1 files changed, 101 insertions, 5 deletions

diff --git a/wrapper.c b/wrapper.c
index a2dff8e5be..0e22d43814 100644
--- a/wrapper.c
+++ b/wrapper.c
@@ -172,8 +172,57 @@ 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
+
+/**
+ * xopen() is the same as open(), but it die()s if the open() fails.
+ */
+int xopen(const char *path, int oflag, ...)
+{
+	mode_t mode = 0;
+	va_list ap;
+
+	/*
+	 * va_arg() will have undefined behavior if the specified type is not
+	 * compatible with the argument type. Since integers are promoted to
+	 * ints, we fetch the next argument as an int, and then cast it to a
+	 * mode_t to avoid undefined behavior.
+	 */
+	va_start(ap, oflag);
+	if (oflag & O_CREAT)
+		mode = va_arg(ap, int);
+	va_end(ap);
+
+	for (;;) {
+		int fd = open(path, oflag, mode);
+		if (fd >= 0)
+			return fd;
+		if (errno == EINTR)
+			continue;
+
+		if ((oflag & O_RDWR) == O_RDWR)
+			die_errno(_("could not open '%s' for reading and writing"), path);
+		else if ((oflag & O_WRONLY) == O_WRONLY)
+			die_errno(_("could not open '%s' for writing"), path);
+		else
+			die_errno(_("could not open '%s' for reading"), path);
+	}
+}
 
 /*
  * xread() is the same a read(), but it automatically restarts read()
@@ -297,6 +346,27 @@ int xdup(int fd)
 	return ret;
 }
 
+/**
+ * xfopen() is the same as fopen(), but it die()s if the fopen() fails.
+ */
+FILE *xfopen(const char *path, const char *mode)
+{
+	for (;;) {
+		FILE *fp = fopen(path, mode);
+		if (fp)
+			return fp;
+		if (errno == EINTR)
+			continue;
+
+		if (*mode && mode[1] == '+')
+			die_errno(_("could not open '%s' for reading and writing"), path);
+		else if (*mode == 'w' || *mode == 'a')
+			die_errno(_("could not open '%s' for writing"), path);
+		else
+			die_errno(_("could not open '%s' for reading"), path);
+	}
+}
+
 FILE *xfdopen(int fd, const char *mode)
 {
 	FILE *stream = fdopen(fd, mode);
@@ -551,19 +621,18 @@ char *xgetcwd(void)
 	return strbuf_detach(&sb, NULL);
 }
 
-int write_file(const char *path, int fatal, const char *fmt, ...)
+static int write_file_v(const char *path, int fatal,
+			const char *fmt, va_list params)
 {
 	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);
+	strbuf_complete_line(&sb);
 	if (write_in_full(fd, sb.buf, sb.len) != sb.len) {
 		int err = errno;
 		close(fd);
@@ -581,3 +650,30 @@ int write_file(const char *path, int fatal, const char *fmt, ...)
 	}
 	return 0;
 }
+
+int write_file(const char *path, const char *fmt, ...)
+{
+	int status;
+	va_list params;
+
+	va_start(params, fmt);
+	status = write_file_v(path, 1, fmt, params);
+	va_end(params);
+	return status;
+}
+
+int write_file_gently(const char *path, const char *fmt, ...)
+{
+	int status;
+	va_list params;
+
+	va_start(params, fmt);
+	status = write_file_v(path, 0, fmt, params);
+	va_end(params);
+	return status;
+}
+
+void sleep_millisec(int millisec)
+{
+	poll(NULL, 0, millisec);
+}