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merge in latest libebus commit 9520d5a3283472c2a53b8396b0796723f660bed7:

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simplified SymbolString interface and let it handle unescaping itself
This commit is contained in:
john30
2014-10-29 23:28:51 +01:00
parent 9ca41eb457
commit 7643b05935
4 changed files with 110 additions and 98 deletions
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src/libebus/result.h
+1
View File
@@ -31,6 +31,7 @@ static const int RESULT_DATA = 2; // some data received
static const int RESULT_SYN = 3; // regular SYN after message received
static const int RESULT_BUS_LOCKED = 4; // bus is locked for access
static const int RESULT_BUS_PRIOR_RETRY = 5; // retry to access bus
static const int RESULT_IN_ESC = 6; // start of escape sequence received
static const int RESULT_ERR_SEND = -1; // send error
static const int RESULT_ERR_EXTRA_DATA = -2; // received bytes > sent bytes
src/libebus/symbol.cpp
+72 -53
View File
@@ -18,6 +18,7 @@
*/
#include "symbol.h"
#include "result.h"
#include <iostream>
#include <iomanip>
@@ -27,7 +28,7 @@ namespace libebus
/**
* @brief CRC8 lookup table for the polynom 0x9b = x^8 + x^7 + x^4 + x^3 + x^1 + 1.
*/
static const unsigned char CRC_LOOKUP_TABLE[]
static const unsigned char CRC_LOOKUP_TABLE[] =
{
0x00, 0x9b, 0xad, 0x36, 0xc1, 0x5a, 0x6c, 0xf7, 0x19, 0x82, 0xb4, 0x2f, 0xd8, 0x43, 0x75, 0xee,
0x32, 0xa9, 0x9f, 0x04, 0xf3, 0x68, 0x5e, 0xc5, 0x2b, 0xb0, 0x86, 0x1d, 0xea, 0x71, 0x47, 0xdc,
@@ -49,41 +50,35 @@ static const unsigned char CRC_LOOKUP_TABLE[]
SymbolString::SymbolString(const std::string str)
: m_crc(0)
: m_unescapeState(0), m_crc(0)
{
// parse + escape
for (size_t i = 0; i+1 < str.size(); i += 2) {
unsigned long value = strtoul(str.substr(i, 2).c_str(), NULL, 16);
push_back_escape((unsigned char)value);
unsigned long value = strtoul(str.substr(i, 2).c_str(), NULL, 16); // TODO check
push_back((unsigned char)value, false, true);
}
// add CRC + escape
push_back_escape(m_crc, false);
push_back(m_crc, false, false);
}
SymbolString::SymbolString(const std::string str, bool escaped)
: m_crc(0)
SymbolString::SymbolString(const std::string str, bool isEscaped)
: m_unescapeState(1), m_crc(0)
{
bool previousEscape = false;
// parse + optionally unescape
for (size_t i = 0; i+1 < str.size(); i += 2) {
unsigned long value = strtoul(str.substr(i, 2).c_str(), NULL, 16);
if (escaped == true) {
push_back_unescape((unsigned char)value, previousEscape, false);
}
else
m_data.push_back((unsigned char)value);
unsigned long value = strtoul(str.substr(i, 2).c_str(), NULL, 16); // TODO check
push_back((unsigned char)value, isEscaped, false);
}
}
const std::string SymbolString::getDataStr(bool unescape)
const std::string SymbolString::getDataStr(const bool unescape)
{
std::stringstream sstr;
bool previousEscape = false;
for (size_t i = 0; i < size(); i++) {
unsigned char value = at(i);
if (unescape == true && previousEscape == true) {
for (size_t i = 0; i < m_data.size(); i++) {
unsigned char value = m_data[i];
if (m_unescapeState == 0 && unescape == true && previousEscape == true) {
if (value == 0x00) {
sstr << "a9"; // ESC
}
@@ -95,7 +90,7 @@ const std::string SymbolString::getDataStr(bool unescape)
}
previousEscape = false;
}
else if (unescape == true && value == ESC) {
else if (m_unescapeState == 0 && unescape == true && value == ESC) {
previousEscape = true; // escape sequence not yet finished
}
else {
@@ -107,56 +102,80 @@ const std::string SymbolString::getDataStr(bool unescape)
return sstr.str();
}
void SymbolString::push_back_escape(const unsigned char value, bool updateCRC)
int SymbolString::push_back(const unsigned char value, const bool isEscaped, const bool updateCRC)
{
if (value == ESC) {
m_data.push_back(ESC);
m_data.push_back(0x00);
if (updateCRC) {
addCRC(ESC);
addCRC(0x00);
if (m_unescapeState == 0) { // store escaped data
if (isEscaped == false && value == ESC) {
m_data.push_back(ESC);
m_data.push_back(0x00);
if (updateCRC) {
addCRC(ESC);
addCRC(0x00);
}
}
}
else if (value == SYN) {
m_data.push_back(ESC);
m_data.push_back(0x01);
if (updateCRC) {
addCRC(ESC);
addCRC(0x01);
else if (isEscaped == false && value == SYN) {
m_data.push_back(ESC);
m_data.push_back(0x01);
if (updateCRC) {
addCRC(ESC);
addCRC(0x01);
}
}
else {
m_data.push_back(value);
if (updateCRC) {
addCRC(value);
}
}
return RESULT_OK;
}
else {
else if (isEscaped == false) {
if (m_unescapeState != 1)
return RESULT_ERR_ESC; // invalid unescape state
m_data.push_back(value);
if (updateCRC) {
if (value == ESC) {
addCRC(ESC);
addCRC(0x00);
}
else if (value == SYN) {
addCRC(ESC);
addCRC(0x01);
}
else {
addCRC(value);
}
}
return RESULT_OK;
}
else if (m_unescapeState != 1) {
if (updateCRC) {
addCRC(value);
}
}
}
unsigned char SymbolString::push_back_unescape(const unsigned char value, bool& previousEscape, bool updateCRC)
{
if (updateCRC) {
addCRC(value);
}
if (previousEscape == true) {
if (value == 0x00) {
m_data.push_back(ESC);
previousEscape = false;
return ESC;
m_unescapeState = 1;
return RESULT_OK;
}
if (value == 0x01) {
m_data.push_back(SYN);
previousEscape = false;
return SYN;
m_unescapeState = 1;
return RESULT_OK;
}
return 0; // invalid escape sequence
return RESULT_ERR_ESC; // invalid escape sequence
}
if (value == ESC) {
previousEscape = true;
return 1; // escape sequence not yet finished
else if (value == ESC) {
if (updateCRC) {
addCRC(value);
}
m_unescapeState = 2;
return RESULT_IN_ESC;
}
if (updateCRC) {
addCRC(value);
}
m_data.push_back(value);
return value;
return RESULT_OK;
}
void SymbolString::addCRC(const unsigned char value) {
src/libebus/symbol.h
+31 -35
View File
@@ -37,71 +37,61 @@ static const unsigned char BROADCAST = 0xFE; // the broadcast destination addres
/**
* @brief A string of bus symbols.
* @brief A string of escaped or unescaped bus symbols.
*/
class SymbolString
{
public:
/**
* @brief Creates a new empty SymbolString.
* @brief Creates a new unescaped empty instance.
* @param escaped whether to create an escaped instance.
*/
SymbolString() : m_crc(0) {}
SymbolString() : m_unescapeState(1), m_crc(0) {}
/**
* @brief Creates a new escaped SymbolString from an unescaped hex string and adds the calculated CRC.
* @brief Creates a new escaped instance from an unescaped hex string and adds the calculated CRC.
* @param str the unescaped hex string.
*/
SymbolString(const std::string str);
/**
* @brief Creates a new unescaped SymbolString from a hex string.
* @param escaped whether the hex string is escaped and shall be unescaped.
* @brief Creates a new unescaped instance from a hex string.
* @param isEscaped whether the hex string is escaped and shall be unescaped.
* @param str the hex string.
*/
SymbolString(const std::string str, bool escaped);
SymbolString(const std::string str, const bool isEscaped);
/**
* @brief Returns the symbols as hex string.
* @param escaped whether to unescape the symbols.
* @param unescape whether to unescape an escaped instance.
* @return the symbols as hex string.
*/
const std::string getDataStr(bool unescape=false);
const std::string getDataStr(const bool unescape=true);
/**
* @brief Returns the symbol at the specified index.
* @brief Returns a reference to the symbol at the specified index.
* @param index the index of the symbol to return.
* @return the symbol at the specified index.
* @throw std::out_of_range if @a index is invalid.
* @return the reference to the symbol at the specified index.
*/
unsigned char at(const size_t index) { return m_data.at(index); }
unsigned char& operator[](const size_t index) { if (index >= m_data.size()) m_data.resize(index+1); return m_data[index]; }
/**
* @brief Returns the symbol at the specified index.
* @param index the index of the symbol to return.
* @return the symbol at the specified index.
*/
unsigned char operator[](const size_t index) { return m_data[index]; }
const unsigned char& operator[](const size_t index) const { return m_data[index]; }
/**
* @brief Returns the symbol at the specified index.
* @param index the index of the symbol to return.
* @return the symbol at the specified index.
* @brief Returns whether this instance is equal to the other instance.
* @param other the other instance.
* @return true if this instance is equal to the other instance (i.e. both escaped or both unescaped and same symbols).
*/
unsigned char operator[](const size_t index) const { return m_data[index]; }
bool operator==(SymbolString other) { return (m_unescapeState==0)==(m_unescapeState==0) && m_data==other.m_data; }
/**
* @brief Inserts a the symbol at the specified index.
* @param index the index at which to insert the symbol.
* @param value the symbol to insert.
*/
void insert(const size_t index, const unsigned char value) { m_data.insert(m_data.begin()+index, value); }
/**
* @brief Appends a the symbol to the end of the symbol string and escapes it if necessary.
* @brief Appends a the symbol to the end of the symbol string and escapes/unescapes it if necessary.
* @param value the symbol to append.
* @param isEscaped whether the symbol is escaped.
* @param updateCrc whether to update the calculated CRC in @a m_crc.
* @return RESULT_OK if another symbol was appended,
* RESULT_IN_ESC if this is an unescaped instance and the symbol is escaped and the start of the escape sequence was received,
* RESULT_ERR_ESC if this is an unescaped instance and an invalid escaped sequence was detected.
*/
void push_back_escape(const unsigned char value, bool updateCRC=true);
/**
* @brief Appends a the symbol to the end of the symbol string and unescapes it.
* @param value the symbol to append.
* @param previousEscape whether the previous value was the escape symbol (set to false for the initial call).
* @param updateCrc whether to update the calculated CRC in @a m_crc.
* @return if previousEscape is false on return: the unescaped symbol. otherwise: zero if the escape sequence was invalid, one if the escape sequence is not yet finished.
*/
unsigned char push_back_unescape(const unsigned char value, bool& previousEscape, bool updateCRC=true);
int push_back(const unsigned char value, const bool isEscaped, const bool updateCRC=true);
/**
* @brief Returns the number of symbols in this symbol string.
* @return the number of available symbols.
@@ -115,7 +105,7 @@ public:
/**
* @brief Clears the symbols.
*/
void clear() { m_crc=0; m_data.clear(); }
void clear() { m_data.clear(); m_unescapeState = m_unescapeState==0 ? 0 : 1; m_crc = 0; }
private:
/**
@@ -128,6 +118,12 @@ private:
* @brief the string of bus symbols.
*/
std::vector<unsigned char> m_data;
/**
* @brief 0 if the symbols in @a m_data are escaped,
* 1 if the symbols in @a m_data are unescaped and the last symbol passed to @a push_back was a normal symbol,
* 2 if the symbols in @a m_data are unescaped and the last symbol passed to @a push_back was the escape symbol.
*/
int m_unescapeState;
/**
* @brief the calculated CRC.
*/
src/test/test_symbol.cpp
+6 -10
View File
@@ -25,15 +25,9 @@ using namespace libebus;
int main ()
{
SymbolString sstr("10feb5050427a915aa");
SymbolString sstr = SymbolString("10feb5050427a915aa");
std::stringstream out;
for (size_t i = 0; i<sstr.size(); i++) {
out << std::nouppercase << std::setw(2) << std::hex
<< std::setfill('0') << static_cast<unsigned>(sstr[i]);
}
std::string gotStr = out.str(), expectStr = "10feb5050427a90015a90177";
std::string gotStr = sstr.getDataStr(false), expectStr = "10feb5050427a90015a90177";
if (strcasecmp(gotStr.c_str(), expectStr.c_str()) == 0)
std::cout << "ctor escaped successful." << std::endl;
@@ -54,7 +48,7 @@ int main ()
<< std::setfill('0') << static_cast<unsigned>(expectCrc)
<< std::endl;
gotStr = sstr.getDataStr(true), expectStr = "10feb5050427a915aa77";
gotStr = sstr.getDataStr(), expectStr = "10feb5050427a915aa77";
if (strcasecmp(gotStr.c_str(), expectStr.c_str()) == 0)
std::cout << "unescape successful." << std::endl;
@@ -63,7 +57,9 @@ int main ()
<< ", expected " << expectStr << std::endl;
sstr = SymbolString("10feb5050427a90015a90177", true);
gotStr = sstr.getDataStr(false);
gotStr = sstr.getDataStr();
if (strcasecmp(gotStr.c_str(), expectStr.c_str()) == 0)
std::cout << "ctor unescaped successful." << std::endl;
else