Mercurial > dovecot > core-2.2
view src/lib/istream-limit.c @ 3239:904a268921af HEAD
Added seekable variable to struct istream.
author | Timo Sirainen <tss@iki.fi> |
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date | Mon, 28 Mar 2005 16:06:43 +0300 |
parents | c20a64efd608 |
children | b79853b4b005 |
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/* Copyright (C) 2003 Timo Sirainen */ #include "lib.h" #include "istream-internal.h" struct limit_istream { struct _istream istream; struct istream *input; uoff_t v_start_offset, v_size; }; static void _close(struct _iostream *stream __attr_unused__) { } static void _destroy(struct _iostream *stream) { struct limit_istream *lstream = (struct limit_istream *) stream; /* get to same position in parent stream */ i_stream_seek(lstream->input, lstream->v_start_offset + lstream->istream.istream.v_offset); i_stream_unref(lstream->input); } static void _set_max_buffer_size(struct _iostream *stream, size_t max_size) { struct limit_istream *lstream = (struct limit_istream *) stream; i_stream_set_max_buffer_size(lstream->input, max_size); } static ssize_t _read(struct _istream *stream) { struct limit_istream *lstream = (struct limit_istream *) stream; uoff_t left; ssize_t ret; size_t pos; if (stream->istream.v_offset + (stream->pos - stream->skip) >= lstream->v_size) { stream->istream.eof = TRUE; return -1; } if (lstream->input->v_offset != lstream->v_start_offset + stream->istream.v_offset) { i_stream_seek(lstream->input, lstream->v_start_offset + stream->istream.v_offset); } stream->buffer = i_stream_get_data(lstream->input, &pos); if (pos <= stream->pos) { if ((ret = i_stream_read(lstream->input)) == -2) { if (stream->skip == 0) return -2; } stream->istream.eof = lstream->input->eof; stream->buffer = i_stream_get_data(lstream->input, &pos); } else { ret = 0; } stream->pos -= stream->skip; stream->skip = 0; if (lstream->v_size != (uoff_t)-1) { left = lstream->v_size - stream->istream.v_offset; if (pos > left) pos = left; } ret = pos > stream->pos ? (ssize_t)(pos - stream->pos) : (ret == 0 ? 0 : -1); stream->pos = pos; return ret; } static void _seek(struct _istream *stream, uoff_t v_offset) { struct limit_istream *lstream = (struct limit_istream *) stream; i_assert(v_offset <= lstream->v_size); stream->istream.stream_errno = 0; stream->istream.v_offset = v_offset; stream->skip = stream->pos = 0; } static uoff_t _get_size(struct _istream *stream) { struct limit_istream *lstream = (struct limit_istream *) stream; return lstream->v_size != (uoff_t)-1 ? lstream->v_size : i_stream_get_size(lstream->input); } struct istream *i_stream_create_limit(pool_t pool, struct istream *input, uoff_t v_start_offset, uoff_t v_size) { struct limit_istream *lstream; i_stream_ref(input); lstream = p_new(pool, struct limit_istream, 1); lstream->input = input; lstream->v_start_offset = v_start_offset; lstream->v_size = v_size; lstream->istream.istream.v_offset = input->v_offset < v_start_offset ? 0 : input->v_offset - v_start_offset > v_size ? v_size : input->v_offset - v_start_offset; lstream->istream.iostream.close = _close; lstream->istream.iostream.destroy = _destroy; lstream->istream.iostream.set_max_buffer_size = _set_max_buffer_size; lstream->istream.read = _read; lstream->istream.seek = _seek; lstream->istream.get_size = _get_size; lstream->istream.istream.seekable = input->seekable; return _i_stream_create(&lstream->istream, pool, i_stream_get_fd(input), input->real_stream->abs_start_offset + v_start_offset); }