Views generated by each read stat 0, as acme's do: data, xdata, index, layout, recent and listeners; fs.md says which files have real lengths

A stat of index, layout, recent or listeners built the whole view to
count it, and data and xdata reported the body's length though a read
answers what addr selects. Those now stat 0, as screen and pane/new
already did, and fs.md lists the files whose length is real and says to
read the rest to the end.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 5 insertions, 21 deletions

diff --git a/src/ninep/pane.zig b/src/ninep/pane.zig
index 14877f0f..3b5f2e6c 100644
--- a/src/ninep/pane.zig
+++ b/src/ninep/pane.zig
@@ -398,7 +398,9 @@ pub fn fileSize(p: *Pardes, id: usize, f: PaneFile) u64 {
     return switch (f) {
         // A terminal's body reads its screen and history, as text.
         .body => if (pane.file == null and pane.isTerminal()) panes.terminal.screenTextLen(pane) else if (pdfText(p, pane)) |t| t.len else bodyOf(pane).len,
-        .data, .xdata => bodyOf(pane).len,
+        // What addr selects, generated by each read: no length, as acme's
+        // data and xdata have none.
+        .data, .xdata => 0,
         .tag => tagOf(p, pane).len,
         .name => nameOf(p, pane).len + 1,
         .ctl => ctl: {
@@ -437,23 +439,6 @@ pub fn columnOf(p: *Pardes, id: usize) u32 {
     return pardes.layout.columnSerial(p, at.col);
 }
 
-pub fn indexLen(p: *Pardes) u64 {
-    var n: u64 = 0;
-    var last: u32 = 0;
-    while (tree.nextSerialAfter(p, last)) |serial| {
-        last = serial;
-        const pane = p.panes[p.paneBySerial(serial).?].?;
-        var digits: [16]u8 = undefined;
-        // unreachable: a u32 serial is at most 10 digits
-        n += (std.fmt.bufPrint(&digits, "{d}", .{serial}) catch unreachable).len;
-        var name_buf: [4 * 4096]u8 = undefined;
-        n += 1 + kindOf(pane).len + 3 + events.shown(nameOf(p, pane), &name_buf).len + 1;
-        // unreachable: a column index is under 16 digits
-        n += 1 + (std.fmt.bufPrint(&digits, "{d}", .{columnOf(p, p.paneBySerial(serial).?)}) catch unreachable).len;
-    }
-    return n;
-}
-
 // ---- reads ----
 
 pub fn read(p: *Pardes, req: Req, id: usize, pane: *Pane, file: PaneFile) Reply {
@@ -1081,7 +1066,7 @@ const withFile = th.withFile;
 const serialOf = th.serialOf;
 const Status = tree.Status;
 
-test "index lists serial kind dirty flag and name and stat reports its length" {
+test "index lists serial kind dirty flag and name, and stats 0, a view generated by each read" {
     const gpa = testing.allocator;
     const p = try withFile(gpa, "hello\nthere\n");
     defer p.deinit();
@@ -1095,7 +1080,7 @@ test "index lists serial kind dirty flag and name and stat reports its length" {
     try testing.expect(std.mem.indexOf(u8, a.bytes, clean_row) != null);
     const at = std.mem.indexOf(u8, a.bytes, clean_row).?;
     const stat = call(p, .{ .tag = 1, .op = .getattr, .node = index });
-    try testing.expectEqual(@as(u64, a.bytes.len), stat.reply.attr.size);
+    try testing.expectEqual(@as(u64, 0), stat.reply.attr.size);
     try testing.expectEqual(@as(u16, 0o444), stat.reply.attr.mode);
 
     pane.file.?.saved_revision = pane.file.?.revision -% 1;
@@ -1107,7 +1092,6 @@ test "index lists serial kind dirty flag and name and stat reports its length" {
 
     const serial = try th.newPane(p);
     const both = rd(p, index, 0, 4096);
-    try testing.expectEqual(@as(u64, both.bytes.len), indexLen(p));
     var expected: [4200]u8 = undefined;
     const made = p.panes[p.paneBySerial(serial).?].?;
     try testing.expect(std.mem.endsWith(u8, both.bytes, try std.fmt.bufPrint(&expected, "\n{d} text 0 {s} {d}\n", .{ serial, nameOf(p, made), columnOf(p, p.paneBySerial(serial).?) })));