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.channel.flags = header.flags;
 
-        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 = ch.channel.flags;
+
+      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 {
+    mesh::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

@@ -423,7 +423,12 @@ void MyMesh::onChannelMessageRecv(const mesh::GroupChannel &channel, mesh::Packe
   }
   memcpy(&out_frame[i], text, tlen);
   i += tlen;
-  addToOfflineQueue(out_frame, i);
+
+  if (channel.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];

src/Mesh.h

@@ -4,10 +4,16 @@
 
 namespace mesh {
 
+struct ChannelFlags {
+    bool noStore : 1;
+    uint8_t reserved : 7;  // remaining 7 bits unused
+};
+
 class GroupChannel {
 public:
   uint8_t hash[PATH_HASH_SIZE];
   uint8_t secret[PUB_KEY_SIZE];
+  ChannelFlags flags;
 };
 
 /**

src/helpers/ChannelDetails.h

@@ -6,4 +6,4 @@
 struct ChannelDetails {
   mesh::GroupChannel channel;
   char name[32];
-};
+};