From 0d099a1fa639f0e94c7d4760ad0b86ff2d37c6af Mon Sep 17 00:00:00 2001
From: Francesco Cozzuto <francesco.cozzuto@gmail.com>
Date: Tue, 25 Nov 2025 12:08:33 +0100
Subject: [PATCH] Return version tags in directory listing

---
 inc/ToastyFS.h        | 1 +
 misc/PROTOCOL.txt     | 3 ++-
 src/client.c          | 9 +++++++++
 src/file_tree.c       | 1 +
 src/file_tree.h       | 1 +
 src/metadata_server.c | 2 ++
 6 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/inc/ToastyFS.h b/inc/ToastyFS.h
index ceb587d..e68c4ad 100644
--- a/inc/ToastyFS.h
+++ b/inc/ToastyFS.h
@@ -85,6 +85,7 @@ int toasty_delete(ToastyFS *toasty, ToastyString path, ToastyVersionTag vtag);
 typedef struct {
     char name[128]; // TODO: Implement a proper name length
     bool is_dir;
+    ToastyVersionTag vtag;
 } ToastyListingEntry;
 
 typedef struct {
diff --git a/misc/PROTOCOL.txt b/misc/PROTOCOL.txt
index 89fd141..33abafe 100644
--- a/misc/PROTOCOL.txt
+++ b/misc/PROTOCOL.txt
@@ -178,6 +178,7 @@ The following is the list of messages the Metadata Server may send to a Client:
     When a client sends a LIST request to the metadata server and it succedes, the server replies with a LIST_SUCCESSS message with the following layout:
 
         struct ListItem {
+            uint64_t gen;
             uint8_t  is_dir;
             uint16_t name_len;
             char     name[name_len];
@@ -191,7 +192,7 @@ The following is the list of messages the Metadata Server may send to a Client:
             ListItem items[item_count];
         };
 
-    The gen field contains the generation counter for the directory.
+    The ListSuccessMessage gen field contains the generation counter for the directory, while the gen field in ListItem is the counter for that specific child.
 
     If the truncated field is non-zero, the actual item count for this directory is greater than the one sent in the message.
 
diff --git a/src/client.c b/src/client.c
index 7629873..f595675 100644
--- a/src/client.c
+++ b/src/client.c
@@ -950,6 +950,14 @@ static void process_event_for_list(ToastyFS *toasty,
 
     // Parse each list item
     for (uint32_t i = 0; i < item_count; i++) {
+
+        uint64_t gen;
+        if (!binary_read(&reader, &gen, sizeof(gen))) {
+            toasty->operations[opidx].result = (ToastyResult) { .type=TOASTY_RESULT_LIST_ERROR, .user=toasty->operations[opidx].user };
+            sys_free(entities);
+            return;
+        }
+
         uint8_t is_dir;
         if (!binary_read(&reader, &is_dir, sizeof(is_dir))) {
             toasty->operations[opidx].result = (ToastyResult) { .type=TOASTY_RESULT_LIST_ERROR, .user=toasty->operations[opidx].user };
@@ -971,6 +979,7 @@ static void process_event_for_list(ToastyFS *toasty,
             return;
         }
 
+        entities[i].vtag = gen;
         entities[i].is_dir = is_dir;
 
         if (name_len > sizeof(entities[i].name)-1) {
diff --git a/src/file_tree.c b/src/file_tree.c
index 483037d..65a2d2e 100644
--- a/src/file_tree.c
+++ b/src/file_tree.c
@@ -257,6 +257,7 @@ int file_tree_list(FileTree *ft, string path,
 
         items[i].name_len = name_cpy;
         items[i].is_dir = c->is_dir;
+        items[i].gen = c->gen;
     }
 
     assert(e->gen != NO_GENERATION);
diff --git a/src/file_tree.h b/src/file_tree.h
index 60e67fc..bec2d55 100644
--- a/src/file_tree.h
+++ b/src/file_tree.h
@@ -51,6 +51,7 @@ typedef struct {
     char name[1<<8];
     int  name_len;
     bool is_dir;
+    uint64_t gen;
 } ListItem;
 
 #define MAX_COMPS 32
diff --git a/src/metadata_server.c b/src/metadata_server.c
index bf4ebf9..b512320 100644
--- a/src/metadata_server.c
+++ b/src/metadata_server.c
@@ -362,6 +362,8 @@ process_client_list(MetadataServer *state, int conn_idx, ByteView msg)
 
         for (int i = 0; i < ret && i < MAX_LIST_SIZE; i++) {
 
+            message_write(&writer, &items[i].gen, sizeof(items[i].gen));
+
             uint8_t is_dir = items[i].is_dir;
             message_write(&writer, &is_dir, sizeof(is_dir));