fix(api): Add prng as parameter of send mam API

This is a temporary option to let application like tangle ID to be able to
create unique channel and keep it stateless. This will be deprecated
once JS binding of mam is done.

accelerator/apis.c

@@ -237,25 +237,37 @@ status_t api_mam_send_message(const iota_config_t* const tangle, const iota_clie
   const bool last_packet = true;
   bundle_transactions_t* bundle = NULL;
   bundle_transactions_new(&bundle);
+  tryte_t* prng = NULL;
   tryte_t channel_id[MAM_CHANNEL_ID_TRYTE_SIZE];
   trit_t msg_id[MAM_MSG_ID_SIZE];
   ta_send_mam_req_t* req = send_mam_req_new();
   ta_send_mam_res_t* res = send_mam_res_new();
 
-  // Creating MAM API
-  if (mam_api_init(&mam, (tryte_t*)SEED)) {
+  if (send_mam_req_deserialize(payload, req)) {
     ret = SC_MAM_FAILED_INIT;
     goto done;
   }
 
-  ret = send_mam_req_deserialize(payload, req);
-  if (ret) {
+  // Creating MAM API
+  prng = (req->prng[0]) ? req->prng : SEED;
+  if (mam_api_init(&mam, prng) != RC_OK) {
+    ret = SC_MAM_FAILED_INIT;
     goto done;
   }
 
   // Creating channel
+  // TODO: TA only supports mss depth under 2. Larger than this would result in wasting too much time generate keys.
+  // With depth of 2, user can send a bundle with  3 transaction messages filled (last one is for header).
+  size_t payload_size = strlen(req->payload);
+  size_t payload_depth = 1;
+  if (payload_size > (NUM_TRYTES_SIGNATURE / 2) * 3) {
+    ret = SC_MAM_NO_PAYLOAD;
+    goto done;
+  } else if (payload_size > (NUM_TRYTES_SIGNATURE / 2)) {
+    payload_depth = 2;
+  }
   mam.channel_ord = req->channel_ord;
-  if (map_channel_create(&mam, channel_id)) {
+  if (map_channel_create(&mam, channel_id, payload_depth)) {
     ret = SC_MAM_NULL;
     goto done;
   }
@@ -284,8 +296,10 @@ status_t api_mam_send_message(const iota_config_t* const tangle, const iota_clie
 
 done:
   // Destroying MAM API
-  if (mam_api_destroy(&mam)) {
-    ret = SC_MAM_FAILED_DESTROYED;
+  if (ret != SC_MAM_FAILED_INIT) {
+    if (mam_api_destroy(&mam)) {
+      ret = SC_MAM_FAILED_DESTROYED;
+    }
   }
   bundle_transactions_free(&bundle);
   send_mam_req_free(&req);

request/BUILD

@@ -11,6 +11,7 @@ cc_library(
     deps = [
         "//accelerator:ta_errors",
         "@entangled//common:errors",
+        "@entangled//common/model:transaction",
         "@entangled//common/trinary:tryte",
         "@entangled//utils/containers/hash:hash243_queue",
         "@entangled//utils/containers/hash:hash81_queue",

request/ta_send_mam.c

@@ -3,6 +3,7 @@
 ta_send_mam_req_t* send_mam_req_new() {
   ta_send_mam_req_t* req = (ta_send_mam_req_t*)malloc(sizeof(ta_send_mam_req_t));
   if (req) {
+    req->prng[0] = 0;
     req->payload = NULL;
     req->channel_ord = 0;
   }

request/ta_send_mam.h

@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include "accelerator/errors.h"
+#include "common/model/transaction.h"
 #include "common/trinary/tryte.h"
 
 #ifdef __cplusplus
@@ -16,6 +17,7 @@ extern "C" {
 
 /** struct of ta_send_transfer_req_t */
 typedef struct send_mam_req_s {
+  tryte_t prng[NUM_TRYTES_ADDRESS + 1];
   char* payload;
   uint8_t channel_ord;
 } ta_send_mam_req_t;

serializer/serializer.c

@@ -550,6 +550,17 @@ status_t send_mam_req_deserialize(const char* const obj, ta_send_mam_req_t* req)
     goto done;
   }
 
+  json_result = cJSON_GetObjectItemCaseSensitive(json_obj, "prng");
+  if (json_result != NULL) {
+    size_t prng_size = strlen(json_result->valuestring);
+
+    if (prng_size != NUM_TRYTES_HASH) {
+      ret = SC_SERIALIZER_INVALID_REQ;
+      goto done;
+    }
+    snprintf(req->prng, prng_size + 1, "%s", json_result->valuestring);
+  }
+
   json_result = cJSON_GetObjectItemCaseSensitive(json_obj, "message");
   if (json_result != NULL) {
     size_t payload_size = strlen(json_result->valuestring);

tests/test_serializer.c

@@ -236,12 +236,11 @@ void test_deserialize_send_mam_message_response(void) {
 }
 
 void test_deserialize_send_mam_message(void) {
-  const char* json = "{\"message\":\"" TEST_PAYLOAD
-                     "\","
-                     "\"order\":2}";
+  const char* json = "{\"prng\":\"" TRYTES_81_1 "\",\"message\":\"" TEST_PAYLOAD "\",\"order\":2}";
   ta_send_mam_req_t* req = send_mam_req_new();
 
   send_mam_req_deserialize(json, req);
+  TEST_ASSERT_EQUAL_STRING(TRYTES_81_1, req->prng);
   TEST_ASSERT_EQUAL_STRING(TEST_PAYLOAD, req->payload);
   TEST_ASSERT_EQUAL_INT(2, req->channel_ord);