LibSQL: Remove and update `VERIFY`s

We are performing a lot of checks on pointers that are performed again
immediately afterwards because of a dereference. This removes the
redundant `VERIFY`s and simplifies a couple others.

Userland/Libraries/LibSQL/BTree.cpp

@@ -65,7 +65,6 @@ bool BTree::insert(Key const& key)
 {
     if (!m_root)
         initialize_root();
-    VERIFY(m_root);
     return m_root->insert(key);
 }
 
@@ -73,7 +72,6 @@ bool BTree::update_key_pointer(Key const& key)
 {
     if (!m_root)
         initialize_root();
-    VERIFY(m_root);
     return m_root->update_key_pointer(key);
 }
 
@@ -81,7 +79,6 @@ Optional<u32> BTree::get(Key& key)
 {
     if (!m_root)
         initialize_root();
-    VERIFY(m_root);
     return m_root->get(key);
 }
 
@@ -89,7 +86,6 @@ BTreeIterator BTree::find(Key const& key)
 {
     if (!m_root)
         initialize_root();
-    VERIFY(m_root);
     for (auto node = m_root->node_for(key); node; node = node->up()) {
         for (auto ix = 0u; ix < node->size(); ix++) {
             auto match = (*node)[ix].match(key);

Userland/Libraries/LibSQL/HashIndex.cpp

@@ -187,13 +187,11 @@ Key const& HashBucket::operator[](size_t ix)
 {
     if (!m_inflated)
         m_hash_index.serializer().deserialize_block_to(pointer(), *this);
-    VERIFY(ix < size());
     return m_entries[ix];
 }
 
 Key const& HashBucket::operator[](size_t ix) const
 {
-    VERIFY(ix < m_entries.size());
     return m_entries[ix];
 }
 

Userland/Libraries/LibSQL/Heap.h

@@ -70,13 +70,11 @@ public:
 
     u32 user_value(size_t index) const
     {
-        VERIFY(index < m_user_values.size());
         return m_user_values[index];
     }
 
     void set_user_value(size_t index, u32 value)
     {
-        VERIFY(index < m_user_values.size());
         m_user_values[index] = value;
         update_zero_block();
     }

Userland/Libraries/LibSQL/Serializer.h

@@ -28,7 +28,6 @@ public:
 
     void get_block(u32 pointer)
     {
-        VERIFY(m_heap.ptr() != nullptr);
         auto buffer_or_error = m_heap->read_block(pointer);
         if (buffer_or_error.is_error())
             VERIFY_NOT_REACHED();
@@ -110,7 +109,7 @@ public:
     template<typename T>
     bool serialize_and_write(T const& t)
     {
-        VERIFY(m_heap.ptr() != nullptr);
+        VERIFY(!m_heap.is_null());
         reset();
         serialize<T>(t);
         m_heap->add_to_wal(t.pointer(), m_buffer);
@@ -120,20 +119,17 @@ public:
     [[nodiscard]] size_t offset() const { return m_current_offset; }
     u32 new_record_pointer()
     {
-        VERIFY(m_heap.ptr() != nullptr);
         return m_heap->new_record_pointer();
     }
 
     bool has_block(u32 pointer) const
     {
-        VERIFY(m_heap.ptr() != nullptr);
         return pointer < m_heap->size();
     }
 
     Heap& heap()
     {
-        VERIFY(m_heap.ptr() != nullptr);
-        return *(m_heap.ptr());
+        return *m_heap;
     }
 
 private:

Userland/Libraries/LibSQL/Value.h

@@ -68,7 +68,6 @@ public:
 
     [[nodiscard]] auto const& value() const
     {
-        VERIFY(m_value.has_value());
         return *m_value;
     }