ladybird/AK/MappedFile.cpp
Andreas Kling c79b048198 MappedFile: Fix misuse of StringView::characters().
This makes me wonder if the open() syscall should take characters+length
and we'd compute the length at the LibC layer instead. That way we could
also provide an optional non-POSIX open() that takes the length directly..
2019-07-08 13:59:10 +02:00

73 lines
1.4 KiB
C++

#include <AK/AKString.h>
#include <AK/MappedFile.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <unistd.h>
//#define DEBUG_MAPPED_FILE
namespace AK {
MappedFile::MappedFile(const StringView& file_name)
{
m_size = PAGE_SIZE;
m_fd = open(String(file_name).characters(), O_RDONLY | O_CLOEXEC);
if (m_fd != -1) {
struct stat st;
fstat(m_fd, &st);
m_size = st.st_size;
m_map = mmap(nullptr, m_size, PROT_READ, MAP_SHARED, m_fd, 0);
if (m_map == MAP_FAILED)
perror("");
}
#ifdef DEBUG_MAPPED_FILE
dbgprintf("MappedFile{%s} := { m_fd=%d, m_size=%u, m_map=%p }\n", file_name.characters(), m_fd, m_size, m_map);
#endif
}
MappedFile::~MappedFile()
{
unmap();
}
void MappedFile::unmap()
{
if (!is_valid())
return;
ASSERT(m_fd != -1);
int rc = munmap(m_map, m_size);
ASSERT(rc == 0);
rc = close(m_fd);
ASSERT(rc == 0);
m_size = 0;
m_fd = -1;
m_map = (void*)-1;
}
MappedFile::MappedFile(MappedFile&& other)
: m_size(other.m_size)
, m_fd(other.m_fd)
, m_map(other.m_map)
{
other.m_size = 0;
other.m_fd = -1;
other.m_map = (void*)-1;
}
MappedFile& MappedFile::operator=(MappedFile&& other)
{
if (this == &other)
return *this;
unmap();
swap(m_size, other.m_size);
swap(m_fd, other.m_fd);
swap(m_map, other.m_map);
return *this;
}
}