Merge branch 'pt/pull-log-n'

diff --git a/wrapper.c b/wrapper.c
index 007ec0d8eac529579cc00b14f9baaddb7ac68487..c1a663fd592133b3e26314f3d598a8bca8bcceb1 100644 (file)
--- a/wrapper.c
+++ b/wrapper.c
@@ -172,8 +172,22 @@ void *xcalloc(size_t nmemb, size_t size)
  * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
  * the absence of bugs, large chunks can result in bad latencies when
  * you decide to kill the process.
+ *
+ * We pick 8 MiB as our default, but if the platform defines SSIZE_MAX
+ * that is smaller than that, clip it to SSIZE_MAX, as a call to
+ * read(2) or write(2) larger than that is allowed to fail.  As the last
+ * resort, we allow a port to pass via CFLAGS e.g. "-DMAX_IO_SIZE=value"
+ * to override this, if the definition of SSIZE_MAX given by the platform
+ * is broken.
  */
-#define MAX_IO_SIZE (8*1024*1024)
+#ifndef MAX_IO_SIZE
+# define MAX_IO_SIZE_DEFAULT (8*1024*1024)
+# if defined(SSIZE_MAX) && (SSIZE_MAX < MAX_IO_SIZE_DEFAULT)
+#  define MAX_IO_SIZE SSIZE_MAX
+# else
+#  define MAX_IO_SIZE MAX_IO_SIZE_DEFAULT
+# endif
+#endif
 
 /*
  * xread() is the same a read(), but it automatically restarts read()
@@ -550,3 +564,34 @@ char *xgetcwd(void)
                die_errno(_("unable to get current working directory"));
        return strbuf_detach(&sb, NULL);
 }
+
+int write_file(const char *path, int fatal, const char *fmt, ...)
+{
+       struct strbuf sb = STRBUF_INIT;
+       va_list params;
+       int fd = open(path, O_RDWR | O_CREAT | O_TRUNC, 0666);
+       if (fd < 0) {
+               if (fatal)
+                       die_errno(_("could not open %s for writing"), path);
+               return -1;
+       }
+       va_start(params, fmt);
+       strbuf_vaddf(&sb, fmt, params);
+       va_end(params);
+       if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
+               int err = errno;
+               close(fd);
+               strbuf_release(&sb);
+               errno = err;
+               if (fatal)
+                       die_errno(_("could not write to %s"), path);
+               return -1;
+       }
+       strbuf_release(&sb);
+       if (close(fd)) {
+               if (fatal)
+                       die_errno(_("could not close %s"), path);
+               return -1;
+       }
+       return 0;
+}