Add `Buffer::move()` to transfer ownership of buffer content

Refactor `Buffer`: implement `move()` method to enable efficient transfer of content to a string, leaving the buffer empty. Include unit tests for `move()` functionality to ensure correctness. Remove redundant `#include <cstring>` for cleanup.

Add `Buffer::move()` to transfer ownership of buffer content
Refactor `Buffer`: implement `move()` method to enable efficient transfer of content to a string, leaving the buffer empty. Include unit tests for `move()` functionality to ensure correctness. Remove redundant `#include <cstring>` for cleanup.
m-holger
1 parent 9ff713f4
Showing 3 changed files with 25 additions and 2 deletions
include/qpdf/Buffer.hh
libqpdf/Buffer.cc
libtests/buffer.cc
@@ -66,6 +66,11 @@ class Buffer
     QPDF_DLL
     Buffer copy() const;
  
+    // Move the content of the Buffer. After calling this method, the Buffer will be empty if the
+    // buffer owns its memory. Otherwise, the Buffer will be unchanged.
+    QPDF_DLL
+    std::string move();
+
   private:
     class Members;
  
@@ -2,8 +2,6 @@
  
 #include <qpdf/Buffer.hh>
  
-#include <cstring>
-
 class Buffer::Members
 {
     friend class Buffer;
@@ -96,3 +94,17 @@ Buffer::copy() const
     }
     return {std::string(m->buf, m->size)};
 }
+
+std::string
+Buffer::move()
+{
+    if (m->size == 0) {
+        return {};
+    }
+    if (!m->str.empty()) {
+        m->size = 0;
+        m->buf = nullptr;
+        return std::move(m->str);
+    }
+    return {m->buf, m->size};
+}
@@ -35,6 +35,12 @@ main()
     assert(bc2p[0] == 'R');
     assert(bc2p[1] == 'W');
  
+    // Test move method
+    auto s1 = bc1.move();
+    assert(bc1.getBuffer() == nullptr);
+    assert(bc1.getSize() == 0);
+    assert(s1 == "RW");
+
     // Test Buffer(std:string&&)
     Buffer bc3("QW");
     unsigned char* bc3p = bc3.getBuffer();