# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1615935547 -3600
# Node ID 862b530319c48116785c9ae25b5689d7a907e1c9
# Parent  aa622c059ccd1b0a3e1ee15224bc66057a5b0850
Introduced the flush operation and the file interface to mapped files.
Currently, the flush operation changes file sizes in a fixed way, whereas this
should be configurable.

diff -r aa622c059ccd -r 862b530319c4 Makefile
--- a/Makefile	Tue Mar 16 23:55:32 2021 +0100
+++ b/Makefile	Tue Mar 16 23:59:07 2021 +0100
@@ -19,7 +19,7 @@
 # Compound interfaces.
 
 mapped_file_object_NAME			= MappedFileObject
-mapped_file_object_INTERFACES		= dataspace mapped_file
+mapped_file_object_INTERFACES		= dataspace file mapped_file
 
 opener_context_object_NAME		= OpenerContextObject
 opener_context_object_INTERFACES	= dataspace opener_context
@@ -28,7 +28,7 @@
 
 # Individual interfaces.
 
-CLIENT_INTERFACES_CC			= dataspace mapped_file opener opener_context
+CLIENT_INTERFACES_CC			= dataspace file mapped_file opener opener_context
 
 SERVER_INTERFACES_CC			= opener $(call common_interfaces,$(COMP_INTERFACES_CC))
 
diff -r aa622c059ccd -r 862b530319c4 accessor.cc
--- a/accessor.cc	Tue Mar 16 23:55:32 2021 +0100
+++ b/accessor.cc	Tue Mar 16 23:59:07 2021 +0100
@@ -12,6 +12,13 @@
     return _size;
 }
 
+/* Update the size of the file. */
+
+void Accessor::set_size(offset_t size)
+{
+    _size = size;
+}
+
 /* Perform any closing operation on the file. */
 
 void Accessor::close()
diff -r aa622c059ccd -r 862b530319c4 accessor.h
--- a/accessor.h	Tue Mar 16 23:55:32 2021 +0100
+++ b/accessor.h	Tue Mar 16 23:59:07 2021 +0100
@@ -16,6 +16,8 @@
 
     virtual offset_t get_size();
 
+    virtual void set_size(offset_t size);
+
     virtual void close();
 
     virtual void open();
diff -r aa622c059ccd -r 862b530319c4 file_pager.cc
--- a/file_pager.cc	Tue Mar 16 23:55:32 2021 +0100
+++ b/file_pager.cc	Tue Mar 16 23:59:07 2021 +0100
@@ -19,6 +19,11 @@
     return (ipc_server_handler_type) handle_MappedFileObject;
 }
 
+long FilePager::flush(offset_t populated_size, offset_t *size)
+{
+    return Pager::flush(populated_size, size);
+}
+
 long FilePager::mmap(offset_t position, offset_t length, offset_t *start_pos, offset_t *end_pos, offset_t *data_end)
 {
     /* Set the limits of the paged region. */
diff -r aa622c059ccd -r 862b530319c4 file_pager.h
--- a/file_pager.h	Tue Mar 16 23:55:32 2021 +0100
+++ b/file_pager.h	Tue Mar 16 23:59:07 2021 +0100
@@ -21,6 +21,10 @@
     void *interface()
     { return static_cast<MappedFileObject *>(this); }
 
+    /* File methods. */
+
+    virtual long flush(offset_t populated_size, offset_t *size);
+
     /* Pager and mapped file methods. */
 
     virtual long map(unsigned long offset, l4_addr_t hot_spot, flags_t flags, l4_snd_fpage_t *region);
diff -r aa622c059ccd -r 862b530319c4 page_mapper.cc
--- a/page_mapper.cc	Tue Mar 16 23:55:32 2021 +0100
+++ b/page_mapper.cc	Tue Mar 16 23:59:07 2021 +0100
@@ -97,6 +97,13 @@
     return _accessor->get_size();
 }
 
+/* Set the maximum extent of the mapped resource. */
+
+void PageMapper::set_data_size(offset_t size)
+{
+    _accessor->set_size(size);
+}
+
 /* Internal flexpage retrieval methods. */
 
 /* Find an existing flexpage for 'offset'. Where the accessor has registered a
diff -r aa622c059ccd -r 862b530319c4 page_mapper.h
--- a/page_mapper.h	Tue Mar 16 23:55:32 2021 +0100
+++ b/page_mapper.h	Tue Mar 16 23:59:07 2021 +0100
@@ -42,6 +42,8 @@
 
     offset_t get_data_size();
 
+    void set_data_size(offset_t size);
+
     /* Data transfer methods, implementing PageOwner. */
 
     void fill(Flexpage *flexpage);
diff -r aa622c059ccd -r 862b530319c4 pager.cc
--- a/pager.cc	Tue Mar 16 23:55:32 2021 +0100
+++ b/pager.cc	Tue Mar 16 23:59:07 2021 +0100
@@ -15,6 +15,26 @@
     _mapper->detach();
 }
 
+/* Flush data to the file. */
+
+long Pager::flush(offset_t populated_size, offset_t *size)
+{
+    offset_t limit = _start + populated_size;
+    offset_t file_size = _mapper->get_data_size();
+
+    /* Extend the file if the populated size of the region goes beyond the
+       current size. */
+
+    if (limit > file_size)
+    {
+        file_size = limit;
+        _mapper->set_data_size(file_size);
+    }
+
+    *size = file_size;
+    return L4_EOK;
+}
+
 /* Expose a region of the file. */
 
 long Pager::mmap(offset_t position, offset_t length, offset_t *start_pos, offset_t *end_pos, offset_t *data_end)
diff -r aa622c059ccd -r 862b530319c4 pager.h
--- a/pager.h	Tue Mar 16 23:55:32 2021 +0100
+++ b/pager.h	Tue Mar 16 23:59:07 2021 +0100
@@ -29,6 +29,10 @@
 
     offset_t get_data_size();
 
+    /* File methods. */
+
+    virtual long flush(offset_t populated_size, offset_t *size);
+
     /* Mapped file methods. */
 
     virtual long mmap(offset_t position, offset_t length, offset_t *start_pos, offset_t *end_pos, offset_t *data_end);