1 files changed, 215 insertions, 0 deletions
diff --git a/externals/discord-rpc/src/serialization.h b/externals/discord-rpc/src/serialization.h
new file mode 100644
index 0000000000..9c462dc283
--- /dev/null
+++ b/externals/discord-rpc/src/serialization.h
@@ -0,0 +1,215 @@
+#pragma once
+
+#include <stdint.h>
+
+#ifndef __MINGW32__
+#pragma warning(push)
+
+#pragma warning(disable : 4061) // enum is not explicitly handled by a case label
+#pragma warning(disable : 4365) // signed/unsigned mismatch
+#pragma warning(disable : 4464) // relative include path contains
+#pragma warning(disable : 4668) // is not defined as a preprocessor macro
+#pragma warning(disable : 6313) // Incorrect operator
+#endif                          // __MINGW32__
+
+#include "rapidjson/document.h"
+#include "rapidjson/stringbuffer.h"
+#include "rapidjson/writer.h"
+
+#ifndef __MINGW32__
+#pragma warning(pop)
+#endif // __MINGW32__
+
+// if only there was a standard library function for this
+template <size_t Len>
+inline size_t StringCopy(char (&dest)[Len], const char* src)
+{
+    if (!src || !Len) {
+        return 0;
+    }
+    size_t copied;
+    char* out = dest;
+    for (copied = 1; *src && copied < Len; ++copied) {
+        *out++ = *src++;
+    }
+    *out = 0;
+    return copied - 1;
+}
+
+size_t JsonWriteHandshakeObj(char* dest, size_t maxLen, int version, const char* applicationId);
+
+// Commands
+struct DiscordRichPresence;
+size_t JsonWriteRichPresenceObj(char* dest,
+                                size_t maxLen,
+                                int nonce,
+                                int pid,
+                                const DiscordRichPresence* presence);
+size_t JsonWriteSubscribeCommand(char* dest, size_t maxLen, int nonce, const char* evtName);
+
+size_t JsonWriteUnsubscribeCommand(char* dest, size_t maxLen, int nonce, const char* evtName);
+
+size_t JsonWriteJoinReply(char* dest, size_t maxLen, const char* userId, int reply, int nonce);
+
+// I want to use as few allocations as I can get away with, and to do that with RapidJson, you need
+// to supply some of your own allocators for stuff rather than use the defaults
+
+class LinearAllocator {
+public:
+    char* buffer_;
+    char* end_;
+    LinearAllocator()
+    {
+        assert(0); // needed for some default case in rapidjson, should not use
+    }
+    LinearAllocator(char* buffer, size_t size)
+      : buffer_(buffer)
+      , end_(buffer + size)
+    {
+    }
+    static const bool kNeedFree = false;
+    void* Malloc(size_t size)
+    {
+        char* res = buffer_;
+        buffer_ += size;
+        if (buffer_ > end_) {
+            buffer_ = res;
+            return nullptr;
+        }
+        return res;
+    }
+    void* Realloc(void* originalPtr, size_t originalSize, size_t newSize)
+    {
+        if (newSize == 0) {
+            return nullptr;
+        }
+        // allocate how much you need in the first place
+        assert(!originalPtr && !originalSize);
+        // unused parameter warning
+        (void)(originalPtr);
+        (void)(originalSize);
+        return Malloc(newSize);
+    }
+    static void Free(void* ptr)
+    {
+        /* shrug */
+        (void)ptr;
+    }
+};
+
+template <size_t Size>
+class FixedLinearAllocator : public LinearAllocator {
+public:
+    char fixedBuffer_[Size];
+    FixedLinearAllocator()
+      : LinearAllocator(fixedBuffer_, Size)
+    {
+    }
+    static const bool kNeedFree = false;
+};
+
+// wonder why this isn't a thing already, maybe I missed it
+class DirectStringBuffer {
+public:
+    using Ch = char;
+    char* buffer_;
+    char* end_;
+    char* current_;
+
+    DirectStringBuffer(char* buffer, size_t maxLen)
+      : buffer_(buffer)
+      , end_(buffer + maxLen)
+      , current_(buffer)
+    {
+    }
+
+    void Put(char c)
+    {
+        if (current_ < end_) {
+            *current_++ = c;
+        }
+    }
+    void Flush() {}
+    size_t GetSize() const { return (size_t)(current_ - buffer_); }
+};
+
+using MallocAllocator = rapidjson::CrtAllocator;
+using PoolAllocator = rapidjson::MemoryPoolAllocator<MallocAllocator>;
+using UTF8 = rapidjson::UTF8<char>;
+// Writer appears to need about 16 bytes per nested object level (with 64bit size_t)
+using StackAllocator = FixedLinearAllocator<2048>;
+constexpr size_t WriterNestingLevels = 2048 / (2 * sizeof(size_t));
+using JsonWriterBase =
+  rapidjson::Writer<DirectStringBuffer, UTF8, UTF8, StackAllocator, rapidjson::kWriteNoFlags>;
+class JsonWriter : public JsonWriterBase {
+public:
+    DirectStringBuffer stringBuffer_;
+    StackAllocator stackAlloc_;
+
+    JsonWriter(char* dest, size_t maxLen)
+      : JsonWriterBase(stringBuffer_, &stackAlloc_, WriterNestingLevels)
+      , stringBuffer_(dest, maxLen)
+      , stackAlloc_()
+    {
+    }
+
+    size_t Size() const { return stringBuffer_.GetSize(); }
+};
+
+using JsonDocumentBase = rapidjson::GenericDocument<UTF8, PoolAllocator, StackAllocator>;
+class JsonDocument : public JsonDocumentBase {
+public:
+    static const int kDefaultChunkCapacity = 32 * 1024;
+    // json parser will use this buffer first, then allocate more if needed; I seriously doubt we
+    // send any messages that would use all of this, though.
+    char parseBuffer_[32 * 1024];
+    MallocAllocator mallocAllocator_;
+    PoolAllocator poolAllocator_;
+    StackAllocator stackAllocator_;
+    JsonDocument()
+      : JsonDocumentBase(rapidjson::kObjectType,
+                         &poolAllocator_,
+                         sizeof(stackAllocator_.fixedBuffer_),
+                         &stackAllocator_)
+      , poolAllocator_(parseBuffer_, sizeof(parseBuffer_), kDefaultChunkCapacity, &mallocAllocator_)
+      , stackAllocator_()
+    {
+    }
+};
+
+using JsonValue = rapidjson::GenericValue<UTF8, PoolAllocator>;
+
+inline JsonValue* GetObjMember(JsonValue* obj, const char* name)
+{
+    if (obj) {
+        auto member = obj->FindMember(name);
+        if (member != obj->MemberEnd() && member->value.IsObject()) {
+            return &member->value;
+        }
+    }
+    return nullptr;
+}
+
+inline int GetIntMember(JsonValue* obj, const char* name, int notFoundDefault = 0)
+{
+    if (obj) {
+        auto member = obj->FindMember(name);
+        if (member != obj->MemberEnd() && member->value.IsInt()) {
+            return member->value.GetInt();
+        }
+    }
+    return notFoundDefault;
+}
+
+inline const char* GetStrMember(JsonValue* obj,
+                                const char* name,
+                                const char* notFoundDefault = nullptr)
+{
+    if (obj) {
+        auto member = obj->FindMember(name);
+        if (member != obj->MemberEnd() && member->value.IsString()) {
+            return member->value.GetString();
+        }
+    }
+    return notFoundDefault;
+}