src/lib/ostream-private.h

#ifndef OSTREAM_PRIVATE_H
#define OSTREAM_PRIVATE_H

#include "ostream.h"
#include "iostream-private.h"

struct ostream_private {
/* inheritance: */
    struct iostream_private iostream;

/* methods: */
    void (*cork)(struct ostream_private *stream, bool set);
    int (*flush)(struct ostream_private *stream);
    void (*set_flush_callback)(struct ostream_private *stream,
                   stream_flush_callback_t *callback,
                   void *context);
    void (*flush_pending)(struct ostream_private *stream, bool set);
    size_t (*get_used_size)(const struct ostream_private *stream);
    int (*seek)(struct ostream_private *stream, uoff_t offset);
    ssize_t (*sendv)(struct ostream_private *stream,
             const struct const_iovec *iov,
             unsigned int iov_count);
    int (*write_at)(struct ostream_private *stream,
            const void *data, size_t size, uoff_t offset);
    enum ostream_send_istream_result
        (*send_istream)(struct ostream_private *outstream,
                struct istream *instream);
    void (*switch_ioloop_to)(struct ostream_private *stream,
                 struct ioloop *ioloop);

/* data: */
    struct ostream ostream;
    size_t max_buffer_size;

    struct ostream *parent; /* for filter streams */

    int fd;
    struct timeval last_write_timeval;

    stream_flush_callback_t *callback;
    void *context;

    bool corked:1;
    bool finished:1;
    bool closing:1;
    bool last_errors_not_checked:1;
    bool error_handling_disabled:1;
    bool noverflow:1;
    bool finish_also_parent:1;
    bool finish_via_child:1;
};

struct ostream *
o_stream_create(struct ostream_private *_stream, struct ostream *parent, int fd)
    ATTR_NULL(2);

enum ostream_send_istream_result
io_stream_copy(struct ostream *outstream, struct istream *instream);

void o_stream_copy_error_from_parent(struct ostream_private *_stream);
/* This should be called before sending data to parent stream. It makes sure
   that the parent stream's output buffer doesn't become too large.
   Returns 1 if more data can be safely added, 0 if not, -1 if error. */
int o_stream_flush_parent_if_needed(struct ostream_private *_stream);

/* Call this in flush() handler to flush the parent stream. It will call
   either o_stream_flush() or o_stream_finish() depending on whether this
   stream is already finished. If the parent fails, its error will be also
   copied to this stream. */
int o_stream_flush_parent(struct ostream_private *_stream);

#endif