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 @@ public:
 
     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 @@ public:
 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 };