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/*
** ANSI C file I/O.
*/
#ifndef UPB_STDC_IO_H_
#define UPB_STDC_IO_H_
#include <stdio.h>
#include "upb/bytestream.h"
UPB_BEGIN_EXTERN_C
/* upb_stdio ******************************************************************/
// bytesrc/bytesink for ANSI C stdio, which is less efficient than posixfd, but
// more portable.
//
// Specifically, stdio functions acquire locks on every operation (unless you
// use the f{read,write,...}_unlocked variants, which are not standard) and
// performs redundant buffering (unless you disable it with setvbuf(), but we
// can only do this on newly-opened filehandles).
typedef struct {
uint64_t ofs;
size_t len;
uint32_t refcount;
char data[];
} upb_stdio_buf;
// We use a single object for both bytesrc and bytesink for simplicity.
// The object is still not thread-safe, and may only be used by one reader
// and one writer at a time.
typedef struct {
upb_bytesrc src;
upb_bytesink sink;
FILE *file;
bool should_close;
upb_stdio_buf **bufs;
int nbuf;
uint32_t szbuf;
} upb_stdio;
void upb_stdio_init(upb_stdio *stdio);
// Caller should call upb_stdio_flush prior to calling this to ensure that
// all data is flushed, otherwise data can be silently dropped if an error
// occurs flushing the remaining buffers.
void upb_stdio_uninit(upb_stdio *stdio);
// Resets the object to read/write to the given "file." The caller is
// responsible for closing the file, which must outlive this object.
void upb_stdio_reset(upb_stdio *stdio, FILE *file);
// As an alternative to upb_stdio_reset(), initializes the object by opening a
// file, and will handle closing it. This may result in more efficient I/O
// than the previous since we can call setvbuf() to disable buffering.
void upb_stdio_open(upb_stdio *stdio, const char *filename, const char *mode,
upb_status *s);
upb_bytesrc *upb_stdio_bytesrc(upb_stdio *stdio);
upb_bytesink *upb_stdio_bytesink(upb_stdio *stdio);
UPB_END_EXTERN_C
#endif /* UPB_STDC_IO_H_ */
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