Having the ability to create buffers from const memory.

2 files changed, 13 insertions, 2 deletions

diff --git a/includes/Buffer.h b/includes/Buffer.h
index 50dd47b..be86162 100644
--- a/includes/Buffer.h
+++ b/includes/Buffer.h
@@ -6,7 +6,9 @@ namespace Balau {
 
 class Buffer : public SeekableHandle {
   public:
-      Buffer() throw (GeneralException) : m_buffer(NULL), m_bufSize(0), m_numBlocks(0) { }
+      Buffer(const uint8_t * buffer) : m_buffer(const_cast<uint8_t *>(buffer)), m_fromConst(true) { }
+      Buffer() throw (GeneralException) : m_buffer(NULL), m_fromConst(false), m_bufSize(0), m_numBlocks(0) { }
+      virtual ~Buffer();
     virtual void close() throw (GeneralException);
     virtual ssize_t read(void * buf, size_t count) throw (GeneralException);
     virtual ssize_t write(const void * buf, size_t count) throw (GeneralException);
@@ -19,6 +21,7 @@ class Buffer : public SeekableHandle {
     void reset();
   private:
     uint8_t * m_buffer;
+    bool m_fromConst;
     off_t m_bufSize, m_numBlocks;
 };
 
diff --git a/src/Buffer.cc b/src/Buffer.cc
index f276ec0..a958571 100644
--- a/src/Buffer.cc
+++ b/src/Buffer.cc
@@ -9,6 +9,11 @@
 
 static const int s_blockSize = 16 * 1024;
 
+Balau::Buffer::~Buffer() {
+    if (!m_fromConst)
+        free(m_buffer);
+}
+
 void Balau::Buffer::close() throw (GeneralException) {
     reset();
 }
@@ -30,6 +35,9 @@ ssize_t Balau::Buffer::read(void * buf, size_t count) throw (GeneralException) {
 }
 
 ssize_t Balau::Buffer::write(const void * buf, size_t count) throw (GeneralException) {
+    if (m_fromConst)
+        throw GeneralException("Buffer is read only and can't be written to.");
+
     off_t cursor = wtell();
     off_t end = cursor + count;
     off_t endBlock = (end / s_blockSize) + ((end % s_blockSize) ? 1 : 0);
@@ -64,4 +72,4 @@ bool Balau::Buffer::isEOF() { return rtell() == m_bufSize; }
 const char * Balau::Buffer::getName() { return "Buffer"; }
 off_t Balau::Buffer::getSize() { return m_bufSize; }
 bool Balau::Buffer::canRead() { return true; }
-bool Balau::Buffer::canWrite() { return true; }
+bool Balau::Buffer::canWrite() { return !m_fromConst; }