authorgravatar for takeshi@tetrate.ioTakeshi Yoneda <takeshi@tetrate.io> 2022-12-01 13:56:53+09:00
committergravatar for takeshi@tetrate.ioTakeshi Yoneda <takeshi@tetrate.io> 2022-12-01 13:56:53+09:00
log829bf5a03e510e707de3c48a78bef2f35fe193a6
tree1700f45c5f79ef8c923c437127bd55860557cd0d
parenta943422672a9f456a74c20b4c167107ccbadfb1a

wasi: fixes IterableDir.nextWasi for large directory

Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>

2 files changed, 45 insertions(+), 1 deletions(-)

lib/std/fs.zig+8-1
......@@ -809,7 +809,9 @@ pub const IterableDir = struct {
809809 // and we avoid the code complexity here.
810810 const w = os.wasi;
811811 start_over: while (true) {
812 if (self.index >= self.end_index) {
812 // According to the WASI spec, the last entry might be truncated,
813 // so we need to check if the left buffer contains the whole dirent.
814 if (self.end_index - self.index < @sizeOf(w.dirent_t)) {
813815 var bufused: usize = undefined;
814816 switch (w.fd_readdir(self.dir.fd, &self.buf, self.buf.len, self.cookie, &bufused)) {
815817 .SUCCESS => {},
......@@ -828,6 +830,11 @@ pub const IterableDir = struct {
828830 const entry = @ptrCast(*align(1) w.dirent_t, &self.buf[self.index]);
829831 const entry_size = @sizeOf(w.dirent_t);
830832 const name_index = self.index + entry_size;
833 if (name_index + entry.d_namlen > self.end_index) {
834 // This case, the name is truncated, so we need to call readdir to store the entire name.
835 self.end_index = self.index; // Force fd_readdir in the next loop.
836 continue :start_over;
837 }
831838 const name = mem.span(self.buf[name_index .. name_index + entry.d_namlen]);
832839
833840 const next_index = name_index + entry.d_namlen;
lib/std/fs/test.zig+37
......@@ -186,6 +186,43 @@ test "Dir.Iterator" {
186186 try testing.expect(contains(&entries, .{ .name = "some_dir", .kind = .Directory }));
187187}
188188
189test "Dir.Iterator many entries" {
190 if (builtin.os.tag == .wasi and !builtin.link_libc) try os.initPreopensWasi(std.heap.page_allocator, "/");
191
192 var tmp_dir = tmpIterableDir(.{});
193 defer tmp_dir.cleanup();
194
195 const num = 1024;
196 var i: usize = 0;
197 var buf: [4]u8 = undefined; // Enough to store "1024".
198 while (i < num) : (i += 1) {
199 const name = try std.fmt.bufPrint(&buf, "{}", .{i});
200 const file = try tmp_dir.iterable_dir.dir.createFile(name, .{});
201 file.close();
202 }
203
204 var arena = ArenaAllocator.init(testing.allocator);
205 defer arena.deinit();
206 const allocator = arena.allocator();
207
208 var entries = std.ArrayList(IterableDir.Entry).init(allocator);
209
210 // Create iterator.
211 var iter = tmp_dir.iterable_dir.iterate();
212 while (try iter.next()) |entry| {
213 // We cannot just store `entry` as on Windows, we're re-using the name buffer
214 // which means we'll actually share the `name` pointer between entries!
215 const name = try allocator.dupe(u8, entry.name);
216 try entries.append(.{ .name = name, .kind = entry.kind });
217 }
218
219 i = 0;
220 while (i < num) : (i += 1) {
221 const name = try std.fmt.bufPrint(&buf, "{}", .{i});
222 try testing.expect(contains(&entries, .{ .name = name, .kind = .File }));
223 }
224}
225
189226test "Dir.Iterator twice" {
190227 var tmp_dir = tmpIterableDir(.{});
191228 defer tmp_dir.cleanup();