git-svn-id: https://profuse.googlecode.com/svn/branches/v2@214 aa027e90-d47c-11dd-86d7-074df07e0730

File/MappedFile.cpp

@@ -13,47 +13,83 @@ MappedFile::MappedFile()
 {
     _length = -1;
     _address = MAP_FAILED;
+    _readOnly = true;
 }
 
 MappedFile::MappedFile(MappedFile &mf)
 {
     _address = mf._address;
     _length = mf._length;
+    _readOnly = mf._readOnly;
     
     mf._address = MAP_FAILED;
     mf._length = -1;
+    mf._readOnly = true;
 }
 
-MappedFile::MappedFile(File f, bool readOnly)
+MappedFile::MappedFile(const File &f, bool readOnly, size_t size)
 {
-    #undef __METHOD__
-    #define __METHOD__ "MappedFile::MappedFile"
+    _length = -1;
+    _address = MAP_FAILED;
+    _readOnly = readOnly;
+    
+    init(f, readOnly, size);
+}
 
+
+MappedFile::MappedFile(const char *name, bool readOnly)
+{
+    File f(name, readOnly);
+    
+    _length = -1;
+    _address = MAP_FAILED;
+    _readOnly = readOnly;
+    
+    init(f, readOnly, -1);
+    
+}
+
+
+
+MappedFile::~MappedFile()
+{
+    close();
+}
+
+
+
+void MappedFile::init(const File &f, bool readOnly, size_t size)
+{
+#undef __METHOD__
+#define __METHOD__ "MappedFile::init"
+    
     struct stat st;
     
     // close enough
     if (f.fd() < 0)
         throw POSIXException( __METHOD__, EBADF);
-
-
-    if (::fstat(f.fd(), &st) != 0)
-        throw POSIXException(__METHOD__ ": fstat", errno);
     
-    if (!S_ISREG(st.st_mode))
-        throw POSIXException(__METHOD__, ENODEV);
+    
+    if (size <= 0)
+    {
+        if (::fstat(f.fd(), &st) != 0)
+            throw POSIXException(__METHOD__ ": fstat", errno);
         
-    _length = st.st_size;
+        if (!S_ISREG(st.st_mode))
+            throw POSIXException(__METHOD__, ENODEV);
+        
+        size = st.st_size;
+    }
+    
+    _length = size;
     _address = ::mmap(0, _length, 
-        readOnly ? PROT_READ : PROT_READ | PROT_WRITE, 
-        MAP_FILE | MAP_SHARED, f.fd(), 0); 
-
+                      readOnly ? PROT_READ : PROT_READ | PROT_WRITE, 
+                      MAP_FILE | MAP_SHARED, f.fd(), 0); 
+    
     if (_address == MAP_FAILED)
         throw POSIXException(__METHOD__ ": mmap", errno);
-}
-
-MappedFile::~MappedFile()
-{
-    close();
+    
+    _readOnly = readOnly;
 }
 
 
@@ -70,6 +106,7 @@ void MappedFile::close()
         
         _address = MAP_FAILED;
         _length = -1;
+        _readOnly = true;
         
         if (::munmap(address, length) != 0)
             throw POSIXException(__METHOD__ ": munmap", errno);
@@ -93,13 +130,39 @@ void MappedFile::adopt(MappedFile &mf)
     close();
     _address = mf._address;
     _length = mf._length;
+    _readOnly = mf._readOnly;
     
     mf._address = MAP_FAILED;
     mf._length = -1;
+    mf._readOnly = true;
 }
 
 void MappedFile::swap(MappedFile &mf)
 {
     std::swap(_address, mf._address);
     std::swap(_length, mf._length);
+    std::swap(_readOnly, mf._readOnly);
+}
+
+
+static MappedFile *Create(const char *name, size_t size)
+{
+#undef __METHOD__
+#define __METHOD__ "MappedFile::Create"
+    
+    File fd(::open(name, O_CREAT | O_TRUNC | O_RDWR, 0644));
+
+    if (!fd.isValid())
+    {
+        throw POSIXException(__METHOD__ ": Unable to create file.", errno);        
+    }
+
+    // TODO -- is ftruncate portable?
+    if (::ftruncate(fd.fd(), size) < 0)
+    {
+        // TODO -- unlink?
+        throw POSIXException(__METHOD__ ": Unable to truncate file.", errno);    
+    }
+    
+    return new MappedFile(fd, false, size);
 }