6663b6c9
 adorian
projet complet av...
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#ifndef ESCHER_ACCORDION_H
#define ESCHER_ACCORDION_H
/* Accordion sequentially stores null-terminated char buffers. It moves the free
* space at the end of a buffer if it will be edited. */
class Accordion {
public:
Accordion(char * buffer, int bufferSize);
int numberOfBuffers() { return m_numberOfBuffers; }
const char * bufferAtIndex(int index);
char * editableBufferAtIndex(int index);
int sizeOfEditableBufferAtIndex(int index);
/* sizeOfEditableBufferAtIndex appends the free space at the end of the buffer
* and returns the length of the buffer plus the free space, minus one free
* space char that we never edit in order to keep track of the position of the
* last edited buffer. */
bool appendBuffer(const char * buffer);
bool replaceBufferAtIndex(int index, const char * buffer);
void deleteBufferAtIndex(int index);
void deleteLastBuffer();
void deleteAll();
int freeSpaceSize();
private:
static constexpr char k_freeSpaceMarker = 0x01;
int startOfBufferAtIndex(int index);
int endOfBufferAtIndex(int index);
int startOfFreeSpace();
void cleanFreeSpace();
/* When a buffer is edited, there is garbage after the first null char of the
* buffer. cleanFreeSpace() declares the space after this null char as free,
* by marking it with the FreeSpaceMarker. Because we always keep at least one
* Free Space char out of the editable zone, cleanFreeSpace() just needs to
* put FreeSpaceMarkers after the first null char of the last edited Buffer,
* until the first FreeSpaceMarker char.
* WARNING: We have to call cleanFreeSpace() before any operation on m_history,
* otherwise m_history might contain garbage chars. */
void moveFreeSpaceAtPosition(int i);
void moveFreeSpaceAtEndOfBufferAtIndex(int index);
void moveFreeSpaceAtEndOfHistory();
int m_historySize;
char * m_history;
/* The m_history variable sequentially stores null-terminated char buffers.
* It also contains free space, which is marked with the FreeSpaceMarker. By
* construction, there is always at least one free byte, and the free space is
* always continuous. */
int m_numberOfBuffers;
int m_startOfLastEditedBuffer;
};
#endif
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