summaryrefslogtreecommitdiff
path: root/wrapper.c
diff options
context:
space:
mode:
Diffstat (limited to 'wrapper.c')
-rw-r--r--wrapper.c47
1 files changed, 46 insertions, 1 deletions
diff --git a/wrapper.c b/wrapper.c
index 007ec0d8ea..c1a663fd59 100644
--- 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;
+}