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#ifndef _XC_LINUX_SAVE_H_
#define _XC_LINUX_SAVE_H_
#include <stdarg.h>
#include <stdint.h>
#include <stddef.h>
#ifdef __KERNEL__
#include <linux/errno.h>
#else
#include <errno.h>
#endif
#include "allocate.h"
/** End of input return value. */
#define IOSTREAM_EOF -1
/** An input/output abstraction.
*/
typedef struct IOStream IOStream;
/** Record of the functions to use for operations on an
* IOStream implementation.
*/
typedef struct IOMethods {
/** Read function. Called with the user data, buffer to read into
* and number of bytes to read. Must return number of bytes read
* on success, less than zero on error.
*/
int (*read)(IOStream *stream, void *buf, size_t n);
/** Write function. Called with user data, buffer to write and
* number of bytes to write. Must return number of bytes written on
* success, less than zero otherwise.
*/
int (*write)(IOStream *stream, const void *buf, size_t n);
int (*flush)(IOStream *s);
int (*error)(IOStream *s);
int (*close)(IOStream *s);
void (*free)(IOStream *s);
void (*lock)(IOStream *s);
void (*unlock)(IOStream *s);
} IOMethods;
/** Abstract i/o object.
*/
struct IOStream {
/** Methods to use to implement operations. */
const IOMethods *methods;
/** Private state for the implementation. */
const void *data;
/** Flag indicating whether the stream is closed. */
int closed;
/** Number of bytes written. */
int written;
/** Number of bytes read. */
int read;
};
/** IOStream version of stdin. */
extern IOStream *iostdin;
/** IOStream version of stdout, */
extern IOStream *iostdout;
/** IOStream version of stderr. */
extern IOStream *iostderr;
extern int IOStream_print(IOStream *io, const char *format, ...);
extern int IOStream_vprint(IOStream *io, const char *format, va_list args);
/** Read from a stream.
*
* @param stream input
* @param buf where to put input
* @param n number of bytes to read
* @return if ok, number of bytes read, otherwise negative error code
*/
static inline int IOStream_read(IOStream *stream, void *buf, size_t n){
int result = 0;
if(stream->closed) goto exit;
if(!stream->methods || !stream->methods->read){
result = -EINVAL;
goto exit;
}
result = stream->methods->read(stream, buf, n);
if(result > 0){
stream->read += result;
}
exit:
return result;
}
/** Write to a stream.
*
* @param stream input
* @param buf where to put input
* @param n number of bytes to write
* @return if ok, number of bytes read, otherwise negative error code
*/
static inline int IOStream_write(IOStream *stream, const void *buf, size_t n){
int result = 0;
if(stream->closed) goto exit;
if(!stream->methods || !stream->methods->write){
result = -EINVAL;
goto exit;
}
result = stream->methods->write(stream, buf, n);
if(result > 0){
stream->written += result;
}
exit:
return result;
}
/** Flush the stream.
*
* @param stream stream
* @return 0 on success, IOSTREAM_EOF otherwise
*/
static inline int IOStream_flush(IOStream *stream){
int result = 0;
if(stream->closed){
result = IOSTREAM_EOF;
} else if(stream->methods->flush){
result = stream->methods->flush(stream);
if(result < 0) result = IOSTREAM_EOF;
}
return result;
}
/** Check whether the stream has an error.
*
* @param stream to check
* @return 1 for error, 0 otherwise
*/
static inline int IOStream_error(IOStream *stream){
int err = 0;
if(stream->methods && stream->methods->error){
err = stream->methods->error(stream);
}
return err;
}
/** Close the stream.
*
* @param stream to close
* @return 1 for error, 0 otherwise
*/
static inline int IOStream_close(IOStream *stream){
int err = 1;
if(stream->methods && stream->methods->close){
err = stream->methods->close(stream);
}
return err;
}
/** Test if the stream has been closed.
*
* @param stream to check
* @return 1 if closed, 0 otherwise
*/
static inline int IOStream_is_closed(IOStream *stream){
return stream->closed;
}
/** Free the memory used by the stream.
*
* @param stream to free
*/
static inline void IOStream_free(IOStream *stream){
if(stream->methods && stream->methods->free){
stream->methods->free(stream);
}
*stream = (IOStream){};
deallocate(stream);
}
/** Print a character to a stream, like fputc().
*
* @param stream to print to
* @param c character to print
* @return result code from the print
*/
static inline int IOStream_putc(IOStream *stream, int c){
int err;
unsigned char b = (unsigned char)c;
err = IOStream_write(stream, &b, 1);
if(err < 1){
err = IOSTREAM_EOF;
} else {
err = b;
}
return err;
}
/** Read from a stream, like fgetc().
*
* @param stream to read from
* @return IOSTREAM_EOF on error, character read otherwise
*/
static inline int IOStream_getc(IOStream *stream){
int err, rc;
unsigned char b;
err = IOStream_read(stream, &b, 1);
if(err < 1){
rc = IOSTREAM_EOF;
} else {
rc = b;
}
return rc;
}
/** Get number of bytes read.
*
* @param stream to get from
* @return number of bytes read
*/
static inline int IOStream_get_read(IOStream *stream){
return stream->read;
}
/** Get number of bytes written.
*
* @param stream to get from
* @return number of bytes written
*/
static inline int IOStream_get_written(IOStream *stream){
return stream->written;
}
#endif /* ! _XC_LINUX_SAVE_H_ */
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