From ab843e3244e98f92e16b9c9c1f06dbab87e97175 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Wed, 7 Feb 2018 17:47:39 +0100 Subject: [PATCH] libbb: shrink wget/tftp progress indicator code for 32-bit function old new delta bb_progress_update 756 654 -102 Signed-off-by: Denys Vlasenko --- libbb/progress.c | 78 +++++++++++++++++++++++------------------------- 1 file changed, 38 insertions(+), 40 deletions(-) diff --git a/libbb/progress.c b/libbb/progress.c index 64e6529ac..17272fd17 100644 --- a/libbb/progress.c +++ b/libbb/progress.c @@ -71,7 +71,7 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p, uoff_t transferred, uoff_t totalsize) { - uoff_t beg_and_transferred; + unsigned beg_and_transferred; /* does not need uoff_t, see scaling code below */ unsigned since_last_update, elapsed; int notty; int kiloscale; @@ -102,33 +102,24 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p, * without risking overflow: we guarantee 10 highest bits to be 0. * Introduced error is less than 1 / 2^12 ~= 0.025% */ - if (ULONG_MAX > 0xffffffff || sizeof(off_t) == 4 || sizeof(off_t) != 8) { - /* - * 64-bit CPU || small off_t: in either case, - * >> is cheap, single-word operation. - * ... || strange off_t: also use this code - * (it is safe, just suboptimal wrt code size), - * because 32/64 optimized one works only for 64-bit off_t. - */ - if (totalsize >= (1 << 22)) { - totalsize >>= 10; - beg_size >>= 10; - transferred >>= 10; - kiloscale = 1; - } - } else { - /* 32-bit CPU and 64-bit off_t. - * Use a 40-bit shift, it is easier to do on 32-bit CPU. - */ -/* ONE suppresses "warning: shift count >= width of type" */ -#define ONE (sizeof(off_t) > 4) - if (totalsize >= (uoff_t)(1ULL << 54*ONE)) { - totalsize = (uint32_t)(totalsize >> 32*ONE) >> 8; - beg_size = (uint32_t)(beg_size >> 32*ONE) >> 8; - transferred = (uint32_t)(transferred >> 32*ONE) >> 8; - kiloscale = 4; - } + while (totalsize >= (1 << 22)) { + totalsize >>= 10; + beg_size >>= 10; + transferred >>= 10; + kiloscale++; } + /* If they were huge, now they are scaled down to [4194303,4096] range. + * (N * totalsize) won't overflow 32 bits for N up to 1024. + * The downside is that files larger than 4194303 kbytes (>4GB) + * never show kbytes download size, they show "0M","1M"... right away + * since kiloscale is already >1. + */ +#if ULONG_MAX == 0xffffffff +/* 32-bit CPU, uoff_t arithmetic is complex on it, cast variables to narrower types */ +# define totalsize ((unsigned)totalsize) +# define beg_size ((unsigned)beg_size) +# define transferred ((unsigned)transferred) +#endif notty = !isatty(STDERR_FILENO); @@ -146,13 +137,18 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p, barlength = get_terminal_width(2) - 49; if (barlength > 0) { - /* god bless gcc for variable arrays :) */ - char buf[barlength + 1]; - unsigned stars = (unsigned)barlength * beg_and_transferred / totalsize; - memset(buf, ' ', barlength); - buf[barlength] = '\0'; - memset(buf, '*', stars); - fprintf(stderr, " |%s|", buf); + if (barlength > 999) + barlength = 999; + { + /* god bless gcc for variable arrays :) */ + char buf[barlength + 1]; + unsigned stars = (unsigned)barlength * beg_and_transferred / totalsize; + /* can't overflow ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */ + memset(buf, ' ', barlength); + buf[barlength] = '\0'; + memset(buf, '*', stars); + fprintf(stderr, " |%s|", buf); + } } } @@ -184,16 +180,18 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p, fprintf(stderr, " --:--:-- ETA"); } else { unsigned eta, secs, hours; + unsigned bytes; - totalsize -= beg_size; /* now it's "total to upload" */ + bytes = totalsize - beg_size; /* Estimated remaining time = - * estimated_sec_to_dl_totalsize_bytes - elapsed_sec = - * totalsize / average_bytes_sec_so_far - elapsed = - * totalsize / (transferred/elapsed) - elapsed = - * totalsize * elapsed / transferred - elapsed + * estimated_sec_to_dl_bytes - elapsed_sec = + * bytes / average_bytes_sec_so_far - elapsed = + * bytes / (transferred/elapsed) - elapsed = + * bytes * elapsed / transferred - elapsed */ - eta = totalsize * elapsed / transferred - elapsed; + eta = (unsigned long)bytes * elapsed / transferred - elapsed; + /* if 32bit, can overflow ^^^^^^^^^^, but this would only show bad ETA */ if (eta >= 1000*60*60) eta = 1000*60*60 - 1; secs = eta % 3600; -- 2.25.1