Added support for custom reader classes

src/ArduinoJson/Deserialization/Readers/FlashReader.hpp

@@ -0,0 +1,52 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#pragma once
+
+namespace ARDUINOJSON_NAMESPACE {
+
+template <>
+struct Reader<const __FlashStringHelper*, void> {
+  const char* _ptr;
+
+ public:
+  explicit Reader(const __FlashStringHelper* ptr)
+      : _ptr(reinterpret_cast<const char*>(ptr)) {}
+
+  int read() {
+    return pgm_read_byte(_ptr++);
+  }
+
+  size_t readBytes(char* buffer, size_t length) {
+    memcpy_P(buffer, _ptr, length);
+    _ptr += length;
+    return length;
+  }
+};
+
+template <>
+struct BoundedReader<const __FlashStringHelper*, void> {
+  const char* _ptr;
+  const char* _end;
+
+ public:
+  explicit BoundedReader(const __FlashStringHelper* ptr, size_t size)
+      : _ptr(reinterpret_cast<const char*>(ptr)), _end(_ptr + size) {}
+
+  int read() {
+    if (_ptr < _end)
+      return pgm_read_byte(_ptr++);
+    else
+      return -1;
+  }
+
+  size_t readBytes(char* buffer, size_t length) {
+    size_t available = static_cast<size_t>(_end - _ptr);
+    if (available < length) length = available;
+    memcpy_P(buffer, _ptr, length);
+    _ptr += length;
+    return length;
+  }
+};
+}  // namespace ARDUINOJSON_NAMESPACE