src/lib/ostream-buffer.c

	ostream-buffer.c revision 9a755930537f13e9746c4fc8c1bc42a83e52275e
/* Copyright (c) 2002-2012 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "buffer.h"
#include "ostream-private.h"

struct buffer_ostream {
    struct ostream_private ostream;
    buffer_t *buf;
};

static int o_stream_buffer_seek(struct ostream_private *stream, uoff_t offset)
{
    stream->ostream.offset = offset;
    return 1;
}

static int
o_stream_buffer_write_at(struct ostream_private *stream,
             const void *data, size_t size, uoff_t offset)
{
    struct buffer_ostream *bstream = (struct buffer_ostream *)stream;

    buffer_write(bstream->buf, offset, data, size);
    return 0;
}

static ssize_t
o_stream_buffer_sendv(struct ostream_private *stream,
              const struct const_iovec *iov, unsigned int iov_count)
{
    struct buffer_ostream *bstream = (struct buffer_ostream *)stream;
    size_t left, n;
    ssize_t ret = 0;
    unsigned int i;

    for (i = 0; i < iov_count; i++) {
        left = bstream->ostream.max_buffer_size -
            stream->ostream.offset;
        n = I_MIN(left, iov[i].iov_len);
        buffer_write(bstream->buf, stream->ostream.offset,
                 iov[i].iov_base, n);
        ret += n;
        if (n != iov[i].iov_len)
            break;
    }
    stream->ostream.offset += ret;
    return ret;
}

struct ostream *o_stream_create_buffer(buffer_t *buf)
{
    struct buffer_ostream *bstream;
    struct ostream *output;

    bstream = i_new(struct buffer_ostream, 1);
    bstream->ostream.max_buffer_size = (size_t)-1;
    bstream->ostream.seek = o_stream_buffer_seek;
    bstream->ostream.sendv = o_stream_buffer_sendv;
    bstream->ostream.write_at = o_stream_buffer_write_at;

    bstream->buf = buf;
    output = o_stream_create(&bstream->ostream, NULL);
    o_stream_set_name(output, "(buffer)");
    return output;
}