Add per-channel flags; support "no store" channels

examples/companion_radio/DataStore.cpp

@@ -324,9 +324,11 @@ void DataStore::loadChannels(DataStoreHost* host) {
       uint8_t channel_idx = 0;
       while (!full) {
         ChannelDetails ch;
-        uint8_t unused[4];
+        ChannelHeader header;
+
+        bool success = (file.read((uint8_t*)&header, sizeof(ChannelHeader)) == sizeof(ChannelHeader));
+        ch.flags.noStore = header.flags.noStore;
 
-        bool success = (file.read(unused, 4) == 4);
         success = success && (file.read((uint8_t *)ch.name, 32) == 32);
         success = success && (file.read((uint8_t *)ch.channel.secret, 32) == 32);
 
@@ -347,11 +349,12 @@ void DataStore::saveChannels(DataStoreHost* host) {
   if (file) {
     uint8_t channel_idx = 0;
     ChannelDetails ch;
-    uint8_t unused[4];
-    memset(unused, 0, 4);
-
+
     while (host->getChannelForSave(channel_idx, ch)) {
-      bool success = (file.write(unused, 4) == 4);
+      ChannelHeader header{};
+      header.flags.noStore = ch.flags.noStore;
+
+      bool success = (file.write((uint8_t *)&header, sizeof(ChannelHeader)) == sizeof(ChannelHeader));
       success = success && (file.write((uint8_t *)ch.name, 32) == 32);
       success = success && (file.write((uint8_t *)ch.channel.secret, 32) == 32);
 

examples/companion_radio/DataStore.h

@@ -5,6 +5,12 @@
 #include <helpers/ChannelDetails.h>
 #include "NodePrefs.h"
 
+struct ChannelHeader {
+    ChannelFlags flags;
+    uint8_t unused[3];
+};
+static_assert(sizeof(ChannelHeader) == 4, "ChannelHeader must be 4 bytes");
+
 class DataStoreHost {
 public:
   virtual bool onContactLoaded(const ContactInfo& contact) =0;

examples/companion_radio/MyMesh.cpp

@@ -52,6 +52,8 @@
 #define CMD_SEND_PATH_DISCOVERY_REQ   52
 #define CMD_SET_FLOOD_SCOPE           54   // v8+
 #define CMD_SEND_CONTROL_DATA         55   // v8+
+#define CMD_GET_CHANNEL_FLAG_NOSTORE  56
+#define CMD_SET_CHANNEL_FLAG_NOSTORE  57
 
 #define RESP_CODE_OK                  0
 #define RESP_CODE_ERR                 1
@@ -77,6 +79,7 @@
 #define RESP_CODE_CUSTOM_VARS         21
 #define RESP_CODE_ADVERT_PATH         22
 #define RESP_CODE_TUNING_PARAMS       23
+#define RESP_CODE_CHANNEL_FLAG_NOSTORE 24 // a reply to CMD_GET_CHANNEL_FLAG_NOSTORE
 
 #define SEND_TIMEOUT_BASE_MILLIS        500
 #define FLOOD_SEND_TIMEOUT_FACTOR       16.0f
@@ -455,7 +458,14 @@ void MyMesh::onChannelMessageRecv(const mesh::GroupChannel &channel, mesh::Packe
   }
   memcpy(&out_frame[i], text, tlen);
   i += tlen;
-  addToOfflineQueue(out_frame, i);
+
+  ChannelDetails channel_details;
+  bool foundDetails = getChannel(channel_idx, channel_details);
+  if (foundDetails && channel_details.flags.noStore && !_serial->isConnected()) {
+    MESH_DEBUG_PRINTLN("INFO: not storing message for noStore channel");
+  } else {
+    addToOfflineQueue(out_frame, i);
+  }
 
   if (_serial->isConnected()) {
     uint8_t frame[1];
@@ -469,8 +479,7 @@ void MyMesh::onChannelMessageRecv(const mesh::GroupChannel &channel, mesh::Packe
 #ifdef DISPLAY_CLASS
   // Get the channel name from the channel index
   const char *channel_name = "Unknown";
-  ChannelDetails channel_details;
-  if (getChannel(channel_idx, channel_details)) {
+  if (foundDetails) {
     channel_name = channel_details.name;
   }
   if (_ui) _ui->newMsg(path_len, channel_name, text, offline_queue_len);
@@ -1553,6 +1562,30 @@ void MyMesh::handleCmdFrame(size_t len) {
     } else {
       writeErrFrame(ERR_CODE_TABLE_FULL);
     }
+  } else if (cmd_frame[0] == CMD_GET_CHANNEL_FLAG_NOSTORE && len >= 2) {
+    uint8_t channel_idx = cmd_frame[1];
+    ChannelDetails channel;
+    if (getChannel(channel_idx, channel)) {
+      out_frame[0] = RESP_CODE_CHANNEL_FLAG_NOSTORE;
+      out_frame[1] = static_cast<uint8_t>(channel.flags.noStore);
+      _serial->writeFrame(out_frame, 2);
+    } else {
+      writeErrFrame(ERR_CODE_NOT_FOUND);
+    }
+  } else if (cmd_frame[0] == CMD_SET_CHANNEL_FLAG_NOSTORE && len >= 3) {
+    uint8_t channel_idx = cmd_frame[1];
+    ChannelDetails channel;
+    if (getChannel(channel_idx, channel)) {
+      channel.flags.noStore = static_cast<bool>(cmd_frame[2]);
+      if (setChannel(channel_idx, channel)) {
+        saveChannels();
+        writeOKFrame();
+      } else {
+        writeErrFrame(ERR_CODE_NOT_FOUND);
+      }
+    } else {
+      writeErrFrame(ERR_CODE_NOT_FOUND);
+    }
   } else {
     writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
     MESH_DEBUG_PRINTLN("ERROR: unknown command: %02X", cmd_frame[0]);

src/helpers/ChannelDetails.h

@@ -3,7 +3,13 @@
 #include <Arduino.h>
 #include <Mesh.h>
 
+struct ChannelFlags {
+    bool noStore : 1;
+    uint8_t reserved : 7;  // remaining 7 bits unused
+};
+
 struct ChannelDetails {
   mesh::GroupChannel channel;
   char name[32];
-};
+  ChannelFlags flags;
+};