This patch adds checking for AT command prefix and postfix to determine
data completeness.
---
src/shared/blueatchat.c | 109 ++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 94 insertions(+), 15 deletions(-)
diff --git a/src/shared/blueatchat.c b/src/shared/blueatchat.c
index a32a7bf..c7eee4a 100644
--- a/src/shared/blueatchat.c
+++ b/src/shared/blueatchat.c
@@ -22,6 +22,8 @@
*/
#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
#include <glib.h>
#include "cbuffer.h"
@@ -38,6 +40,77 @@ struct blueatchat_session {
blueatchat_debug_func_t debug_callback;
};
+/*
+ * returns offset:
+ * > 0 - if complete command found, which ends at offset
+ * < 0 - if no complete command found wait for more
+ * = 0 - some garbage was consumed check again
+ */
+static int blueatchat_get_complete_cmd_end(struct blueatchat_session *session)
+{
+ struct blueatchat_config *config = session->config;
+ struct circular_buffer *buffer = session->buffer;
+ int offset;
+ unsigned int prelen = strlen(config->cmd_prefix);
+
+ /* Check for command prefix */
+ offset = cbuffer_seek_tail_for_seq(buffer, config->cmd_prefix, 0);
+
+ /* Not enough data if only prefix in the buffer */
+ if (cbuffer_get_length(session->buffer) == prelen)
+ return -ENODATA;
+
+ /* No prefix - drain the buffer */
+ if (offset < 0) {
+ cbuffer_drain(buffer);
+ return -ENODATA;
+ }
+
+ /* Discard data before the prefix */
+ if (offset) {
+ cbuffer_discard(session->buffer, offset);
+ return 0;
+ }
+
+ /* check for postfix */
+ offset = cbuffer_seek_tail_for_seq(buffer, config->cmd_postfix, prelen);
+
+ /* If prefix != postfix check for multiple prefixing before postfix */
+ if (strncmp(config->cmd_prefix, config->cmd_postfix, prelen)) {
+ int off = cbuffer_seek_tail_for_seq(buffer, config->cmd_prefix,
+ prelen);
+
+ /* If second prefix exist before postfix consume */
+ if (off > 0 && off < offset) {
+ cbuffer_discard(session->buffer, off);
+ return 0;
+ }
+ }
+
+ /* If <fix><fix> consume one fix and check again later */
+ if (offset == (int)prelen) {
+ cbuffer_discard(session->buffer, offset);
+ return 0;
+ } else if (offset > 0) {
+ return offset + strlen(config->cmd_postfix);
+ }
+
+ /* If offset == 0 no tail found wait for more */
+ return -ENODATA;
+}
+
+static void process_bufferred_data(struct blueatchat_session *session)
+{
+ struct circular_buffer *buffer = session->buffer;
+ int offset;
+
+ while ((offset = blueatchat_get_complete_cmd_end(session)) >= 0) {
+ /* TODO: parse the data */
+
+ if (cbuffer_is_empty(buffer))
+ return;
+ }
+}
bool blueatchat_read(struct blueatchat_session *session, GIOChannel *gio)
{
@@ -48,10 +121,24 @@ bool blueatchat_read(struct blueatchat_session *session, GIOChannel *gio)
gsize len;
gsize i;
- /* read all data into the buffer */
+ /* Fill the buffer in chunks if needed to drain the IO */
do {
freechunk = cbuffer_get_free_chunk_size(session->buffer);
+ /* Free some space by processing the buffer if its full */
+ if (!freechunk) {
+ process_bufferred_data(session);
+
+ /* If couldn't process anything discard all data */
+ if (!cbuffer_get_free_chunk_size(session->buffer))
+ cbuffer_drain(session->buffer);
+ continue;
+ }
+
+ /*
+ * If there is no space after processing or draining the buffer
+ * we have a serious buffer error.
+ */
msg = cbuffer_get_free_cell(session->buffer);
if (!msg) {
BLUEATCHAT_DEBUG(session, "Buffer malfunction!");
@@ -65,25 +152,17 @@ bool blueatchat_read(struct blueatchat_session *session, GIOChannel *gio)
return false;
}
- if (len != 0)
- BLUEATCHAT_DEBUG(session,
- "Blueatchat red %u bytes: %.*s",
- (unsigned int)len, (unsigned int)len,
- msg);
-
for (i = 0; i < len; ++i)
cbuffer_consume_next_cell(session->buffer);
+
+ freechunk = cbuffer_get_free_chunk_size(session->buffer);
} while ((len != 0) && (ret != G_IO_STATUS_EOF));
- /* TODO: process buffered data
- * -> check for complete command (check for head, tail)
- * -> start consuming buffered data and parsing it
- * -> iterate through session->cmd_list and match commands
- * -> peek a char to choose appropriate parser routine or use
- * syntax descriptor string?
- * -> fill in sessions GSList* data with parsed data
- * -> call '*(session->cmd_list[cmd_index].notify)(session->data)
+ /*
+ * Now check for data completeness (command prefix and postfix).
+ * Than parse it and consume parsed data from the buffer.
*/
+ process_bufferred_data(session);
return true;
}
--
1.7.9.5
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