impr: Load small files into memory, open larger files as read-only by default

#841, #1585

lib/libimhex/source/providers/provider.cpp

@@ -102,6 +102,52 @@ namespace hex::prv {
         this->markDirty();
     }
 
+    void Provider::insertRaw(u64 offset, u64 size) {
+        auto oldSize = this->getActualSize();
+        this->resizeRaw(oldSize + size);
+
+        std::vector<u8> buffer(0x1000);
+        const std::vector<u8> zeroBuffer(0x1000);
+
+        auto position = oldSize;
+        while (position > offset) {
+            const auto readSize = std::min<size_t>(position - offset, buffer.size());
+
+            position -= readSize;
+
+            this->readRaw(position, buffer.data(), readSize);
+            this->writeRaw(position, zeroBuffer.data(), readSize);
+            this->writeRaw(position + size, buffer.data(), readSize);
+        }
+    }
+
+    void Provider::removeRaw(u64 offset, u64 size) {
+        if (offset > this->getActualSize() || size == 0)
+            return;
+
+        if ((offset + size) > this->getActualSize())
+            size = this->getActualSize() - offset;
+
+        auto oldSize = this->getActualSize();
+
+        std::vector<u8> buffer(0x1000);
+
+        const auto newSize = oldSize - size;
+        auto position = offset;
+        while (position < newSize) {
+            const auto readSize = std::min<size_t>(newSize - position, buffer.size());
+
+            this->readRaw(position + size, buffer.data(), readSize);
+            this->writeRaw(position, buffer.data(), readSize);
+
+            position += readSize;
+        }
+
+        this->resizeRaw(newSize);
+    }
+
+
+
     void Provider::applyOverlays(u64 offset, void *buffer, size_t size) const {
         for (auto &overlay : m_overlays) {
             auto overlayOffset = overlay->getAddress();