wget: shrink progress meter code; strink wget and add debug logging

function                                             old     new   delta
fgets_and_trim                                         -      73     +73
retrieve_file_data                                   367     349     -18
bb_progress_update                                   723     699     -24
wget_main                                           2220    2190     -30
ftpcmd                                               133      87     -46
gethdr                                               200     153     -47
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/5 up/down: 73/-165)           Total: -92 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 105 insertions, 64 deletions

diff --git a/libbb/progress.c b/libbb/progress.c
index ced04ac32..a490b8390 100644
--- a/libbb/progress.c
+++ b/libbb/progress.c
@@ -60,9 +60,16 @@ void FAST_FUNC bb_progress_init(bb_progress_t *p)
         p->inited = 1;
 }
 
+/* File already had beg_size bytes.
+ * Then we started downloading.
+ * We downloaded "transferred" bytes so far.
+ * Download is expected to stop when total size (beg_size + transferred)
+ * will be "totalsize" bytes.
+ * If totalsize == 0, then it is unknown.
+ */
 void FAST_FUNC bb_progress_update(bb_progress_t *p,
                 const char *curfile,
-                uoff_t beg_range,
+                uoff_t beg_size,
                 uoff_t transferred,
                 uoff_t totalsize)
 {
@@ -72,32 +79,53 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
         int barlength;
         int kiloscale;
 
-        /* totalsize == 0 if it is unknown */
-
-        beg_and_transferred = beg_range + transferred;
+        beg_and_transferred = beg_size + transferred;
 
         elapsed = monotonic_sec();
         since_last_update = elapsed - p->lastupdate_sec;
-        /* Do not update on every call
-         * (we can be called on every network read!) */
+        /*
+         * Do not update on every call
+         * (we can be called on every network read!)
+         */
         if (since_last_update == 0 && beg_and_transferred < totalsize)
                 return;
 
-        /* Scale sizes down if they are close to overflowing.
-         * If off_t is only 32 bits, this allows calculations
-         * like (100 * transferred / totalsize) without risking overflow.
-         * Introduced error is < 0.1%
-         */
         kiloscale = 0;
-        if (totalsize >= (1 << 20)) {
-                totalsize >>= 10;
-                beg_range >>= 10;
-                transferred >>= 10;
-                beg_and_transferred >>= 10;
-                kiloscale++;
+        /*
+         * Scale sizes down if they are close to overflowing.
+         * This allows calculations like (100 * transferred / totalsize)
+         * 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,
+                 * even if suboptimal), because 32/64 optimized one
+                 * works only for 64-bit off_t.
+                 */
+                if (totalsize >= (1 << 22)) {
+                        totalsize >>= 10;
+                        beg_size >>= 10;
+                        transferred >>= 10;
+                        beg_and_transferred >>= 10;
+                        kiloscale = 1;
+                }
+        } else {
+                /* 32-bit CPU and 64-bit off_t.
+                 * Pick a shift (40 bits) which is easier to do on 32-bit CPU.
+                 */
+                if (totalsize >= (uoff_t)(1ULL << 54)) {
+                        totalsize = (uint32_t)(totalsize >> 32) >> 8;
+                        beg_size = (uint32_t)(beg_size >> 32) >> 8;
+                        transferred = (uint32_t)(transferred >> 32) >> 8;
+                        beg_and_transferred = (uint32_t)(beg_and_transferred >> 32) >> 8;
+                        kiloscale = 4;
+                }
         }
 
-        if (beg_and_transferred >= totalsize)
+        if (beg_and_transferred > totalsize)
                 beg_and_transferred = totalsize;
 
         ratio = 100 * beg_and_transferred / totalsize;
@@ -124,14 +152,14 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
         }
 
         while (beg_and_transferred >= 100000) {
-                kiloscale++;
                 beg_and_transferred >>= 10;
+                kiloscale++;
         }
         /* see http://en.wikipedia.org/wiki/Tera */
         fprintf(stderr, "%6u%c ", (unsigned)beg_and_transferred, " kMGTPEZY"[kiloscale]);
 #define beg_and_transferred dont_use_beg_and_transferred_below()
 
-        if (transferred > p->lastsize) {
+        if (transferred != p->lastsize) {
                 p->lastupdate_sec = elapsed;
                 p->lastsize = transferred;
                 if (since_last_update >= STALLTIME) {
@@ -141,20 +169,27 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
                 }
                 since_last_update = 0; /* we are un-stalled now */
         }
+
         elapsed -= p->start_sec; /* now it's "elapsed since start" */
 
         if (since_last_update >= STALLTIME) {
                 fprintf(stderr, " - stalled -");
+        } else if (!totalsize || !transferred || (int)elapsed <= 0) {
+                fprintf(stderr, "--:--:-- ETA");
         } else {
-                uoff_t to_download = totalsize - beg_range;
-                if (!totalsize || (int)elapsed <= 0 || transferred > to_download) {
-                        fprintf(stderr, "--:--:-- ETA");
-                } else {
-                        /* to_download / (transferred/elapsed) - elapsed: */
-                        unsigned eta = to_download * elapsed / transferred - elapsed;
-                        unsigned secs = eta % 3600;
-                        unsigned hours = eta / 3600;
-                        fprintf(stderr, "%02u:%02u:%02u ETA", hours, secs / 60, secs % 60);
-                }
+                unsigned eta, secs, hours;
+
+                totalsize -= beg_size; /* now it's "total to upload" */
+
+                /* 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
+                 */
+                eta = totalsize * elapsed / transferred - elapsed;
+                secs = eta % 3600;
+                hours = eta / 3600;
+                fprintf(stderr, "%02u:%02u:%02u ETA", hours, secs / 60, secs % 60);
         }
 }
diff --git a/networking/wget.c b/networking/wget.c
index 931882fde..d81426e8d 100644
--- a/networking/wget.c
+++ b/networking/wget.c
@@ -10,6 +10,10 @@
  */
 #include "libbb.h"
 
+//#define log_io(...) bb_error_msg(__VA_ARGS__)
+#define log_io(...) ((void)0)
+
+
 struct host_info {
         // May be used if we ever will want to free() all xstrdup()s...
         /* char *allocated; */
@@ -197,25 +201,39 @@ static FILE *open_socket(len_and_sockaddr *lsa)
         return fp;
 }
 
+/* Returns '\n' if it was seen, else '\0'. Trims at first '\r' or '\n' */
+static char fgets_and_trim(FILE *fp)
+{
+        char c;
+        char *buf_ptr;
+
+        if (fgets(G.wget_buf, sizeof(G.wget_buf) - 1, fp) == NULL)
+                bb_perror_msg_and_die("error getting response");
+
+        buf_ptr = strchrnul(G.wget_buf, '\n');
+        c = *buf_ptr;
+        *buf_ptr = '\0';
+        buf_ptr = strchrnul(G.wget_buf, '\r');
+        *buf_ptr = '\0';
+
+        log_io("< %s", G.wget_buf);
+
+        return c;
+}
+
 static int ftpcmd(const char *s1, const char *s2, FILE *fp)
 {
         int result;
         if (s1) {
-                if (!s2) s2 = "";
+                if (!s2)
+                        s2 = "";
                 fprintf(fp, "%s%s\r\n", s1, s2);
                 fflush(fp);
+                log_io("> %s%s", s1, s2);
         }
 
         do {
-                char *buf_ptr;
-
-                if (fgets(G.wget_buf, sizeof(G.wget_buf)-2, fp) == NULL) {
-                        bb_perror_msg_and_die("error getting response");
-                }
-                buf_ptr = strstr(G.wget_buf, "\r\n");
-                if (buf_ptr) {
-                        *buf_ptr = '\0';
-                }
+                fgets_and_trim(fp);
         } while (!isdigit(G.wget_buf[0]) || G.wget_buf[3] != ' ');
 
         G.wget_buf[3] = '\0';
@@ -284,7 +302,7 @@ static void parse_url(char *src_url, struct host_info *h)
         sp = h->host;
 }
 
-static char *gethdr(FILE *fp /*, int *istrunc*/)
+static char *gethdr(FILE *fp)
 {
         char *s, *hdrval;
         int c;
@@ -292,19 +310,16 @@ static char *gethdr(FILE *fp /*, int *istrunc*/)
         /* *istrunc = 0; */
 
         /* retrieve header line */
-        if (fgets(G.wget_buf, sizeof(G.wget_buf), fp) == NULL)
-                return NULL;
+        c = fgets_and_trim(fp);
 
-        /* see if we are at the end of the headers */
-        for (s = G.wget_buf; *s == '\r'; ++s)
-                continue;
-        if (*s == '\n')
+        /* end of the headers? */
+        if (G.wget_buf[0] == '\0')
                 return NULL;
 
         /* convert the header name to lower case */
         for (s = G.wget_buf; isalnum(*s) || *s == '-' || *s == '.'; ++s) {
                 /* tolower for "A-Z", no-op for "0-9a-z-." */
-                *s = (*s | 0x20);
+                *s |= 0x20;
         }
 
         /* verify we are at the end of the header name */
@@ -315,20 +330,12 @@ static char *gethdr(FILE *fp /*, int *istrunc*/)
         *s++ = '\0';
         hdrval = skip_whitespace(s);
 
-        /* locate the end of header */
-        while (*s && *s != '\r' && *s != '\n')
-                ++s;
-
-        /* end of header found */
-        if (*s) {
-                *s = '\0';
-                return hdrval;
+        if (c != '\n') {
+                /* Rats! The buffer isn't big enough to hold the entire header value */
+                while (c = getc(fp), c != EOF && c != '\n')
+                        continue;
         }
 
-        /* Rats! The buffer isn't big enough to hold the entire header value */
-        while (c = getc(fp), c != EOF && c != '\n')
-                continue;
-        /* *istrunc = 1; */
         return hdrval;
 }
 
@@ -520,9 +527,9 @@ static void NOINLINE retrieve_file_data(FILE *dfp, int output_fd)
                 if (!G.chunked)
                         break;
 
-                fgets(G.wget_buf, sizeof(G.wget_buf), dfp); /* This is a newline */
+                fgets_and_trim(dfp); /* This is a newline */
  get_clen:
-                fgets(G.wget_buf, sizeof(G.wget_buf), dfp);
+                fgets_and_trim(dfp);
                 G.content_len = STRTOOFF(G.wget_buf, NULL, 16);
                 /* FIXME: error check? */
                 if (G.content_len == 0)
@@ -757,8 +764,7 @@ int wget_main(int argc UNUSED_PARAM, char **argv)
                  * Retrieve HTTP response line and check for "200" status code.
                  */
  read_response:
-                if (fgets(G.wget_buf, sizeof(G.wget_buf), sfp) == NULL)
-                        bb_error_msg_and_die("no response from server");
+                fgets_and_trim(sfp);
 
                 str = G.wget_buf;
                 str = skip_non_whitespace(str);