Font: Clean up AK::MappedFile and use it for mapping font files.

AK/MappedFile.cpp

@@ -1,15 +1,16 @@
-#include "MappedFile.h"
+#include <AK/MappedFile.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <cstdio>
+#include <unistd.h>
+#include <stdio.h>
 
 namespace AK {
 
-MappedFile::MappedFile(String&& file_name)
- : m_file_name(std::move(file_name))
+MappedFile::MappedFile(const String& file_name)
+ : m_file_name(file_name)
 {
- m_file_length = 1024;
+ m_file_length = PAGE_SIZE;
  m_fd = open(m_file_name.characters(), O_RDONLY);
 
  if (m_fd != -1) {
@@ -22,19 +23,29 @@ MappedFile::MappedFile(String&& file_name)
  perror("");
  }
 
- printf("MappedFile{%s} := { m_fd=%d, m_file_length=%zu, m_map=%p }\n", m_file_name.characters(), m_fd, m_file_length, m_map);
+ dbgprintf("MappedFile{%s} := { m_fd=%d, m_file_length=%zu, m_map=%p }\n", m_file_name.characters(), m_fd, m_file_length, m_map);
 }
 
 MappedFile::~MappedFile()
 {
- if (m_map != (void*)-1) {
- ASSERT(m_fd != -1);
- munmap(m_map, m_file_length);
- }
+ unmap();
+}
+
+void MappedFile::unmap()
+{
+ if (!is_valid())
+ return;
+ ASSERT(m_fd != -1);
+ int rc = munmap(m_map, m_file_length);
+ ASSERT(rc == 0);
+ m_file_name = { };
+ m_file_length = 0;
+ m_fd = -1;
+ m_map = (void*)-1;
 }
 
 MappedFile::MappedFile(MappedFile&& other)
- : m_file_name(std::move(other.m_file_name))
+ : m_file_name(move(other.m_file_name))
  , m_file_length(other.m_file_length)
  , m_fd(other.m_fd)
  , m_map(other.m_map)
@@ -44,5 +55,17 @@ MappedFile::MappedFile(MappedFile&& other)
  other.m_map = (void*)-1;
 }
 
+MappedFile& MappedFile::operator=(MappedFile&& other)
+{
+ if (this == &other)
+ return *this;
+ unmap();
+ swap(m_file_name, other.m_file_name);
+ swap(m_file_length, other.m_file_length);
+ swap(m_fd, other.m_fd);
+ swap(m_map, other.m_map);
+ return *this;
+}
+
 }
 

AK/MappedFile.h

@@ -7,11 +7,14 @@ namespace AK {
 class MappedFile {
 public:
  MappedFile() { }
- explicit MappedFile(String&& file_name);
+ explicit MappedFile(const String& file_name);
  MappedFile(MappedFile&&);
  ~MappedFile();
 
+ MappedFile& operator=(MappedFile&&);
+
  bool is_valid() const { return m_map != (void*)-1; }
+ void unmap();
 
  void* pointer() { return m_map; }
  const void* pointer() const { return m_map; }

LibC/Makefile

@@ -4,6 +4,7 @@ AK_OBJS = \
  ../AK/StringBuilder.o \
  ../AK/FileSystemPath.o \
  ../AK/StdLibExtras.o \
+ ../AK/MappedFile.o \
  ../AK/kmalloc.o
 
 LIBC_OBJS = \

SharedGraphics/Font.cpp

@@ -2,7 +2,7 @@
 #include <AK/kmalloc.h>
 #include <AK/BufferStream.h>
 #include <AK/StdLibExtras.h>
-
+#include <AK/MappedFile.h>
 #include <LibC/unistd.h>
 #include <LibC/stdio.h>
 #include <LibC/fcntl.h>
@@ -90,10 +90,6 @@ Font::Font(const String& name, unsigned* rows, byte* widths, bool is_fixed_width
 
 Font::~Font()
 {
- if (m_mmap_ptr) {
- int rc = munmap(m_mmap_ptr, 4096 * 3);
- ASSERT(rc == 0);
- }
 }
 
 RetainPtr<Font> Font::load_from_memory(const byte* data)
@@ -119,25 +115,12 @@ RetainPtr<Font> Font::load_from_memory(const byte* data)
 
 RetainPtr<Font> Font::load_from_file(const String& path)
 {
- int fd = open(path.characters(), O_RDONLY, 0644);
- if (fd < 0) {
- dbgprintf("open(%s) got fd=%d, failed: %s\n", path.characters(), fd, strerror(errno));
- perror("open");
+ MappedFile mapped_file(path);
+ if (!mapped_file.is_valid())
  return nullptr;
- }
 
- auto* mapped_file = (byte*)mmap(nullptr, 4096 * 3, PROT_READ, MAP_SHARED, fd, 0);
- if (mapped_file == MAP_FAILED) {
- int rc = close(fd);
- ASSERT(rc == 0);
- return nullptr;
- }
-
- auto font = load_from_memory(mapped_file);
- font->m_mmap_ptr = mapped_file;
-
- int rc = close(fd);
- ASSERT(rc == 0);
+ auto font = load_from_memory((const byte*)mapped_file.pointer());
+ font->m_mapped_file = move(mapped_file);
  return font;
 }
 

SharedGraphics/Font.h

@@ -4,6 +4,7 @@
 #include <AK/Retainable.h>
 #include <AK/RetainPtr.h>
 #include <AK/AKString.h>
+#include <AK/MappedFile.h>
 #include <AK/Types.h>
 
 // FIXME: Make a MutableGlyphBitmap buddy class for FontEditor instead?
@@ -47,8 +48,6 @@ class Font : public Retainable<Font> {
 
  RetainPtr<Font> clone() const;
 
- static RetainPtr<Font> load_from_memory(const byte*);
-
  static RetainPtr<Font> load_from_file(const String& path);
  bool write_to_file(const String& path);
 
@@ -78,11 +77,13 @@ class Font : public Retainable<Font> {
 private:
  Font(const String& name, unsigned* rows, byte* widths, bool is_fixed_width, byte glyph_width, byte glyph_height);
 
+ static RetainPtr<Font> load_from_memory(const byte*);
+
  String m_name;
 
  unsigned* m_rows { nullptr };
  byte* m_glyph_widths { nullptr };
- void* m_mmap_ptr { nullptr };
+ MappedFile m_mapped_file;
 
  byte m_glyph_width { 0 };
  byte m_glyph_height { 0 };