| #pragma once |
| |
| #include <prdf_types.h> |
| |
| namespace libhei |
| { |
| |
| class BitStringBuffer; |
| |
| /** This type is used to take advantage of the most efficient memory reference |
| * size for a specific CPU architecture. */ |
| typedef uint32_t CPU_WORD; |
| |
| //############################################################################## |
| // BitString class |
| //############################################################################## |
| |
| /** |
| * A BitString is general purpose class providing the ability to manipulate |
| * individual bits within an allocated section of contiguous memory. |
| * |
| * A BitString does not "own" the memory, it only accesses and manipulates the |
| * bits in the range specified. Users will need to ensure memory is allocated |
| * and deallocated appropriately. As an alternative, a BitStringBuffer is a |
| * BitString that will allocate and maintain its own memory. |
| * |
| * The length of a BitString is only limited by the amount of memory that |
| * contains the data buffer. |
| * |
| * The CPU_WORD type is used internally to reference memory and as the interface |
| * type for the field. Ensure that any buffer allocated for a BitString is |
| * CPU_WORD aligned so that the BitString does not accidentally access memory |
| * beyond availability. For example, say we have a buffer allocated for 6 byte |
| * (48 bits) and those 6 bytes are allocated at the very end of accessible |
| * memory. When the BitString tries to access the second CPU_WORD, which |
| * contains the last 2 bytes of the buffer, an expection will be thrown because |
| * the BitString always access an entire CPU_WORD (4 bytes) at a time and the |
| * last two bytes are not accessible. Utilize the static function |
| * getNumCpuWords() to get the minimum number of CPU_WORDs required to allocate |
| * sufficient space in the buffer. For example, getNumCpuWords(48) returns 2. |
| * |
| * The bit positions are ordered 0 to n (left to right), where n is the bit |
| * length minus one. By default, position 0 will be the first bit of the |
| * buffer's start address. The optional constructor allows users to input an |
| * offset anywhere within the buffer, which is then used as position 0. This is |
| * useful when the data within the buffer is a right-justified. |
| */ |
| class BitString |
| { |
| public: // constants |
| |
| /** Bit length of a CPU_WORD */ |
| static const uint32_t CPU_WORD_BIT_LEN; |
| |
| /** A CPU_WORD with all of the bits set to 1 */ |
| static const CPU_WORD CPU_WORD_MASK; |
| |
| public: // functions |
| |
| /** |
| * @brief Constructor |
| * @param i_bitLen The number of bits in the bit string. |
| * @param i_bufAddr The starting address of the memory buffer. |
| * @param i_offset Optional input to indicate the actual starting position |
| * of the bit string within the memory buffer. |
| * @post It is possible that i_bitLen + i_offset may not be CPU_WORD |
| * aligned, however, the memory space allocated for i_bufAddr must be |
| * CPU_WORD aligned to avoid functions in this class accessing memory |
| * outside the available memory space. Use getNumCpuWords() to |
| * calulate the number of CPU_WORDs needed to allocate sufficient |
| * memory space. |
| */ |
| BitString( uint32_t i_bitLen, CPU_WORD * i_bufAddr, |
| uint32_t i_offset = 0 ) : |
| iv_bitLen(i_bitLen), iv_bufAddr(i_bufAddr), iv_offset(i_offset) |
| {} |
| |
| /** @brief Destructor */ |
| virtual ~BitString() {} |
| |
| /** @return The number of bits in the bit string buffer. */ |
| uint32_t getBitLen() const { return iv_bitLen; } |
| |
| /** @return The address of the bit string buffer. Note that this may |
| * return nullptr. */ |
| CPU_WORD * getBufAddr() const { return iv_bufAddr; } |
| |
| /** |
| * @param i_bitLen The number of bits for a bit string. |
| * @param i_offset Optional starting position of the bit string within the |
| * memory buffer. |
| * @return The minimum number of CPU_WORDs required to allocate sufficient |
| * memory space for a bit string. |
| */ |
| static uint32_t getNumCpuWords( uint32_t i_bitLen, uint32_t i_offset = 0 ) |
| { |
| return (i_bitLen + i_offset + CPU_WORD_BIT_LEN-1) / CPU_WORD_BIT_LEN; |
| } |
| |
| /** |
| * @brief Returns a left-justified value of the given length from the bit |
| * string starting at the given position. |
| * @param i_pos The starting position of the target range. |
| * @param i_len The number of bits of the target range. |
| * @return The value of the field range specified (left-justified). |
| * @pre nullptr != getBufAddr() |
| * @pre 0 < i_len |
| * @pre i_len <= CPU_WORD_BIT_LEN |
| * @pre i_pos + i_len <= getBitLen() |
| */ |
| CPU_WORD getField( uint32_t i_pos, uint32_t i_len ) const; |
| |
| /** |
| * @brief Returns a right-justified value of the given length from the bit |
| * string starting at the given position. |
| * @param i_pos The starting position of the target range. |
| * @param i_len The number of bits of the target range. |
| * @return The value of the field range specified (right-justified). |
| * @pre nullptr != getBufAddr() |
| * @pre 0 < i_len |
| * @pre i_len <= CPU_WORD_BIT_LEN |
| * @pre i_pos + i_len <= getBitLen() |
| */ |
| CPU_WORD getFieldJustify( uint32_t i_pos, uint32_t i_len ) const |
| { |
| return getField(i_pos, i_len) >> (CPU_WORD_BIT_LEN - i_len); |
| } |
| |
| /** |
| * @brief Sets a left-justified value of the given length into the bit |
| * string starting at the given position. |
| * @param i_pos The starting position of the target range. |
| * @param i_len The number of bits of the target range. |
| * @param i_val The left-justified value to set. |
| * @pre nullptr != getBufAddr() |
| * @pre 0 < i_len |
| * @pre i_len <= CPU_WORD_BIT_LEN |
| * @pre i_pos + i_len <= getBitLen() |
| */ |
| void setField( uint32_t i_pos, uint32_t i_len, CPU_WORD i_val ); |
| |
| /** |
| * @brief Sets a right-justified value of the given length into the bit |
| * string starting at the given position. |
| * @param i_pos The starting position of the target range. |
| * @param i_len The number of bits of the target range. |
| * @param i_val The right-justified value to set. |
| * @pre nullptr != getBufAddr() |
| * @pre 0 < i_len |
| * @pre i_len <= CPU_WORD_BIT_LEN |
| * @pre i_pos + i_len <= getBitLen() |
| */ |
| void setFieldJustify( uint32_t i_pos, uint32_t i_len, CPU_WORD i_val ) |
| { |
| setField( i_pos, i_len, i_val << (CPU_WORD_BIT_LEN - i_len) ); |
| } |
| |
| /** |
| * @param i_pos The target position. |
| * @return True if the bit at the given position is set(1), false otherwise. |
| * @pre i_pos < getBitLen(). |
| */ |
| bool isBitSet( uint32_t i_pos ) const { return 0 != getField(i_pos, 1); } |
| |
| /** |
| * @brief Sets the target position to 1. |
| * @param i_pos The target position. |
| * @pre i_pos < getBitLen(). |
| */ |
| void setBit( uint32_t i_pos ) { setFieldJustify( i_pos, 1, 1 ); } |
| |
| /** @brief Sets the entire bit string to 1's. */ |
| void setAll() { setPattern(CPU_WORD_MASK); } |
| |
| /** |
| * @brief Sets the target position to 0. |
| * @param i_pos The target position. |
| * @pre i_pos < getBitLen(). |
| */ |
| void clearBit( uint32_t i_pos ) { setFieldJustify( i_pos, 1, 0 ); } |
| |
| /** @brief Sets the entire bit string to 0's. */ |
| void clearAll() { setPattern(0); } |
| |
| /** |
| * @brief Sets a range within the string based on the pattern and length |
| * provided. |
| * @param i_sPos Starting position of this string. |
| * @param i_sLen The length of the target range. |
| * @param i_pattern The pattern to set (right justified). |
| * @param i_pLen The length of the pattern. |
| * @pre nullptr != getBufAddr() |
| * @pre 0 < i_sLen |
| * @pre i_sPos + i_sLen <= getBitLen() |
| * @pre 0 < i_pLen <= CPU_WORD_BIT_LEN |
| * @post The pattern is repeated/truncated as needed. |
| * |
| * Examples: i_sPos(0), i_sLen(10), i_pattern(0xA), i_pLen(4) |
| * Old String: 0000000000 |
| * New String: 1010101010 |
| * |
| * i_sPos(3), i_sLen(4), i_pattern(0x3), i_pLen(3) |
| * Old String: 0001001000 |
| * New String: 0000110000 |
| */ |
| void setPattern( uint32_t i_sPos, uint32_t i_sLen, |
| CPU_WORD i_pattern, uint32_t i_pLen ); |
| |
| /** |
| * @brief Sets entire string based on the pattern and length provided. |
| * @param i_pattern The pattern to set (right justified). |
| * @param i_pLen The length of the pattern. |
| * @note See definition above for prerequisites. |
| * @post The entire string is filled with the pattern. |
| * @post The pattern is repeated/truncated as needed. |
| */ |
| void setPattern( CPU_WORD i_pattern, uint32_t i_pLen ) |
| { |
| setPattern( 0, getBitLen(), i_pattern, i_pLen ); |
| } |
| |
| /** |
| * @brief Sets entire string based on the pattern provided (length of |
| * CPU_WORD). |
| * @param i_pattern The pattern to set. |
| * @note See definition above for prerequisites. |
| * @post The entire string is filled with the pattern. |
| * @post The pattern is repeated/truncated as needed. |
| */ |
| void setPattern( CPU_WORD i_pattern ) |
| { |
| setPattern( i_pattern, CPU_WORD_BIT_LEN ); |
| } |
| |
| /** |
| * @brief Set bits in this string based on the given string. |
| * @param i_sStr The source string. |
| * @param i_sPos The starting position of the source string. |
| * @param i_sLen The number of bits to copy from the source string. |
| * @param i_dPos The starting position of the this string. |
| * @pre nullptr != getBufAddr() |
| * @pre nullptr != i_sStr.getBufAddr() |
| * @pre 0 < i_sLen |
| * @pre i_sPos + i_sLen <= i_sStr.getBitLen() |
| * @pre i_dPos < getBitLen() |
| * @post Source bits in given range are copied to this starting at i_dPos. |
| * @note If the length of the given string is greater than the length of |
| * this string, then the extra bits are ignored. |
| * @note If the length of the given string is less than the length of this |
| * string, then the extra bits in this string are not modified. |
| * @note This string and the source string may specify overlapping memory. |
| */ |
| void setString( const BitString & i_sStr, uint32_t i_sPos, |
| uint32_t i_sLen, uint32_t i_dPos = 0 ); |
| |
| /** |
| * @brief Set bits in this string based on the provided string. |
| * @param i_sStr The source string. |
| * @note This will try to copy as much of the source as possible to this |
| * string, starting with the first bit in each string. |
| * @note See the other definition of this function for details and |
| * restrictions. |
| */ |
| void setString( const BitString & i_sStr ) |
| { |
| setString( i_sStr, 0, i_sStr.getBitLen() ); |
| } |
| |
| /** |
| * @brief Masks (clears) any bits set in this string that correspond to bits |
| * set in the given string (this & ~mask). |
| * @param i_mask The mask string. |
| * @note If the length of the given string is greater than the length of |
| * this string, then the extra bits are ignored. |
| * @note If the length of the given string is less than the length of this |
| * string, then the extra bits in this string are not modified. |
| */ |
| void maskString( const BitString & i_mask ); |
| |
| /** |
| * @param i_str The string to compare. |
| * @return True if the strings are equivalent, false otherwise. |
| * @pre Both strings must be of equal length and have same values to be |
| * equal. |
| */ |
| bool isEqual( const BitString & i_str ) const; |
| |
| /** @return True if there are no bit set(1) in this bit string, false |
| * otherwise. */ |
| bool isZero() const; |
| |
| /** |
| * @param i_pos The starting position of the target range. |
| * @param i_len The length of the target range. |
| * @return The number of bits that are set(1) in given range of this string. |
| * @pre nullptr != getBufAddr() |
| * @pre i_pos + i_len <= getBitLen() |
| */ |
| uint32_t getSetCount( uint32_t i_pos, uint32_t i_len ) const; |
| |
| /** @return The number of bits that are set(1) in this string. */ |
| uint32_t getSetCount() const { return getSetCount( 0, getBitLen() ); } |
| |
| /** @brief Comparison operator. */ |
| bool operator==( const BitString & i_str ) const { return isEqual(i_str); } |
| |
| /** @brief Bitwise NOT operator. */ |
| BitStringBuffer operator~() const; |
| |
| /** @brief Bitwise AND operator. */ |
| BitStringBuffer operator&( const BitString & i_bs ) const; |
| |
| /** @brief Bitwise OR operator. */ |
| BitStringBuffer operator|( const BitString & i_bs ) const; |
| |
| /** @brief Right shift operator. */ |
| BitStringBuffer operator>>( uint32_t i_shift ) const; |
| |
| /** @brief Left shift operator. */ |
| BitStringBuffer operator<<( uint32_t i_shift ) const; |
| |
| protected: // functions |
| |
| /** |
| * @param i_newBufAddr The starting address of the new bit string buffer. |
| * @pre Before calling this function, make sure you deallocate the old |
| * buffer to avoid memory leaks. |
| */ |
| void setBufAddr( CPU_WORD * i_newBufAddr ) { iv_bufAddr = i_newBufAddr; } |
| |
| /** @param i_newBitLen The new bit length of this bit string buffer. */ |
| void setBitLen( uint32_t i_newBitLen ) { iv_bitLen = i_newBitLen; } |
| |
| private: // functions |
| |
| // Prevent the assignment operator and copy constructor from a |
| // BitStringBuffer. While technically these could be done. We run into |
| // serious problems like with the operator functions above that all return |
| // a BitStringBuffer. If we allowed these, the BitString would end up |
| // pointing to memory that is no longer in context. |
| BitString & operator=( const BitStringBuffer & i_bsb ); |
| BitString( const BitStringBuffer & i_bsb ); |
| |
| /** |
| * @brief Given a bit position within the bit string, this function returns |
| * the address that contains the bit position and the bit position |
| * relative to that address. |
| * @param o_relPos The returned relative position. |
| * @param i_absPos The inputted absolute position. |
| * @return The relative address. |
| * @pre nullptr != getBufAddr() |
| * @pre i_absPos < getBitLen() |
| */ |
| CPU_WORD * getRelativePosition( uint32_t & o_relPos, |
| uint32_t i_absPos ) const; |
| |
| private: // instance variables |
| |
| uint32_t iv_bitLen; ///< The bit length of this buffer. |
| CPU_WORD * iv_bufAddr; ///< The beginning address of this buffer. |
| uint32_t iv_offset; ///< Start position offset |
| }; |
| |
| //############################################################################## |
| // BitStringBuffer class |
| //############################################################################## |
| |
| /** A BitStringBuffer is a BitString that maintains its own buffer in memory. It |
| * guarantees that sufficient memory is allocated and deallocated in the |
| * constructor and destructor, respectively. In addition, the assignment |
| * operator will adjust the amount of memory needed, as necessary, for the |
| * assignment. */ |
| class BitStringBuffer : public BitString |
| { |
| public: // functions |
| |
| /** |
| * @brief Constructor |
| * @param i_bitLen Number of bits in the string. |
| */ |
| explicit BitStringBuffer( uint32_t i_bitLen ); |
| |
| /** @brief Destructor */ |
| ~BitStringBuffer(); |
| |
| /** @brief Copy constructor from BitString */ |
| BitStringBuffer( const BitString & i_bs ); |
| |
| /** @brief Copy constructor from BitStringBuffer */ |
| BitStringBuffer( const BitStringBuffer & i_bsb ); |
| |
| /** @brief Assignment from BitString */ |
| BitStringBuffer & operator=( const BitString & i_bs ); |
| |
| /** @brief Assignment from BitStringBuffer */ |
| BitStringBuffer & operator=( const BitStringBuffer & i_bsb ); |
| |
| private: // functions |
| |
| /** @brief Deallocates the old buffer, if needed, and initializes the new |
| * buffer. */ |
| void initBuffer(); |
| }; |
| |
| } // end namespace libhei |
| |