server: Add support for maintaining a client-side directory cache.

Signed-off-by: Alexandre Julliard <julliard@winehq.org>

include/wine/server_protocol.h

@@ -1452,6 +1452,21 @@ enum server_fd_type
 
 
 
+struct get_directory_cache_entry_request
+{
+    struct request_header __header;
+    obj_handle_t handle;
+};
+struct get_directory_cache_entry_reply
+{
+    struct reply_header __header;
+    int          entry;
+    /* VARARG(free,ints); */
+    char __pad_12[4];
+};
+
+
+
 struct flush_request
 {
     struct request_header __header;
@@ -5401,6 +5416,7 @@ enum request
     REQ_alloc_file_handle,
     REQ_get_handle_unix_name,
     REQ_get_handle_fd,
+    REQ_get_directory_cache_entry,
     REQ_flush,
     REQ_lock_file,
     REQ_unlock_file,
@@ -5679,6 +5695,7 @@ union generic_request
     struct alloc_file_handle_request alloc_file_handle_request;
     struct get_handle_unix_name_request get_handle_unix_name_request;
     struct get_handle_fd_request get_handle_fd_request;
+    struct get_directory_cache_entry_request get_directory_cache_entry_request;
     struct flush_request flush_request;
     struct lock_file_request lock_file_request;
     struct unlock_file_request unlock_file_request;
@@ -5955,6 +5972,7 @@ union generic_reply
     struct alloc_file_handle_reply alloc_file_handle_reply;
     struct get_handle_unix_name_reply get_handle_unix_name_reply;
     struct get_handle_fd_reply get_handle_fd_reply;
+    struct get_directory_cache_entry_reply get_directory_cache_entry_reply;
     struct flush_reply flush_reply;
     struct lock_file_reply lock_file_reply;
     struct unlock_file_reply unlock_file_reply;
@@ -6184,6 +6202,6 @@ union generic_reply
     struct terminate_job_reply terminate_job_reply;
 };
 
-#define SERVER_PROTOCOL_VERSION 502
+#define SERVER_PROTOCOL_VERSION 503
 
 #endif /* __WINE_WINE_SERVER_PROTOCOL_H */

server/change.c

@@ -141,6 +141,8 @@ struct dir
     struct list    change_records;   /* data for the change */
     struct list    in_entry; /* entry in the inode dirs list */
     struct inode  *inode;    /* inode of the associated directory */
+    struct process *client_process;  /* client process that has a cache for this directory */
+    int             client_entry;    /* entry in client process cache */
 };
 
 static struct fd *dir_get_fd( struct object *obj );
@@ -149,6 +151,7 @@ static int dir_set_sd( struct object *obj, const struct security_descriptor *sd,
                        unsigned int set_info );
 static void dir_dump( struct object *obj, int verbose );
 static struct object_type *dir_get_type( struct object *obj );
+static int dir_close_handle( struct object *obj, struct process *process, obj_handle_t handle );
 static void dir_destroy( struct object *obj );
 
 static const struct object_ops dir_ops =
@@ -169,7 +172,7 @@ static const struct object_ops dir_ops =
     no_link_name,             /* link_name */
     NULL,                     /* unlink_name */
     no_open_file,             /* open_file */
-    fd_close_handle,          /* close_handle */
+    dir_close_handle,         /* close_handle */
     dir_destroy               /* destroy */
 };
 
@@ -192,6 +195,86 @@ static const struct fd_ops dir_fd_ops =
 
 static struct list change_list = LIST_INIT(change_list);
 
+/* per-process structure to keep track of cache entries on the client size */
+struct dir_cache
+{
+    unsigned int  size;
+    unsigned int  count;
+    unsigned char state[1];
+};
+
+enum dir_cache_state
+{
+    DIR_CACHE_STATE_FREE,
+    DIR_CACHE_STATE_INUSE,
+    DIR_CACHE_STATE_RELEASED
+};
+
+/* return an array of cache entries that can be freed on the client side */
+static int *get_free_dir_cache_entries( struct process *process, data_size_t *size )
+{
+    int *ret;
+    struct dir_cache *cache = process->dir_cache;
+    unsigned int i, j, count;
+
+    if (!cache) return NULL;
+    for (i = count = 0; i < cache->count && count < *size / sizeof(*ret); i++)
+        if (cache->state[i] == DIR_CACHE_STATE_RELEASED) count++;
+    if (!count) return NULL;
+
+    if ((ret = malloc( count * sizeof(*ret) )))
+    {
+        for (i = j = 0; j < count; i++)
+        {
+            if (cache->state[i] != DIR_CACHE_STATE_RELEASED) continue;
+            cache->state[i] = DIR_CACHE_STATE_FREE;
+            ret[j++] = i;
+        }
+        *size = count * sizeof(*ret);
+    }
+    return ret;
+}
+
+/* allocate a new client-side directory cache entry */
+static int alloc_dir_cache_entry( struct dir *dir, struct process *process )
+{
+    unsigned int i = 0;
+    struct dir_cache *cache = process->dir_cache;
+
+    if (cache)
+        for (i = 0; i < cache->count; i++)
+            if (cache->state[i] == DIR_CACHE_STATE_FREE) goto found;
+
+    if (!cache || cache->count == cache->size)
+    {
+        unsigned int size = cache ? cache->size * 2 : 256;
+        if (!(cache = realloc( cache, offsetof( struct dir_cache, state[size] ))))
+        {
+            set_error( STATUS_NO_MEMORY );
+            return -1;
+        }
+        process->dir_cache = cache;
+        cache->size = size;
+    }
+    cache->count = i + 1;
+
+found:
+    cache->state[i] = DIR_CACHE_STATE_INUSE;
+    return i;
+}
+
+/* release a directory cache entry; it will be freed on the client side on the next cache request */
+static void release_dir_cache_entry( struct dir *dir )
+{
+    struct dir_cache *cache;
+
+    if (!dir->client_process) return;
+    cache = dir->client_process->dir_cache;
+    cache->state[dir->client_entry] = DIR_CACHE_STATE_RELEASED;
+    release_object( dir->client_process );
+    dir->client_process = NULL;
+}
+
 static void dnotify_adjust_changes( struct dir *dir )
 {
 #if defined(F_SETSIG) && defined(F_NOTIFY)
@@ -385,6 +468,15 @@ static struct change_record *get_first_change_record( struct dir *dir )
     return LIST_ENTRY( ptr, struct change_record, entry );
 }
 
+static int dir_close_handle( struct object *obj, struct process *process, obj_handle_t handle )
+{
+    struct dir *dir = (struct dir *)obj;
+
+    if (!fd_close_handle( obj, process, handle )) return 0;
+    if (obj->handle_count == 1) release_dir_cache_entry( dir ); /* closing last handle, release cache */
+    return 1;  /* ok to close */
+}
+
 static void dir_destroy( struct object *obj )
 {
     struct change_record *record;
@@ -402,6 +494,7 @@ static void dir_destroy( struct object *obj )
 
     while ((record = get_first_change_record( dir ))) free( record );
 
+    release_dir_cache_entry( dir );
     release_object( dir->fd );
 
     if (inotify_fd && list_empty( &change_list ))
@@ -1104,6 +1197,7 @@ struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
     dir->fd = fd;
     dir->mode = mode;
     dir->uid  = ~(uid_t)0;
+    dir->client_process = NULL;
     set_fd_user( fd, &dir_fd_ops, &dir->obj );
 
     dir_add_to_existing_notify( dir );
@@ -1111,6 +1205,32 @@ struct object *create_dir_obj( struct fd *fd, unsigned int access, mode_t mode )
     return &dir->obj;
 }
 
+/* retrieve (or allocate) the client-side directory cache entry */
+DECL_HANDLER(get_directory_cache_entry)
+{
+    struct dir *dir;
+    int *free_entries;
+    data_size_t free_size;
+
+    if (!(dir = get_dir_obj( current->process, req->handle, 0 ))) return;
+
+    if (!dir->client_process)
+    {
+        if ((dir->client_entry = alloc_dir_cache_entry( dir, current->process )) == -1) goto done;
+        dir->client_process = (struct process *)grab_object( current->process );
+    }
+
+    if (dir->client_process == current->process) reply->entry = dir->client_entry;
+    else set_error( STATUS_SHARING_VIOLATION );
+
+done:  /* allow freeing entries even on failure */
+    free_size = get_reply_max_size();
+    free_entries = get_free_dir_cache_entries( current->process, &free_size );
+    if (free_entries) set_reply_data_ptr( free_entries, free_size );
+
+    release_object( dir );
+}
+
 /* enable change notifications for a directory */
 DECL_HANDLER(read_directory_changes)
 {

server/process.c

@@ -526,6 +526,7 @@ struct thread *create_process( int fd, struct thread *parent_thread, int inherit
     process->idle_event      = NULL;
     process->peb             = 0;
     process->ldt_copy        = 0;
+    process->dir_cache       = NULL;
     process->winstation      = 0;
     process->desktop         = 0;
     process->token           = NULL;
@@ -630,6 +631,7 @@ static void process_destroy( struct object *obj )
     if (process->idle_event) release_object( process->idle_event );
     if (process->id) free_ptid( process->id );
     if (process->token) release_object( process->token );
+    free( process->dir_cache );
 }
 
 /* dump a process on stdout for debugging purposes */

server/process.h

@@ -90,6 +90,7 @@ struct process
     struct list          dlls;            /* list of loaded dlls */
     client_ptr_t         peb;             /* PEB address in client address space */
     client_ptr_t         ldt_copy;        /* pointer to LDT copy in client addr space */
+    struct dir_cache    *dir_cache;       /* map of client-side directory cache */
     unsigned int         trace_data;      /* opaque data used by the process tracing mechanism */
     struct list          rawinput_devices;/* list of registered rawinput devices */
     const struct rawinput_device *rawinput_mouse; /* rawinput mouse device, if any */

server/protocol.def

@@ -1200,6 +1200,15 @@ enum server_fd_type
 };
 
 
+/* Retrieve (or allocate) the client-side directory cache entry */
+@REQ(get_directory_cache_entry)
+    obj_handle_t handle;        /* handle to the directory */
+@REPLY
+    int          entry;         /* cache entry on the client side */
+    VARARG(free,ints);          /* entries that can be freed */
+@END
+
+
 /* Flush a file buffers */
 @REQ(flush)
     int            blocking;    /* whether it's a blocking flush */

server/request.h

@@ -156,6 +156,7 @@ DECL_HANDLER(open_file_object);
 DECL_HANDLER(alloc_file_handle);
 DECL_HANDLER(get_handle_unix_name);
 DECL_HANDLER(get_handle_fd);
+DECL_HANDLER(get_directory_cache_entry);
 DECL_HANDLER(flush);
 DECL_HANDLER(lock_file);
 DECL_HANDLER(unlock_file);
@@ -433,6 +434,7 @@ static const req_handler req_handlers[REQ_NB_REQUESTS] =
     (req_handler)req_alloc_file_handle,
     (req_handler)req_get_handle_unix_name,
     (req_handler)req_get_handle_fd,
+    (req_handler)req_get_directory_cache_entry,
     (req_handler)req_flush,
     (req_handler)req_lock_file,
     (req_handler)req_unlock_file,
@@ -975,6 +977,10 @@ C_ASSERT( FIELD_OFFSET(struct get_handle_fd_reply, cacheable) == 12 );
 C_ASSERT( FIELD_OFFSET(struct get_handle_fd_reply, access) == 16 );
 C_ASSERT( FIELD_OFFSET(struct get_handle_fd_reply, options) == 20 );
 C_ASSERT( sizeof(struct get_handle_fd_reply) == 24 );
+C_ASSERT( FIELD_OFFSET(struct get_directory_cache_entry_request, handle) == 12 );
+C_ASSERT( sizeof(struct get_directory_cache_entry_request) == 16 );
+C_ASSERT( FIELD_OFFSET(struct get_directory_cache_entry_reply, entry) == 8 );
+C_ASSERT( sizeof(struct get_directory_cache_entry_reply) == 16 );
 C_ASSERT( FIELD_OFFSET(struct flush_request, blocking) == 12 );
 C_ASSERT( FIELD_OFFSET(struct flush_request, async) == 16 );
 C_ASSERT( sizeof(struct flush_request) == 56 );

server/trace.c

@@ -1717,6 +1717,17 @@ static void dump_get_handle_fd_reply( const struct get_handle_fd_reply *req )
     fprintf( stderr, ", options=%08x", req->options );
 }
 
+static void dump_get_directory_cache_entry_request( const struct get_directory_cache_entry_request *req )
+{
+    fprintf( stderr, " handle=%04x", req->handle );
+}
+
+static void dump_get_directory_cache_entry_reply( const struct get_directory_cache_entry_reply *req )
+{
+    fprintf( stderr, " entry=%d", req->entry );
+    dump_varargs_ints( ", free=", cur_size );
+}
+
 static void dump_flush_request( const struct flush_request *req )
 {
     fprintf( stderr, " blocking=%d", req->blocking );
@@ -4344,6 +4355,7 @@ static const dump_func req_dumpers[REQ_NB_REQUESTS] = {
     (dump_func)dump_alloc_file_handle_request,
     (dump_func)dump_get_handle_unix_name_request,
     (dump_func)dump_get_handle_fd_request,
+    (dump_func)dump_get_directory_cache_entry_request,
     (dump_func)dump_flush_request,
     (dump_func)dump_lock_file_request,
     (dump_func)dump_unlock_file_request,
@@ -4618,6 +4630,7 @@ static const dump_func reply_dumpers[REQ_NB_REQUESTS] = {
     (dump_func)dump_alloc_file_handle_reply,
     (dump_func)dump_get_handle_unix_name_reply,
     (dump_func)dump_get_handle_fd_reply,
+    (dump_func)dump_get_directory_cache_entry_reply,
     (dump_func)dump_flush_reply,
     (dump_func)dump_lock_file_reply,
     NULL,
@@ -4892,6 +4905,7 @@ static const char * const req_names[REQ_NB_REQUESTS] = {
     "alloc_file_handle",
     "get_handle_unix_name",
     "get_handle_fd",
+    "get_directory_cache_entry",
     "flush",
     "lock_file",
     "unlock_file",