reftable/stack: stop using `fsync_component()` directly

We're executing `fsync_component()` directly in the reftable library so
that we can fsync data to disk depending on "core.fsync". But as we're
in the process of converting the reftable library to become standalone
we cannot use that function in the library anymore.

Refactor the code such that users of the library can inject a custom
fsync function via the write options. This allows us to get rid of the
dependency on "write-or-die.h".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 32 insertions, 17 deletions

diff --git a/reftable/stack.c b/reftable/stack.c
index 9ae716ff37..c67bdd952c 100644
--- a/reftable/stack.c
+++ b/reftable/stack.c
@@ -8,7 +8,6 @@ https://developers.google.com/open-source/licenses/bsd
 
 #include "stack.h"
 
-#include "../write-or-die.h"
 #include "system.h"
 #include "constants.h"
 #include "merged.h"
@@ -43,17 +42,28 @@ static int stack_filename(struct reftable_buf *dest, struct reftable_stack *st,
 	return 0;
 }
 
-static ssize_t reftable_fd_write(void *arg, const void *data, size_t sz)
+static int stack_fsync(const struct reftable_write_options *opts, int fd)
 {
-	int *fdp = (int *)arg;
-	return write_in_full(*fdp, data, sz);
+	if (opts->fsync)
+		return opts->fsync(fd);
+	return fsync(fd);
 }
 
-static int reftable_fd_flush(void *arg)
+struct fd_writer {
+	const struct reftable_write_options *opts;
+	int fd;
+};
+
+static ssize_t fd_writer_write(void *arg, const void *data, size_t sz)
 {
-	int *fdp = (int *)arg;
+	struct fd_writer *writer = arg;
+	return write_in_full(writer->fd, data, sz);
+}
 
-	return fsync_component(FSYNC_COMPONENT_REFERENCE, *fdp);
+static int fd_writer_flush(void *arg)
+{
+	struct fd_writer *writer = arg;
+	return stack_fsync(writer->opts, writer->fd);
 }
 
 int reftable_new_stack(struct reftable_stack **dest, const char *dir,
@@ -765,7 +775,7 @@ int reftable_addition_commit(struct reftable_addition *add)
 		goto done;
 	}
 
-	err = fsync_component(FSYNC_COMPONENT_REFERENCE, lock_file_fd);
+	err = stack_fsync(&add->stack->opts, lock_file_fd);
 	if (err < 0) {
 		err = REFTABLE_IO_ERROR;
 		goto done;
@@ -858,8 +868,10 @@ int reftable_addition_add(struct reftable_addition *add,
 	struct reftable_buf next_name = REFTABLE_BUF_INIT;
 	struct reftable_writer *wr = NULL;
 	struct tempfile *tab_file = NULL;
+	struct fd_writer writer = {
+		.opts = &add->stack->opts,
+	};
 	int err = 0;
-	int tab_fd;
 
 	reftable_buf_reset(&next_name);
 
@@ -887,10 +899,10 @@ int reftable_addition_add(struct reftable_addition *add,
 			goto done;
 		}
 	}
-	tab_fd = get_tempfile_fd(tab_file);
 
-	err = reftable_writer_new(&wr, reftable_fd_write, reftable_fd_flush,
-				  &tab_fd, &add->stack->opts);
+	writer.fd = get_tempfile_fd(tab_file);
+	err = reftable_writer_new(&wr, fd_writer_write, fd_writer_flush,
+				  &writer, &add->stack->opts);
 	if (err < 0)
 		goto done;
 
@@ -973,8 +985,11 @@ static int stack_compact_locked(struct reftable_stack *st,
 	struct reftable_buf next_name = REFTABLE_BUF_INIT;
 	struct reftable_buf tab_file_path = REFTABLE_BUF_INIT;
 	struct reftable_writer *wr = NULL;
+	struct fd_writer writer=  {
+		.opts = &st->opts,
+	};
 	struct tempfile *tab_file;
-	int tab_fd, err = 0;
+	int err = 0;
 
 	err = format_name(&next_name, reftable_reader_min_update_index(st->readers[first]),
 			  reftable_reader_max_update_index(st->readers[last]));
@@ -994,7 +1009,6 @@ static int stack_compact_locked(struct reftable_stack *st,
 		err = REFTABLE_IO_ERROR;
 		goto done;
 	}
-	tab_fd = get_tempfile_fd(tab_file);
 
 	if (st->opts.default_permissions &&
 	    chmod(get_tempfile_path(tab_file), st->opts.default_permissions) < 0) {
@@ -1002,8 +1016,9 @@ static int stack_compact_locked(struct reftable_stack *st,
 		goto done;
 	}
 
-	err = reftable_writer_new(&wr, reftable_fd_write, reftable_fd_flush,
-				  &tab_fd, &st->opts);
+	writer.fd = get_tempfile_fd(tab_file);
+	err = reftable_writer_new(&wr, fd_writer_write, fd_writer_flush,
+				  &writer, &st->opts);
 	if (err < 0)
 		goto done;
 
@@ -1460,7 +1475,7 @@ static int stack_compact_range(struct reftable_stack *st,
 		goto done;
 	}
 
-	err = fsync_component(FSYNC_COMPONENT_REFERENCE, get_lock_file_fd(&tables_list_lock));
+	err = stack_fsync(&st->opts, get_lock_file_fd(&tables_list_lock));
 	if (err < 0) {
 		err = REFTABLE_IO_ERROR;
 		unlink(new_table_path.buf);