SDL/src/io/SDL_iostream.c at main · rom1v/SDL

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  Simple DirectMedia Layer
  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.
  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:
  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
#include "SDL_internal.h"
#if defined(SDL_PLATFORM_WINDOWS)
#include "../core/windows/SDL_windows.h"
#include <unistd.h>
#ifdef HAVE_STDIO_H
#include <stdio.h>
#include <errno.h>
#include <sys/stat.h>
#ifdef HAVE_LIMITS_H
#include <limits.h>
#ifdef SDL_PLATFORM_APPLE
#include <fcntl.h>
#include "SDL_iostream_c.h"
/* This file provides a general interface for SDL to read and write
   data sources.  It can easily be extended to files, memory, etc.
struct SDL_IOStream
    SDL_IOStreamInterface iface;
    void *userdata;
    SDL_IOStatus status;
    SDL_PropertiesID props;
#ifdef SDL_PLATFORM_3DS
#include "n3ds/SDL_iostreamromfs.h"
#endif // SDL_PLATFORM_3DS
#ifdef SDL_PLATFORM_ANDROID
#include <unistd.h>
#include "../core/android/SDL_android.h"
#if defined(SDL_PLATFORM_WINDOWS)
typedef struct IOStreamWindowsData
    HANDLE h;
    void *data;
    size_t size;
    size_t left;
    bool append;
    bool autoclose;
} IOStreamWindowsData;
// Functions to read/write Win32 API file pointers
#ifndef INVALID_SET_FILE_POINTER
#define INVALID_SET_FILE_POINTER 0xFFFFFFFF
#define READAHEAD_BUFFER_SIZE 1024
static HANDLE SDLCALL windows_file_open(const char *filename, const char *mode)
#if !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
    UINT old_error_mode;
    HANDLE h;
    DWORD r_right, w_right;
    DWORD must_exist, truncate;
    int a_mode;
    // "r" = reading, file must exist
    // "w" = writing, truncate existing, file may not exist
    // "wx"= writing, file must 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
    // "w+x"= read, write, file must 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 (truncate && (SDL_strchr(mode, 'x') != NULL)) {
        truncate = CREATE_NEW;
    if (!r_right && !w_right) {
        return INVALID_HANDLE_VALUE; // inconsistent mode
    // failed (invalid call)
#if !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
    // Do not open a dialog box if failure
    old_error_mode = SetErrorMode(SEM_NOOPENFILEERRORBOX | SEM_FAILCRITICALERRORS);
        LPWSTR str = WIN_UTF8ToStringW(filename);
        h = CreateFileW(str,
                       (w_right | r_right),
                       (w_right) ? 0 : FILE_SHARE_READ,
                       (must_exist | truncate | a_mode),
                       FILE_ATTRIBUTE_NORMAL,
                       NULL);
        SDL_free(str);
#if !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)
    // restore old behavior
    SetErrorMode(old_error_mode);
    if (h == INVALID_HANDLE_VALUE) {
        char *error;
        if (SDL_asprintf(&error, "Couldn't open %s", filename) > 0) {
            WIN_SetError(error);
            SDL_free(error);
        } else {
            SDL_SetError("Couldn't open %s", filename);
    return h;
static Sint64 SDLCALL windows_file_size(void *userdata)
    IOStreamWindowsData *iodata = (IOStreamWindowsData *) userdata;
    LARGE_INTEGER size;
    if (!GetFileSizeEx(iodata->h, &size)) {
        return WIN_SetError("windows_file_size");
    return size.QuadPart;
static Sint64 SDLCALL windows_file_seek(void *userdata, Sint64 offset, SDL_IOWhence whence)
    IOStreamWindowsData *iodata = (IOStreamWindowsData *) userdata;
    DWORD windowswhence;
    LARGE_INTEGER windowsoffset;
    // FIXME: We may be able to satisfy the seek within buffered data
    if ((whence == SDL_IO_SEEK_CUR) && (iodata->left)) {
        offset -= iodata->left;
    iodata->left = 0;
    switch (whence) {
    case SDL_IO_SEEK_SET:
        windowswhence = FILE_BEGIN;
        break;
    case SDL_IO_SEEK_CUR:
        windowswhence = FILE_CURRENT;
        break;
    case SDL_IO_SEEK_END:
        windowswhence = FILE_END;
        break;
    default:
        SDL_SetError("windows_file_seek: Unknown value for 'whence'");
        return -1;
    windowsoffset.QuadPart = offset;
    if (!SetFilePointerEx(iodata->h, windowsoffset, &windowsoffset, windowswhence)) {
        return WIN_SetError("Error seeking in datastream");
    return windowsoffset.QuadPart;
static size_t SDLCALL windows_file_read(void *userdata, void *ptr, size_t size, SDL_IOStatus *status)
    IOStreamWindowsData *iodata = (IOStreamWindowsData *) userdata;
    size_t total_need = size;
    size_t total_read = 0;
    size_t read_ahead;
    DWORD bytes;
    if (iodata->left > 0) {
        void *data = (char *)iodata->data +
                     iodata->size -
                     iodata->left;
        read_ahead = SDL_min(total_need, iodata->left);
        SDL_memcpy(ptr, data, read_ahead);
        iodata->left -= read_ahead;
        if (read_ahead == total_need) {
            return size;
        ptr = (char *)ptr + read_ahead;
        total_need -= read_ahead;
        total_read += read_ahead;
    if (total_need < READAHEAD_BUFFER_SIZE) {
        if (!ReadFile(iodata->h, iodata->data, READAHEAD_BUFFER_SIZE, &bytes, NULL)) {
            DWORD error = GetLastError();
            switch (error) {
            case ERROR_BROKEN_PIPE:
                *status = SDL_IO_STATUS_EOF;
                break;
            case ERROR_NO_DATA:
                *status = SDL_IO_STATUS_NOT_READY;
                break;
            default:
                *status = SDL_IO_STATUS_ERROR;
                WIN_SetError("Error reading from datastream");
                break;
            return 0;  // !!! FIXME: this should return the bytes read from any readahead we finished out before this (the `iodata->left > 0` code above). In that case, fail on the next read.
        } else if (bytes == 0) {
            *status = SDL_IO_STATUS_EOF;
        read_ahead = SDL_min(total_need, bytes);
        SDL_memcpy(ptr, iodata->data, read_ahead);
        iodata->size = bytes;
        iodata->left = bytes - read_ahead;
        total_read += read_ahead;
    } else {
        if (!ReadFile(iodata->h, ptr, (DWORD)total_need, &bytes, NULL)) {
            DWORD error = GetLastError();
            switch (error) {
            case ERROR_BROKEN_PIPE:
                *status = SDL_IO_STATUS_EOF;
                break;
            case ERROR_NO_DATA:
                *status = SDL_IO_STATUS_NOT_READY;
                break;
            default:
                *status = SDL_IO_STATUS_ERROR;
                WIN_SetError("Error reading from datastream");
                break;
            return 0;  // !!! FIXME: this should return the bytes read from any readahead we finished out before this (the `iodata->left > 0` code above). In that case, fail on the next read.
        } else if (bytes == 0) {
            *status = SDL_IO_STATUS_EOF;
        total_read += bytes;
    return total_read;
static size_t SDLCALL windows_file_write(void *userdata, const void *ptr, size_t size, SDL_IOStatus *status)
    IOStreamWindowsData *iodata = (IOStreamWindowsData *) userdata;
    DWORD bytes;
    if (iodata->left) {
        if (!SetFilePointer(iodata->h, -(LONG)iodata->left, NULL, FILE_CURRENT)) {
            *status = SDL_IO_STATUS_ERROR;
            WIN_SetError("Error seeking in datastream");
            return 0;
        iodata->left = 0;
    // if in append mode, we must go to the EOF before write
    if (iodata->append) {
        LARGE_INTEGER windowsoffset;
        windowsoffset.QuadPart = 0;
        if (!SetFilePointerEx(iodata->h, windowsoffset, &windowsoffset, FILE_END)) {
            *status = SDL_IO_STATUS_ERROR;
            WIN_SetError("Error seeking in datastream");
            return 0;
    if (!WriteFile(iodata->h, ptr, (DWORD)size, &bytes, NULL)) {
        *status = SDL_IO_STATUS_ERROR;
        WIN_SetError("Error writing to datastream");
        return 0;
    } else if (bytes == 0 && size > 0) {
        *status = SDL_IO_STATUS_NOT_READY;
    return bytes;
static bool SDLCALL windows_file_flush(void *userdata, SDL_IOStatus *status)
    IOStreamWindowsData *iodata = (IOStreamWindowsData *) userdata;
    if (!FlushFileBuffers(iodata->h)) {
        return WIN_SetError("Error flushing datastream");
    return true;
static bool SDLCALL windows_file_close(void *userdata)
    IOStreamWindowsData *iodata = (IOStreamWindowsData *) userdata;
    if (iodata->h != INVALID_HANDLE_VALUE) {
        if (iodata->autoclose) {
            CloseHandle(iodata->h);
        iodata->h = INVALID_HANDLE_VALUE; // to be sure
    SDL_free(iodata->data);
    SDL_free(iodata);
    return true;
SDL_IOStream *SDL_IOFromHandle(HANDLE handle, const char *mode, bool autoclose)
    IOStreamWindowsData *iodata = (IOStreamWindowsData *) SDL_calloc(1, sizeof (*iodata));
    if (!iodata) {
        if (autoclose) {
            CloseHandle(handle);
        return NULL;
    SDL_IOStreamInterface iface;
    SDL_INIT_INTERFACE(&iface);
    if (GetFileType(handle) == FILE_TYPE_DISK) {
        iface.size = windows_file_size;
        iface.seek = windows_file_seek;
    iface.read = windows_file_read;
    iface.write = windows_file_write;
    iface.flush = windows_file_flush;
    iface.close = windows_file_close;
    iodata->h = handle;
    iodata->append = (SDL_strchr(mode, 'a') != NULL);
    iodata->autoclose = autoclose;
    iodata->data = (char *)SDL_malloc(READAHEAD_BUFFER_SIZE);
    if (!iodata->data) {
        iface.close(iodata);
        return NULL;
    SDL_IOStream *iostr = SDL_OpenIO(&iface, iodata);
    if (!iostr) {
        iface.close(iodata);
    } else {
        const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
        if (props) {
            SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_WINDOWS_HANDLE_POINTER, iodata->h);
    return iostr;
#endif // defined(SDL_PLATFORM_WINDOWS)
#if !defined(SDL_PLATFORM_WINDOWS)
// Functions to read/write file descriptors. Not used for windows.
typedef struct IOStreamFDData
    int fd;
    bool autoclose;
    bool regular_file;
} IOStreamFDData;
static int SDL_fdatasync(int fd)
    int result = 0;
#if defined(SDL_PLATFORM_APPLE)  // Apple doesn't have fdatasync (rather, the symbol exists as an incompatible system call).
    result = fcntl(fd, F_FULLFSYNC);
#elif defined(SDL_PLATFORM_HAIKU)
    result = fsync(fd);
#elif defined(HAVE_FDATASYNC)
    result = fdatasync(fd);
    return result;
static Sint64 SDLCALL fd_seek(void *userdata, Sint64 offset, SDL_IOWhence whence)
    IOStreamFDData *iodata = (IOStreamFDData *) userdata;
    int fdwhence;
    switch (whence) {
    case SDL_IO_SEEK_SET:
        fdwhence = SEEK_SET;
        break;
    case SDL_IO_SEEK_CUR:
        fdwhence = SEEK_CUR;
        break;
    case SDL_IO_SEEK_END:
        fdwhence = SEEK_END;
        break;
    default:
        SDL_SetError("Unknown value for 'whence'");
        return -1;
    off_t result = lseek(iodata->fd, (off_t)offset, fdwhence);
    if (result < 0) {
        SDL_SetError("Couldn't get stream offset: %s", strerror(errno));
    return result;
static size_t SDLCALL fd_read(void *userdata, void *ptr, size_t size, SDL_IOStatus *status)
    IOStreamFDData *iodata = (IOStreamFDData *) userdata;
    ssize_t bytes;
        bytes = read(iodata->fd, ptr, size);
    } while ((bytes < 0) && (errno == EINTR));
    ssize_t result = bytes;
    if ((bytes > 0) && (bytes < size)) {   // was it a short read, EOF, or error?
        // try to read the difference, so we can rule out a short read.
        do {
            result = read(iodata->fd, ((Uint8 *) ptr) + bytes, size - bytes);
        } while ((result < 0) && (errno == EINTR));
        if (result > 0) {
            bytes += result;
            result = bytes;
            SDL_assert(bytes <= size);
    if (result < 0) {
        if (errno == EAGAIN) {
            *status = SDL_IO_STATUS_NOT_READY;
        } else {
            *status = SDL_IO_STATUS_ERROR;
            SDL_SetError("Error reading from datastream: %s", strerror(errno));
        if (bytes < 0) {
            bytes = 0;
    } else if (result == 0) {
        *status = SDL_IO_STATUS_EOF;
    } else if (result < size) {
        *status = SDL_IO_STATUS_NOT_READY;;
    return (size_t)bytes;
static size_t SDLCALL fd_write(void *userdata, const void *ptr, size_t size, SDL_IOStatus *status)
    IOStreamFDData *iodata = (IOStreamFDData *) userdata;
    ssize_t bytes;
        bytes = write(iodata->fd, ptr, size);
    } while ((bytes < 0) && (errno == EINTR));
    ssize_t result = bytes;
    if ((bytes > 0) && (bytes < size)) {   // was it a short write, or error?
        // try to write the difference, so we can rule out a short read.
        do {
            result = write(iodata->fd, ((Uint8 *) ptr) + bytes, size - bytes);
        } while ((result < 0) && (errno == EINTR));
        if (result > 0) {
            bytes += result;
            result = bytes;
            SDL_assert(bytes <= size);
    if (result < 0) {
        if (errno == EAGAIN) {
            *status = SDL_IO_STATUS_NOT_READY;
        } else {
            *status = SDL_IO_STATUS_ERROR;
            SDL_SetError("Error writing to datastream: %s", strerror(errno));
        if (bytes < 0) {
            bytes = 0;
    } else if (result < size) {
        *status = SDL_IO_STATUS_NOT_READY;;
    return (size_t)bytes;
static bool SDLCALL fd_flush(void *userdata, SDL_IOStatus *status)
    IOStreamFDData *iodata = (IOStreamFDData *) userdata;
    int result;
        result = SDL_fdatasync(iodata->fd);
    } while (result < 0 && errno == EINTR);
    // We get EINVAL when flushing a pipe, just make that a no-op
    if (result < 0 && errno != EINVAL) {
        return SDL_SetError("Error flushing datastream: %s", strerror(errno));
    return true;
static bool SDLCALL fd_close(void *userdata)
    IOStreamFDData *iodata = (IOStreamFDData *) userdata;
    bool status = true;
    if (iodata->autoclose) {
        if (close(iodata->fd) < 0) {
            status = SDL_SetError("Error closing datastream: %s", strerror(errno));
    SDL_free(iodata);
    return status;
SDL_IOStream *SDL_IOFromFD(int fd, bool autoclose)
    IOStreamFDData *iodata = (IOStreamFDData *) SDL_calloc(1, sizeof (*iodata));
    if (!iodata) {
        if (autoclose) {
           close(fd);
        return NULL;
    SDL_IOStreamInterface iface;
    SDL_INIT_INTERFACE(&iface);
    // There's no fd_size because SDL_GetIOSize emulates it the same way we'd do it for fd anyhow.
    iface.seek = fd_seek;
    iface.read = fd_read;
    iface.write = fd_write;
    iface.flush = fd_flush;
    iface.close = fd_close;
    iodata->fd = fd;
    iodata->autoclose = autoclose;
    struct stat st;
    iodata->regular_file = ((fstat(fd, &st) == 0) && S_ISREG(st.st_mode));
    SDL_IOStream *iostr = SDL_OpenIO(&iface, iodata);
    if (!iostr) {
        iface.close(iodata);
    } else {
        const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
        if (props) {
            SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_FILE_DESCRIPTOR_NUMBER, fd);
    return iostr;
#endif // !defined(SDL_PLATFORM_WINDOWS)
#if defined(HAVE_STDIO_H) && !defined(SDL_PLATFORM_WINDOWS)
// Functions to read/write stdio file pointers. Not used for windows.
typedef struct IOStreamStdioData
    FILE *fp;
    bool autoclose;
    bool regular_file;
} IOStreamStdioData;
#ifdef HAVE_FOPEN64
#define fopen fopen64
#ifdef HAVE_FSEEKO64
#define fseek_off_t off64_t
#define fseek       fseeko64
#define ftell       ftello64
#elif defined(HAVE_FSEEKO)
#if defined(OFF_MIN) && defined(OFF_MAX)
#define FSEEK_OFF_MIN OFF_MIN
#define FSEEK_OFF_MAX OFF_MAX
#elif defined(HAVE_LIMITS_H)
/* POSIX doesn't specify the minimum and maximum macros for off_t so
 * we have to improvise and dance around implementation-defined
 * behavior. This may fail if the off_t type has padding bits or
 * is not a two's-complement representation. The compilers will detect
 * and eliminate the dead code if off_t has 64 bits.
#define FSEEK_OFF_MAX (((((off_t)1 << (sizeof(off_t) * CHAR_BIT - 2)) - 1) << 1) + 1)
#define FSEEK_OFF_MIN (-(FSEEK_OFF_MAX)-1)
#define fseek_off_t off_t
#define fseek       fseeko
#define ftell       ftello
#elif defined(HAVE__FSEEKI64)
#define fseek_off_t __int64
#define fseek       _fseeki64
#define ftell       _ftelli64
#ifdef HAVE_LIMITS_H
#define FSEEK_OFF_MIN LONG_MIN
#define FSEEK_OFF_MAX LONG_MAX
#define fseek_off_t long
static Sint64 SDLCALL stdio_seek(void *userdata, Sint64 offset, SDL_IOWhence whence)
    IOStreamStdioData *iodata = (IOStreamStdioData *) userdata;
    int stdiowhence;
    switch (whence) {
    case SDL_IO_SEEK_SET:
        stdiowhence = SEEK_SET;
        break;
    case SDL_IO_SEEK_CUR:
        stdiowhence = SEEK_CUR;
        break;
    case SDL_IO_SEEK_END:
        stdiowhence = SEEK_END;
        break;
    default:
        SDL_SetError("Unknown value for 'whence'");
        return -1;
#if defined(FSEEK_OFF_MIN) && defined(FSEEK_OFF_MAX)
    if (offset < (Sint64)(FSEEK_OFF_MIN) || offset > (Sint64)(FSEEK_OFF_MAX)) {
        SDL_SetError("Seek offset out of range");
        return -1;
    // don't make a possibly-costly API call for the noop seek from SDL_TellIO
    const bool is_noop = (whence == SDL_IO_SEEK_CUR) && (offset == 0);
    if (is_noop || fseek(iodata->fp, (fseek_off_t)offset, stdiowhence) == 0) {
        const Sint64 pos = ftell(iodata->fp);
        if (pos < 0) {
            SDL_SetError("Couldn't get stream offset: %s", strerror(errno));
            return -1;
        return pos;
    SDL_SetError("Error seeking in datastream: %s", strerror(errno));
    return -1;
static size_t SDLCALL stdio_read(void *userdata, void *ptr, size_t size, SDL_IOStatus *status)
    IOStreamStdioData *iodata = (IOStreamStdioData *) userdata;
    const size_t bytes = fread(ptr, 1, size, iodata->fp);
    if (bytes < size) {
        if (ferror(iodata->fp)) {
            if (errno == EAGAIN) {
                *status = SDL_IO_STATUS_NOT_READY;
                clearerr(iodata->fp);
            } else {
                *status = SDL_IO_STATUS_ERROR;
                SDL_SetError("Error reading from datastream: %s", strerror(errno));
        } else {
            SDL_assert(feof(iodata->fp));
            *status = SDL_IO_STATUS_EOF;
    return bytes;
static size_t SDLCALL stdio_write(void *userdata, const void *ptr, size_t size, SDL_IOStatus *status)
    IOStreamStdioData *iodata = (IOStreamStdioData *) userdata;
    const size_t bytes = fwrite(ptr, 1, size, iodata->fp);
    if (bytes == 0 && ferror(iodata->fp)) {
        if (errno == EAGAIN) {
            *status = SDL_IO_STATUS_NOT_READY;
            clearerr(iodata->fp);
        } else {
            *status = SDL_IO_STATUS_ERROR;
            SDL_SetError("Error writing to datastream: %s", strerror(errno));
    return bytes;
static bool SDLCALL stdio_flush(void *userdata, SDL_IOStatus *status)
    IOStreamStdioData *iodata = (IOStreamStdioData *) userdata;
    if (fflush(iodata->fp) != 0) {
        if (errno == EAGAIN) {
            *status = SDL_IO_STATUS_NOT_READY;
            return false;
        } else {
            return SDL_SetError("Error flushing datastream: %s", strerror(errno));
    int result;
    int fd = fileno(iodata->fp);
        result = SDL_fdatasync(fd);
    } while (result < 0 && errno == EINTR);
    if (result < 0) {
        return SDL_SetError("Error flushing datastream: %s", strerror(errno));
    return true;
static bool SDLCALL stdio_close(void *userdata)
    IOStreamStdioData *iodata = (IOStreamStdioData *) userdata;
    bool status = true;
    if (iodata->autoclose) {
        if (fclose(iodata->fp) != 0) {
            status = SDL_SetError("Error closing datastream: %s", strerror(errno));
    SDL_free(iodata);
    return status;
SDL_IOStream *SDL_IOFromFP(FILE *fp, bool autoclose)
    IOStreamStdioData *iodata = (IOStreamStdioData *) SDL_calloc(1, sizeof (*iodata));
    if (!iodata) {
        if (autoclose) {
           fclose(fp);
        return NULL;
    SDL_IOStreamInterface iface;
    SDL_INIT_INTERFACE(&iface);
    // There's no stdio_size because SDL_GetIOSize emulates it the same way we'd do it for stdio anyhow.
    iface.seek = stdio_seek;
    iface.read = stdio_read;
    iface.write = stdio_write;
    iface.flush = stdio_flush;
    iface.close = stdio_close;
    iodata->fp = fp;
    iodata->autoclose = autoclose;
    struct stat st;
    iodata->regular_file = ((fstat(fileno(fp), &st) == 0) && S_ISREG(st.st_mode));
    SDL_IOStream *iostr = SDL_OpenIO(&iface, iodata);
    if (!iostr) {
        iface.close(iodata);
    } else {
        const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
        if (props) {
            SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_STDIO_FILE_POINTER, fp);
            SDL_SetNumberProperty(props, SDL_PROP_IOSTREAM_FILE_DESCRIPTOR_NUMBER, fileno(fp));
    return iostr;
#endif // !HAVE_STDIO_H && !defined(SDL_PLATFORM_WINDOWS)
// Functions to read/write memory pointers
typedef struct IOStreamMemData
    Uint8 *base;
    Uint8 *here;
    Uint8 *stop;
    SDL_PropertiesID props;
} IOStreamMemData;
static Sint64 SDLCALL mem_size(void *userdata)
    const IOStreamMemData *iodata = (IOStreamMemData *) userdata;
    return (iodata->stop - iodata->base);
static Sint64 SDLCALL mem_seek(void *userdata, Sint64 offset, SDL_IOWhence whence)
    IOStreamMemData *iodata = (IOStreamMemData *) userdata;
    Uint8 *newpos;
    switch (whence) {
    case SDL_IO_SEEK_SET:
        newpos = iodata->base + offset;
        break;
    case SDL_IO_SEEK_CUR:
        newpos = iodata->here + offset;
        break;
    case SDL_IO_SEEK_END:
        newpos = iodata->stop + offset;
        break;
    default:
        SDL_SetError("Unknown value for 'whence'");
        return -1;
    if (newpos < iodata->base) {
        newpos = iodata->base;
    if (newpos > iodata->stop) {
        newpos = iodata->stop;
    iodata->here = newpos;
    return (Sint64)(iodata->here - iodata->base);
static size_t mem_io(void *userdata, void *dst, const void *src, size_t size)
    IOStreamMemData *iodata = (IOStreamMemData *) userdata;
    const size_t mem_available = (iodata->stop - iodata->here);
    if (size > mem_available) {
        size = mem_available;
    SDL_memcpy(dst, src, size);
    iodata->here += size;
    return size;
static size_t SDLCALL mem_read(void *userdata, void *ptr, size_t size, SDL_IOStatus *status)
    IOStreamMemData *iodata = (IOStreamMemData *) userdata;
    const size_t retval = mem_io(userdata, ptr, iodata->here, size);
    if ((retval < size) && (iodata->stop == iodata->here)) {
        *status = SDL_IO_STATUS_EOF;
    return retval;
static size_t SDLCALL mem_write(void *userdata, const void *ptr, size_t size, SDL_IOStatus *status)
    IOStreamMemData *iodata = (IOStreamMemData *) userdata;
    const size_t retval = mem_io(userdata, iodata->here, ptr, size);
    if ((retval < size) && (iodata->stop == iodata->here)) {
        SDL_SetError("Memory buffer is full");
        *status = SDL_IO_STATUS_ERROR;
    return retval;
static bool SDLCALL mem_close(void *userdata)
    IOStreamMemData *iodata = (IOStreamMemData *) userdata;
    SDL_free_func free_func = SDL_GetPointerProperty(iodata->props, SDL_PROP_IOSTREAM_MEMORY_FREE_FUNC_POINTER, NULL);
    if (free_func) {
        free_func(iodata->base);
    SDL_free(userdata);
    return true;
// Functions to create SDL_IOStream structures from various data sources
#if defined(HAVE_STDIO_H) && !defined(SDL_PLATFORM_WINDOWS)
static bool IsRegularFileOrPipe(FILE *f)
#ifndef SDL_PLATFORM_EMSCRIPTEN
    struct stat st;
    if (fstat(fileno(f), &st) < 0 || !(S_ISREG(st.st_mode) || S_ISFIFO(st.st_mode))) {
        return false;
#endif // !SDL_PLATFORM_EMSCRIPTEN
    return true;
SDL_IOStream *SDL_IOFromFile(const char *file, const char *mode)
    SDL_IOStream *iostr = NULL;
    CHECK_PARAM(!file || !*file) {
        SDL_InvalidParamError("file");
        return NULL;
    CHECK_PARAM(!mode || !*mode) {
        SDL_InvalidParamError("mode");
        return NULL;
#ifdef SDL_PLATFORM_ANDROID
#ifdef HAVE_STDIO_H
    // Try to open the file on the filesystem first
    if (*file == '/') {
        FILE *fp = fopen(file, mode);
        if (fp) {
            if (!IsRegularFileOrPipe(fp)) {
                fclose(fp);
                SDL_SetError("%s is not a regular file or pipe", file);
                return NULL;
            return SDL_IOFromFP(fp, true);
    } else if (SDL_strncmp(file, "content://", 10) == 0) {
        // Try opening content:// URI
        int fd = Android_JNI_OpenFileDescriptor(file, mode);
        if (fd == -1) {
            // SDL error is already set.
            return NULL;
        FILE *fp = fdopen(fd, mode);
        if (!fp) {
            close(fd);
            SDL_SetError("Unable to open file descriptor (%d) from URI %s: %s", fd, file, strerror(errno));
            return NULL;
        return SDL_IOFromFP(fp, true);
    } else {
        // Try opening it from internal storage if it's a relative path
        char *path = NULL;
        SDL_asprintf(&path, "%s/%s", SDL_GetAndroidInternalStoragePath(), file);
        if (path) {
            FILE *fp = fopen(path, mode);
            SDL_free(path);
            if (fp) {
                if (!IsRegularFileOrPipe(fp)) {
                    fclose(fp);
                    SDL_SetError("%s is not a regular file or pipe", path);
                    return NULL;
                return SDL_IOFromFP(fp, true);
#endif // HAVE_STDIO_H
    // Try to open the file from the asset system
    void *iodata = NULL;
    if (!Android_JNI_FileOpen(&iodata, file, mode)) {
        return NULL;
    SDL_IOStreamInterface iface;
    SDL_INIT_INTERFACE(&iface);
    iface.size = Android_JNI_FileSize;
    iface.seek = Android_JNI_FileSeek;
    iface.read = Android_JNI_FileRead;
    iface.write = Android_JNI_FileWrite;
    iface.close = Android_JNI_FileClose;
    iostr = SDL_OpenIO(&iface, iodata);
    if (!iostr) {
        iface.close(iodata);
    } else {
        const SDL_PropertiesID props = SDL_GetIOProperties(iostr);
        if (props) {
            SDL_SetPointerProperty(props, SDL_PROP_IOSTREAM_ANDROID_AASSET_POINTER, iodata);
#elif defined(SDL_PLATFORM_IOS)
    // Try to open the file on the filesystem first
    FILE *fp = NULL;
    if (*file == '/') {
        fp = fopen(file, mode);
    } else {
        // We can't write to the current directory, so use a writable path
        char *base = SDL_GetPrefPath("", "");
        if (!base) {
            return NULL;
        char *path = NULL;
        SDL_asprintf(&path, "%s%s", base, file);
        SDL_free(base);
        if (!path) {
            return NULL;
        fp = fopen(path, mode);
        SDL_free(path);
    if (!fp) {
        SDL_SetError("Couldn't open %s: %s", file, strerror(errno));
    } else if (!IsRegularFileOrPipe(fp)) {
        fclose(fp);
        SDL_SetError("%s is not a regular file or pipe", file);
    } else {
        iostr = SDL_IOFromFP(fp, true);
#elif defined(SDL_PLATFORM_WINDOWS)
    HANDLE handle = windows_file_open(file, mode);
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