# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1715384883 -7200
# Node ID 5c1c19c5e2a39cbb563c87516b25de024f07cd88
# Parent  d9ea3cac8ace0dca5a7c9f46b085ee8659f3bd8d# Parent  d7e231b756a5ee9342c5c4f720c877ad2b592b50
Merged changes from the default branch.

diff -r d9ea3cac8ace -r 5c1c19c5e2a3 docs/wiki/Components
--- a/docs/wiki/Components	Fri May 10 21:51:44 2024 +0200
+++ b/docs/wiki/Components	Sat May 11 01:48:03 2024 +0200
@@ -348,7 +348,7 @@
   Directory -> Reader1;
   Reader1 -> Client2;
 
-  Client3 -> Reader2 [label="current_region()"];
+  Client3 -> Reader2 [label="refresh()"];
   Reader3 -> Memory -> Client4;
 }
 }}}
@@ -360,7 +360,7 @@
 
 {{{
 reader = directory.opendir()
-reader.current_region()
+reader.refresh()
 entries = reader.read() # this being a memory access operation
 }}}
 
@@ -397,14 +397,13 @@
 fully populated region. Naturally, the reader may not advance ahead of the
 writer.
 
-Pipes implement the `Pipe` interface and a number of operations to support
-this interaction mechanism.
+Pipes implement a number of operations to support this interaction mechanism.
 
 The details of an endpoint's current region can be queried using the following
-operation:
+operation from the `Flush` interface:
 
 {{{
-current_region(inout offset_t position, out offset_t populated_size, out offset_t size)
+refresh(out offset_t position, out offset_t size, out offset_t region_size)
 }}}
 
 This provides details of the recorded access position in a region, the
@@ -413,7 +412,7 @@
 the same.
 
 Navigation to the next available region of the pipe is performed using the
-following operation:
+following operation from the `Pipe` interface:
 
 {{{
 next_region(inout offset_t populated_size, out offset_t size)
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libfsclient/include/fsclient/file.h
--- a/libfsclient/include/fsclient/file.h	Fri May 10 21:51:44 2024 +0200
+++ b/libfsclient/include/fsclient/file.h	Sat May 11 01:48:03 2024 +0200
@@ -114,13 +114,17 @@
 /* File and region operations. */
 
 long file_flush(file_t *file);
+long file_refresh(file_t *file);
+
 long file_mmap(file_t *file, offset_t position, offset_t length,
                offset_t start_visible, offset_t end_visible,
                rm_flags_t region_flags);
 long file_mmap_only(file_t *file, offset_t position, offset_t length,
                     offset_t start_visible, offset_t end_visible);
+
 flags_t file_opening_flags(rm_flags_t rm_flags);
 rm_flags_t file_region_flags(flags_t flags);
+
 long file_resize(file_t *file, offset_t size);
 
 /* File and region properties. */
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libfsclient/lib/src/client.cc
--- a/libfsclient/lib/src/client.cc	Fri May 10 21:51:44 2024 +0200
+++ b/libfsclient/lib/src/client.cc	Sat May 11 01:48:03 2024 +0200
@@ -281,10 +281,7 @@
   /* Synchronise the state of the stream, testing for pipe-based access and
      switching to memory mapped access if not supported. */
 
-  long err = client_sync_stream(stream);
-
-  if (err == -L4_EBADPROTO)
-    stream->object_flags |= OBJECT_SUPPORTS_MMAP;
+  client_sync_stream(stream);
 
   /* Enforce blocking if necessary.
      NOTE: Ignoring any event subscription error. */
@@ -314,7 +311,13 @@
   if (!client_opened(file))
     return -L4_EINVAL;
 
-  return pipe_current(file, 1);
+  long err = pipe_current(file, 1);
+
+  if (err != -L4_EBADPROTO)
+    return err;
+
+  file->object_flags |= OBJECT_SUPPORTS_MMAP;
+  return file_refresh(file);
 }
 
 
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libfsclient/lib/src/file.cc
--- a/libfsclient/lib/src/file.cc	Fri May 10 21:51:44 2024 +0200
+++ b/libfsclient/lib/src/file.cc	Sat May 11 01:48:03 2024 +0200
@@ -62,6 +62,11 @@
 
   else
     file->data_end = 0;
+
+  /* Reset the current position if a region is empty. */
+
+  if (!file->data_end)
+    file->data_current = 0;
 }
 
 
@@ -343,8 +348,7 @@
 
 
 
-/* Flush populated data and obtain an updated file size and populated data
-   details. */
+/* Flush populated data and obtain an updated file size. */
 
 long file_flush(file_t *file)
 {
@@ -362,6 +366,24 @@
   return L4_EOK;
 }
 
+/* Refresh position and size data from the file or pipe. */
+
+long file_refresh(file_t *file)
+{
+  if (l4_is_invalid_cap(file->ref))
+    return -L4_EINVAL;
+
+  client_Flush _file(file->ref);
+  long err = _file.refresh(&file->data_current, &file->size, &file->end_pos);
+
+  if (err)
+    return err;
+
+  _update_extent(file);
+
+  return L4_EOK;
+}
+
 /* Map a region of the given file to a memory region, obtaining an updated file
    size and populated data details. Unmap any previously mapped region. */
 
@@ -449,7 +471,7 @@
   return rm_flags;
 }
 
-/* Resize a file, obtaining updated file size and populated data details. */
+/* Resize a file, obtaining updated file size details. */
 
 long file_resize(file_t *file, offset_t size)
 {
@@ -682,25 +704,20 @@
 
 long pipe_current(file_t *pipe, int sync)
 {
-  client_Pipe _pipe(pipe->ref);
+  client_Flush _pipe(pipe->ref);
   offset_t data_current;
-  long err = _pipe.current_region(&data_current, &pipe->data_end, &pipe->size);
+  long err = _pipe.refresh(&data_current, &pipe->size, &pipe->end_pos);
 
   if (err)
     return err;
 
-  pipe->end_pos = pipe->size;
+  _update_extent(pipe);
 
   /* Obtain the current position if synchronising position state. */
 
   if (sync)
     pipe->data_current = data_current;
 
-  /* Handle any case where the current region has been exhausted. */
-
-  if (!file_populated_span(pipe))
-    pipe->data_current = 0;
-
   /* Attach memory if necessary. */
 
   if (pipe->memory == NULL)
@@ -714,23 +731,26 @@
 }
 
 /* Access the next region for a pipe endpoint, updating the eventual size of
-   the current region. */
+   the current region if writing. */
 
 long pipe_next(file_t *pipe)
 {
   client_Pipe _pipe(pipe->ref);
-  long err = _pipe.next_region(&pipe->data_end, &pipe->size);
+  offset_t size = pipe->data_current;
+  long err = _pipe.next_region(&size, &pipe->end_pos);
 
   if (err)
     return err;
 
+  pipe->size = size;
+  _update_extent(pipe);
+
   if (pipe->memory != NULL)
     err = ipc_detach_dataspace(pipe->memory);
 
   if (err)
     return err;
 
-  pipe->end_pos = pipe->size;
   pipe->data_current = 0;
   pipe->memory = NULL;
 
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libfsserver/include/fsserver/file_pager.h
--- a/libfsserver/include/fsserver/file_pager.h	Fri May 10 21:51:44 2024 +0200
+++ b/libfsserver/include/fsserver/file_pager.h	Sat May 11 01:48:03 2024 +0200
@@ -34,6 +34,7 @@
 protected:
     FileProvider *_provider;
     flags_t _flags;
+    offset_t _data_current;
 
     /* Notification endpoint for event subscription. */
 
@@ -61,10 +62,15 @@
     void *interface()
     { return static_cast<MappedFileObject *>(this); }
 
-    /* File methods. */
+    /* Flush methods. */
 
     virtual long flush(offset_t position, offset_t *size);
 
+    virtual long refresh(offset_t *position, offset_t *populated_size,
+                         offset_t *region_size);
+
+    /* File methods. */
+
     virtual long reopen(flags_t flags, offset_t *size, l4_cap_idx_t *file,
                         object_flags_t *object_flags);
 
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libfsserver/include/fsserver/pipe_pager.h
--- a/libfsserver/include/fsserver/pipe_pager.h	Fri May 10 21:51:44 2024 +0200
+++ b/libfsserver/include/fsserver/pipe_pager.h	Sat May 11 01:48:03 2024 +0200
@@ -1,7 +1,7 @@
 /*
  * A pipe pager providing access to pipe content and navigation support.
  *
- * Copyright (C) 2021, 2022, 2023 Paul Boddie <paul@boddie.org.uk>
+ * Copyright (C) 2021, 2022, 2023, 2024 Paul Boddie <paul@boddie.org.uk>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -66,14 +66,14 @@
 
     virtual long closed(int *closed);
 
-    virtual long current_region(offset_t *position, offset_t *populated_size, offset_t *size);
-
     virtual long next_region(offset_t *populated_size, offset_t *size);
 
     /* Flushing/synchronisation. */
 
     virtual long flush(offset_t position, offset_t *size);
 
+    virtual long refresh(offset_t *position, offset_t *populated_size, offset_t *size);
+
     /* Notification methods. */
 
     virtual long subscribe(l4_cap_idx_t notifier, notify_flags_t flags);
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libfsserver/lib/files/file_pager.cc
--- a/libfsserver/lib/files/file_pager.cc	Fri May 10 21:51:44 2024 +0200
+++ b/libfsserver/lib/files/file_pager.cc	Sat May 11 01:48:03 2024 +0200
@@ -37,6 +37,10 @@
 : Pager(provider->mapper(), file_region_flags(flags)),
   _provider(provider), _flags(flags), fileid(fileid)
 {
+    /* Initialise any recorded position in the mapped region for this
+       endpoint. */
+
+    _data_current = 0;
 }
 
 ipc_server_default_config_type FilePager::config()
@@ -62,12 +66,14 @@
 
 
 
-/* File-specific operations. */
+/* Flush operations. */
 
 long FilePager::flush(offset_t position, offset_t *size)
 {
     long err = Pager::flush(position, size);
 
+    _data_current = position;
+
     if (_resized)
     {
         _provider->notify_others(_notifier, NOTIFY_CONTENT_AVAILABLE, NOTIFY_VALUES_NULL);
@@ -77,6 +83,20 @@
     return err;
 }
 
+long FilePager::refresh(offset_t *position, offset_t *size,
+                        offset_t *region_size)
+{
+    *position = _data_current;
+    *size = _mapper->get_data_size();
+    *region_size = _size;
+
+    return L4_EOK;
+}
+
+
+
+/* File-specific operations. */
+
 long FilePager::reopen(flags_t flags, offset_t *size, l4_cap_idx_t *file,
                        object_flags_t *object_flags)
 {
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libfsserver/lib/pipes/pipe_pager.cc
--- a/libfsserver/lib/pipes/pipe_pager.cc	Fri May 10 21:51:44 2024 +0200
+++ b/libfsserver/lib/pipes/pipe_pager.cc	Sat May 11 01:48:03 2024 +0200
@@ -36,7 +36,8 @@
 
     _size = _paging->region_size();
 
-    /* Initialise any recorded position in the region. */
+    /* Initialise any recorded position in the mapped region for this
+       endpoint. */
 
     _data_current = 0;
 
@@ -96,7 +97,7 @@
 
 /* Return details of the current region. */
 
-long PipePager::current_region(offset_t *position, offset_t *populated_size, offset_t *size)
+long PipePager::refresh(offset_t *position, offset_t *populated_size, offset_t *size)
 {
     if (_mapper != NULL)
     {
@@ -133,7 +134,7 @@
     _mapper = mapper;
     _data_current = 0;
 
-    return current_region(NULL, populated_size, size);
+    return refresh(NULL, populated_size, size);
 }
 
 long PipePager::next_region_for_writer(offset_t *populated_size, offset_t *size)
@@ -153,7 +154,7 @@
     _mapper = mapper;
     _data_current = 0;
 
-    return current_region(NULL, populated_size, size);
+    return refresh(NULL, populated_size, size);
 }
 
 long PipePager::pipe_error()
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libsystypes/idl/flush.idl
--- a/libsystypes/idl/flush.idl	Fri May 10 21:51:44 2024 +0200
+++ b/libsystypes/idl/flush.idl	Sat May 11 01:48:03 2024 +0200
@@ -9,4 +9,10 @@
      indicates the point from which data is being consumed by a client. */
 
   [opcode(5)] void flush(in offset_t position, out offset_t size);
+
+  /* Refresh any recorded position and size information, also obtaining the span
+     of the mapped region used to access the file or pipe. */
+
+  [opcode(16)] void refresh(out offset_t position, out offset_t size,
+                            out offset_t region_size);
 };
diff -r d9ea3cac8ace -r 5c1c19c5e2a3 libsystypes/idl/pipe.idl
--- a/libsystypes/idl/pipe.idl	Fri May 10 21:51:44 2024 +0200
+++ b/libsystypes/idl/pipe.idl	Sat May 11 01:48:03 2024 +0200
@@ -4,12 +4,11 @@
 
 interface Pipe
 {
-  /* Obtain details of the current region of shared memory. */
+  /* Advance to the next region of shared memory, indicating and obtaining the
+     populated limit of the region and obtaining the region size.
 
-  [opcode(16)] void current_region(out offset_t position, out offset_t populated_size, out offset_t size);
-
-  /* Advance to the next region of shared memory, indicating and obtaining the
-     populated limit of the region and obtaining the region size. */
+     The current region details are available via the Flush interface's refresh
+     operation. */
 
   [opcode(17)] void next_region(inout offset_t populated_size, out offset_t size);