syscall: Add read and write for stream resources

1 files changed, 28 insertions, 0 deletions

diff --git a/src/lib/vfs.zig b/src/lib/vfs.zig
index 56834d6..3a1fbff 100644
--- a/src/lib/vfs.zig
+++ b/src/lib/vfs.zig
@@ -16,6 +16,8 @@ pub const Error = error{
     NotADirectory,
     NoAbsoluteContainingDirectory,
     TooManyReferences,
+    ReadNotSupported,
+    WriteNotSupported,
 };
 
 // A stream is a resource that provides a shared data stream with a driver.
@@ -127,6 +129,32 @@ pub const ResourceDescriptor = struct {
     pub fn deinit(self: ResourceDescriptor) void {
         self.inode.refs -|= 1;
     }
+
+    pub fn read(self: ResourceDescriptor, buffer: []u8) sysexchange.Result(usize) {
+        const err_unsupported = sysexchange.Result(usize).fromAnyTypeOrError(Error.ReadNotSupported);
+
+        return switch (self.inode.resource) {
+            .stream => |stream| blk: {
+                const readFn = stream.readFn orelse return err_unsupported;
+                break :blk readFn(buffer);
+            },
+            .hook => err_unsupported,
+            else => err_unsupported,
+        };
+    }
+
+    pub fn write(self: ResourceDescriptor, bytes: []const u8) sysexchange.Result(usize) {
+        const err_unsupported = sysexchange.Result(usize).fromAnyTypeOrError(Error.WriteNotSupported);
+
+        return switch (self.inode.resource) {
+            .stream => |stream| blk: {
+                const writeFn = stream.writeFn orelse return err_unsupported;
+                break :blk writeFn(bytes);
+            },
+            .hook => err_unsupported,
+            else => err_unsupported,
+        };
+    }
 };
 
 pub const UserInfo = union(enum) {