reftable/stack: stop using write_in_full()

Similar to the preceding commit, drop our use of `write_in_full()` and
implement a new wrapper `reftable_write_full()` that handles this logic
for us. This is done to reduce our dependency on the Git library.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: pks-t

reftable/stack.c

@@ -48,6 +48,25 @@ static int stack_fsync(const struct reftable_write_options *opts, int fd)
 	return fsync(fd);
 }
 
+static ssize_t reftable_write_data(int fd, const void *data, size_t size)
+{
+	size_t total_written = 0;
+	const char *p = data;
+
+	while (total_written < size) {
+		ssize_t bytes_written = write(fd, p, size - total_written);
+		if (bytes_written < 0 && (errno == EAGAIN || errno == EINTR))
+			continue;
+		if (bytes_written < 0)
+			return REFTABLE_IO_ERROR;
+
+		total_written += bytes_written;
+		p += bytes_written;
+	}
+
+	return total_written;
+}
+
 struct fd_writer {
 	const struct reftable_write_options *opts;
 	int fd;
@@ -56,7 +75,7 @@ struct fd_writer {
 static ssize_t fd_writer_write(void *arg, const void *data, size_t sz)
 {
 	struct fd_writer *writer = arg;
-	return write_in_full(writer->fd, data, sz);
+	return reftable_write_data(writer->fd, data, sz);
 }
 
 static int fd_writer_flush(void *arg)
@@ -784,7 +803,8 @@ int reftable_addition_commit(struct reftable_addition *add)
 			goto done;
 	}
 
-	err = write_in_full(add->tables_list_lock.fd, table_list.buf, table_list.len);
+	err = reftable_write_data(add->tables_list_lock.fd,
+				  table_list.buf, table_list.len);
 	reftable_buf_release(&table_list);
 	if (err < 0) {
 		err = REFTABLE_IO_ERROR;
@@ -1470,8 +1490,8 @@ static int stack_compact_range(struct reftable_stack *st,
 			goto done;
 	}
 
-	err = write_in_full(tables_list_lock.fd,
-			    tables_list_buf.buf, tables_list_buf.len);
+	err = reftable_write_data(tables_list_lock.fd,
+				  tables_list_buf.buf, tables_list_buf.len);
 	if (err < 0) {
 		err = REFTABLE_IO_ERROR;
 		unlink(new_table_path.buf);