discord-rpc: Formatting

3rdparty/discord-rpc/discord_serialization.h

@@ -0,0 +1,186 @@
+#pragma once
+
+#include <rapidjson/document.h>
+#include <rapidjson/stringbuffer.h>
+#include <rapidjson/writer.h>
+
+namespace discord_rpc {
+
+// 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, const size_t maxLen, const int nonce, const 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 static_cast<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;
+
+}
+
+}  // namespace discord_rpc