From ba2cbded0fb9e118bdd4b8a0069c89928716c342 Mon Sep 17 00:00:00 2001
From: Iskandar Safarov <sapharow@gmail.com>
Date: Wed, 21 Jun 2023 12:26:13 +1000
Subject: [PATCH 1/2] Added multiple pop_front as an atomic operation

---
 circular_buffer.h          | 24 +++++++++++++++++++-----
 tests/member_func_test.cpp | 28 ++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/circular_buffer.h b/circular_buffer.h
index 0c3beec..b250585 100644
--- a/circular_buffer.h
+++ b/circular_buffer.h
@@ -85,6 +85,7 @@ class CircularBuffer {
 	void push_back(const value_type& data);
 	void push_back(value_type&& data) noexcept;
 	void pop_front();
+    void pop_front(size_t count);
 	reference front();
 	reference back(); 
 	const_reference front() const; 
@@ -119,7 +120,7 @@ class CircularBuffer {
 		
 private:
 	void _increment_bufferstate();
-	void _decrement_bufferstate();
+    void _decrement_bufferstate(size_t count);
 	mutable std::mutex _mtx;
 	std::unique_ptr<value_type[]> _buff;
 	size_type _head = 0;
@@ -366,14 +367,27 @@ void CircularBuffer<T>::pop_front(){
 	std::lock_guard<std::mutex> _lck(_mtx);
 	if(empty())
 		throw std::length_error("pop_front called on empty buffer");
-	_decrement_bufferstate();
+	_decrement_bufferstate(1);
+}
+
+template<typename T>
+inline
+void CircularBuffer<T>::pop_front(size_t count){
+    if(count > 0) {
+        if(empty())
+            throw std::length_error("pop_front called on empty buffer");
+        if (count > _size) {
+            count = _size;
+        }
+        _decrement_bufferstate(count);
+    }
 }
 
 template<typename T>
 inline 
-void CircularBuffer<T>::_decrement_bufferstate(){
-	--_size;
-	_tail = (_tail + 1)%_max_size;
+void CircularBuffer<T>::_decrement_bufferstate(size_t count){
+	_size -= count;
+	_tail = (_tail + count)%_max_size;
 }
 
 template<typename T>
diff --git a/tests/member_func_test.cpp b/tests/member_func_test.cpp
index e429f44..70e9c0e 100644
--- a/tests/member_func_test.cpp
+++ b/tests/member_func_test.cpp
@@ -148,6 +148,34 @@ TEST_F(CircularBufferTest, PopFrontTest){
 }
 
 
+TEST_F(CircularBufferTest, MultiPopFrontTest){
+	// push back & pop individual elements
+	test_buff.push_back("string1");
+	test_buff.push_back("string2");
+	test_buff.push_back("string3");
+	EXPECT_EQ(test_buff.size(), 3);
+	test_buff.pop_front(2);	
+	EXPECT_EQ(test_buff.size(), 1);
+	EXPECT_EQ(test_buff.front(), "string3");
+
+	//create full buffer
+	for(int i=0; i<TEST_BUFFER_SIZE; i++)
+		test_buff.push_back("string" + std::to_string(i));
+	//pop all elements
+	test_buff.pop_front(TEST_BUFFER_SIZE);
+	EXPECT_TRUE(test_buff.empty());
+	EXPECT_EQ(test_buff.size(), 0);
+	//try pop on empty buffer
+	try {
+		test_buff.pop_front(10);
+		FAIL() << "Expected std::length_error";
+	}
+	catch(const std::length_error& err){
+		EXPECT_EQ(err.what(), std::string("pop_front called on empty buffer"));
+	}
+}
+
+
 TEST_F(CircularBufferTest, FrontTest){
 	// push back & front for  individual elements
 	test_buff.push_back("string1");

From 4c3e660a8e4dc65240a9c260d45515b1e3c90afa Mon Sep 17 00:00:00 2001
From: Iskandar Safarov <sapharow@gmail.com>
Date: Wed, 21 Jun 2023 12:49:42 +1000
Subject: [PATCH 2/2] Fixed whitespaces

---
 circular_buffer.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/circular_buffer.h b/circular_buffer.h
index b250585..0264535 100644
--- a/circular_buffer.h
+++ b/circular_buffer.h
@@ -85,7 +85,7 @@ class CircularBuffer {
 	void push_back(const value_type& data);
 	void push_back(value_type&& data) noexcept;
 	void pop_front();
-    void pop_front(size_t count);
+	void pop_front(size_t count);
 	reference front();
 	reference back(); 
 	const_reference front() const; 
@@ -120,7 +120,7 @@ class CircularBuffer {
 		
 private:
 	void _increment_bufferstate();
-    void _decrement_bufferstate(size_t count);
+	void _decrement_bufferstate(size_t count);
 	mutable std::mutex _mtx;
 	std::unique_ptr<value_type[]> _buff;
 	size_type _head = 0;