Added BasicJsonDocument to support custom allocator (issue #876)

src/ArduinoJson/Document/BasicJsonDocument.hpp

@@ -0,0 +1,89 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#pragma once
+
+#include "JsonDocument.hpp"
+
+namespace ARDUINOJSON_NAMESPACE {
+
+template <typename TAllocator>
+class AllocatorOwner {
+ protected:
+  AllocatorOwner() {}
+  AllocatorOwner(const AllocatorOwner& src) : _allocator(src._allocator) {}
+  AllocatorOwner(TAllocator allocator) : _allocator(allocator) {}
+
+  void* allocate(size_t n) {
+    return _allocator.allocate(n);
+  }
+
+  void deallocate(void* p) {
+    _allocator.deallocate(p);
+  }
+
+ private:
+  TAllocator _allocator;
+};
+
+template <typename TAllocator>
+class BasicJsonDocument : AllocatorOwner<TAllocator>, public JsonDocument {
+ public:
+  explicit BasicJsonDocument(size_t capa, TAllocator allocator = TAllocator())
+      : AllocatorOwner<TAllocator>(allocator), JsonDocument(allocPool(capa)) {}
+
+  BasicJsonDocument(const BasicJsonDocument& src)
+      : AllocatorOwner<TAllocator>(src),
+        JsonDocument(allocPool(src.memoryUsage())) {
+    set(src);
+  }
+
+  template <typename T>
+  BasicJsonDocument(const T& src,
+                    typename enable_if<IsVisitable<T>::value>::type* = 0)
+      : JsonDocument(allocPool(src.memoryUsage())) {
+    set(src);
+  }
+
+  // disambiguate
+  BasicJsonDocument(VariantRef src)
+      : JsonDocument(allocPool(src.memoryUsage())) {
+    set(src);
+  }
+
+  ~BasicJsonDocument() {
+    freePool();
+  }
+
+  BasicJsonDocument& operator=(const BasicJsonDocument& src) {
+    reallocPoolIfTooSmall(src.memoryUsage());
+    set(src);
+    return *this;
+  }
+
+  template <typename T>
+  BasicJsonDocument& operator=(const T& src) {
+    reallocPoolIfTooSmall(src.memoryUsage());
+    set(src);
+    return *this;
+  }
+
+ private:
+  MemoryPool allocPool(size_t requiredSize) {
+    size_t capa = addPadding(requiredSize);
+    return MemoryPool(reinterpret_cast<char*>(this->allocate(capa)), capa);
+  }
+
+  void reallocPoolIfTooSmall(size_t requiredSize) {
+    if (requiredSize <= capacity()) return;
+    freePool();
+    replacePool(allocPool(addPadding(requiredSize)));
+  }
+
+  void freePool() {
+    this->deallocate(memoryPool().buffer());
+  }
+};
+
+}  // namespace ARDUINOJSON_NAMESPACE

src/ArduinoJson/Document/DynamicJsonDocument.hpp

@@ -4,66 +4,22 @@
 
 #pragma once
 
-#include "JsonDocument.hpp"
+#include "BasicJsonDocument.hpp"
 
 #include <stdlib.h>  // malloc, free
 
 namespace ARDUINOJSON_NAMESPACE {
 
-class DynamicJsonDocument : public JsonDocument {
- public:
-  explicit DynamicJsonDocument(size_t capa) : JsonDocument(allocPool(capa)) {}
-
-  DynamicJsonDocument(const DynamicJsonDocument& src)
-      : JsonDocument(allocPool(src.memoryUsage())) {
-    set(src);
+struct DefaultAllocator {
+  void* allocate(size_t n) {
+    return malloc(n);
   }
 
-  template <typename T>
-  DynamicJsonDocument(const T& src,
-                      typename enable_if<IsVisitable<T>::value>::type* = 0)
-      : JsonDocument(allocPool(src.memoryUsage())) {
-    set(src);
-  }
-
-  // disambiguate
-  DynamicJsonDocument(VariantRef src)
-      : JsonDocument(allocPool(src.memoryUsage())) {
-    set(src);
-  }
-
-  ~DynamicJsonDocument() {
-    freePool();
-  }
-
-  DynamicJsonDocument& operator=(const DynamicJsonDocument& src) {
-    reallocPoolIfTooSmall(src.memoryUsage());
-    set(src);
-    return *this;
-  }
-
-  template <typename T>
-  DynamicJsonDocument& operator=(const T& src) {
-    reallocPoolIfTooSmall(src.memoryUsage());
-    set(src);
-    return *this;
-  }
-
- private:
-  MemoryPool allocPool(size_t requiredSize) {
-    size_t capa = addPadding(requiredSize);
-    return MemoryPool(reinterpret_cast<char*>(malloc(capa)), capa);
-  }
-
-  void reallocPoolIfTooSmall(size_t requiredSize) {
-    if (requiredSize <= capacity()) return;
-    freePool();
-    replacePool(allocPool(addPadding(requiredSize)));
-  }
-
-  void freePool() {
-    free(memoryPool().buffer());
+  void deallocate(void* p) {
+    free(p);
   }
 };
 
+typedef BasicJsonDocument<DefaultAllocator> DynamicJsonDocument;
+
 }  // namespace ARDUINOJSON_NAMESPACE