refactor Buffer insert and delete operations

add Buffer functions to insert/erase data chunks

src/core/Buffer.cc

@@ -171,49 +171,61 @@ void Buffer::exit_insert_mode()
 void Buffer::insert_code_point(const Buffer::Iterator & position, uint32_t code_point)
 {
     push_operation();
-    Buffer::Iterator local_position = position;
+    uint8_t encoded[Encoding::MAX_CODE_POINT_SIZE * 2];
-    if ((code_point != '\n') && (size() == 0u))
-    {
-        insert_code_point(position, '\n');
-    }
-    uint8_t encoded[Encoding::MAX_CODE_POINT_SIZE];
     uint8_t bytes = Encoding::encode(code_point, m_encoding, encoded);
-    m_gap_buffer->insert(local_position.offset(), encoded, bytes);
+    if ((size() == 0u) && (code_point != '\n'))
-    record_change(encoded, bytes, local_position.offset(), true);
+    {
-    ssize_t lines = (code_point == '\n') ? 1 : 0;
+        bytes += Encoding::encode('\n', m_encoding, &encoded[bytes]);
-    warp_iterators(local_position.offset(), bytes, lines, true);
+    }
+    insert_data(position.offset(), encoded, bytes);
     pop_operation();
 }
 
+void Buffer::insert_data(size_t offset, const uint8_t data[], size_t length)
+{
+    m_gap_buffer->insert(offset, data, length);
+    record_change(data, length, offset, true);
+    warp_iterators_after_insert(offset, length);
+    post_warp_cursors();
+}
+
 void Buffer::erase_code_point(const Buffer::Iterator & position)
 {
     if (position.valid())
     {
         push_operation();
-        Buffer::Iterator local_position = position;
+        erase_data(position.offset(), Encoding::num_bytes_in_code_point(m_encoding, position.address()));
-        uint8_t bytes = 0u;
-        uint32_t code_point = Encoding::decode(m_encoding, local_position.address(), &bytes);
-        record_change(local_position.address(), bytes, local_position.offset(), false);
-        m_gap_buffer->erase(local_position.offset(), bytes);
-        ssize_t lines = (code_point == '\n') ? -1 : 0;
-        warp_iterators(local_position.offset(), -(ssize_t)bytes, lines, false);
         pop_operation();
     }
 }
 
-void Buffer::warp_iterators(size_t offset, ssize_t offset_adjustment, ssize_t lines_adjustment, bool include_equal)
+void Buffer::erase_data(size_t offset, size_t length)
 {
-    if (!include_equal)
+    warp_iterators_before_delete(offset, length);
+    /* FIXME: erased data may not be contiguous in gap buffer. */
+    record_change(m_gap_buffer->address(offset), length, offset, false);
+    m_gap_buffer->erase(offset, length);
+    post_warp_cursors();
+}
+
+size_t Buffer::lines_in_data(size_t offset, size_t length)
+{
+    size_t lines = 0u;
+    for (size_t i = 0u; i < length; )
     {
-        offset++;
+        uint8_t bytes;
-    }
+        uint32_t c = Encoding::decode(m_encoding, m_gap_buffer->address(offset), &bytes);
-    for (auto iterator : m_iterators)
+        if (c == '\n')
         {
-        if (iterator->offset() >= offset)
+            lines++;
-        {
-            iterator->warp(offset_adjustment, lines_adjustment);
         }
+        i += bytes;
     }
+    return lines;
+}
+
+void Buffer::post_warp_cursors()
+{
     for (auto cursor : m_cursors)
     {
         if ((*cursor == *m_eof_iterator) && (size() > 0u))
@@ -223,6 +235,40 @@ void Buffer::warp_iterators(size_t offset, ssize_t offset_adjustment, ssize_t li
     }
 }
 
+void Buffer::warp_iterators_after_insert(size_t offset, size_t length)
+{
+    size_t lines = lines_in_data(offset, length);
+    for (auto iterator : m_iterators)
+    {
+        if (iterator->offset() >= offset)
+        {
+            iterator->warp(length, lines);
+        }
+    }
+}
+
+void Buffer::warp_iterators_before_delete(size_t offset, size_t length)
+{
+    size_t lines = lines_in_data(offset, length);
+    for (auto iterator : m_iterators)
+    {
+        /* Move any iterators within the chunk to be deleted to after it. */
+        while ((iterator->offset() >= offset) &&
+                (iterator->offset() < (offset + length)))
+        {
+            iterator->go_forward();
+            if (!iterator->valid())
+            {
+                break;
+            }
+        }
+        if (iterator->offset() >= offset)
+        {
+            iterator->warp(-(ssize_t)length, -(ssize_t)lines);
+        }
+    }
+}
+
 void Buffer::pop_operation()
 {
     if (m_operation_level > 0)
@@ -235,7 +281,7 @@ void Buffer::pop_operation()
     }
 }
 
-void Buffer::record_change(uint8_t data[], size_t length, size_t buffer_position, bool insert)
+void Buffer::record_change(const uint8_t data[], size_t length, size_t buffer_position, bool insert)
 {
     if (!m_current_change_operation)
     {

src/core/Buffer.h

@@ -152,9 +152,14 @@ protected:
     void load_empty_buffer();
     bool load_from_memory(const uint8_t * data, size_t data_length);
     void load_text_in_buffer(uint8_t * buffer, size_t buffer_size, size_t data_length);
-    void record_change(uint8_t data[], size_t length, size_t buffer_position, bool insert);
+    void record_change(const uint8_t data[], size_t length, size_t buffer_position, bool insert);
     void save_current_operation();
-    void warp_iterators(size_t offset, ssize_t offset_adjustment, ssize_t lines_adjustments, bool include_equal);
+    void warp_iterators_after_insert(size_t offset, size_t length);
+    void warp_iterators_before_delete(size_t offset, size_t length);
+    void insert_data(size_t offset, const uint8_t data[], size_t length);
+    void erase_data(size_t offset, size_t length);
+    size_t lines_in_data(size_t offset, size_t length);
+    void post_warp_cursors();
 };
 
 #endif