sketched pragma decoder

lib/c/labcomm.h

@@ -125,6 +125,21 @@ int labcomm_decoder_ioctl(struct labcomm_decoder *decoder,
 			  uint32_t ioctl_action,
 			  ...);
 
+/* pragma */
+struct labcomm_pragma_handler {
+  //struct labcomm_decoder_registry *registry;
+  //TODO: implement  map (char * pragma_type) --> decoder_registry *
+  //to allow having different sets of handlers for different pragma types
+  int foo;
+};
+
+typedef int (*labcomm_handle_pragma_callback)(
+  struct labcomm_decoder *decoder,
+  char *pragma_type);
+
+void labcomm_decoder_register_pragma_handler(struct labcomm_decoder *d,
+		labcomm_handle_pragma_callback pragma_dispatcher);
+
 /*
  * Encoder
  */

lib/c/labcomm_decoder.c

@@ -25,6 +25,7 @@
 #include "labcomm_private.h"
 #include "labcomm_ioctl.h"
 #include "labcomm_dynamic_buffer_writer.h"
+#include "labcomm_bytearray_reader.h"
 
 struct sample_entry {
   int remote_index;
@@ -75,7 +76,27 @@ struct labcomm_decoder *labcomm_decoder_new(
   }
   return result;
 }
+#ifndef WITHOUT_PRAGMA
+/* Internal aux function to allow temporary internal decoders
+ * to share the same memory.
+ * This function only frees the decoder, not the memory
+ */
+static void internal_labcomm_decoder_free(struct labcomm_decoder* d)
+{
+  struct labcomm_memory *memory = d->memory;
+  labcomm_reader_free(d->reader, d->reader->action_context);
+  LABCOMM_SIGNATURE_ARRAY_FREE(memory, d->local, struct sample_entry);
+  LABCOMM_SIGNATURE_ARRAY_FREE(memory, d->remote_to_local, int);
+}
 
+void labcomm_decoder_free(struct labcomm_decoder* d)
+{
+  struct labcomm_memory *memory = d->memory;
+  internal_labcomm_decoder_free(d);
+  labcomm_memory_free(memory, 0, d);
+}
+
+#else
 void labcomm_decoder_free(struct labcomm_decoder* d)
 {
   struct labcomm_memory *memory = d->memory;
@@ -85,6 +106,7 @@ void labcomm_decoder_free(struct labcomm_decoder* d)
   LABCOMM_SIGNATURE_ARRAY_FREE(memory, d->remote_to_local, int);
   labcomm_memory_free(memory, 0, d);
 }
+#endif
 
 static int decode_sample_def(struct labcomm_decoder *d, int kind)
 {
@@ -207,6 +229,57 @@ static int decode_version(struct labcomm_decoder *d, int remote_index)
 out:   
   return result;
 }
+
+static int decoder_skip(struct labcomm_decoder *d, int len)
+{
+  int i;
+  for(i = 0; i <len; i++){
+    labcomm_read_byte(d->reader);
+    if (d->reader->error < 0) {
+      return d->reader->error;
+    }
+  }
+  return 0;
+}
+static int decode_pragma(struct labcomm_decoder *d, int len)
+{
+  char *pragma_type;
+  int result;
+  pragma_type = labcomm_read_string(d->reader);
+  if (d->reader->error < 0) {
+    result = d->reader->error;
+    goto out;
+  }
+  int bytes = labcomm_size_string(pragma_type);
+  int psize = len-bytes;
+  if(0 /*d->pragma_handler*/) {
+  //read the entire packet to a buffer and then run
+  // decode on that through a bytearray_reader.
+  // (to easily handle multiple labcomm packets in one metadata packet)
+    int i;
+    unsigned char pragma_data[psize] ;
+    for(i=0; i<psize; i++) {
+       pragma_data[i] = labcomm_read_byte(d->reader);
+       if (d->reader->error < 0) {
+         result = d->reader->error;
+         goto out;
+       }
+     }
+     struct labcomm_reader *pr = labcomm_bytearray_reader_new(
+                                     d->reader->memory, pragma_data, psize);
+     struct labcomm_decoder *pd = labcomm_decoder_new(
+                                     pr, d->error, d->memory, d->scheduler);
+    /* d->prama_handler(pd, ptype, plen); */
+
+     internal_labcomm_decoder_free(pd);
+     result = 0;
+   } else {
+     result = decoder_skip(d, psize);
+   }
+out:
+  return result;
+}
+
 int labcomm_decoder_decode_one(struct labcomm_decoder *d)
 {
   int result, remote_index, length;
@@ -229,8 +302,8 @@ int labcomm_decoder_decode_one(struct labcomm_decoder *d)
     result = -ECONNRESET;
   } else if (remote_index == LABCOMM_SAMPLE_DEF) {
     result = decode_sample_def(d, remote_index); 
-  } else if (remote_index == LABCOMM_PRAGMA && 0 /* d->pragma_handler*/) {
-    /* d->prama_handler(...); */
+  } else if (remote_index == LABCOMM_PRAGMA ){
+    result = decode_pragma(d, length);
   } else if (remote_index < LABCOMM_USER) {
     fprintf(stderr, "SKIP %d %d\n", remote_index, length);
     result = remote_index;