6918e3bf Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sun, 2 Dec 2007 03:27:42 +0000 Subject: Introduce FEATURE_COPYBUF_KB. People who want smaller stack at any cost may use it to reduce cp's stack usage (FEATURE_COPYBUF_KB=1). Desktop people may get faster copy of big files (FEATURE_COPYBUF_KB=32 is ~30% faster than 4kb) --- libbb/copyfd.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) (limited to 'libbb/copyfd.c') diff --git a/libbb/copyfd.c b/libbb/copyfd.c index 3255e424a..ed383ae28 100644 --- a/libbb/copyfd.c +++ b/libbb/copyfd.c @@ -9,31 +9,42 @@ #include "libbb.h" -#if BUFSIZ < 4096 -#undef BUFSIZ -#define BUFSIZ 4096 -#endif - /* Used by NOFORK applets (e.g. cat) - must not use xmalloc */ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) { int status = -1; off_t total = 0; - char buffer[BUFSIZ]; +#if CONFIG_FEATURE_COPYBUF_KB <= 4 + char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024]; + enum { buffer_size = sizeof(buffer) }; +#else + char *buffer; + int buffer_size; + + buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANON, + /* ignored: */ -1, 0); + buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024; + if (buffer == MAP_FAILED) { + buffer = alloca(4 * 1024); + buffer_size = 4 * 1024; + } +#endif if (src_fd < 0) goto out; if (!size) { - size = BUFSIZ; + size = buffer_size; status = 1; /* copy until eof */ } while (1) { ssize_t rd; - rd = safe_read(src_fd, buffer, size > BUFSIZ ? BUFSIZ : size); + rd = safe_read(src_fd, buffer, size > buffer_size ? buffer_size : size); if (!rd) { /* eof - all done */ status = 0; @@ -62,6 +73,11 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size) } } out: + +#if CONFIG_FEATURE_COPYBUF_KB > 4 + if (buffer_size != 4 * 1024) + munmap(buffer, buffer_size); +#endif return status ? -1 : total; } -- cgit v1.2.3