ossp-pkg/l2/l2_ch_buffer.c
1.19
/*
** L2 - OSSP Logging Library
** Copyright (c) 2001 The OSSP Project (http://www.ossp.org/)
** Copyright (c) 2001 Cable & Wireless Deutschland (http://www.cw.com/de/)
**
** This file is part of OSSP L2, a flexible logging library which
** can be found at http://www.ossp.org/pkg/l2/.
**
** Permission to use, copy, modify, and distribute this software for
** any purpose with or without fee is hereby granted, provided that
** the above copyright notice and this permission notice appear in all
** copies.
**
** THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR
** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
** USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
** ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
** OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
** OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
**
** l2_ch_buffer.c: buffering channel implementation
*/
#include "l2.h"
#include <string.h>
/* declare private channel configuration */
typedef struct {
char *buf;
int bufpos;
int bufsize;
} l2_ch_buffer_t;
/* create channel */
static l2_result_t hook_create(l2_context_t *ctx, l2_channel_t *ch)
{
l2_ch_buffer_t *cfg;
/* allocate private channel configuration */
if ((cfg = (l2_ch_buffer_t *)malloc(sizeof(l2_ch_buffer_t))) == NULL)
return L2_ERR_MEM;
/* initialize configuration with reasonable defaults */
cfg->buf = NULL;
cfg->bufpos = 0;
cfg->bufsize = 4096;
/* link private channel configuration into channel context */
ctx->vp = cfg;
return L2_OK;
}
/* configure channel */
static l2_result_t hook_configure(l2_context_t *ctx, l2_channel_t *ch, const char *fmt, va_list ap)
{
l2_ch_buffer_t *cfg = (l2_ch_buffer_t *)ctx->vp;
l2_param_t pa[2];
l2_result_t rv;
/* feed and call generic parameter parsing engine */
L2_PARAM_SET(pa[0], size, INT, &cfg->bufsize);
L2_PARAM_END(pa[1]);
rv = l2_util_setparams(pa, fmt, ap);
if (cfg->bufsize < 0)
return L2_ERR_ARG;
return rv;
}
/* open channel */
static l2_result_t hook_open(l2_context_t *ctx, l2_channel_t *ch)
{
l2_ch_buffer_t *cfg = (l2_ch_buffer_t *)ctx->vp;
l2_channel_t *downstream = l2_channel_downstream(ch);
l2_result_t rv;
/* open channel buffer */
if (cfg->bufsize > 0) {
if ((cfg->buf = malloc(cfg->bufsize)) == NULL)
return L2_ERR_MEM;
cfg->bufpos = 0;
}
/* optionally open downstream channel, too */
if ((rv = l2_channel_open(downstream)) != L2_OK)
return rv;
return L2_OK;
}
/* write to channel */
static l2_result_t hook_write(l2_context_t *ctx, l2_channel_t *ch,
l2_level_t level, const char *buf, size_t buf_size)
{
l2_ch_buffer_t *cfg = (l2_ch_buffer_t *)ctx->vp;
l2_channel_t *downstream = l2_channel_downstream(ch);
l2_result_t rv;
if (buf_size > (cfg->bufsize - cfg->bufpos)) {
/* flush buffer if necessary */
if (cfg->bufpos > 0) {
if ((rv = l2_channel_write(downstream, level, cfg->buf, cfg->bufpos)) != L2_OK)
return rv;
cfg->bufpos = 0;
}
/* pass through immediately to downstream if still too large */
if (buf_size > cfg->bufsize)
return l2_channel_write(downstream, level, buf, buf_size);
}
/* write message to channel buffer */
memcpy(cfg->buf+cfg->bufpos, buf, buf_size);
cfg->bufpos += buf_size;
return L2_OK;
}
/* flush channel */
static l2_result_t hook_flush(l2_context_t *ctx, l2_channel_t *ch)
{
l2_ch_buffer_t *cfg = (l2_ch_buffer_t *)ctx->vp;
l2_channel_t *downstream = l2_channel_downstream(ch);
l2_result_t rv;
/* write the buffer contents downstream */
if (cfg->bufpos > 0) { /* !---------! */
if ((rv = l2_channel_write(downstream, L2_LEVEL_PANIC, cfg->buf, cfg->bufpos)) != L2_OK)
return rv; /* !! FIXME !! */
cfg->bufpos = 0; /* !---------! */
}
/* optionally flush downstream channel, too */
if ((rv = l2_channel_flush(downstream)) != L2_OK)
return rv;
return L2_OK;
}
/* close channel */
static l2_result_t hook_close(l2_context_t *ctx, l2_channel_t *ch)
{
l2_ch_buffer_t *cfg = (l2_ch_buffer_t *)ctx->vp;
l2_channel_t *downstream = l2_channel_downstream(ch);
l2_result_t rv;
/* write pending data before closing down */
if (cfg->bufpos > 0) { /* !---------! */
if ((rv = l2_channel_write(downstream, L2_LEVEL_PANIC, cfg->buf, cfg->bufpos)) != L2_OK)
return rv; /* !! FIXME !! */
cfg->bufpos = 0; /* !---------! */
}
/* optionally close downstream channel, too */
if ((rv = l2_channel_close(downstream)) != L2_OK)
return rv;
/* close channel buffer */
if (cfg->buf != NULL) {
free(cfg->buf);
cfg->buf = NULL;
}
return L2_OK;
}
/* destroy channel */
static l2_result_t hook_destroy(l2_context_t *ctx, l2_channel_t *ch)
{
l2_ch_buffer_t *cfg = (l2_ch_buffer_t *)ctx->vp;
l2_channel_t *downstream = l2_channel_downstream(ch);
l2_result_t rv;
/* if not already closed, close channel buffer now */
if (cfg->buf != NULL) {
free(cfg->buf);
cfg->buf = NULL;
}
/* destroy channel configuration */
free(cfg);
/* optionally destroy downstream channel, too */
if ((rv = l2_channel_destroy(downstream)) != L2_OK)
return rv;
return L2_OK;
}
/* exported channel handler structure */
l2_handler_t l2_handler_buffer = {
L2_CHANNEL_FILTER,
hook_create,
hook_configure,
hook_open,
hook_write,
hook_flush,
hook_close,
hook_destroy
};