--- l2_ch_buffer.c 2001/08/23 05:30:58 1.7
+++ l2_ch_buffer.c 2001/08/24 15:16:43 1.8
@@ -32,33 +32,45 @@
#include <string.h>
+/* declare private channel configuration */
typedef struct {
char *buf;
int bufpos;
int bufsize;
} l2_ch_buffer_t;
+/* create channel */
static int hook_create(l2_context_t *ctx)
{
l2_ch_buffer_t *cfg;
+ /* allocate private channel configuration */
if ((cfg = (l2_ch_buffer_t *)malloc(sizeof(l2_ch_buffer_t))) == NULL)
return L2_ERROR;
+
+ /* 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 int hook_configure(l2_context_t *ctx, const char *fmt, va_list ap)
{
l2_ch_buffer_t *cfg;
l2_param_t pa[3];
l2_result_t rv;
+ /* parameter checks */
if ((cfg = (l2_ch_buffer_t *)ctx->vp) == NULL)
return L2_ERROR;
+
+ /* feed and call generic parameter parsing engine */
L2_PARAM_SET(pa[0], size, INT, &cfg->bufsize);
L2_PARAM_END(pa[2]);
rv = l2_channel_setparams(pa, fmt, ap);
@@ -67,89 +79,119 @@
return rv;
}
+/* open channel */
static int hook_open(l2_context_t *ctx, l2_channel_t *downstream)
{
l2_ch_buffer_t *cfg;
+ /* parameter checks */
if ((cfg = (l2_ch_buffer_t *)ctx->vp) == NULL)
return L2_ERROR;
+
+ /* open channel buffer */
if (cfg->bufsize > 0) {
if ((cfg->buf = malloc(cfg->bufsize)) == NULL)
return L2_ERROR;
cfg->bufpos = 0;
}
+
+ /* optionally open downstream channel, too */
if (downstream != NULL)
if (l2_channel_open(downstream) == L2_ERROR)
return L2_ERROR;
+
return L2_OK;
}
+/* write to channel */
static int hook_write(l2_context_t *ctx, l2_channel_t *downstream,
const char *buf, size_t bufsize)
{
l2_ch_buffer_t *cfg;
+ /* parameter checks */
if ((cfg = (l2_ch_buffer_t *)ctx->vp) == NULL)
return L2_ERROR;
-
if (bufsize > (cfg->bufsize - cfg->bufpos))
return L2_ERROR; /* The buffer is too small */
+ /* write message to channel buffer */
memcpy(cfg->buf+cfg->bufpos, buf, bufsize);
cfg->bufpos += bufsize;
return L2_OK;
}
+/* flush channel */
static int hook_flush(l2_context_t *ctx, l2_channel_t *downstream)
{
l2_ch_buffer_t *cfg;
+ /* parameter checks */
if ((cfg = (l2_ch_buffer_t *)ctx->vp) == NULL)
return L2_ERROR;
+ /* write the buffer contents downstream */
if (cfg->bufpos > 0) {
if (downstream != NULL)
if (l2_channel_write(downstream, cfg->buf, cfg->bufpos) == L2_ERROR)
return L2_ERROR;
cfg->bufpos = 0;
- memset(cfg->buf, 0x5A, cfg->bufsize); /* Guard against improper usage */
}
+ /* optionally flush downstream channel, too */
if (downstream != NULL)
if (l2_channel_flush(downstream) == L2_ERROR)
return L2_ERROR;
+
return L2_OK;
}
+/* close channel */
static int hook_close(l2_context_t *ctx, l2_channel_t *downstream)
{
l2_ch_buffer_t *cfg;
+ /* optionally close downstream channel, too */
if (downstream != NULL)
if (l2_channel_close(downstream) == L2_ERROR)
return L2_ERROR;
+
+ /* parameter checks */
if ((cfg = (l2_ch_buffer_t *)ctx->vp) == NULL)
return L2_ERROR;
+
+ /* close channel buffer */
if (cfg->buf != NULL) {
free(cfg->buf);
cfg->buf = NULL;
}
+
return L2_OK;
}
+/* destroy channel */
static int hook_destroy(l2_context_t *ctx)
{
l2_ch_buffer_t *cfg;
+ /* parameter checks */
if ((cfg = (l2_ch_buffer_t *)ctx->vp) == NULL)
return L2_ERROR;
- if (cfg->buf != NULL)
+
+ /* if not already closed, close channel buffer now */
+ if (cfg->buf != NULL) {
free(cfg->buf);
+ cfg->buf = NULL;
+ }
+
+ /* destroy channel configuration */
free(cfg);
+
return L2_OK;
}
+/* exported channel handler structure */
l2_handler_t l2_handler_buffer = {
hook_create,
hook_configure,
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