[src/trunk]: src/usr.bin/gzip now that we are processing SIGINFO write can be...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9f01a6996480
branches:  trunk
changeset: 826246:9f01a6996480
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Aug 23 13:04:17 2017 +0000

description:
now that we are processing SIGINFO write can be interrupted and return
partial results (well, it could before too but it was harder to trigger);
provide write_fully like we have read_fully already.

diffstat:

 usr.bin/gzip/gzip.c |  39 +++++++++++++++++++++++++++++++--------
 1 files changed, 31 insertions(+), 8 deletions(-)

diffs (106 lines):

diff -r 811f3f5e4cc4 -r 9f01a6996480 usr.bin/gzip/gzip.c
--- a/usr.bin/gzip/gzip.c       Wed Aug 23 13:02:14 2017 +0000
+++ b/usr.bin/gzip/gzip.c       Wed Aug 23 13:04:17 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: gzip.c,v 1.111 2017/08/04 07:27:08 mrg Exp $   */
+/*     $NetBSD: gzip.c,v 1.112 2017/08/23 13:04:17 christos Exp $      */
 
 /*
  * Copyright (c) 1997, 1998, 2003, 2004, 2006, 2008, 2009, 2010, 2011, 2015, 2017
@@ -31,7 +31,7 @@
 #ifndef lint
 __COPYRIGHT("@(#) Copyright (c) 1997, 1998, 2003, 2004, 2006, 2008,\
  2009, 2010, 2011, 2015, 2017 Matthew R. Green.  All rights reserved.");
-__RCSID("$NetBSD: gzip.c,v 1.111 2017/08/04 07:27:08 mrg Exp $");
+__RCSID("$NetBSD: gzip.c,v 1.112 2017/08/23 13:04:17 christos Exp $");
 #endif /* not lint */
 
 /*
@@ -212,6 +212,7 @@
 __dead static  void    display_version(void);
 static const suffixes_t *check_suffix(char *, int);
 static ssize_t read_retry(int, void *, size_t);
+static ssize_t write_retry(int, const void *, size_t);
 
 #ifdef SMALL
 #define infile_set(f,t) infile_set(f)
@@ -605,7 +606,7 @@
        crc = crc32(0L, Z_NULL, 0);
        for (;;) {
                if (z.avail_out == 0) {
-                       if (write(out, outbufp, BUFLEN) != BUFLEN) {
+                       if (write_retry(out, outbufp, BUFLEN) != BUFLEN) {
                                maybe_warn("write");
                                out_tot = -1;
                                goto out;
@@ -655,7 +656,7 @@
 
                len = (char *)z.next_out - outbufp;
 
-               w = write(out, outbufp, len);
+               w = write_retry(out, outbufp, len);
                if (w == -1 || (size_t)w != len) {
                        maybe_warn("write");
                        out_tot = -1;
@@ -690,7 +691,7 @@
        if (in_tot > 0xffffffff)
                maybe_warn("input file size >= 4GB cannot be saved");
 #endif
-       if (write(out, outbufp, i) != i) {
+       if (write_retry(out, outbufp, i) != i) {
                maybe_warn("write");
                in_tot = -1;
        } else
@@ -957,7 +958,7 @@
                                    /* don't write anything with -t */
                                    tflag == 0 &&
 #endif
-                                   write(out, outbufp, wr) != wr) {
+                                   write_retry(out, outbufp, wr) != wr) {
                                        maybe_warn("error writing to output");
                                        goto stop_and_fail;
                                }
@@ -1699,7 +1700,7 @@
        ssize_t w;
 
        in_tot = count;
-       w = write(STDOUT_FILENO, prepend, count);
+       w = write_retry(STDOUT_FILENO, prepend, count);
        if (w == -1 || (size_t)w != count) {
                maybe_warn("write to stdout");
                return -1;
@@ -1716,7 +1717,7 @@
                }
                infile_newdata(rv);
 
-               if (write(STDOUT_FILENO, buf, rv) != rv) {
+               if (write_retry(STDOUT_FILENO, buf, rv) != rv) {
                        maybe_warn("write to stdout");
                        break;
                }
@@ -2226,3 +2227,25 @@
 
        return sz - left;
 }
+
+static ssize_t
+write_retry(int fd, const void *buf, size_t sz)
+{
+       const char *cp = buf;
+       size_t left = MIN(sz, (size_t) SSIZE_MAX);
+
+       while (left > 0) {
+               ssize_t ret;
+
+               ret = write(fd, cp, left);
+               if (ret == -1) {
+                       return ret;
+               } else if (ret == 0) {
+                       abort();        /* Can't happen */
+               }
+               cp += ret;
+               left -= ret;
+       }
+
+       return sz - left;
+}