diff options
Diffstat (limited to 'tools/libxutil/iostream.h')
| -rw-r--r-- | tools/libxutil/iostream.h | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/tools/libxutil/iostream.h b/tools/libxutil/iostream.h new file mode 100644 index 0000000000..5dbe14a0b4 --- /dev/null +++ b/tools/libxutil/iostream.h @@ -0,0 +1,243 @@ +#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_ */ |