pfodCircularLineBuffer.h

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#ifndef PFOD_CIRCULAR_LINE_BUFFER_H
#define PFOD_CIRCULAR_LINE_BUFFER_H
 
#include <Arduino.h>
 
struct BufferRange {
    size_t startPos;      // Starting byte position in buffer
    size_t endPos;        // Ending byte position in buffer (exclusive)
    size_t startLine;     // Line number at start position
    size_t endLine;       // Line number at end position
};
 
class pfodCircularLineBuffer : public Stream {
public:
    pfodCircularLineBuffer(size_t bufferSize = 4096);
 
    ~pfodCircularLineBuffer();
 
    size_t addLine(const char* line);
 
    size_t addLine(const String& line);
 
    void getRange(size_t fromLineCount, BufferRange& range);
 
    void getAllRange(BufferRange& range);
 
    void setReadRange(const BufferRange& range);
 
    void resetForRead();
 
    size_t getStartLineCount() const { return startLineCount; }
 
    size_t getEndLineCount() const { return endLineCount; }
 
    size_t getLineCount() const { return endLineCount - startLineCount; }
 
    size_t getBufferSize() const { return bufferSize; }
 
    size_t getUsedBytes() const;
 
    size_t getAvailableBytes() const { return bufferSize - getUsedBytes(); }
 
    bool isEmpty() const { return head == tail; }
 
    void clear();
 
    void debugBufferRange(Print* outPtr);
 
    // Stream interface implementation (read operations)
 
    virtual int available() override;
 
    virtual int peek() override;
 
    virtual int read() override;
 
    // Print interface implementation (write operations for adding data)
 
    virtual size_t write(uint8_t c) override;
 
    virtual size_t write(const uint8_t *buffer, size_t size) override;
 
private:
    size_t bufferSize;        // Configured buffer size
    uint8_t* buffer;          // Circular buffer storage
    size_t head;              // Write position (next byte to write)
    size_t tail;              // Read position (first byte to read)
    size_t startLineCount;    // Line number at tail position
    size_t endLineCount;      // Line number at head position (next line to write)
 
    // Current read range for Stream interface
    size_t readPos;           // Current read position within readRange
    size_t readEndPos;        // End position of current read range
    size_t lineByteCount;
    uint8_t prevByte;
 
 
    bool findNextLine(size_t fromPos, size_t& lineEnd);
 
 
    size_t bytesInRange(size_t start, size_t end) const;
};
 
#endif // PFOD_CIRCULAR_LINE_BUFFER_H