1 | /********************************************************************\ |
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2 | |
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3 | General code to start a server of the Evidence Control System |
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4 | |
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5 | - The server is started with the given name. |
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6 | - DIM exit and error handlers are implemented. |
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7 | - The Status service is published (special format, see below). |
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8 | It can be updated with the State() method. The text will also be logged. |
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9 | - If the severity of a State() call is FATAL, exit() will be called (with |
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10 | this severity, the call to State() is guranteed not to return). |
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11 | - Configuration data can be requested by GetConfig(). |
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12 | - Signal handlers to ignore common signals are installed. |
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13 | These signals will then cause pause() to return which can be used |
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14 | by the application to terminate gracefully. |
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15 | - The static method ToString() converts the contents of a |
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16 | DIMInfo service into text |
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17 | |
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18 | All memory allocated by the non-static methods will be freed by the |
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19 | class destructor. |
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20 | |
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21 | Oliver Grimm, December 2009 |
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22 | |
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23 | \********************************************************************/ |
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24 | |
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25 | #include "Evidence.h" |
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26 | |
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27 | bool EvidenceServer::ExitRequest = false; |
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28 | |
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29 | // Constructor starts server with given name |
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30 | EvidenceServer::EvidenceServer(const char *Name) { |
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31 | |
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32 | // Initialize |
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33 | Status = NULL; |
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34 | ConfigList = NULL; |
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35 | ConfigNum = 0; |
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36 | |
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37 | // Catch some signals |
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38 | signal(SIGQUIT, &SignalHandler); // CTRL-Backspace |
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39 | signal(SIGTERM, &SignalHandler); // Termination signal |
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40 | signal(SIGINT, &SignalHandler); // CTRL-C |
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41 | signal(SIGHUP, &SignalHandler); // Terminal closed |
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42 | |
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43 | // Create server name |
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44 | if (MakeString(&StatusName, "%s/Status", Name) == -1) { |
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45 | State(FATAL, "Could not generate service name, asprintf() failed"); |
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46 | } |
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47 | |
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48 | // Start server |
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49 | Status = new DimService(StatusName, (char *) "Server started"); |
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50 | |
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51 | start(Name); |
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52 | addExitHandler(this); |
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53 | } |
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54 | |
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55 | // Destructor: Free memory |
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56 | EvidenceServer::~EvidenceServer() { |
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57 | |
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58 | free(StatusName); |
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59 | |
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60 | for (unsigned int i=0; i<ConfigNum; i++) { |
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61 | delete[] ConfigList[i].Name; |
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62 | delete[] ConfigList[i].Value; |
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63 | } |
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64 | free(ConfigList); |
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65 | } |
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66 | |
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67 | // DIM exit handler |
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68 | void EvidenceServer::exitHandler(int Code) { |
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69 | State(INFO, "Server stopped (DIM exit code %d)", Code); |
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70 | exit(EXIT_SUCCESS); |
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71 | } |
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72 | |
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73 | // DIM error handler |
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74 | void EvidenceServer::errorHandler(int Severity, int Code, char *Message) { |
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75 | State(ERROR, "%s (DIM error code %d, severity %d)\n", Message, Code, Severity); |
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76 | } |
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77 | |
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78 | // Set status of server |
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79 | // |
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80 | // The message format is special: after the string-terminating '\0' the Severity |
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81 | // is given, terminated by another '\0' The buffer for the DIM service must have |
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82 | // the same lifetime as the DIM service. If Severity is FATAL, exit() will be invoked. |
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83 | void EvidenceServer::State(StateType Severity, const char *Format, ...) { |
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84 | |
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85 | static const char* StateString[] = {"Info", "Warn", "Error", "Fatal"}; |
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86 | static char ErrorString[] = "vasprintf() failed in State()"; |
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87 | static char SBuf[STATUS_SIZE]; |
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88 | char TBuf[STATUS_SIZE]; |
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89 | char *Tmp; |
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90 | |
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91 | // Assemble message from application |
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92 | va_list ArgumentPointer; |
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93 | va_start(ArgumentPointer, Format); |
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94 | if (vasprintf(&Tmp, Format, ArgumentPointer) == -1) Tmp = ErrorString; |
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95 | va_end(ArgumentPointer); |
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96 | |
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97 | snprintf(TBuf, sizeof(TBuf), "%s (%s): %s", StatusName, StateString[Severity], Tmp); |
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98 | snprintf(SBuf, sizeof(SBuf), "%s\0%d", Tmp); |
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99 | |
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100 | if (Tmp != ErrorString) free(Tmp); |
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101 | |
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102 | // Send message to console and log file |
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103 | printf("%s\n", TBuf); |
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104 | if (Severity != INFO) DimClient::sendCommand("DColl/Log", TBuf); |
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105 | |
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106 | // Update DIM status service (including severity encoding) |
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107 | if (Status != NULL) Status->updateService(SBuf, strlen(SBuf)+2); |
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108 | |
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109 | // Terminate if message type is fatal |
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110 | if (Severity == FATAL) exit(EXIT_FAILURE); |
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111 | } |
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112 | |
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113 | // Get configuration data (program terminates if data is missing) |
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114 | // |
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115 | // The memory allocated by all calls to this function will be freed by |
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116 | // the destructor. |
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117 | char* EvidenceServer::GetConfig(const char *Item) { |
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118 | |
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119 | // Determine configuration file update time |
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120 | DimCurrentInfo ModifyTime("Config/ModifyTime", 0); |
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121 | int Time = ModifyTime.getInt(), ItemNo = -1; |
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122 | |
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123 | // Check if configuration request already in list |
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124 | for (int i=0; i<ConfigNum; i++) { |
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125 | if (strcmp(ConfigList[i].Name, Item) == 0) { |
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126 | // Return original value if still up to date |
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127 | if (ConfigList[i].Time >= Time) return ConfigList[i].Value; |
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128 | |
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129 | // Otherwise, free memory of old value |
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130 | delete[] ConfigList[i].Name; |
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131 | delete[] ConfigList[i].Value; |
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132 | ItemNo = i; |
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133 | break; |
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134 | } |
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135 | } |
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136 | |
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137 | // Make configuration request |
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138 | DimRpcInfo Config((char *) "ConfigRequest", (char *) ""); |
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139 | Config.setData((char *) Item); |
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140 | |
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141 | // Terminate if not successful |
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142 | if (strlen(Config.getString()) == 0) { |
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143 | State(FATAL, "Missing configuration data '%s'", Item); |
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144 | } |
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145 | |
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146 | // Enlarge memory to hold new pointer if necessary |
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147 | if (ItemNo == -1) { |
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148 | void *N = realloc(ConfigList, sizeof(struct ConfigItem)*(++ConfigNum)); |
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149 | if (N == NULL) { |
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150 | State(WARN, "Could not realloc() memory for configuration, will lose memory (%s)", strerror(errno)); |
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151 | ConfigNum--; |
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152 | } |
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153 | else ConfigList = (struct ConfigItem *) N; |
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154 | |
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155 | ItemNo = ConfigNum-1; |
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156 | } |
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157 | |
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158 | // Allocate memory for strings, and copy data to this memory |
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159 | ConfigList[ItemNo].Value = new char [strlen(Config.getString())+1]; |
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160 | ConfigList[ItemNo].Name = new char [strlen(Item)+1]; |
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161 | strcpy(ConfigList[ItemNo].Name, Item); |
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162 | strcpy(ConfigList[ItemNo].Value, Config.getString()); |
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163 | |
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164 | ConfigList[ItemNo].Time = Time; |
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165 | |
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166 | // Return address to configuration value |
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167 | return ConfigList[ItemNo].Value; |
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168 | } |
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169 | |
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170 | |
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171 | // ====== Static methods ====== |
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172 | |
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173 | // Signal handler (causes pause() and other syscalls to return) |
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174 | void EvidenceServer::SignalHandler(int) { |
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175 | |
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176 | EvidenceServer::ExitRequest = true; |
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177 | } |
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178 | |
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179 | // Translates DIMInfo to string (memory has to be freed by caller) |
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180 | // No DIM structures are supported (only a single number or string is converted) |
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181 | char *EvidenceServer::ToString(DimInfo *Item) { |
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182 | |
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183 | char *Text; |
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184 | |
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185 | if (strlen(Item->getFormat()) != 1) return NULL; |
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186 | |
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187 | switch (*(Item->getFormat())) { |
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188 | case 'I': MakeString(&Text, "%d", Item->getInt()); break; |
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189 | case 'C': MakeString(&Text, "%s", Item->getString()); break; |
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190 | case 'S': MakeString(&Text, "%hd", Item->getShort()); break; |
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191 | case 'F': MakeString(&Text, "%.5f", Item->getFloat()); break; |
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192 | case 'D': MakeString(&Text, "%.5f", Item->getDouble()); break; |
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193 | case 'X': MakeString(&Text, "%lld", Item->getLonglong()); break; |
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194 | default: return NULL; |
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195 | } |
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196 | |
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197 | return Text; |
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198 | } |
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199 | |
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200 | // |
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201 | // Generate string with vasprintf() |
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202 | // |
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203 | // The pointer will be set to NULL in case of error, so can always safely passed to free(). |
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204 | // In case vasprintf() is not available on a particular system, the functionality can |
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205 | // be manually implemented in this routine. |
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206 | // |
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207 | int EvidenceServer::MakeString(char **Pointer, const char *Format, ...) { |
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208 | |
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209 | int Ret; |
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210 | va_list ArgumentPointer; |
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211 | |
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212 | va_start(ArgumentPointer, Format); |
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213 | if ((Ret = vasprintf(Pointer, Format, ArgumentPointer)) == -1) Pointer = NULL; |
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214 | va_end(ArgumentPointer); |
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215 | |
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216 | return Ret; |
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217 | } |
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