refactor: Add common msgpack array packer with callback.

There will be more object arrays that need to be packed. This function
takes care of NULL (creating an empty array), and putting the correct
array size and calling the per-element callback the right amount of
times.

Author: iphydf

other/bootstrap_daemon/docker/tox-bootstrapd.sha256

@@ -1 +1 @@
-c31bc1cd7249c62b4f1d2c9ea26c9e8528d9b897dc29afbdbe95894d30c92c8d  /usr/local/bin/tox-bootstrapd
+95bcb5742f9d92cf0cc29a3aa840887bc1074c76637a9eabe5c63a2e4e709737  /usr/local/bin/tox-bootstrapd

other/event_tooling/generate_event_c.cpp

@@ -452,6 +452,7 @@ void generate_event_impl(const std::string& event_name, const std::vector<EventT
     f << "bool tox_event_" << event_name_l << "_unpack(\n";
     f << "    Tox_Event_" << event_name << " **event, Bin_Unpack *bu, const Memory *mem)\n{\n";
     f << "    assert(event != nullptr);\n";
+    f << "    assert(*event == nullptr);\n";
     f << "    *event = tox_event_" << event_name_l << "_new(mem);\n\n";
     f << "    if (*event == nullptr) {\n        return false;\n    }\n\n";
     f << "    return tox_event_" << event_name_l << "_unpack_into(*event, bu);\n}\n\n";

toxcore/bin_pack.c

@@ -109,6 +109,26 @@ bool bin_pack_obj_array_b(bin_pack_array_cb *callback, const void *arr, uint32_t
     return true;
 }
 
+bool bin_pack_obj_array(Bin_Pack *bp, bin_pack_array_cb *callback, const void *arr, uint32_t arr_size, const Logger *logger)
+{
+    if (arr == nullptr) {
+        assert(arr_size == 0);
+        return bin_pack_array(bp, 0);
+    }
+
+    if (!bin_pack_array(bp, arr_size)) {
+        return false;
+    }
+
+    for (uint32_t i = 0; i < arr_size; ++i) {
+        if (!callback(arr, i, logger, bp)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
 bool bin_pack_array(Bin_Pack *bp, uint32_t size)
 {
     return cmp_write_array(&bp->ctx, size);

toxcore/bin_pack.h

@@ -17,6 +17,11 @@ extern "C" {
 /**
  * @brief Binary serialisation object.
  *
+ * Naming convention:
+ * - Functions ending in `_b` (or `_b_size`) are NOT MessagePack, i.e. write
+ *   data in plain big endian binary format.
+ * - All other functions encode their input in MessagePack format.
+ *
  * Some notes on parameter order:
  *
  * - We pass the `obj` pointer as `this`-like pointer first to the callbacks.
@@ -66,7 +71,9 @@ uint32_t bin_pack_obj_size(bin_pack_cb *callback, const void *obj, const Logger
 /** @brief Pack an object into a buffer of a given size.
  *
  * This function creates and initialises a `Bin_Pack` packer object, calls the callback with the
- * packer object and the to-be-packed object, and then cleans up the packer object.
+ * packer object and the to-be-packed object, and then cleans up the packer object. Note that
+ * there is nothing MessagePack-specific about this function, so it can be used for both custom
+ * binary and MessagePack formats.
  *
  * You can use `bin_pack_obj_size` to determine the minimum required size of `buf`. If packing
  * overflows `uint32_t`, this function returns `false`.
@@ -102,13 +109,8 @@ uint32_t bin_pack_obj_array_b_size(bin_pack_array_cb *callback, const void *arr,
 
 /** @brief Pack an object array into a buffer of a given size.
  *
- * Calls the callback `arr_size` times with increasing `index` argument from 0 to
- * `arr_size`. This function is here just so we don't need to write the same
- * trivial loop many times and so we don't need an extra struct just to contain
- * an array with size so it can be passed to `bin_pack_obj`.
- *
- * Similar to `bin_pack_obj` but for arrays. Does not write the array length, so
- * if you need that, write it manually using `bin_pack_array`.
+ * Similar to `bin_pack_obj_array` but does not write the array length, so
+ * if you need that, encoding it is on you.
  *
  * Passing NULL for `arr` has no effect, but requires that `arr_size` is 0.
  *
@@ -125,6 +127,32 @@ uint32_t bin_pack_obj_array_b_size(bin_pack_array_cb *callback, const void *arr,
 non_null(1, 5) nullable(2, 4)
 bool bin_pack_obj_array_b(bin_pack_array_cb *callback, const void *arr, uint32_t arr_size, const Logger *logger, uint8_t *buf, uint32_t buf_size);
 
+/** @brief Encode an object array as MessagePack array into a bin packer.
+ *
+ * Calls the callback `arr_size` times with increasing `index` argument from 0 to
+ * `arr_size`. This function is here just so we don't need to write the same
+ * trivial loop many times and so we don't need an extra struct just to contain
+ * an array with size so it can be passed to `bin_pack_obj`.
+ *
+ * Similar to `bin_pack_obj` but for arrays. Note that a `Bin_Pack` object is
+ * required here, so it must be called from within a callback to one of the
+ * functions above.
+ *
+ * Passing NULL for `arr` requires that `arr_size` is 0. This will write a 0-size
+ * MessagePack array to the packer.
+ *
+ * @param bp Bin packer object.
+ * @param callback The function called on the created packer and packed object
+ *   array.
+ * @param arr The object array to be packed, passed as `arr` to the callback.
+ * @param arr_size The number of elements in the object array.
+ * @param logger Optional logger object to pass to the callback.
+ *
+ * @retval false if an error occurred (e.g. buffer overflow).
+ */
+non_null(1, 2) nullable(3, 5)
+bool bin_pack_obj_array(Bin_Pack *bp, bin_pack_array_cb *callback, const void *arr, uint32_t arr_size, const Logger *logger);
+
 /** @brief Start packing a MessagePack array.
  *
  * A call to this function must be followed by exactly `size` calls to other functions below.

toxcore/events/conference_connected.c

@@ -119,6 +119,7 @@ bool tox_event_conference_connected_unpack(
     Tox_Event_Conference_Connected **event, Bin_Unpack *bu, const Memory *mem)
 {
     assert(event != nullptr);
+    assert(*event == nullptr);
     *event = tox_event_conference_connected_new(mem);
 
     if (*event == nullptr) {

toxcore/events/conference_invite.c

@@ -187,6 +187,7 @@ bool tox_event_conference_invite_unpack(
     Tox_Event_Conference_Invite **event, Bin_Unpack *bu, const Memory *mem)
 {
     assert(event != nullptr);
+    assert(*event == nullptr);
     *event = tox_event_conference_invite_new(mem);
 
     if (*event == nullptr) {

toxcore/events/conference_message.c

@@ -203,6 +203,7 @@ bool tox_event_conference_message_unpack(
     Tox_Event_Conference_Message **event, Bin_Unpack *bu, const Memory *mem)
 {
     assert(event != nullptr);
+    assert(*event == nullptr);
     *event = tox_event_conference_message_new(mem);
 
     if (*event == nullptr) {

toxcore/events/conference_peer_list_changed.c

@@ -119,6 +119,7 @@ bool tox_event_conference_peer_list_changed_unpack(
     Tox_Event_Conference_Peer_List_Changed **event, Bin_Unpack *bu, const Memory *mem)
 {
     assert(event != nullptr);
+    assert(*event == nullptr);
     *event = tox_event_conference_peer_list_changed_new(mem);
 
     if (*event == nullptr) {

toxcore/events/conference_peer_name.c

@@ -185,6 +185,7 @@ bool tox_event_conference_peer_name_unpack(
     Tox_Event_Conference_Peer_Name **event, Bin_Unpack *bu, const Memory *mem)
 {
     assert(event != nullptr);
+    assert(*event == nullptr);
     *event = tox_event_conference_peer_name_new(mem);
 
     if (*event == nullptr) {

toxcore/events/conference_title.c

@@ -185,6 +185,7 @@ bool tox_event_conference_title_unpack(
     Tox_Event_Conference_Title **event, Bin_Unpack *bu, const Memory *mem)
 {
     assert(event != nullptr);
+    assert(*event == nullptr);
     *event = tox_event_conference_title_new(mem);
 
     if (*event == nullptr) {