v1.4.4

source/core/StarBuffer.hpp

@@ -0,0 +1,122 @@
+#ifndef STAR_BUFFER_HPP
+#define STAR_BUFFER_HPP
+
+#include "StarIODevice.hpp"
+#include "StarString.hpp"
+
+namespace Star {
+
+STAR_CLASS(Buffer);
+STAR_CLASS(ExternalBuffer);
+
+// Wraps a ByteArray to an IODevice
+class Buffer : public IODevice {
+public:
+  // Constructs buffer open ReadWrite
+  Buffer();
+  Buffer(size_t initialSize);
+  Buffer(ByteArray b);
+  Buffer(Buffer const& buffer);
+  Buffer(Buffer&& buffer);
+
+  StreamOffset pos() override;
+  void seek(StreamOffset pos, IOSeek mode = IOSeek::Absolute) override;
+  void resize(StreamOffset size) override;
+  bool atEnd() override;
+
+  size_t read(char* data, size_t len) override;
+  size_t write(char const* data, size_t len) override;
+
+  size_t readAbsolute(StreamOffset readPosition, char* data, size_t len) override;
+  size_t writeAbsolute(StreamOffset writePosition, char const* data, size_t len) override;
+
+  void open(IOMode mode) override;
+
+  String deviceName() const override;
+
+  StreamOffset size() override;
+
+  ByteArray& data();
+  ByteArray const& data() const;
+
+  // If this class holds the underlying data, then this method is cheap, and
+  // will move the data out of this class into the returned array, otherwise,
+  // this will incur a copy.  Afterwards, this Buffer will be left empty.
+  ByteArray takeData();
+
+  // Returns a pointer to the beginning of the Buffer.
+  char* ptr();
+  char const* ptr() const;
+
+  // Same thing as size(), just size_t type (since this is in-memory)
+  size_t dataSize() const;
+  void reserve(size_t size);
+
+  // Clears buffer, moves position to 0.
+  void clear();
+  bool empty() const;
+
+  // Reset buffer with new contents, moves position to 0.
+  void reset(size_t newSize);
+  void reset(ByteArray b);
+
+  Buffer& operator=(Buffer const& buffer);
+  Buffer& operator=(Buffer&& buffer);
+
+private:
+  size_t doRead(size_t pos, char* data, size_t len);
+  size_t doWrite(size_t pos, char const* data, size_t len);
+
+  size_t m_pos;
+  ByteArray m_bytes;
+};
+
+// Wraps an externally held sequence of bytes to a read-only IODevice
+class ExternalBuffer : public IODevice {
+public:
+  // Constructs an empty ReadOnly ExternalBuffer.
+  ExternalBuffer();
+  // Constructs a ReadOnly ExternalBuffer pointing to the given external data, which
+  // must be valid for the lifetime of the ExternalBuffer.
+  ExternalBuffer(char const* externalData, size_t len);
+
+  ExternalBuffer(ExternalBuffer const& buffer) = default;
+  ExternalBuffer& operator=(ExternalBuffer const& buffer) = default;
+
+  StreamOffset pos() override;
+  void seek(StreamOffset pos, IOSeek mode = IOSeek::Absolute) override;
+  bool atEnd() override;
+
+  size_t read(char* data, size_t len) override;
+  size_t write(char const* data, size_t len) override;
+
+  size_t readAbsolute(StreamOffset readPosition, char* data, size_t len) override;
+  size_t writeAbsolute(StreamOffset writePosition, char const* data, size_t len) override;
+
+  String deviceName() const override;
+
+  StreamOffset size() override;
+
+  // Returns a pointer to the beginning of the Buffer.
+  char const* ptr() const;
+
+  // Same thing as size(), just size_t type (since this is in-memory)
+  size_t dataSize() const;
+
+  // Clears buffer, moves position to 0.
+  bool empty() const;
+
+  // Reset buffer with new contents, moves position to 0.
+  void reset(char const* externalData, size_t len);
+
+private:
+  size_t doRead(size_t pos, char* data, size_t len);
+
+  size_t m_pos;
+  char const* m_bytes;
+  size_t m_size;
+};
+
+}
+
+#endif