From 86ce0a68a325f8104b796a11bf7d2af5b924d831 Mon Sep 17 00:00:00 2001
From: Drew Galbraith <dgalbraith33@gmail.com>
Date: Wed, 22 Nov 2023 16:42:42 -0800
Subject: [PATCH] [Mammoth/Teton] Add an OpenFile interface and use it to load
 a font.

---
 lib/mammoth/CMakeLists.txt    |  6 ++++-
 lib/mammoth/file/file.cpp     | 45 +++++++++++++++++++++++++++++++++++
 lib/mammoth/file/file.h       | 25 +++++++++++++++++++
 sys/teton/framebuffer/psf.cpp |  6 ++---
 sys/teton/framebuffer/psf.h   |  9 +++----
 sys/teton/teton.cpp           | 14 +----------
 6 files changed, 84 insertions(+), 21 deletions(-)
 create mode 100644 lib/mammoth/file/file.cpp
 create mode 100644 lib/mammoth/file/file.h

diff --git a/lib/mammoth/CMakeLists.txt b/lib/mammoth/CMakeLists.txt
index 0029633..95754d5 100644
--- a/lib/mammoth/CMakeLists.txt
+++ b/lib/mammoth/CMakeLists.txt
@@ -1,4 +1,5 @@
 add_library(mammoth STATIC
+  file/file.cpp
   ipc/channel.cpp
   ipc/endpoint_client.cpp
   ipc/endpoint_server.cpp
@@ -23,7 +24,10 @@ target_include_directories(mammoth
 target_link_libraries(mammoth
   glacier
   c
-  zion_stub)
+  victoriafalls_yunq
+  yellowstone_yunq
+  zion_stub
+  )
 
 set_target_properties(mammoth PROPERTIES
   COMPILE_FLAGS "${CMAKE_CXX_FLAGS} ${BASE_COMPILE_FLAGS}"
diff --git a/lib/mammoth/file/file.cpp b/lib/mammoth/file/file.cpp
new file mode 100644
index 0000000..77c50d4
--- /dev/null
+++ b/lib/mammoth/file/file.cpp
@@ -0,0 +1,45 @@
+#include "file/file.h"
+
+#include <victoriafalls/victoriafalls.yunq.client.h>
+#include <yellowstone/yellowstone.yunq.client.h>
+#include <zglobal.h>
+
+#include "util/debug.h"
+
+namespace mmth {
+namespace {
+
+VFSClient* gVfsClient = nullptr;
+
+}  // namespace
+
+File File::Open(glcr::StringView path) {
+  if (gVfsClient == 0) {
+    YellowstoneClient client(gInitEndpointCap);
+
+    GetEndpointRequest yreq;
+    yreq.set_endpoint_name("victoriafalls");
+    Endpoint yresp;
+    check(client.GetEndpoint(yreq, yresp));
+
+    gVfsClient = new VFSClient(yresp.endpoint());
+  }
+
+  OpenFileRequest req;
+  req.set_path(path);
+  OpenFileResponse resp;
+  check(gVfsClient->OpenFile(req, resp));
+
+  return File(OwnedMemoryRegion::FromCapability(resp.memory()));
+}
+
+glcr::StringView File::as_str() {
+  return glcr::StringView((char*)raw_ptr(), file_data_.size());
+}
+
+void* File::raw_ptr() { return reinterpret_cast<void*>(file_data_.vaddr()); }
+uint8_t* File::byte_ptr() {
+  return reinterpret_cast<uint8_t*>(file_data_.vaddr());
+}
+
+}  // namespace mmth
diff --git a/lib/mammoth/file/file.h b/lib/mammoth/file/file.h
new file mode 100644
index 0000000..15021c5
--- /dev/null
+++ b/lib/mammoth/file/file.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <glacier/memory/move.h>
+#include <glacier/string/string_view.h>
+
+#include "mammoth/util/memory_region.h"
+
+namespace mmth {
+
+class File {
+ public:
+  static File Open(glcr::StringView path);
+
+  glcr::StringView as_str();
+
+  void* raw_ptr();
+  uint8_t* byte_ptr();
+
+ private:
+  OwnedMemoryRegion file_data_;
+
+  File(OwnedMemoryRegion&& file) : file_data_(glcr::Move(file)) {}
+};
+
+}  // namespace mmth
diff --git a/sys/teton/framebuffer/psf.cpp b/sys/teton/framebuffer/psf.cpp
index 6c9770e..43714c6 100644
--- a/sys/teton/framebuffer/psf.cpp
+++ b/sys/teton/framebuffer/psf.cpp
@@ -9,9 +9,9 @@ const uint32_t kMagic = 0x864AB572;
 
 }
 
-Psf::Psf(mmth::OwnedMemoryRegion&& psf_file)
-    : psf_file_(glcr::Move(psf_file)),
-      header_(reinterpret_cast<PsfHeader*>(psf_file_.vaddr())) {
+Psf::Psf(glcr::StringView path)
+    : psf_file_(mmth::File::Open(path)),
+      header_(reinterpret_cast<PsfHeader*>(psf_file_.raw_ptr())) {
   EnsureValid();
 }
 
diff --git a/sys/teton/framebuffer/psf.h b/sys/teton/framebuffer/psf.h
index 944d406..bfa890d 100644
--- a/sys/teton/framebuffer/psf.h
+++ b/sys/teton/framebuffer/psf.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <mammoth/util/memory_region.h>
+#include <mammoth/file/file.h>
 
 struct PsfHeader {
   uint32_t magic;         /* magic bytes to identify PSF */
@@ -15,7 +15,7 @@ struct PsfHeader {
 
 class Psf {
  public:
-  Psf(mmth::OwnedMemoryRegion&& psf_file);
+  Psf(glcr::StringView path);
 
   void DumpHeader();
 
@@ -24,12 +24,13 @@ class Psf {
   uint32_t height() { return header_->height; }
 
   uint8_t* glyph(uint32_t index) {
-    return reinterpret_cast<uint8_t*>(psf_file_.vaddr() + header_->headersize +
+    return reinterpret_cast<uint8_t*>(psf_file_.byte_ptr() +
+                                      header_->headersize +
                                       (index * header_->bytesperglyph));
   }
 
  private:
-  mmth::OwnedMemoryRegion psf_file_;
+  mmth::File psf_file_;
   PsfHeader* header_;
 
   void EnsureValid();
diff --git a/sys/teton/teton.cpp b/sys/teton/teton.cpp
index e530b09..e0b4900 100644
--- a/sys/teton/teton.cpp
+++ b/sys/teton/teton.cpp
@@ -25,19 +25,7 @@ uint64_t main(uint64_t init_port) {
 
   // 2. Parse a font file.
 
-  GetEndpointRequest req;
-  req.set_endpoint_name("victoriafalls");
-  Endpoint resp;
-  check(client.GetEndpoint(req, resp));
-
-  VFSClient vfs(resp.endpoint());
-
-  OpenFileRequest freq;
-  freq.set_path("/default8x16.psfu");
-  OpenFileResponse fresp;
-  check(vfs.OpenFile(freq, fresp));
-
-  Psf psf(mmth::OwnedMemoryRegion::FromCapability(fresp.memory()));
+  Psf psf("/default8x16.psfu");
   psf.DumpHeader();
 
   Console console(fbuf, psf);