src/lib/ostream-buffer.c

	ostream-buffer.c revision e59faf65ce864fe95dc00f5d52b8323cdbd0608a
/* Copyright (c) 2002-2010 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "buffer.h"
#include "ostream-internal.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;

    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;
    return o_stream_create(&bstream->ostream);
}