/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2006 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library 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

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Sam Lantinga

slouken@libsdl.org

*/

#include "SDL_config.h"

/* This file provides a general interface for SDL to read and write

data sources. It can easily be extended to files, memory, etc.

*/

#include "SDL_endian.h"

#include "SDL_rwops.h"

#if defined(__WIN32__) && !defined(__SYMBIAN32__)

/* Functions to read/write Win32 API file pointers */

/* Will not use it on WinCE because stdio is buffered, it means

faster, and all stdio functions anyway are embedded in coredll.dll -

the main wince dll*/

#define WINDOWS_LEAN_AND_MEAN

#include <windows.h>

#ifndef INVALID_SET_FILE_POINTER

#define INVALID_SET_FILE_POINTER 0xFFFFFFFF

#endif

#define READAHEAD_BUFFER_SIZE 1024

static int SDLCALL win32_file_open(SDL_RWops *context, const char *filename, const char *mode)

{

#ifndef _WIN32_WCE

UINT old_error_mode;

#endif

HANDLE h;

DWORD r_right, w_right;

DWORD must_exist, truncate;

int a_mode;

if (!context)

return -1;

context->hidden.win32io.h = INVALID_HANDLE_VALUE; /* mark this as unusable */

context->hidden.win32io.buffer.data = NULL;

context->hidden.win32io.buffer.size = 0;

context->hidden.win32io.buffer.left = 0;

/* "r" = reading, file must exist */

/* "w" = writing, truncate existing, file may not exist */

/* "r+"= reading or writing, file must exist */

/* "a" = writing, append file may not exist */

/* "a+"= append + read, file may not exist */

/* "w+" = read, write, truncate. file may not exist */

must_exist = ( SDL_strchr(mode,'r') != NULL ) ? OPEN_EXISTING : 0;

truncate = ( SDL_strchr(mode,'w') != NULL ) ? CREATE_ALWAYS : 0;

r_right = ( SDL_strchr(mode,'+') != NULL || must_exist ) ? GENERIC_READ : 0;

a_mode = ( SDL_strchr(mode,'a') != NULL ) ? OPEN_ALWAYS : 0;

w_right = ( a_mode || SDL_strchr(mode,'+') || truncate ) ? GENERIC_WRITE : 0;

if (!r_right && !w_right) /* inconsistent mode */

return -1; /* failed (invalid call)*/

context->hidden.win32io.buffer.data = (char *)SDL_malloc(READAHEAD_BUFFER_SIZE);

if (!context->hidden.win32io.buffer.data) {

SDL_OutOfMemory();

return -1;

}

#ifdef _WIN32_WCE

{

size_t size = SDL_strlen(filename)+1;

wchar_t *filenameW = SDL_stack_alloc(wchar_t, size);

if ( MultiByteToWideChar(CP_UTF8, 0, filename, -1, filenameW, size) == 0 ) {

SDL_SetError("Unable to convert filename to Unicode");

SDL_stack_free(filenameW);

SDL_free(context->hidden.win32io.buffer.data);

context->hidden.win32io.buffer.data = NULL;

return -1;

}

h = CreateFile(filenameW, (w_right|r_right), (w_right)? 0 : FILE_SHARE_READ,

NULL, (must_exist|truncate|a_mode), FILE_ATTRIBUTE_NORMAL,NULL);

SDL_stack_free(filenameW);

}

#else

/* Do not open a dialog box if failure */

old_error_mode = SetErrorMode(SEM_NOOPENFILEERRORBOX|SEM_FAILCRITICALERRORS);

h = CreateFile(filename, (w_right|r_right), (w_right)? 0 : FILE_SHARE_READ,

NULL, (must_exist|truncate|a_mode), FILE_ATTRIBUTE_NORMAL,NULL);

/* restore old behaviour */

SetErrorMode(old_error_mode);

#endif /* _WIN32_WCE */

if (h==INVALID_HANDLE_VALUE) {

SDL_SetError("Couldn't open %s",filename);

SDL_free(context->hidden.win32io.buffer.data);

context->hidden.win32io.buffer.data = NULL;

return -2; /* failed (CreateFile) */

}

context->hidden.win32io.h = h;

context->hidden.win32io.append = a_mode;

return 0; /* ok */

}

static int SDLCALL win32_file_seek(SDL_RWops *context, int offset, int whence)

{

DWORD win32whence;

int file_pos;

if (!context || context->hidden.win32io.h == INVALID_HANDLE_VALUE) {

SDL_SetError("win32_file_seek: invalid context/file not opened");

return -1;

}

/* FIXME: We may be able to satisfy the seek within buffered data */

if (whence == RW_SEEK_CUR && context->hidden.win32io.buffer.left) {

offset -= context->hidden.win32io.buffer.left;

}

context->hidden.win32io.buffer.left = 0;

switch (whence) {

case RW_SEEK_SET:

win32whence = FILE_BEGIN; break;

case RW_SEEK_CUR:

win32whence = FILE_CURRENT; break;

case RW_SEEK_END:

win32whence = FILE_END; break;

default:

SDL_SetError("win32_file_seek: Unknown value for 'whence'");

return -1;

}

file_pos = SetFilePointer(context->hidden.win32io.h,offset,NULL,win32whence);

if ( file_pos != INVALID_SET_FILE_POINTER )

return file_pos; /* success */

SDL_Error(SDL_EFSEEK);

return -1; /* error */

}

static int SDLCALL win32_file_read(SDL_RWops *context, void *ptr, int size, int maxnum)

{

int total_need;

int total_read = 0;

int read_ahead;

DWORD byte_read;

total_need = size*maxnum;

if (!context || context->hidden.win32io.h == INVALID_HANDLE_VALUE || total_need<=0 || !size)

return 0;

if (context->hidden.win32io.buffer.left > 0) {

void *data = (char *)context->hidden.win32io.buffer.data +

context->hidden.win32io.buffer.size -

context->hidden.win32io.buffer.left;

read_ahead = SDL_min(total_need, context->hidden.win32io.buffer.left);

SDL_memcpy(ptr, data, read_ahead);

context->hidden.win32io.buffer.left -= read_ahead;

if (read_ahead == total_need) {

return maxnum;

}

ptr = (char *)ptr + read_ahead;

total_need -= read_ahead;

total_read += read_ahead;

}

if (total_need < READAHEAD_BUFFER_SIZE) {

if (!ReadFile(context->hidden.win32io.h,context->hidden.win32io.buffer.data,READAHEAD_BUFFER_SIZE,&byte_read,NULL)) {

SDL_Error(SDL_EFREAD);

return 0;

}

read_ahead = SDL_min(total_need, (int)byte_read);

SDL_memcpy(ptr, context->hidden.win32io.buffer.data, read_ahead);

context->hidden.win32io.buffer.size = byte_read;

context->hidden.win32io.buffer.left = byte_read-read_ahead;

total_read += read_ahead;

} else {

if (!ReadFile(context->hidden.win32io.h,ptr,total_need,&byte_read,NULL)) {

SDL_Error(SDL_EFREAD);

return 0;

}

total_read += byte_read;

}

return (total_read/size);

}

static int SDLCALL win32_file_write(SDL_RWops *context, const void *ptr, int size, int num)

{

int total_bytes;

DWORD byte_written,nwritten;

total_bytes = size*num;

if (!context || context->hidden.win32io.h==INVALID_HANDLE_VALUE || total_bytes<=0 || !size)

return 0;

if (context->hidden.win32io.buffer.left) {

SetFilePointer(context->hidden.win32io.h,-context->hidden.win32io.buffer.left,NULL,FILE_CURRENT);

context->hidden.win32io.buffer.left = 0;

}

/* if in append mode, we must go to the EOF before write */

if (context->hidden.win32io.append) {

if ( SetFilePointer(context->hidden.win32io.h,0L,NULL,FILE_END) == INVALID_SET_FILE_POINTER ) {

SDL_Error(SDL_EFWRITE);

return 0;

}

}

if (!WriteFile(context->hidden.win32io.h,ptr,total_bytes,&byte_written,NULL)) {

SDL_Error(SDL_EFWRITE);

return 0;

}

nwritten = byte_written/size;

return nwritten;

}

static int SDLCALL win32_file_close(SDL_RWops *context)

{

if ( context ) {

if (context->hidden.win32io.h != INVALID_HANDLE_VALUE) {

CloseHandle(context->hidden.win32io.h);

context->hidden.win32io.h = INVALID_HANDLE_VALUE; /* to be sure */

}

if (context->hidden.win32io.buffer.data) {

SDL_free(context->hidden.win32io.buffer.data);

context->hidden.win32io.buffer.data = NULL;

}

SDL_FreeRW(context);

}

return(0);

}

#endif /* __WIN32__ */

#ifdef HAVE_STDIO_H

/* Functions to read/write stdio file pointers */

static int SDLCALL stdio_seek(SDL_RWops *context, int offset, int whence)

{

if ( fseek(context->hidden.stdio.fp, offset, whence) == 0 ) {

return(ftell(context->hidden.stdio.fp));

} else {

SDL_Error(SDL_EFSEEK);

return(-1);

}

}

static int SDLCALL stdio_read(SDL_RWops *context, void *ptr, int size, int maxnum)

{

size_t nread;

nread = fread(ptr, size, maxnum, context->hidden.stdio.fp);

if ( nread == 0 && ferror(context->hidden.stdio.fp) ) {

SDL_Error(SDL_EFREAD);

}

return(nread);

}

static int SDLCALL stdio_write(SDL_RWops *context, const void *ptr, int size, int num)

{

size_t nwrote;

nwrote = fwrite(ptr, size, num, context->hidden.stdio.fp);

if ( nwrote == 0 && ferror(context->hidden.stdio.fp) ) {

SDL_Error(SDL_EFWRITE);

}

return(nwrote);

}

static int SDLCALL stdio_close(SDL_RWops *context)

{

if ( context ) {

if ( context->hidden.stdio.autoclose ) {

/* WARNING: Check the return value here! */

fclose(context->hidden.stdio.fp);

}

SDL_FreeRW(context);

}

return(0);

}

#endif /* !HAVE_STDIO_H */

/* Functions to read/write memory pointers */

static int SDLCALL mem_seek(SDL_RWops *context, int offset, int whence)

{

Uint8 *newpos;

switch (whence) {

case RW_SEEK_SET:

newpos = context->hidden.mem.base+offset;

break;

case RW_SEEK_CUR:

newpos = context->hidden.mem.here+offset;

break;

case RW_SEEK_END:

newpos = context->hidden.mem.stop+offset;

break;

default:

SDL_SetError("Unknown value for 'whence'");

return(-1);

}

if ( newpos < context->hidden.mem.base ) {

newpos = context->hidden.mem.base;

}

if ( newpos > context->hidden.mem.stop ) {

newpos = context->hidden.mem.stop;

}

context->hidden.mem.here = newpos;

return(context->hidden.mem.here-context->hidden.mem.base);

}

static int SDLCALL mem_read(SDL_RWops *context, void *ptr, int size, int maxnum)

{

size_t total_bytes;

size_t mem_available;

total_bytes = (maxnum * size);

if ( (maxnum <= 0) || (size <= 0) || ((total_bytes / maxnum) != (size_t) size) ) {

return 0;

}

mem_available = (context->hidden.mem.stop - context->hidden.mem.here);

if (total_bytes > mem_available) {

total_bytes = mem_available;

}

SDL_memcpy(ptr, context->hidden.mem.here, total_bytes);

context->hidden.mem.here += total_bytes;

return (total_bytes / size);

}

static int SDLCALL mem_write(SDL_RWops *context, const void *ptr, int size, int num)

{

if ( (context->hidden.mem.here + (num*size)) > context->hidden.mem.stop ) {

num = (context->hidden.mem.stop-context->hidden.mem.here)/size;

}

SDL_memcpy(context->hidden.mem.here, ptr, num*size);

context->hidden.mem.here += num*size;

return(num);

}

static int SDLCALL mem_writeconst(SDL_RWops *context, const void *ptr, int size, int num)

{

SDL_SetError("Can't write to read-only memory");

return(-1);

}

static int SDLCALL mem_close(SDL_RWops *context)

{

if ( context ) {

SDL_FreeRW(context);

}

return(0);

}

/* Functions to create SDL_RWops structures from various data sources */

#ifdef __MACOS__

/*

* translate unix-style slash-separated filename to mac-style colon-separated

* name; return malloced string

*/

static char *unix_to_mac(const char *file)

{

int flen = SDL_strlen(file);

char *path = SDL_malloc(flen + 2);

const char *src = file;

char *dst = path;

if(*src == '/') {

/* really depends on filesystem layout, hope for the best */

src++;

} else {

/* Check if this is a MacOS path to begin with */

if(*src != ':')

*dst++ = ':'; /* relative paths begin with ':' */

}

while(src < file + flen) {

const char *end = SDL_strchr(src, '/');

int len;

if(!end)

end = file + flen; /* last component */

len = end - src;

if(len == 0 || (len == 1 && src[0] == '.')) {

/* remove repeated slashes and . */

} else {

if(len == 2 && src[0] == '.' && src[1] == '.') {

/* replace .. with the empty string */

} else {

SDL_memcpy(dst, src, len);

dst += len;

}

if(end < file + flen)

*dst++ = ':';

}

src = end + 1;

}

*dst++ = '\0';

return path;

}

#endif /* __MACOS__ */

SDL_RWops *SDL_RWFromFile(const char *file, const char *mode)

{

SDL_RWops *rwops = NULL;

#ifdef HAVE_STDIO_H

FILE *fp = NULL;

#endif

if ( !file || !*file || !mode || !*mode ) {

SDL_SetError("SDL_RWFromFile(): No file or no mode specified");

return NULL;

}

#if defined(__WIN32__) && !defined(__SYMBIAN32__)

rwops = SDL_AllocRW();

if (!rwops)

return NULL; /* SDL_SetError already setup by SDL_AllocRW() */

rwops->hidden.win32io.h = INVALID_HANDLE_VALUE;

if (win32_file_open(rwops,file,mode)) {

SDL_FreeRW(rwops);

return NULL;

}

rwops->seek = win32_file_seek;

rwops->read = win32_file_read;

rwops->write = win32_file_write;

rwops->close = win32_file_close;

#elif HAVE_STDIO_H

#ifdef __MACOS__

{

char *mpath = unix_to_mac(file);

fp = fopen(mpath, mode);

SDL_free(mpath);

}

#else

fp = fopen(file, mode);

#endif

if ( fp == NULL ) {

SDL_SetError("Couldn't open %s", file);

} else {

rwops = SDL_RWFromFP(fp, 1);

}

#else

SDL_SetError("SDL not compiled with stdio support");

#endif /* !HAVE_STDIO_H */

return(rwops);

}

#ifdef HAVE_STDIO_H

SDL_RWops *SDL_RWFromFP(FILE *fp, int autoclose)

{

SDL_RWops *rwops = NULL;

rwops = SDL_AllocRW();

if ( rwops != NULL ) {

rwops->seek = stdio_seek;

rwops->read = stdio_read;

rwops->write = stdio_write;

rwops->close = stdio_close;

rwops->hidden.stdio.fp = fp;

rwops->hidden.stdio.autoclose = autoclose;

}

return(rwops);

}

#endif /* HAVE_STDIO_H */

SDL_RWops *SDL_RWFromMem(void *mem, int size)

{

SDL_RWops *rwops;

rwops = SDL_AllocRW();

if ( rwops != NULL ) {

rwops->seek = mem_seek;

rwops->read = mem_read;

rwops->write = mem_write;

rwops->close = mem_close;

rwops->hidden.mem.base = (Uint8 *)mem;

rwops->hidden.mem.here = rwops->hidden.mem.base;

rwops->hidden.mem.stop = rwops->hidden.mem.base+size;

}

return(rwops);

}

SDL_RWops *SDL_RWFromConstMem(const void *mem, int size)

{

SDL_RWops *rwops;

rwops = SDL_AllocRW();

if ( rwops != NULL ) {

rwops->seek = mem_seek;

rwops->read = mem_read;

rwops->write = mem_writeconst;

rwops->close = mem_close;

rwops->hidden.mem.base = (Uint8 *)mem;

rwops->hidden.mem.here = rwops->hidden.mem.base;

rwops->hidden.mem.stop = rwops->hidden.mem.base+size;

}

return(rwops);

}

SDL_RWops *SDL_AllocRW(void)

{

SDL_RWops *area;

area = (SDL_RWops *)SDL_malloc(sizeof *area);

if ( area == NULL ) {

SDL_OutOfMemory();

}

return(area);

}

void SDL_FreeRW(SDL_RWops *area)

{

SDL_free(area);

}

/* Functions for dynamically reading and writing endian-specific values */

Uint16 SDL_ReadLE16 (SDL_RWops *src)

{

Uint16 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapLE16(value));

}

Uint16 SDL_ReadBE16 (SDL_RWops *src)

{

Uint16 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapBE16(value));

}

Uint32 SDL_ReadLE32 (SDL_RWops *src)

{

Uint32 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapLE32(value));

}

Uint32 SDL_ReadBE32 (SDL_RWops *src)

{

Uint32 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapBE32(value));

}

Uint64 SDL_ReadLE64 (SDL_RWops *src)

{

Uint64 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapLE64(value));

}

Uint64 SDL_ReadBE64 (SDL_RWops *src)

{

Uint64 value;

SDL_RWread(src, &value, (sizeof value), 1);

return(SDL_SwapBE64(value));

}

int SDL_WriteLE16 (SDL_RWops *dst, Uint16 value)

{

value = SDL_SwapLE16(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteBE16 (SDL_RWops *dst, Uint16 value)

{

value = SDL_SwapBE16(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteLE32 (SDL_RWops *dst, Uint32 value)

{

value = SDL_SwapLE32(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteBE32 (SDL_RWops *dst, Uint32 value)

{

value = SDL_SwapBE32(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteLE64 (SDL_RWops *dst, Uint64 value)

{

value = SDL_SwapLE64(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}

int SDL_WriteBE64 (SDL_RWops *dst, Uint64 value)

{

value = SDL_SwapBE64(value);

return(SDL_RWwrite(dst, &value, (sizeof value), 1));

}