/* Copyright (C) 2007-2010 The Android Open Source Project ** ** This software is licensed under the terms of the GNU General Public ** License version 2, as published by the Free Software Foundation, and ** may be copied, distributed, and modified under those terms. ** ** This program is distributed in the hope that it will be useful, ** but WITHOUT ANY WARRANTY; without even the implied warranty of ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** GNU General Public License for more details. */ /* * Contains implementation of routines that implement platform-independent * file I/O. */ #include "stddef.h" #include "sys/types.h" #include "errno.h" #ifdef WIN32 #include "windows.h" #else // WIN32 #include #endif // WIN32 #include #include #include #include "mapfile.h" MapFile* mapfile_open(const char* path, int oflag, int share_mode) { #ifdef WIN32 DWORD win32_share; DWORD win32_desired_access; DWORD win32_disposition; DWORD win32_flags; /* Convert to Win32 desired access. */ if ((oflag & O_RDWR) == O_RDWR) { win32_desired_access = GENERIC_READ | GENERIC_WRITE; } else if ((oflag & O_ACCMODE) == O_RDONLY) { win32_desired_access = GENERIC_READ; } else if ((oflag & O_WRONLY) == O_WRONLY) { win32_desired_access = GENERIC_WRITE; } /* Convert to Win32 sharing. */ win32_share = 0; if ((share_mode & S_IWRITE) != 0) { win32_share |= FILE_SHARE_WRITE; } if ((share_mode & S_IREAD) != 0) { win32_share |= FILE_SHARE_READ; } /* Convert to Win32 disposition. */ if ((oflag & O_CREAT) == O_CREAT) { if ((oflag & O_EXCL) == O_EXCL) { win32_disposition = CREATE_NEW; } else { win32_disposition = OPEN_ALWAYS; } } if ((oflag & O_TRUNC) == O_TRUNC) { win32_desired_access = TRUNCATE_EXISTING; } else { win32_disposition = OPEN_EXISTING; } /* Convert to Win32 flags. */ win32_flags = 0; #if defined(O_DSYNC) if ((oflag & O_DSYNC) == O_DSYNC || (oflag & O_RSYNC) == O_RSYNC || (oflag & O_RSYNC) == O_SYNC) { win32_flags |= FILE_FLAG_WRITE_THROUGH; } #endif // O_DSYNC HANDLE file_handle = CreateFile(path, win32_desired_access, win32_share, NULL, win32_disposition, win32_flags, NULL); if (file_handle == INVALID_HANDLE_VALUE) { errno = GetLastError(); } #else // WIN32 int file_handle = open(path, oflag, share_mode); #endif // WIN32 return (MapFile*)file_handle; } int mapfile_close(MapFile* handle) { #ifdef WIN32 if (CloseHandle(handle)) { return 0; } else { errno = GetLastError(); return -1; } #else // WIN32 return close((int)handle); #endif // WIN32 } ssize_t mapfile_read(MapFile* handle, void* buf, size_t nbyte) { #ifdef WIN32 ssize_t ret_bytes; DWORD read_bytes; if (ReadFile(handle, buf, nbyte, &read_bytes, NULL)) { ret_bytes = (ssize_t)read_bytes; } else { errno = GetLastError(); ret_bytes = -1; } return ret_bytes; #else // WIN32 ssize_t ret; do { ret = read((int)handle, buf, nbyte); } while (ret < 0 && errno == EINTR); return ret; #endif // WIN32 } ssize_t mapfile_read_at(MapFile* handle, size_t offset, void* buf, size_t nbyte) { #ifdef WIN32 LARGE_INTEGER convert; convert.QuadPart = offset; if ((SetFilePointer(handle, convert.LowPart, &convert.HighPart, FILE_BEGIN) == INVALID_SET_FILE_POINTER) && (GetLastError() != NO_ERROR)) { errno = GetLastError(); return -1; } return mapfile_read(handle, buf, nbyte); #else // WIN32 ssize_t res = lseek((int)handle, offset, SEEK_SET); return res >= 0 ? mapfile_read(handle, buf, nbyte) : res; #endif // WIN32 } void* mapfile_map(MapFile* handle, size_t offset, size_t size, int prot, void** mapped_offset, size_t* mapped_size) { void* mapped_at = NULL; size_t align_mask; size_t map_offset; size_t map_size; /* Get the mask for mapping offset alignment. */ #ifdef WIN32 DWORD win32_prot; DWORD win32_map; HANDLE map_handle; LARGE_INTEGER converter; SYSTEM_INFO sys_info; GetSystemInfo(&sys_info); align_mask = sys_info.dwAllocationGranularity - 1; #else // WIN32 align_mask = getpagesize() - 1; #endif // WIN32 /* Adjust mapping offset and mapping size accordingly to * the mapping alignment requirements. */ map_offset = offset & ~align_mask; map_size = (size_t)(offset - map_offset + size); /* Make sure mapping size doesn't exceed 4G. */ if (map_size < size) { errno = EFBIG; return NULL; } /* Map the section. */ #ifdef WIN32 /* Convert to Win32 page protection and mapping type. */ win32_prot = PAGE_READONLY; win32_map = FILE_MAP_READ; if (prot != PROT_NONE) { if ((prot & (PROT_WRITE | PROT_EXEC)) == 0) { win32_prot = PAGE_READONLY; win32_map = FILE_MAP_READ; } else if ((prot & (PROT_WRITE | PROT_EXEC)) == (PROT_WRITE | PROT_EXEC)) { win32_prot = PAGE_EXECUTE_READWRITE; win32_map = FILE_MAP_WRITE; } else if ((prot & PROT_WRITE) == PROT_WRITE) { win32_prot = PAGE_READWRITE; win32_map = FILE_MAP_WRITE; } else if ((prot & PROT_EXEC) == PROT_EXEC) { win32_prot = PAGE_EXECUTE_READ; win32_map = FILE_MAP_READ; } } converter.QuadPart = map_offset + map_size; map_handle = CreateFileMapping(handle, NULL, win32_prot, converter.HighPart, converter.LowPart, NULL); if (map_handle != NULL) { converter.QuadPart = map_offset; mapped_at = MapViewOfFile(map_handle, win32_map, converter.HighPart, converter.LowPart, map_size); /* Memory mapping (if successful) will hold extra references to the * mapping, so we can close it right after we mapped file view. */ CloseHandle(map_handle); } if (mapped_at == NULL) { errno = GetLastError(); return NULL; } #else // WIN32 mapped_at = mmap(0, map_size, PROT_READ, MAP_SHARED, (int)handle, map_offset); if (mapped_at == MAP_FAILED) { return NULL; } #endif // WIN32 *mapped_offset = (char*)mapped_at + (offset - map_offset); *mapped_size = size; return mapped_at; } int mapfile_unmap(void* mapped_at, size_t len) { #ifdef WIN32 if (!UnmapViewOfFile(mapped_at)) { errno = GetLastError(); return -1; } return 0; #else // WIN32 return munmap(mapped_at, len); #endif // WIN32 }